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.

Auger Problem Deflection

Several problems

• absolute count rate drops
• low KE auger really bad
• Octopole does not have normal effect on counts
• low mag image of #3 aperture offset
• switch back to Cu110 sample, not normal

Deflection voltages

• Xa+ is bad, stuck at -5.5 V from 20 to 100% (load or no load). 10% -1.16, 5% -0.3, 0% +6.8
• Xa- tracks, opposite of Xa+
• Ya+, 0% -1, 10% -.8, 20% to 100% -.4
• Ya- tracks Ya+
• B X&Y stuck at zero independent of control settings.

Ground all 8 electrodes to 'system ground'

Cu110 CRR5 3 kV max, low KE distorted

More or less normal spectra at high KV

Good Cu110 spectrum recorded when quadrupole worked, 30 tilt

Now try to cycle power on PC and EAC

While power is off, remove and physically inspect EAC deflection boards. No visible damage. These seem pure analog, GPIB decode and voltage generation elsewhere? +/- pairs seem to be on deflection boards (op amp circuits)

• Before EIS starts, voltage (disconnected from analyzer) at -40 V on XA+
• Voltages different from before but still bad, should be -40 to + 40 V for 0-100%
• Xa+  0% 7.2, 10% -7.2, 20% and above -15.9; Xa- is opposite
• Ya+ 0% 0 10% -.8, 20% and above -0.4; Ya- tracks
• XY b zero always

Now try ISEM. Do EA SEM image manual deflection, X and Y 25%, values go to -20.0 V for Xa+, Ya+. What does this mean?

Now EIS Octopole control works!!!

Optimize at 80 V, spectrum normal above 135, drops off quickly below that. Nothing below 60 V. Better but still different from before.

residual B field from lens after higher KV operation???

Something charging near sample???

Better with octopole, but problems below 135 eV

EAC Control

Build Labview routine to control EAC instead of EIS.

• mult on off
• CAE/CRR and Epass
• KE, span and fraction
• quadrupoles

EIS quits if LV cable disconnected and GPIB write fails - no error handling

Changes needed to FPGA:

1. remove DAC1 mode, not supported?
2. Decimate should have a separate Delta T routine, 32 bits, call once per transfer cycle, no need to slice into 10 us intervals then sum back to 10 ms...

Changes to PC GUI

1. Add gpib controls
2. add noise calculation
3. decimate by summation

ISEM DMA acquisition problems

ISEM DMA modes do not work. Image acquisition otherwise hopelessly slow.

• verify Hsync, Vsync, Pixel clock outputs from Zeiss PC, these look good.
• Pull multichannel receiver out of rack, verify signals arrive on board, they do.\
• Shut down PC and reseat PCI cards (Zeiss control and Omicron data acq)
• this was suggested as a possible fix for detector contrast problem
• Now try ISEM DMA
• now it works. no obvious problem fixed???
• put back in rack, still works

ISEM tests

• image acq will be painfully slow. Test with spectra at, for example, 1 ms acq time. cannot see Si KLL on Si, for example
• with CRR 3 and 25 ms/pixel, can start to see spectra (10 kV max current)
• with 200 ms, not bad
• image time line by line ~ 2-3x raw image time (zeiss) for fast scans, overhead may reduce
• optimal image (no OH) at 0.2 sec, for 2x512x384, around 20 hours...
• there is a line scan mode, can do point by point or line by line, but cannot get line data, only peak/back. No chance for own processing.
• for Au on Si, large backscatter and noise effects, swamps real contrast

To try

• can take reduced image for test
• can modify data 'schema' to get access to raw images peak/back acquired line by line, for post process later
• can try multipoint acq to get family of spectra, but OH and data format may be a pain.
• need to test data export, image dynamic range may be reduced either to 256 or 100 values (bad)

SiAu Expt continued

Take nice high res spectra Si KLL and Au MNN regions

Si peak structure in eutectic regions quite modified.


Au film far (~ 100 um) from dewet area shows no Si

Near edge clear Si. Also in squares and dewet droplets, more in the latter case. Suggestion droplets less Si than squares..

