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Auger10  192.168.1.100 to WinXP Zeiss 192.168.1.10

 August 16, 2021 System maintanance

Replace prep chamber ion gauge with official Omicron Th Ir filament. Wires on gauge crimped/spot welded seem floppy. Tried to spot weld, not sure it helped. Pumping down 4.5e-5 on intro gauge.

Open prep gate valve 3.5e-6

Python environment setup

With a fresh install of Anaconda 4.2.0 64-bit python=3.5 we can set up a python environment for the new version of ScopeFoundry.

pip install pyqtgraph
conda install pyserial
pip install pydaqmx

Anaconda Python reinstall

Time for a clean up of Python packages.

Uninstalled two different versions of anaconda installed at c:\anaconda and  C:\Users\NIuser\Anaconda2

Before uninstall, `conda list >pkg_list.txt`

These package lists are attached.

Install Anaconda 4.2.0 python 3.5 64bit

Aperture Alignment

Imaging Conditions Au/C sample

• Scan rotation set 180 degrees so image motion matches piezo stage directions, plate handle at image bottom. Up/Down buttons move Up/Down, L/R buttons move R/L (reversed)
• To see Au grains of ~ 30 to 120 nm, need 10 to 50 kX mag (relative to 19/21 inch display)
• Working with 120 um aperture 3 nA mode
• Gun -53.0 -65.0
• App +54.1 +79.5
• Stig -23.7 +13.7
• WD 9.098
• Apparent Image Shift with increasing WD
• if Ax becomes more positive, shift direction becomes more left
• if Ay becomes more positive, shift direction becomes more vertical
• Wobble method:
• set wobble amplitude to 5%
• adjust Ax and Ay to minimize wobble
• problem, as you go through best value, phase reverses, hard to catch
• Manual Focus method:
• put manual cross hairs on a feature
• increase WD, see which direction feature moves
• if it moves right, increase Ax
• if it moves down, increase Ay
• if you change aperture position significantly, you will need to re-adjust WD and Stig to recover a sharp image
• once you have the best value, Au/C should look good, you can check with wobble method

Aperture 6, 120 um 3 nA

• Gun -53.0 +65.0
• Aperture +54.1 +79.5
• Stig -23.7 +13.7
• Stig Bal X upper 84.8 lower 100.0
• Stig Bal Y upper 71.3 lower 99.2

Changing to other current/condenser settings mainly changes WD

• For 3.0 nA, WD 9.098 stig -23.4 +15.2
• For 2.5 nA, WD 9.032
• For 2.0 nA, WD 8.986  stig -21.2 +15.8
• For 1.5 nA, WD 8.950  stig -19.5 +17.9  

Defocus of 10 nm is significant (should be less for smaller apertures)

Stig change of 1% is significant

Aperture 1, 60 um (on axis)

• Gun -2.5 -54.5
• App +0.5 +70.3
• Stig +2.0 +27.0
• Stig Bal X upper 84.1 lower 100.0
• Stig Bal Y upper 70.2 lower 99.8
• WD 200 pA 8.915

Other current settings

• Max WD  9.012  stig +14.2 +40.9
• 200 pA WD 8.915  stig +2.0 +27.0
• 100 pA WD 8.905 stig +1.9 +29.3

Aperture 5 90 um

• Gun +10.1 -6.7
• App -14.5 +20.6
• Stig +2.0 +5.7
• Stig Bal X upper 85.8 lower 100.0
• Stig Bal Y upper 69.7 lower 99.1
• WD 1 nA 8.954
• WD 800 pA 8.938 stig +2.2 +6.9

Aperture 3 30 um

• Gun =45.5 -45.2
• App -51.9 +57.2
• Stig +14.7 +2.5
• Stig Bal X upper 86.7 lower 100.0
• Stig Bal Y upper 71.7 lower 100
• 80 pA WD 8.941 stig +14.7 +2.5
• 60 pA WD 8.929 +15.0 +3.1
• 40 pA WD 8.922 +15. +6.0

 Apps 2 and 4, 20 um and 75 um cannot be aligned properly, out of range with current filament

Auger alignment March 2013

data files in calibration/130318 auger align

Cu auger spectra distorted below 300 eV, all apertures open, 3 kV max @ 23 nA.

Record auger images # 3 2 mm aperture, lowest 3 kV mag. As sample is scanned around (large hole aperture plate) max disk shifts ~ 10% width, major shift if on slope in hole aperture.

• Image 0-2 2 kV CRR 5 gain 0.1
• image 2-3 15 deg tilt instead of 30
• image 4-5 flat, spot gets elongated as now 60 deg takeoff to analyzer
• image 6-7 30 deg tilt 1 kV gain .15
• image 8-9 600 eV
• image 10-11 octo correct 41.8, 46.5
• image 12-13 360 eV no correct gain .2
• image 14-15 octo 42, 46

try auger spectrum spot mode centered at 360 eV maxima with 42, 46 octo, totally distorted

when switching to spot mode counts change dramatically, unstable in time, less than in image mode. Something charging???

Try hard ground instead of SCM, no better.

Go back to reproduce original spectra, even stranger, shut down EIS.

Imaging gave strong hints, reduced area images shifted, depended on scan rates etc. Set sample stage flat, wiggle sample holder etc. Now seems better.

No more jumpy spectra, but still poor low KE performance. Charging or alignment??

SEM Gun/Aperture/Stig Realign - Jan 2017

Mechanical align shown in previous post, here is optical/electrical done at 3 kV

Aperture plate at 3 kV Max settings

Center aperture 60 um #1

1. Used for MAX, 200 and 100 pA
2. Shift gun align onto aperture, must adjust aperture to compensate when emission image vanishes.
3. Gun -2.5, -54.5%, App +2.0, +63.4, tweak gun to maximize current in spot mode image center.
4. On 10 um grid rough focus with aperture align, enough to see grid squares 10 um. 
5. Leave stig zero for now, fix on Au/hopg

Max current align #1 60 um
Green text is wrong, Gun -2.5, -54.5, App +4.0, +61.4, WD 9.24

120 um #6

1. 1.5 to 3 nA settings
2. Gun -53.0, -65.5 App +61.0, +71.5, WD 9.30 
3. To get rough aperture align, do gun align, then find min and max aperture values to illuminate without clipping (one axis at a time) then pick average. 

