There’s been some discussion on whether furnace-annealed-only wafers are more uniform than RTP’ed ones. Today, I looked at several samples from wafer 304 (FA 1000 C) at different positions along the y-axis. (0, 5) – 25kx (0,2) – 25kx (0,1) – 50kx (0, -1) – 25kx (0, -4) – 25kx There’s a clear change in…
Here are the conversion ratios for the URMC TEM images (so we’re all using the same standard): 30kx – 0.39 px/nm50kx – 0.67 px/nm150kx – 2.2 px/nm300kx – 4.5 px/nm These numbers should be used for wafers 187, 189, and > 310. Unlike the RC TEM conversions, these numbers seem to be consistent between the…
Using Mike B.’s MATLAB script, I was able to generate some histograms and stats for wafer 187, 310, 319 and 320. I excluded the “small pore background”, as I do not believe these features go all the way through the membrane. wafer 187 wafer 310 wafer 319 wafer 320 The reason why I did not…
Production this week focused on varying the RTP temperature of membranes deposited under identical conditions. wafer 316 – 800 C RTP (120 s) (0,-5) @ 50 kx Material still appears to be amorphous. Wrinkled at edges. wafer 318 – 900 C RTP (120 s) (0, 0) @ 50kx (-5, 0) @ 50kx A few, very…
I’ve been doing some reading, and came across this article by researchers at Sandia Nat’l Labs. They are looking at the stress evolution in thin films, and have observed “nanovoids” in their amorphous silicon. Here is a cross-sectional TEM image (XTEM) from the article. Floro et. al. PRL 2003 There are three layers of a-si…
This week’s production included wafers of antimony (Sb) and phosphorus (P) doping. Process parameters The deposition heater was re-brazed prior to this deposition. We were concerned with the original brazing job because there were areas with “globs” of material and cracks in the solder. The new braze covers most of the surface, and although is…
I took a closer look at some of Lingyun’s samples today, and captured some interesting TEM images. wafer 205 with 10 nm Ti @ 35kx wafer 205 with 10nm Ti @ 250kx wafer 205 with 10nm Ti & 10nm Au @ 35kx wafer 205 with 10nm Ti & 10nm Au @ 200kx The higher mag….
The objective of last week’s production was to track down the source of Cu contamination. The good news is that none of the wafers showed signs of Cu. The bad news is we are not sure why it has disappeared all of the sudden. Chris and I observed that there are particles in the well…
Below is an optical image that shows the amount of area loss caused by the preferential EDP etch. Based on these numbers, our most recent membrane slits measure 115 um x 2014 um.