1. Batch 4 I-V and Conductivity Analysis 3-26-08

2. List of Samples P134C 14 (SH) 2 20μm wells SU-8 (old) P135C 14 (SH) 2 40μm wells SU-8 (old) P136C 14 (SH) 2 20μm wells SU-8 (new) P137C 14 (SH) 2 40μm wells SU-8 (new) P138C 14 (SH) 2 20μm wells deBoer photoresist P139C 14 (SH) 2 40μm wells deBoer photoresist P140C 14 SH 20μm wells SU-8 P141C 14 SH 40μm wells SU-8 P142C 14 SH 20μm wells deBoer photoresist P143C 14 SH 40μm wells deBoer photoresist P144C 16 SH 40μm wells SU-8

3. Type 2Type 1 Reference: Different I-V Curve Types Observed

4. DeBoer range is 10 6 Zero Crossing Values of  /L

5. 10 5 10 6 10 7 10 8 10 9 10

6. Zero Crossing Values of  /L 10 5 10 6 10 7 10 8 10 9 10

7. Observations Almost all contacts had higher conductivities than deBoer (shorted). No hysteresis in this batch (only one isolated case at high voltage). Possible reasons: no silver, different deposition conditions. Types 1 and 2 mostly occurred at the lower conductivities of the range, however, type 1 also occurred over a very wide range and at high conductivities (as in batch 2). Occurrence rate of type 1 (at only 7%) is still lower than the 20% as in batches 1 and 2. No type 1 occurred with the deBoer photoresist (deBoer photoresist is nearing expiration and may be bad). C16SH had many good contacts, including one very good contact comparable to deBoer’s paper and able to be brought as high as ±1 V with no hysteresis and type 1 pattern.

8. Batch 1 (samples P14-P18) (60 μm wells, TEM grids) - deBoer photoresist Batch 2 (samples P28-P37) (20 μm wells, TEM grids) - deBoer photoresist - over-cooked Au deposition Batch 3 (samples P58-P70) (20 and 40 μm wells, improved contact design) - SU-8 photoresist Batch 4 (samples P134-P144) (20 and 40 μm wells, improved contact design) - SU-8 photoresist -deBoer photoresist - no silver Type 1 occurrence (% of wells) 20% (not including C 16 NC which had 100% type 1 but we did not make again) 22%5%7 % Type 1 Conductivity Range (in S/m 2 ) (deBoer range is  1x10 6 ) 5x10 3 to 8x10 6 1x10 8 1x10 5 to 1x10 7 5x10 5 to 2x10 8 Significant Hysteresis?No YesNo Comparison to Previous Batches

9. Comments No hysteresis means type of photoresist probably not a factor. Silver could have been the cause of the hysteresis in batch 3. SU-8 appears to be OK to use, especially since C16SH had a good contact. We have recently found out (from deBoer) that SAM might break down or degrade at temperatures greater than 50°C in the evaporator. This is consistent with all of our batches having conductivities that are too high. We plan to modify the evaporator (with a cooling stage and heat blockers) to make sure the SAM stays cool.

10. P134 Completely shorted C 14 (SH) 2 SU-8 20 micron (old)

11. DATA

22. P135 C 14 (SH) 2 SU-8 40 micron (old)

26. S/m 2

28. R = 7.36 ohms

34. P136 C 14 (SH) 2 SU-8 20 micron (new)

43. S/m 2

50. P137 C 14 (SH) 2 SU-8 40 micron (new)

61. P138 C 14 (SH) 2 deBoer photoresist 20 micron

77. P139 C 14 (SH) 2 deBoer photoresist 40 micron Sample is completely shorted

88. P140 Completely shorted C 14 SH SU-8 photoresist 20 micron

100. P141 Completely shorted C 14 SH SU-8 photoresist 40 micron

111. P142 Completely shorted C 14 SH DeBoer photoresist 20 micron

122. P143 Completely shorted C 14 SH DeBoer photoresist 40 micron

134. P144 C 16 SH SU-8 photoresist 20 micron

148. S/m 2