Compare Au film far from DZ and at edge of DZ

Compare Au film far from DZ and at edge of DZ

Si region for DZ and eutectic

Si region for DZ and eutectic

X-ray Levels of Elements

info from CRXO.lbl.gov x-ray data base

Carbon (C ) Z = 6

• Atomic Weight : 12.011
• Density : 2.20 g/cm^3

  K1     284.2 (ref.2)

Oxygen (O ) Z = 8

• Atomic Weight : 15.999
• Density : 0.143E-02 g/cm^3

  L1      41.6 (ref.2)
  K1     543.1 (ref.2)

Silicon (Si) Z = 14

• Atomic Weight : 28.086
• Density : 2.33 g/cm^3

  L3      99.8 (ref.4)
  L2     100.4 (ref.4)
  L1     149.7 (ref.2)
  K1    1838.9 (ref.1) 

K-related Auger peaks

1540

1551

1557

1576

1582

1598

1609

1617 strongest

Electron Level Widths (eV)

  L3     0.014
  L2     0.015
  L1     1.030
  K      0.480

Vanadium (V ) Z = 23

• Atomic Weight : 50.942
• Density : 6.11 g/cm^3

  M3      37.2 (ref.3)
  M2      37.2 (ref.3)
  M1      66.3 (ref.3)
  L3     512.1 (ref.3)
  L2     519.8 (ref.3)
  L1     626.7 (ref.3)
  K1    5463.8 (ref.5) 

Electron Level Widths (eV)

  L3     0.240
  L2     0.260
  L1     2.410
  K      1.010

Copper (Cu) Z = 29

• Atomic Weight : 63.546
• Density : 8.96 g/cm^3

  M3      75.1 (ref.3)
  M2      77.3 (ref.3)
  M1     122.5 (ref.3)
  L3     932.5 (ref.3)
  L2     952.3 (ref.3)
  L1    1096.7 (ref.3)
  K1    8980.5 (ref.5) 

Electron Level Widths (eV)

  L3     0.560
  L2     0.620
  L1     3.060
  K      1.550 

Gold (Au) Z = 79

• Atomic Weight : 196.967
• Density : 19.3 g/cm^3

  O3      57.2 (ref.3)
  O2      74.2 (ref.3)
  O1     107.2 (ref.3)
  N7      83.9 (ref.3)
  N6      87.6 (ref.3)
  N5     335.1 (ref.3)
  N4     353.2 (ref.3)
  N3     546.3 (ref.3)
  N2     642.7 (ref.3)
  N1     762.1 (ref.3)
  M5    2205.7 (ref.1)
  M4    2291.1 (ref.1)
  M3    2743.0 (ref.1)
  M2    3147.8 (ref.1)
  M1    3424.9 (ref.1)
  L3   11919.7 (ref.5)
  L2   13734.2 (ref.5)
  L1   14355.3 (ref.5)
  K1   80724.9 (ref.1)

M4,5 related Auger peaks

observed 10 kV CRR 10 and CAE 200 Omicron Auger up to 2200 eV

1499

1518

1588

1651 weak

1743

1765

1828

1858

1929

1992

2016 strongest

2022

2072

2101 strong

Electron Level Widths (eV)

  L3     5.410
  L2     6.000
  L1    10.500
  K     52.000
 

SiAu dewetting expt

Play around with conditions. Si and Au LMM peaks much better for 8 kV than 3 kV. % is OK but 8 is better. Did not try above yet. Peak stronger background less.

At 8 kV hard to get signal below ~ 250 eV regardless of deflection settings.
For 8 kV 1600 V approx +36.7,51.5 octopole

On eutectic squares and blobs, AuSi silicon peak is dramatically changed in shape
Doublet 1616.5, 1609 and 1557.5, 1552.5

Pure Si more like 1617, 1598, 1577, 1559, 1543

Au core levels
4s 763
4p  643, 547
4d 353, 335
5s ~ 110
4f 84, 88
5p 57, 74

SEM Contrast Problem

• System working normally, then SEM went dark on return from spot mode. 
• Contrast control has no effect. 
• In lens detector no signal
• SE2 detector turns on and off when selected, but SEM software does not control voltage. Good image with manual control.
• Image from Auger detector is good, beam hits sample.
• Exit SmartSEM, restart windows, restart SmartSEM, still broken.

Suspect SmartSEM programing voltage for CEM failed. Fuse??

Check voltages.

Brightness is +2.6 V for 100%, 0 for 50%, -2.6 for 0%, both SED and InLens. This seems right.

(pin to right of center in audio plug)

Contrast (center pin) is stuck at 1.92 V for SED and between 0.51 and 0.74 V (non linear) for InLens

Both should be 0 to +5 V for for 0 to 100%.

