The unwashed membrane has a definite “film” over it which makes the pores look textured. The MeOH & H2O seems to clear the pores up, but there are some places where there is remaining PVP that sticks to the inside walls of the pore.
This week, we explored the possible differences a thermal oxide making layer had versus a TEOS on membrane morphology. Here’s what we found: The top image shows wafer 410 @ (1,0) and the bottom wafer 503 @ (1,0). Both wafers were annealed, cleaned, sputtered using the same conditions. The only difference was the masking material….
Tom prepared two PVP coated TEM samples for me to image today. One of the samples was washed with dH20 and the other left untouched. Below is a series of three images, from left to right: no PVP, PVP no wash, PVP & wash. I wasn’t able to tell any differences under the River Campus…
Chris and I got to play on the new Zeiss scanning transmission electron microscope (STEM) today (learn about STEM here). We didn’t get to spend a lot of time on it, but here are some quick images we snapped. wafer 416 @ 25kx (left) and 65kx (right) Even though we’re imaging in transmission mode, the…
Wafer 416-T is a TEOS wafer annealed at 900 C. Pinhole density is relatively low. left: (1,0) @ 35kx; right (0,4) @ 35kx left: (1,0) @ 50kx; right (0,4) @ 50kx
Wafer 398 was deposited on 2/14/2008 but just etched yesterday in the new cell (it’s a beauty esp. when you compare it to the old one). I’ve etched several wafers now in the new cell and none of the membranes show signs of cigarette burns or tears. Good news in regards to the copper contamination…
Wafer 415-T has been delivered to the lab. It was processed with TEOS and annealed at 950 C. There are a few usable samples, especially along the edge of the wafer. Pinhole density increases as you move towards the center. The uniformity across the wafer is good. From left to right, top to bottom: (0,1)…
The new sputtering system is scheduled for delivery at the end of June. It will bring several advantages over our current system; which translates (hopefully) into stronger and more consistent material. 75 days… AJA Sputter Full Blueprint
Last week I attempted to use the ozone cleaner and RTP to grow an oxide on bare 4″ wafers. I used the spectroscopic ellipsometer to measure the film thickness. I found that ~4 min. in the RTP @ 1150 C with 3 LPM of O2 grew nearly 50 nm of silicon dioxide. Using Tom’s standard…
Production this week yielded mixed results. We ran eight wafers through four different RTP temperatures with/without the susceptor. We wanted to test our theory that temperature non-uniformity inside the chamber was causing the morphology change across the wafer. This proved to not be the case! Wafers that were treated with and without susceptor showed the…