120 um #6,
(image is mis-labeled, originally confused 120 and 90)

90 um #5

1. 0.6 to 1.0 nA settings
2. Gun +8.6, -6.7 App -8.3, +11.9, WD 9.17

90 um

75 um #4

1. 400 pA setting only
2. Gun +31.0, -92.5 Aperture -33.5, +98.0, WD 9.48

75 um

30 um #3

1. 40 to 80 pA
2. Gun 45.5, -45.2 App -49.0, +51.4 WD 9.42

30 um

20 um #2

1. used for 20 pA only
2. Cannot align, out of range

20 um, out of range of gun and aperture alignment

SEM Mechanical Source Condenser Realign Jan 2017

Current status

• More than one year since the last align
• Still original source, 47,244 hours
• Fill 2.330 A, Ext 5.02 kV, Current 263 uA (EHT off)
• EHT on 8 kV, 197 uA 25.7% extraction

Procedure

1. Start with 10 um grid on Si, flat calibration sample
1. note, clean it next time, lots of dust and particles
2. Delete old recipes
3. Set user and service alignments to neutral
4. record "before" emission images, 3 and 8 kV
5. clear shift relative to 11/8/13, relatively uniform illumination but way off center

3 kV after mechanical source align, all electronic corrections off

3 kV max condenser after source align, all electronic corrections off

3 kV, all electronic alignments neutral, condenser off/on

Any attempt to get closer to mechanical center strongly clips beam

Probably time for source replacement, emitter must be off center in grid cap

Condenser Align

1. Instructions say bring center aperture to mechanical center by mechanical source alignment. Not possible. Come as close as possible, 90 um not too far from center
2. Goal is to avoid image shift with condenser.
3. In Aperture Calibration, for each aperture, select "Cal Gun/Aper Align" and zero gun and aperture alignments, click OK. Now changing probe current only changes condenser. Note some controls disabled if Condenser Normal unchecked. Others disabled while in Cal mode.
4. Draw circle around 120 um aperture (only one fully on screen without electronic shift) with cond off, with 20 pA current, and with max current. Condenser at zero, low and high excitation
5. Pretty good at 3 kV. Somewhat off at 8 and 15 kV, but condenser  excitation is less, so should be less critical. 
6. NOTE: at 15 kV condenser is off for 20 pA, while it is on low excitation for 8 or 3 kV.
7. NOTE: do not change voltages in emission mode, toggle  back to normal for change in EHT so condenser settings update.

After 3 kV condenser align, circles for MAX, 20 pA and condensers off

At 8 kV, MAX off-center relative to 20 pA and OFF

At 15 kV, off-center relative to 20 pA/OFF

Vacuum Loss SEM Electronics Failure

Vacuum Loss

• After bakeout and testing, ion gun turbo was on with gate valve.
• Overnight analysis chamber lost vacuum. Probably turbo roughing pump stopped, then turbo lost speed and vented, causing ion pumps & gauges to stop.
• SEM electronics running, software also but unable to control system.
• Multiple errors on restarted SEM, Software could not communicate with hardware, did not identify boards.

SEM troubleshooting

• In EM server got many "Vac Check" errors (~5) then Vac, EO, etc boards were not ID'ed (no revision, serial number, firmware).
• This is a symptom of loss of +24 V power to vac board. Vac board runs a series of checks on power up (column valve, pressure, water flow etc). It quits on first failure, does not (usually) provide clear error messages.
• Quick check is used volt meter to check for +24 V on gun column interlocks. If absent bad sign.
• Next remove right side of SEM console, power board is exposed.
• The power supply consists of 3 transformers in a shielded box, with a large PC board with multiple supplies (+5 V, +15 V, -15 V, +24 for optics/lenses, +- 15 for optics and scan, etc. 
• Each supply has a green LED to indicate function. Starting from the back, these are +5 V. + and - 15 V, then the 4th is 24 V for VAC board. In standby mode these 4 are on. In Run mode, once the vac tests are passed, the other (at least 6) LEDs come on.

SEM Fuses

• Lots of fuses, On rear panel, externally accessible fuses in a long row, F1 to F15. These are mostly for external accessories including switched 208 VAC plugs. Also large breaker
• Behind side panel, power board, large fuses below power board for transformer primary. Also a row of fuses on power PC board for individual supplies, (5x20 mm glass or ceramic).
• Many pin fuses on vac board (flip-down board behind rear upper panel). These are brown 8x6 mm cylinders perpendicular to PC board with two pins. Can be bought from Newark, some spares in Zeiss kits. Also cartridge fuses on "piggy board" on vac board that supplies interlocks. These can blow if exposed metal interlock parts are accidentally shorted to chamber.

SEM Power Supply Details

• Each supply has a green typically 6 wire connector at the top bringing in the appropriate transformer output (each has multiple windings). The AC input is fused then routed to a diode bridge on a water cooled heat sink above the large board, and bridge output back to board.
• Each supply has 2 or more 4.7 mF filter caps, usually two high-current  nFET power transistors on the water-cooled brass heat sink at the bottom of the board, a TL431 shunt voltage reference with a trim-pot for adjusting the voltage, and a TVS zenner protection diode.
• Failed 24 V supply had the TVS protection diode blown. When replaced, blew again.
• Suspect shunt volt ref failed, leading to FETs dropping to minimum resistance, resulting in ~ 30+ volt rectifier output appearing across 28 V diode, which then failed.
• Replacing both nFETs, TVS diode and TL431 ref fixed power supply. FETs might have been OK but taking board on and off is a pain.

TiN and InSnO reference

InSnO

sample commercial 25 mm fused quartz with ITO, defects and inhomogenieties visible in SEM

also piece of In 99.99% foil Goodfellow, exposed to ambient many months

Lots of C and O plus In.

ALD TiN

Deposited by Aaron and Adam, before 6/12/14, substrate??

See some C, Ti, O, N peak convolved with Ti

Clear difference spectra shape from metallic Ti (PHI Auger book)

Sputter 30 sec 15 mPa using PVi-ko3-Frank settings, modified from Changhyun

After sputter no C, Ar visible, 415:419 peak ratio changes, relative increase 419

previous marks, scan squares, point spots, disappear. 

Cond 80, obj 59.5 2 kV no raster offset (-.2, -.7), specimen current 280 nA.

Only minor changes 2 more 30 sec sputter cycles, total 90s.

Now additional 90 sex

InP reference wafer, n type, AXP, N doped,

New unopened InP wafer from Shaul, American Xtal Tech, n-type
Cleave and mount sample, 3 kV 20 nA 30 tilt, "large hole" holder

C and O contamination, but P and In clear. Take survey CRR 5-10-15-20 and CAE 20

Tried REELS, 5 eV pass, apertures less important, 1400 nominal peak 1392.20 SCM on

InP NW experiments

samples

Dry transfer InP NW onto Si, wires grown by Shaul ~ last year (?)