HV Monitor on Supra is +1.227 V for 100%, 0.314 for 25%.

On InLens is +0.018 V. 

work around

still no news from Omicron 11/8/12

Run SED in local mode, works, but must remember to shut down if not required, for sputter, etc. Also no brightness control.

Modify InLens, open housing, disconnect voltage monitor wire and use BNC for external brightness control. Write external LabView app to control voltage.

Ion Gun Operation

FIG-5 Setup

1. Start Diff Pump Turbo (pump control 3)
1. run for at least 10 minutes after reaching 100%
2. PV Turboviewer gives details, pump power should be <~ 10 W steady state
2. Start 20-066 ion gun control power supply (brown box in rack)
3. Start the Pfeiffer RVC050 controller (grey box above 20-066) with the white toggle switch in Set Point mode.
4. Start FIG5 control program
5. Open FIG5 differential pumping
1. system pressure should stay constant or drop somewhat
6. In software set mode to Standby then click the ON button
1. Standby means the filament will heat but no the ion acceleration voltage is OFF
2. Parameters in Orange are not at desired values, parameters in green are good. In standby mode it is normal for Energy, Condenser and Objective to be orange, since the ion accelerating voltage is off, as shown below. They go green when the gun is on (Etch/Neutralize)
7. Wait for the Extractor Pressure to drop below 1 mPa. This shows the gas pressure in the ion gun. Since the Ar valve is still closed, any pressure reading is due to outgassing. This should drop with time.
8. Once the ion gun has degassed, open the leak valve. Click the magnifying glass to get a big pressure display, put it where you can see it on the computer screen from the vacuum system.
1. Slowly (1/10 turn adjustments) open the leak valve. Wait for the pressure to start to rise, ie to several mPa. Also watch the system vacuum. This will rise from the 1e-10 or 1e-11 range into the 1e-9 range.
2. It should take 2-3 turns to open the leak valve. If you open the leak valve too far, too fast, you could cause the ion gauge, ion pump, SEM field emission source to shut down.
1. This is bad.
2. Do not do this. Open the value slowly
3. Open the valve until the pressure exceeds the setpoint, typically 20 mPa. Now the Pfeiffer should stat to regulate the pressure (there will be a non-zero current showing on the Pfeiffer meter). The pressure regulates at ~ 25% above the setpoint when the gun is off, since the pressure sensor reading changes with the gun comes on.
4. Now you are ready for ion sputtering.
5. The system pressure should be in the low 1e-9 range when not sputtering. It may rise to ~ 1e-8 while sputtering.

Operating Conditions

Max current at condenser 66, Obj 61 for 2 kV.

Recorded current, clean copper sample no bias:

66   3.5 uA

70   2.2

80   0.27

85   0.11

90  0.05

Not much beam shift with Cond, Obj

At 1 kV, center shifts to (-0.5,-0.5) from (-0.9, 0.2), FWHM increases to ~ 1.5

Cond 60 387 nA

62  692

64   950

66  1070

68  860

70  590

75  193

80  65

85  27

Update profile Obj 61 Cond 66

Ion Gun tests and calibration

Check ion gun alignment, try to optimize focus etc.

Operating Conditions

Max current at condenser 66, Obj 61 for 2 kV.
Similar at 4 kV.

Recorded current, clean copper sample no bias:

66   3.5 uA

70   2.2

80   0.27

85   0.11

90  0.05

Not much beam shift with Cond, Obj

At 1 kV, center shifts to (-0.5,-0.5) from (-0.9, 0.2), FWHM increases to ~ 1.5

Cond 60 387 nA

62  692

64   950

66  1070

68  860

70  590

75  193

80  65

85  27

Update profile Obj 61 Cond 66

Sputter test

Change to oxide on Si sample, (old and dirty, lots of particles).

2 kV no raster, offset -.9, -.5, cond 66 obj 61, 25 mA emission, 20 mPa gas

After 60 sec carbon reduced, oxygen little change except peak shift.

150 s Si peak LVV starts to evolve, no SEM change yet. Ar peak starts to appear

Approx 300 um diameter spot, ~ 430 um below center. (Aligned by max count rate with apertures open) 

Clear contrast in auger image 93 pass 10, weak contrast SE2, more with inlens

Additional sputter, spot size does not change much. Now try line raster. Also record ion excited Auger. Clear Si, Ar, S

Move to lower end of test area. Center on sputter signal with 2 mm aperture. 

