GPIB-USB driver

if using Mac, need VISA

http://www.rsc.org/chemistryworld/News/2012/February/measuring-solar-cell-efficiency-correctly.asp

hp E3631A power supply

http://www.allaboutcircuits.com/vol_6/chpt_2/4.html

• Introduction or background of the paper topic
• Main experimental and/or theoretical results
• Analysis of the results, clear exposition of the main findings
• Discussion of the significance of the work for the field
• Summary of the work
• References

Turning on the machine:

1. Turning the switch, like starting the car

2. Turn on chiller, to the top position

Sample preparation:

Clean the stage with IPA first

Use carbon tape (conductive, should look into how biological samples are made, sputtering with gold) , press the four corners

When using carbon tape: not too much, because the sample might be damaged when you remove it; not too little, because the sample might fall off the stage when tilted.

IMPORTANT: remember your sample position! Better to draw it on the paper

3. Check whether the SEM machine has warmed up or not, then turn on monitor

4. Put sample in, EVAC
the number （ the 7-segment display) will go down to zero

PREEVAC->HT READY  (at this stage you can run the current)

5. press HT

Current button ( 12 o'clock or 1 o'clock position) Max: 1 o'clock

6. Turn the left monitor on, initial magnitude: X3000

How to tilt the stage?

Command-> stage t50

50 is the angle, t means to tilt; r means to rotate. 

Adjust the focus:

WOBB, should be minimized (by adjusting the handle near the sample container, one is x position, one is y position)

ACCV (from MENU): increase the value, max: 15kV

Or using "stigmatism" 

when adjusting the focus, use small particles

Taking pics:

SL3---the highest quality (this would take up one disk)

ALBUM (on monitor) ---save

TV2--sampling on a higher speed, used the adjust the position of the sample

if the frozen pic has bad quality, or not conformal, reduce the voltage

Turning off the SEM:

1. recude current to 0

press HT

2. LSP1

3. increase Magnitude to max: x300,000

turn off left monitor

4. VENT

5. turn right monitor off

wait until you can take the sample out

put chamber in EVAC again, wait until it's HT READY, or pressure goes to 0

Then turn off SEM and chiller

http://www.fourpointprobes.com/article.html

Q&A for Jandel Resistivity Meter:

http://www.fourpointprobes.com/qa2.html

I will give myself 10 days to finish the following stuff:

About the lithography and developing

• need thicker oxide layer on the back, because KOH etches away the oxide on the back. use SPR 220 instead of 1813. 1000 or 2000 RPM instead of 3000RPM, then hard bake it.
• or thin down wafer: instead of using the current 500+50um wafer, try 400um. Order thinner wafer or etch current wafer.

How to etch current wafer?

Oxidation on both sides, then get rid of the oxide on the front side   (what method should I use??? RIE or PR??)  ; wet etching the front side; then oxidation again.

Back side is rough, so I got holes on the membrane while etching. Try polishing wafer.(wafer that is polished on both sides) (where are they??)

About etching:

KOH conc. higher, etch rate goes down.

Higher temperature, worse selectivity (SiO2, Si), so I should try lower temperature. Also, I need to monitor the temperature of the KOH solution instead of just setting the hot plate.

TMAH:

better selectivity of SiO2 and Si

need to find out how to do TMAH

To reduce surface resistivity: dope the wafer. 

Impurity/dopant increases, resistivity decreases.

Heavy doped material has low resistivity. 

 Things to be really careful with:

• Do NOT use the tweezer while the sample is wet! The tension force of the water might break the sample.
• Be very careful when the etching reaches 6.5 hour, should check it more frequently.
• When using the plastic box, be gentle when clicking.
   

0. Clean wafer first (Heat)

1. Spinner

Apply HMDS--drop in the middle of the wafer, as glue for PR 1813

Operate Spinner, 3000RPM, 15s

2. Heat, 30s, 120 Celsius

3. PR 1813, deposit PR, 3000RPM, 30s in spinner

No bubbles!! No white light, use only yellow light(when using PR)

4. Hot plate, 1~1.5min, 120 Celsius