Auger spectra

No obvious charging, pretty good spectra at 3 nA after careful realign. Max current not good, large spillover onto Si substrate. 

Drift is an issue, works better splitting 50-580 eV spectra, 0.5 eV, 50 ms into two ~ 30 sec parts, otherwise drift off smaller 80-100 nm wide wires.

Mostly In, P, little C, little O, no sign of low energy Au peaks, used 3 kV.

Consider Auger maps, CAE 50, P 121.5 back 140; In 402.5 back 420

Scanning at slow speed shows "glitches", ~ 10 in a speed 11 90 sec frame. Float system, sublimator off, SE2 off, turbo off, no help.

No glitches scan speed 9 and below. In 2048 pixel, however, glitches at speed 9. I think at some scan speed Zeiss syncs to line frequency, this may be related to glitches.....

Auger scale 0.3 LP 6

Labview 2103 August upgrade

• Upgraded PXIe Labview from 2012 f3 to 2013 f2
• Use 2013 DS-2 developer suite distribution, August 2013 release
• 3 DVDs for LV/CVI etc
• 1 DVD device drivers
• 1 DVD additional FPGA/xilink tools
• 2+ hours to run
• share DVD from Matrix-Auger to Auger-pxi
• After upgrade somehow initial daqmx diver install not completed, so projects with analog io were broken
• download and install DAQmx 9.8
• now analog works but cRIO still broken, missing "software or license"
• another hour...
• Download NIRIO130 driver and install
• now cRIO recognized, but software conflict
• use NI MAX remote system/software/Add remove to replace LV 12 environment with LV 13
• now VIs resident on cRIO work, but error from FPGA
• another hour+...
• NI MAX never recognized PXIe 4132 SMU
• needs separate driver, NIDCPWR190
• another GB download and install, almost an hour...
• now SMUs are recognized
• Rebuild FPGA
• go to cRIO/chassis/FPGA target
• rebuild FPGA counter to DAC using existing build spec
• 40 minutes elapsed, no errors
• RT_Omicron.vi still fails, error on FPGA Target RIO0
• Unplug cRIO, try again, now it works, for some reason new bitfiles not downloaded
• communication now OK, Omicron FPGA interface 2.lvproj now works

Now all projects in PXIe Documents/Programs  LV seem to work with 2013. "LV 2012 backups" folder has old versions

SC NbSn wire experiments

Ed build wire cleaving holder, 3 perpendicular wires in clamp.
scribe wire outer diameter by rolling wire on surface with scalpel.
insert wires to scribe mark.
cleave with syringe needle that fits OD

Cleaved in air this time, ~ 1 min exposure before pumpdown.

Wires are Cu clad bundle of 50 um subelements, each should be Cu.96Sn0.04 bronze, with Nb3Sn phase polycyrstalline, ~ 1.5 at. % Ti doped, expect Ti at grain boundaries, also Cu.  intergranular fracture

No problem with Auger, although Ti hard to find. Small Ti 383 peak found but no 418. First peak is L2,3M2,3M2,3, next is L2,3M2,3M4,5 which involves valence levels. See Maline SS 286 p82 1993 for interpretation of Ti Auger.

Ion gun imaging

• Want to use external raster control for 20-066 ion gun control to allow SE imaging for focusing and alignment
• Omicron software does not allow external raster to be enabled
• Install PHI software (from floppy disk!!) version 3.0A 1997
• C:\program files\PHI\EXE
• edit IonGunCrtl.ini

[Ion Gun Control]

ComPort=COM6

RS485ResponseTime=1000

IgunAddress=3

NoHardware=0

ModelNumber=11-066

BlankingOptics=1

[END]

Com port set to COM6, address used by Omicron. Other params left at defaults

Software seems to work.

Pressure control

• Phi software does not generate setpoint voltage
• switch RVG50C Pfeiffer controller to INT setpoint
• knob 1.0 = 13 mPa
• 1.5 = 20 mPa
• 2.0 = 26.5 mPa
• Leak valve needs 2.0 turns for ~ 30 mPa (as of 12/2/13)

PHI software raster

raster is not centered on offset, ie changing raster size shifts sputter area

Y raster half of X gives approximate square image for 30 degree tilt sample

Ion Gun Align

• Use Si 10 um grid 30 degree tilt, sputter off O and C.
• SEM multiplier off and beam blanked.
• Hemisphere CAE 10 eV at 56 eV, entrance slit  3, 2 mm circle
• detect SE from ions
• At 3 kV ions, best focus ~ OBJ 62
• Currents to sample (no bias)
• cond 100, 55 nA
• 95, 85 nA
• 90, 166 nA
• 85, 310 nA
• 80, 700 nA
• around 60, 6.6 uA
• spot center ~ x=1.3, y=0 (at cond 90 obj 70, only weakly dependent)

make Foundry1 profile, 25 mA, grid 150, pressure 20 mPa

cond 85 obj 62 voltage 3000

Auger test postbake

Auger

• Test auger after bake. Reduce multiplier voltage to 8.2 from 9.0, negligible loss in counts.
• Get nice spectrum from Au on C, even 70 eV Au peak at 8 kV.

Align after bake

This is the procedure for a full "service" alignment, this is not for daily fine tuning alignment

Simplified Column Alignment instructions

1. Put large featureless sample, at least 3-4 mm, such as Si wafer in stage, no tilt
1. Get image at 8 kV, focus on sample
2. open "Aperture Calibration" and "Calibrate Stigmation" windows (these only work in service mode)
1. Select probe current max
2. zero gun align and aperture align in service window AND user aperture window
3. zero stig and beam offset
4. All electronic offsets should be neutral
3. Get emission image, uncheck Condenser Normal box
1. all apertures should be evenly illuminated, circles will overlap
1. If circles are clipped, distorted, partial, mechanical source align is required
2. if illumination is good, mechanical source alignment is OK,go to next step
3. loosen 4 6 mm screws at top of column. do push-pull adjustments in X and Y to try to get uniform illumination. 
4. to the extent possible, center illuminated aperture pattern, however uniform illumination is more important than centering.
5. recheck condenser normal. Now large diffuse aperture images will change to sharp smaller circles. These should also be uniform. Reduce SEM contrast since these will be saturated.
6. slowly tighten all four screws to lock source. This will cause shifts, correct as needed to get good illumination with source locked. 