Record Ar excited Auger during sputter. SiO peak and O peaks clear.

So-called ion excited spectra may actually be ions+electrons...

Do not see expected sputter crater. May be shadowed at low angle or problems due to tip transfer lever.

Remove sample. Si sputtered clean except shadow area.

New Test

Second SiO piece same wafer. Put in round beveled 6 mm holder. This one with Faraday Cup, shows 17.8 nA for 3 kV max. 

Had to slightly pull out plate (away from back stop) to get current measurement.

30 deg tilt, 5 kV sputter no raster. Current exceeds 10 uA during sputter. 

Sputter 250 sec total, not thorough yet. Notice noise on AES. Look at beam current stability. Occasional glitches. Effect of sputter? SiO sputter test 3.aes spec 9, 10. 

After several spectra checking stability, spot mode, big C peak. 

Gets better. spec 11 same spot, spec 12 elsewhere, lots of C???? 

Sputter into contamination layer? Was gone before. Contaminated sputter gas?

EIS crashes, most data was saved.

Turn on mass spec, close gun valve, start turbo, close ion pump. 

Turbo only (was not run for a while, may not be that clean. 

Pressure to 3.6e-9, 

MS 28 - 20%,

2 17%

40  12.5

18 8.3

15 7.9

16 7.6

44 5.8

27 4.5

26 4.0

MS 200 uA emission, baseline 3.7 nA H peak 8.8, 28 peak 4.8

Open leak 2e-8, baseline 3.3, Ar+ 8.5, Ar 4.7, H 4.9, 28 3.6

Trend graph Ar+:++ is 70%, 14% or ~ 5:1

slight relative increase in 28.

Open leak 1/8 turn, pressure to 1.3e7

20 rises to 36%, 40 drops to 62%. H2 is 2%. 

Baseline 3.0 nA, 20 is 4.55, 40 is 5.0, H 3.2, 28 3.08

Strange, Ar pressure above ~ 1.5e-8, mass 40 drops wrt 20

Flash TSP close Ar pressure to 1.9e-9 dropping.

Open Ion Pump, 1.5e-9

Much later, +50 s sputter no C but still oxide.

Total 360 sec, now get spot, poor quality, 620 um shifted.

93 eV auger 10 eV pass

Fresh spot

2 kV ions offset -0.9, -0.5 (should have been, first shot -5.0)

First had no effect, sample current was 50 nA at -5, now 5 uA at -0.5.

Now 300 s sputter removes C, oxide still present, peak increased no contamination

1050 s burnthrough, ~ 250 um diameter, 460 um low

93 eV pass 10

Spectrometer apertures and transmission

Sample was flat clean Cu110, tilt 30 degrees, 3 kV max current.

Count rates vs aperture, images saved. 500 eV, pass 50 eV

• 1/1 900 kHz
• 2/1 830
• 3/1 380
• 3/2 285
• 3/3 125
• 4/1 225
• 5/1 350

• Conclusions: exit slit widths, 5:3:1, count rate 2.8:1.8:1, "hot" part of channeltron in center
• Exit slit no effect on image area

• Entrance 5 (1x12) aligned with 4 (1 mm) with 50% more counts
• Entrance 1 (6x12) only 8% more counts than 2 (6 mm)
• Round apertures 6:2:1, count rates 3.7:1.3:1, ideally if lens images sample on slit should be no difference. Angles should be fixed by magnification of 3. This may suggest tweaking lens factors to try to optimize transmission. These results may depend on pass energy....

Au low voltage ref spectra

Try to take spectra from Au/foil Cu110 sample. Go to 3 kV, after previous work at 10 kV. Max current mode, tweak settings. At first poor counts/shape below ~ 150 eV, also 'strange' octopole settings for 30 degree tilt. Expected ~ 49,50. Instead ~ 46 60.