Best align with current filament state, 200 pA mode (60 um aperture)
gun 44.5, 27.5 aperture -47.0 -22.9
user aperture -4.0, -6.0
stig 5.7 19.5 balance X 81.3, 95.9 Y 69.6, 94.7

Best max current
gun 44.5 27.5 aperture -47.0 -22.09
stig 24.7, 39.0 bal X 84.1, 93.0 Y 74.3, 94.7

Condenser lens needs mechanical alignment. Here is emission image for 1 nA, 600 pA, 400 pA all 90 um aperture

clear shift with condenser excitation















Align gun, aperture, stig, stig balance for 120, 90, 60, 30 um apertures

SEM Source Mechanical Align

Prior status

• just after bake, EHT off current up 246 vs 232
• Gun align near user software limit, stig balance off, time for full align

Align

8 kV aperture image condenser at "max"

aperture positions:

1. 60 um center
2. 20 um right
3. 30 um lower left
4. 75 um lower right
5. 90 um left
6. 120 um top right
7. blank top left

Procedure

First check mechanical alignment, use Si 10 um grid for test

Alignment, all offsets zero user and service. Cond normal

condenser off

Clear problems with mechanical alignment

Bring aperture to exact center, bad illumination

very poor aperture illumination on exact mechanical center

condenser on, illumination distorted here too

Procedure says illumination trumps centering

illumination better but is 120 better than 60??

best mechanical source alignment

after this use gun offset/align for center aperture

Post Bake tests

Problems

• FIG5 ion gun filament burned out
• Sample clips on STM stage too loose for good electrical contact, impossible for STM
• Manifold changes needed, existing manifold not optimized, leaking
• evaporator filaments cross wired, not working

Repairs

• FIG5 filament removed, replace with old 04-303 ionizer assembly, almost identical to FIG5 except 3 post rather than 5 post. Send failed ionized to RBD for rebuild
• Stage removed, clips removed, bent to improve sample plate grab, re-installed
• left clip electrically connected to metal "U", right clip isolated
• tricky to get right clip not to short to U since mounting screw passes through kapton washer into U
• changes to manifold, old stuff mostly removed

Bake

• Set for 72 hours, stopped 6 hours early (clock fast)
• bake into turbos, ion pumps open but off
• nano goes to 3e-5 at full temp, constant during bake
• prep 8e-6, slowly drops to 6e-6
• heat off drops to low 8's, with ion pumps running mid 9's, after TSP high 10's
• next day nano 2.5e-10, prep 3.5e-10
• 
  

Ion Gun

• Brief test of filament before bake, 1 mA emission >> 50 mPa extractor, too much outgassing
• After bake, nano 6e-10, FIG5 pump running
• Turn on 1 mA, grid 150 V, beam 0.5 kV, initially no pressure change, extractor or system
• filament will not come on in standby, must go to etch first. go figure.
• Turn off power supply and software, verify filament continuity, turn back on
• this time it works. probably software. Saved "foundry degass" profile new values
• 150 V grid, 1 mA, 500 V, 100% cond obj
• initial pressure 30 mPa, chamber 1.1e-9, 10:45 am
• pressure exceeds 50 mPa 11:15, gun shuts down self-protect, restart at 0.5 mA, initial pressure 14 mPa
• gun off again after 6 min, reduce emission to 0.2 mA, 28 mPa, later to 0.1 mA at 200 V, emission still > 80 mPa
• pressure peaks around noon, starts slow decline, still 0.1 mA 200 V etch
• 3:45 pm now 1.8 mPa at 25 mA. Note pressure may be normalized by emission current in software, higher current seems to reduce reading
• start to condition HV, pressure about 1 mPa now, 4:45 pm
• OK up to 3 kV, later 5 kV
• extractor still 2 mPa in standby

SEM startup

• connect all cables except detectors, including interlocks and column valve
• switch electronics on to standby, verify column valve closed, switch to on, valve opens
• forgot to start water chiller, SEM water flow error
• start chiller, cycle to standby, restart server, still get flow error
• confirm water is running. Open console whack water flow sensor, right side front behind electronics board, restart, still get flow error
• cycle power 5 times, keep hitting, keep getting flow error
• Remove and dis-assemble and clean flow switch, Gentech International 1 liter/min, closed on flow. No problems with switch.
• Flow is actually low. Run output into bucket, some black powdery crud. Flush with ~ 50 liters water. 
• adjust chiller from 2.6 to 3.3 pressure limit (zeiss spec 3.0 bar)
• disable filter change alarm (we have no filter, its optional)
• Now flow switch works
• Now column valve fails. Limit switch does not light. It did on the first run. Loosen tiny set screw so magnetic indicator works
• Close nano chamber gate valve, let pressure rise to mid 8's so zeiss ion pump will start.
• Start gun ramp up
• quick rise to 156 uA, slower increase to 167 and rising
• EHT on 3 kV, gun pressure 7e-9 mbar
• EHT off, 1:45 after gun start, gun 5.3e-10 mbarr, 209.5 uA at 5.02 kV 2.33 A
• next day 5.4e-10, 246 uA
• prior to bake was 223 to 234 back to Jan 2013, around 230 last six months

Manifold

• Ar source, Nano Ar gun, bypass all connected with VCR manifold
• Pump manifold, air lock, gun connection, Ar source, 4.0e-5 after 45 min, let pump over night.
• Overnight 4.1e-7
• apparent small leak in ion gun branch, close valve drops below 4.0, open after few min up to 5
• close manifold valve, no additional drop
• 
  

Vacuum problems during sample intro

• Granville phillips micro ion gauge controller shows 2e-5 air lock pressure
• degass gauge, jiggle connector cable, no help
• Leave pump running ~ 1.5 hour during sample transfer, analysis, then open gate valve
• prep still 8.8e-6, would expect better
• prep chamber 1.8e-7 (low 10's before opening), consistent with intro gauge
• close gate, pressure drops low 9's prep, increase to 1.7e-5
• Connect VQM cable to prep mass spec, turn on, mostly 18 amu in UHV
• open to air lock, lots of 32, 28, leak...
• pump air lock with prep ion pump, turbo valved off
• now mini IG 4.6e-7, prep 3.8e-8
• close valve to air lock, 14 and 28 drop, 18, 2, 44 relative rise, 1.9e-9
• reopen gate
• prep back to 3.8e-8
• 28, 14, 40, 32 rise, water related peaks fall
• now open turbo pumping valve
• pressure to 2.4e-7 prep, 9.8e-6
• 28, 32, 14 rise, also 40, air leak
• close turbo valve, pressure drops, 5e7 in air lock, 4.6e-8 prep, 14, 28, 32, 40 drop
• even with turbo valve closed, air lock pressure rises rapidly from mid 7's to 5's

Air leak in pumping, probably in manifold

• biggest leak was swagelock connected to mini flange at manifold pumping valve, tighten to reduce manifold to 1.1e-6 from 2e-5. 
• gasket (already suspicious) at 2.75" tee caught between flanges, ie offcenter, replaced.
• marginal improvement, still possible leak in manifold somewhere

Ion Gun trouble

Doing Auger alignment tests on Cu110 single crystal. Lots of carbon, system has been baked, maybe vented, since sample was clean. 64 V LVV peak hard to see.

Manifold

• Ar sample cylinder open, Ar supply valve open, manifold pumping disconnected. This was done when bypass valve connected to air lock pumping some months back.
• Ar supply probably contaminated, maybe missing, i.e. air not Ar
• Disconnect bypass 2.75" VCR flange, add 2.75" tee, reconnect bypass and manifold pump. 
• Turbo pumps down to low 1e-5 in airlock, 14 W turbo, at least no major leak
• Reconnect Ar cylinder/regulator. 
• manifold arrangement bad, no way to isolate Ar supply, need to fix

Electronics

• Electronics start up, software connects, gun to standby, initially ~ 11 mPa, pumps down to zero in ~ hour or less (did not watch)
• Analysis chamber 1.3e-10, after FIG5 pump running a while, ionizer degassed, to 6e-11
• Pressure controller stuck at current limit with software running
• verify cables connected
• verify voltage from ~ 10x10x4 cm USB DAC box on top of 3com switch, voltage 2 V for 20 mPa, etc.
• check output pressure ref from 20-066. Stuck at 10 V, so no pressure control.
• Switch gun briefly from standby to run and back. Now pressure reference works!
• Problem seems to be emission current. Controller cannot maintain 25 mA. 
• Could be result of filament O2 exposure. 
• Can get 20 mA by increasing grid to 180 V from 150 V (range is 120 to 200)
• When emission current out of "green" range, pressure ref goes to 10 V. This may be "fail safe" design...
• Open leak valve 2 full turns, pressure to 4.2 mPa, 
• supply ~ 1 bar relative (regulator), 2 bar absolute
• 2.25 turns, now 33 mPa before controller regulates
• Electronics "click", relay like sound, no clear reason why, its always done this, seems to be associated with cut in ion current.

Test

• 30 degree tilt near center of Cu110 large hole sample holder, excellent auger down to ~ 40 eV. 
• sputter 20 mA "20 mPa" 3 kV 30 sec raster 1x1
• old "scan squares are gone
• Cl peak 180 gone, also O, C reduced
• Cu MVV clear, double peak
• after 6 min C gone

Sample change 13/03/17

In:
AS130220a (source ASEB130311A, cleaved, 40nm Au, VT PBN heater holder)
RSB130317a

Stage Modifications

Background

The "bar" for tip transfer holder is in the center of the sample area and has a significant negative effect on Auger performance, particularly at low voltages.

Also Ion Sputtering is affected.

There are issues with beam current (SCM) measurement. Sometimes this works well, sometimes sample is grounded.

Modifications

Check exact electrical conditions (what metal parts are at what potentials. 

• Each spring clip separately connected to external leads.
• "U shaped" body not grounded at all (except by our previous mod)
• Attachment screws for ceramic clip holders (2x2) and U mount (2x2) isolated from U part, floating.
• Thermal clip hard grounded to chamber
• Clip screws connect to U part.

Changes

• Remove bar and and kapton insulator washer so left clip at U potential.
• Right clip still isolated when no sample plate in place
• Ground all floating screws to U part (tack on grounds with spot welder)
• Add new bar on receiver guide to U part, same side as original but ~ 8 mm back
• Extended back of tip carrier spring to engage new bar, removed most of original bar catch.
• Verify modified tip carrier works for airlock-transfer arm-carousel-stage transfer
• Verify piezo motors

Bakeout

• All turbos running, transfer gate between chambers closed, gun valve open also bypass
• Pump down to 9.5e-6 nano 1.6e-6 prep then start bakeout
• Shut down ion pumps, open gate valves (were closed for up-to-air)
• Start 48 hour bake 5 pm friday 3/8/13
• 3/9/13 10 pm: 6.5e-5 nano, 6.5e-6 prep.
• 3/10/13 2 pm: 3.5e-5 nano, 3.1e-6 prep.

during bake

• Start 5 pm Friday, at noon on Saturday ion gun turbo goes off - no apparent cause. Gate valve closes before bakeout interrupted
• Air temp reaches max at 11 pm Fri, switches off 2 pm Sunday (for 48 hour bake).
• Flange reaches 140 after 5 hours, 180 after 11, cools to 70 C in 11 hours after heat off
• Programmed bake temp is 150 C but air temp goes to 190+/- 5 C, SCA flange reaches 187. 
• Unexplained pressure spike 7:45 am in nano chamber, 6e-9 to 2e-5, recovers by 9 am

Sample change 13/02/25

Out:
AS130221b (Si stripe, 1120sec-grwon Au in prep, VT PBN heater holder) from sample stage

In:
AS130225a (source ASEB130221A, 40nm Au, VT PBN heater holder) to Upper 3

Sample change 13/02/21

Out:
AS130220a (source ASEB130203A, 40nm Au, VT PBN heater holder) from sample stage
VO2 nanowire chip B (w/ Ref VO2 nanowire) from Lower 1 (two window sample holder)

In & Out:
AS130221a (source ASEB130203A, 40nm Au, VT PBN heater holder) to sample stage and out

In:
MSB130221a (MoS2 bulk crystal) & CB130221a (99.999% Cu foil-polished) to Lower 1 (two window sample holder) Mo, S, Cu ref for Auger & XPS.
AS130221b (Si stripe, 1120sec-grwon Au in prep, VT PBN heater holder) to prep chamber

Sample change 13/02/16

Transfer:
CS130213a from sample stage to Lower 1

In:

VO2 nanowire chip B (w/ Ref VO2 nanowire) to sample stage (two window sample holder)

Sample change 13/02/15

Transfer:
CS130213a from Upper 3 to sample stage

In:
AS130215a (source ASEB130203A, 40nm Au, VT PBN heater holder) to Upper 3

Out:
AS130212a (source ASEB130203A, 40nm Au, VT PBN heater holder) from sample stage

Sample change 13/02/12

In:
AS130212a (source ASEB130203A, 40nm Au, VT PBN heater holder) to sample stage

Out:
MSA130201a (normal sample holder w/ c-shaped clamp) from Upper 3

VT PBN sample holder issue

One of screws has been broken when it was unscrewed since the nut is stuck with the bolt thread. This screw should be replaced. Other parts look fine.