Cu Graphene

Ultrapure Cu foil, anneal/recrystallize in H2 30 min 1020 C then 15 min growth CH4+H2 1010 C. Changhyun, Wu group

• 121016-1-L-b, 1/6 "large", SEM
• 121016-1-L-a, 1/6 "large"
• 121021-1-R-a, 1/6 "small"
• 121021-1-R-b, 1/6 "small"

large and small refer to Cu grain size. Even "small" is ~ 100 um

Turbo Pump Problem

• Prep chamber turbo did not pump down. Stalled at a few thousand RPM, ~ 40 Watts, bearings started to heat. Weird noise. Possibly scroll pump did not start. Foreline pressure gauge showed ATM. Airlock pressure ~ 25 Torr.
• Cycled power on pump. Now system goes to full speed eventually, but power stays at 66 W instead of dropping to 12-18 W. Foreline still showed ATM.
• Swapped scroll pumps for nano and prep. Start pumps together. Now both start normally, foreline pressures 0.13 mBarr prep (with nano scroll), 0.19  nano (with prep scroll). Both turbos ~ 15+-3 W, normal. Ultimate foreline pressure was ~ 0.055 mBarr, or 0.075 during bake.
• Possibly scroll pumps have trouble, or roughing lines leaking due to sharp bend on hoses. Exchanging scroll pumps seemed to fix problem. need to invert pumps again.

Let turbos run. Both prep and nano running about 10 W next day.

On Friday 10/26 switch scroll pumps back. Now prep turbo is slow to start, eventually reaches 100% with 88 W power. Prep pirani reads "atm". Shut down, disconnect scroll, pull out from rack, clean and reconnect quickflange with no stress on hose. Try again. Better, quick pump down, standby 18 W, foreline 0.10 mbar by pirani

problem was bad foreline pressure, possibly due to leak from strained hose. 

More trouble Nov 8, 2012

• Try to start turbo. Stalls at 63 W 27%. Pirani reads ATM. 
• Vent and retry. Similar results. Airlock shows ~ 10-15 torr.
• Stop again, examine turbo. Remove hose from scroll pump. Near pump the transparent plastic hose looks "misty". Remove hose, moisture condensed on inside ???.
• Reconnect hose, try again. This time system pumps down, foreline pirani indicates rapidly (< 60 s), goes below 0.5 mbar, pump reaches 100%.
• Then power and foreline pressure increase, ~ 40W at 100%, foreline 1.1 to 1.2 to 1.5 to 1.7 mBar over several minutes 
• This is very strange.
• Stop turbo, disconnect foreline, try again. This time 19W at 100%, foreline 0.16 mB and dropping slowly (normal).
• Possibly some water condensed in scroll pump when foreline was leaking, now being slowly pumped away. 
• after one hour foreline 0.12 mB, 17 W

Au foil testing

Move to Au foil reference on Cu sample
Good Auger Au 74, 164, 243 peaks, very weak at 2022 peak, probably due to weak excitation at 3 kV

Try 10 kV, large Octo offset to maximize at 2000 V, octo (50,66) instead of (50,50), now 2 kV peak/background is 11.5 % for 280 kHz at 3 nA aperture, was << 1% at 3 kV

Also 3 nA gun align way off at 10 kV, optimized near (-62,-68)
Max 10 kV gun (-48,-58), current ~ 9x greater

Try full scan this fixed Octo, weird below 1 kV

Optimize 2 kV (50.66)
Optimize 1 kV (50,56) repeat
optimize 500 eV (46,54) repeat, still OK up to 2.2 kV
optimize 250 eV (44.7.51.8) repeat,  OK from ~ 155
optimize 120 eV (43.2.51.0) repeat,  OK from ~ 155
optimize 50 eV (50.2.48.8) repeat,  worse, poor results below 250 eV, 120 opt better, fine above 1 kV
optimize 90 eV (47.6,47.7) strange, worse LV than opt at 250...OK about 700...

repeat 90 V opt with CRR instead of CAE, different results....still below

FPGA and LV 2012 update

Trouble getting FPGA to PC data streaming working after upgrade

ISM testing Cu 110

Testing ISM multipoint, line and SAM image modes

File CuAu test1
30 deg tilt apertures open, 3 kV max current, spot mode
sample cleaned ~ 4 weeks ago
Spectra in CRR mode 5, 10, 20 (max) trace C less O
Spectra in CAE 50, 40, 30, 20, 15, 10, 5

Peak/background and shape very different 5 eV pass, Cu peak/background different
internal scattering?

SED Detector How To

1. Start SmartSEM software
2. Turn on SED Control Unit
3. Push Remote button to enable control by SEM
4. In SmartSEM select signal SE2 on main or Dual Channel window
5. Adjust contrast and brightness
1. "contrast" is Channeltron voltage displayed on controller, value depends on beam current. For large currents may be ~ 1500 V, for small currents, may max out at 2500 V.
2. "brightness" is an offset voltage on the SEM signal, for the SED larger brightness makes the image darker. This is the opposite of the In Lens detector.