Sample change 13/02/05

Transfer:
MSA130201a (normal sample holder w/ c-shaped clamp) from prep chamber to sample stage

Out:
AS130203a (source ASEB130203A, 40nm Au, in-situ PBN heater holder) from Upper 3

Sample change 13/02/04

Transfer:
AS130203a (source ASEB130203A, 40nm Au, in-situ PBN heater holder) from sample stage to Upper 3

In:
MSA130201a (normal sample holder w/ c-shaped clamp) to prep chamber for annealing

Sample change 13/02/03

Out:
AS130201a (in-situ PBN heater holder) from sample stage
MSA130201a (normal sample holder w/ c-shaped clamp) from sample stage for AFM, Raman, PL characterizations

In:
AS130203a (source ASEB130203A, 40nm Au, in-situ PBN heater holder) to sample stage

Sample change 13/02/01

Out:
AS121205a (sample holder) from Lower 1
AS130131a (vac annealing, rectangular window sample holder) from Upper 3
In:
AS130201a (in-situ PBN heater holder) to sample stage
MSA130201a (normal sample holder w/ c-shaped clamp) to sample stage

Sample change 13/01/31

Out:
AS121130f (normal sample holder) from Lower 1
AS121130d (normal sample holder) from Lower 2
AS130125a (in-situ PBN heater holder) from sample stage

In:
AS130131a (in-situ PBN heater holder) to sample stage

SCA Channel 1 not Working

• While taking Auger data, after doing experiments continuously for a week or so, we noticed channel 1 showed zero counts. (Jan 30 2013)
• Red LED was dark at preamp and receiver for Chan 1, other channels normal
• verified CEM HV cable was connected.
• Opened preamp box, 7 modules, 1 per channel. No visible damage, nothing loose. 
• Tried to measure voltages by connecting preamp SHV connectors to Fluke 80K-40 high voltage probe (1 GOhm impedance) 1000:1 voltage divider with Fluke 179 multimeter, hemisphere at 100 V. 
• Got strange values, ~ 240-300 mV but not stable with time. 
• Expected ~ 1.5 V = 1500 V actual. 
• Channel 1 had only 3.4 mV
• With meter connected, channel indicated counts. All 7 similar.
• With multiplier off, swapped channels 1 & 6. preamp cables. Chan 1 still reports no counts, chan 6 OK. Problem not in UHV
• Swapped HV modules in "1127 Multiplier Supply". Problem moved with HV module
• HV module is defective
• Repair/exchange $750, in stock at Omicron US.
• New module installed 2/11/13, works

CEM Gain Adjust

Modified cover of multiplier supply so that the trimpots to set individual CEM voltages are accessible while the cover is closed. This makes CEM voltage adjustment safe and practical. Supply needs to be pulled halfway out of rack.

• Try to balance CEM signals. Pick flat part of spectrum, CAE mode. 
• Chan 2 is low, adjust to max gain. Adjust other channels to ~ match
• Increase supply knob setting to 9.00. No clear plateau in signal vs voltage

Auger imaging parameter optimization

- Sample: Au/Si, AS121130d
- Si peak Auger images were constructed using Auger maps measured at 1616.5, 1635, and 1650 eV.
- Auger maps were measured changing Path energy and Scan time.
- As shown in Fig. 1, optimal path energy for Auger imaging of Si is 160 eV (CRR mode, CAE[eV]/CAE=10).

                                       Fig. 1. Si 1616.5 eV Auger peak height at varying path energy.



- As shown in Fig. 2, as scan time increases, Auger image quality gets better. 21.6 min scan time is enough to get good quality images.

  Fig. 2. Si 1616.5 eV Auger peak height at varying scan time.

Path energy optimization for Nano-auger

- Sample: Si/Au AS121130d
- Auger spectra was measured on (100) Si region at varying Path energy.
- CRR mode from 320 eV to 80 eV
- CAE mode from 70 eV to 5 eV

                                        Fig. 1. Auger spectra measured on Si at varying path energy.

     Fig. 2. Si 1616.5 eV peak intensity vs. path energy and Si 1616.5 eV peak height vs. background ratio.

Transfer rod to Prep Manipulator

1. Set manipulator position:
1. Top (vertical motion) micrometer: 11.05 mm
2. Z (horizontal insertion) screw: 105 mm (scale ends at 100, engraved on one support rod) There is also a red sharpie mark on the support rods
3. Rotary motion 300 degrees (red mark on top of support)
4. These positions are approximate, adjustment may be required to engage sample.
2. To transfer the sample to the stage: Slide the transfer rod forward until the long pins engage the rectangular hole in the side of the manipulator stage. 
1. If there is any resistance, adjust the height, insertion, rotation until the motion is easy.
3. The sample plate should slide into the dock on the manipulator.
1. If there is any resistance, adjust the height, insertion, rotation until the motion is easy.
2. Insert the sample plate fully, until the metal part of the transfer rod touches the dock, then rotate the transfer rod handle to open the jaws.
3. Now retract the transfer rod, leaving the sample plate on the manipulator dock.

Sample Introduction and Airlock

Here is the procedure to transfer samples from air to the long transfer rod in the prep chamber. From there samples can be moved either to the prep manipulator or to the parking carousel in the analysis chamber.

1. Start the "Prep" turbo pump, if it is not running already (see Turbo Pumps how to for details)
1. Start PV TurboViewer software on Auger-pxi. 
1. click connection wizard, set find multiple devices to 3 and click button, software should find three pumps. Drag window taller and click arrange. Click on speed display to toggle between rpm/Hz/% for speed. 
2. pump 001 is nano, 002 is prep/sample intro, 003 is ion gun
2. Prep turbo should reach 100% within a minute or two, power < 20 Watts, foreline pressue (push down arrow on ion gauge controller to see fore pressure) < 0.1 mBar.
2. Vent airlock
1. Close airlock pumping valve (large black plastic handle) and bypass pumping (small green valve handle). 
2. Open N2 vent supply valve (small green valve below table)
3. Turn off air lock ion gauge if on.
4. Open airlock vent valve (below airlock). You should hear gas flowing. Airlock pirani gauge should read about 780 torr (slightly above atmosphere).
5. Open air lock door. Do not let glass door fall open. 
3. Load samples
1. Up to 3 samples can be loaded. Use gloves and clean sample plates.
2. Normally sample surface is to the right as you face airlock. 
3. VT double-plate holders must face right
4. If flat sample plates will be heated on prep manipulator, load upside down (facing left) so sample surface faces heater after transfer.
4. Pump airlock
1. Close N2 vent valve
2. 
   

Gun Arc at 30 kV

• On Thursday 12/6/12 low-level radiation group requested SEM be operated at max voltage and current.
• I set the beam voltage to 30 kV. The system had not be operated above 10 kV for some time. Just as the voltage reached 30 kV I heard the "snap" of an arc. The gun went off, there were no error messages.
• I had trouble restarting the gun, I got "EHT Vac not ready" (see previous notes). Raising pressure, restarting PC no help. After putting electronics to standby and back to run, EHT Vac was good, gun started.
• Emission current almost doubled, from ~ 107 uA to ~ 170 uA. I was afraid filament had been damaged during arc, however the same feature was centered in the field of view, and it was possible to get similar image quality. 
• Robert Ribay from Zeiss happened to be working on the Supra, he looked at the image quality, did a quick alignment, and did not see serious problems.

pBN VT heater test

Test of VT pBN heater plate

• Remove old sample, re-attach top plate, verify thickness of assembly and heater brushes
• 7.6 mm total, 2.9-3.0 from top of brush to bottom of top plate
• 17 ohm left brush (seen from handle) to ground. Right brush grounded.
• Sample Heating Selector to "Direct Current"
• Initial 1.6 V at 0.16 A (10 ohm), gentle pressure rise, manipulator TC increases linearly with time 22 to 28 C over 6 minutes, 0.25 W
• Next 3.24 V 0.40 A 1.3 W 8.1 Ohm
• 4.49 V 0.65 A 2.96 W 6.7 Ohm, temp rises slowly with time
• 5.73 V, 1.04 A, 5.96 W 5.7 Ohm, current rises to 1.18, pressure low 1e7 outgassing
• More tests
• Set 6.26 V 1.05 A Monday 9:23 am
• by 10:14 current limited at 1.49 A, 5.7s C 8.5 W, stage at 270 C
• pressure rose to 1e-7 then down to 2e-9
• increase current to 2.01 A, initial 7.43 V drops to 7.23 steady state, 14.5 W
• stage steady state 332 C. pBN heater uniform "cherry red" 
• contact bars also hot, darker red
• heat shield, top plate, sample straps do not glow
• pressure has dropped to 1e-9
• Set 1.49 A, 5.55 V increases to 5.70, initially 3.72 Ohm -> 3.83
• heater "incipient red" just at visible glow threshold
• steady state base 280 C
• 8.5 W

Photo of heater at 14.5 Watts, pBN "cherry red"

Approximate sample temp vs power for pBN VT holders

Prep chamber heater hints

• Prep chamber manipulator heater powered by TDK-Lambda power supply (60 V, 12.5 A) under system controller.
• push small button on far right under digital displays "out" to enable output
• adjust current and voltage knobs. Depending on load either current or voltage limit will control. Green LED near knobs shows which is limiting. 
• Set Sample Heating/Bias Selector switch to "Resistive" to connect the TDK supply to the pBN heater built in to the prep manipulator.
• This heater is ~ 30 Ohm cold, 5 A max current, 100 W max output
• Increase and decrease heater power slowly to avoid thermal shocks
• 1.45 A requires 27.6 V for 40 W, R ~ 19 Ohm (lower when hot). This gave ~ 525 C at thermocouople, sufficient to dewet Au/Si film at ~ 600 C
• There is a thermocouple attached to the sample plate dock. This temperature will be lower than the actual sample temp, and the difference will be greater when radiation is important, > 500 C.
• temperature will depend on sample properties such as emissivity since heating is by radiation coupling

Estimated temperatures for stage and sample vs power

• The side of the sample plate facing the heater must be flat (no sample, screws, clips, wires, etc.
• For simple plates with the sample mounted below, the sample can face the heater
• For this to work, put the sample in the airlock "reversed" or upside down. 
• The sample can be heated
• transfer to the carousel in the analysis chamber upside down. Then use the wobble stick to flip the sample over for inserting in the Auger/STM stage.
• Do not heat samples mounted with spring clips to high temp (> ~ 200 C) as this will anneal and damage the springs. Mount samples with spot welding for high T.
• VT double plates with direct or pBN heating may be inserted in the manipulator stage face up. 
• The plates can be heated using the manipulator pBN heater, or by using the VT heater since the  "fingers" on the manipulator contact the heating terminal.
• Set the selector switch to "direct current" to use the VT heaters.
• The top of the VT heating contact must be 3.6 to 3.7 mm above the bottom of the VT assembly, also the total thickness should be 7.6 mm
• adjust the VT plate if these distances are not correct. Using a badly set VT plate will bend the contact springs.

SEM Chiller problem

Chiller was much more noisy that normal in pump room. Disconnect brass pump head from motor. Motor quiet, pump hard to turn manually, "rusty" crud in pump. Must be failing

Pump failed once before, shortly after installation, was replaced by Thermo under warranty.

Ed will order new pump, for now run chiller only when SEM in use, not 24/7

On Thursday, took 3 tries to get chiller to run without alarming for low pressure

Pump replaced Wednesday 12/12/12. Old pump had damaged impeller blades. We also ordered a spare pump.

AuSi experiments Nov 30 12

Introduce two new samples on large-circle holders

• AS121130F - 670 C tube furnace, quenched, air, older holder no faraday hole
• AS121130D - 655 C, newer holder with FC hole

Transfer samples to carousel, look at F sample, rather low carbon, can find denuded zones, shadow zone clearly visible in Auger images near O KLL at 3 kV.

Get nice LVV Si and NVV Au at 3 kV. Record auger map images with smart sem 14 bit. Switch to 10 kV for Si KLL and Au MNN.

Need to readjust max current gun align, escecially at 3 kV.

Gun off for thanksgiving

• Extractor 5.02 kV current 107.2 uA fil 2.33 A 15 Nov 12
• Gun vac 2.72 e-10 system 1.2e-10 before gun off
• Gun vac drops slightly to 2.27 e-10 while gun runs down 

before restart on Mon 26 Oct 12

• Gun vac 1.1e-10, system 1.3e-10, gun vac fluctuates near zero
• have "column pumping" = pumping, "ready", occasionally off, EHT vac ready = no
• Throttle ion pump, open Ar leak valve to get system pressure 1e-8, try to get SEM ion pressure stable above 1e-10. Not enough, pressure (ion pump current monitor) fluctuates below 1e-10
• Have to open pump bypass, get ion pump pressure ~ 3 e-10 with no fluctuations below 1e-10, after ~ 100 sec stable pressure, EHT vac goes to ready, now start gun run up

Extractor reaches 5020 V at 9:50

9:50  78.4 uA

9:53  83.4

9.56  85.2  also close bypass, gun vac 8.8e-11

10:13  92.3

11:48 105.6 close to steady state

On Tuesday, gun 107.8 uA EHT off, 62 uA EHT on 3 kV, 42.5% extraction

Toolbar Customize

Added two new toolbar buttons.

• rightmost multi-image sets slow speed, restarts scan, freeze at end, save both channels, or only one if not dual mode, restarts scan faster speed. Current speed 12
• +/- icon on right steps up or down mag in 1/2/5/10 steps between 100 x and 100 kx
• macros can call exe programs, could be used to sync Auger with other pc...

Image tests

Auger Image Test

Si wafer plus oxide

Take auger spectra, zoom into 200x image region, left if image oxidized, right not oxidized.

Verify ImageJ can read 16 bit images, adjust contrast 0.16 DAC1 for CRR5 at 507

Image 9, 10 sequential 507 images, can check for noise

Image 11 is 523, image 12 is 533, 13 is InLens

Change to scan speed 14 512x384 image, 0.8 us/pixel, 2.8 min, record 507
Next 523 then 533.
Auger counts ~ 1 MHz, so 800 cts/pixel, SNR ~ 28

Take spectra at 50, 10, 2, 1 ms point to evaluate SNR, 1 ms is minimum interval, actual elapsed time >> than apparent time.

Processing

ImageJ reads images, can calculate differences, as float data to handle negatives. Reasonable Auger image of O KLL on Si.

• Calibrate Zeiss inputs. Image grey_test_02.tif is 16 bit, start at 1.0 V, descend in -.1 volt steps to 0, again 1.0, then -0.1
• 1 volt region is 4965 counts of 20724, 1756 of 20720.  No 21, 22 or 23. Must be 14 bit A/D
• 0 V is 1784 +/- 4
• if linear, 18.94 k/V. 0.21 mV/bit (14 bit) or 52.8 uV/bit (16 bit)
• min is -.094 V, max is 3.36 V
• 0.1 3582
• 0.2 5564 but spread over ~ 10 values
• .3 7240
• .4 9338
• .5 11258
• .6 13048
• .7  15032
• .8  16886
• .9 18846
• 3.0 V is 58386, 89.1%
• 0 is 1778, 2.7%
• 3.1 is 60278, 3.2 is 62168, 3.3 63976, 3.35 64988

Ion Gun Problems

• Ion gun controller has always had relays clicking, anywhere from every hour or so to every minute or so. Ion current drops momentarily to zero on click
• Today (11/8/12) got essentially no ion current at 2 kV, same settings that were good last week
• sample current monitor ~ 1-2 nA, should be 100's
• no SE detected by hemisphere
• changing offset, obj, cond no help
• pressure sensor DID change with gun standby/sputter
• At 2500 V did get sample current ~ 200 nA. 
• Got SE signal earlier in the afternoon, later no signal.
• Shutdown gun and software, restart, no change.

Fixed

• My bad. When rerouting cables, J8 float voltage was attached to transition lens SHV connector. Therefore gun was floating and operating in a weird mode.
• After fixing cable, 3.6 uA by SCM, also lots of counts.
• Relay clicking, current dropping issue still exists.

Dewetting experiments continued

directory 121108 SiAu

Si reference

• Take SiO sputter sample to get Si reference. Look near region sputtered last week.
• Get Inlens detector working. At 3 kV, very bright region is SiO, darker regions SiC. No clean Si seen
• Sputter sample 2 kV 3x3 raster 20 mPa cond 66 obj 61 grid 150 30 degree tilt

Problem - sputter issues, sample current does not change much, no SE in Auger.

• almost no SE signal
• sample current 2 nA for 2 kV ions. Change to 2.5 kV, now 260 nA, reasonable SE signal 250 kHz CRR 5 at 80 eV
• 2500 V does give reasonable sputter rate. Remove C and O with ~ 150 sec sputter
• also discover software for FIG5 has timer for sputter...

Take reference spectra 121108 SiAu.aes, Si LVV and KLL regions at 3 kV and 10 kV.

• Si KLL ~ 1% peak for 3 kV, ~ 40% for 10 kV. Spectra in CRR and CAE
• Good quality Si data

Auger alignment and low kV

Investigate behavior of auger electron optics
Clean Cu sample with piece of clean gold foil, 6 mm aperture, sloped edge, St. Steel plate

30 kV max current, tilted 30 degrees to analyzer.
SEM WD 9.3 mm

Sample SE2, zoomed out to 72x, not rotated

Energy filtered image, #3 entrance slit 2 mm diameter, 2 kV at CRR 5 gain 0.05
analyzer is to image right

1 kV gain 0.2

500 eV gain 0.4 shifted 0.7 mm 23 degrees

Edge of Au foil visible in upper left of auger image, translate sample, move foil away, no change in Auger image, helps rule out magnetization or charging of sample holder plate

400 eV gain 0.6 shifted 0.8 mm

300 eV gain 0.8 shifted 1.2 mm 14 degrees

same as above CRR 20 gain 2.0, imaging qualities degraded with more decel

200 eV gain 1.2 displaced 1.8 mm  13 degrees

above corrected (-5,-1)% deflection, (-2, -0.4) Volts

100 eV gain 1.5 same deflection as above

Counts optimized at center, (-4.2,-0.7) instead of (-5,-1), counts up ~50%

80 V CRR 5 same def

slower scan for S/N, shift x def -4,2 to -4.1 10% gain in counts, only 40 mV change. "ripples" also visible in image

slit #1 full open, gain 0.3, 80 V CRR5 

optimize counts in center -5.0, +0.4, count rate 850 kHz to 1120 kHz

Shadow of bar that opens tip transfer holder, tilt 25 degrees, 50 eV CRR 3, 3 kV max beam

Green spectrum in shadow, white spectrum with sample translated in +Y/F2 direction (toward wobble stick) 3 kV max current ~ 17 nA, tilt 25

SEM scan rotated 180 degrees so bottom is wobble stick, top is STM, left is analyzer, right is x-ray, positive tilt to left

It is absolutely clear that the tip-transfer holder bar does block low KE electrons, depending on stage position and angle.  Using the wobble stick to pull the sample slightly out of the stage (2-3 mm) lets the center region of the sample be seen by Auger

Now low KE spectra work on AuSi dewetting sample, before this failed due to stage interference.