In an attempt to push the cutoff higher, we annealed two wafers outside the susceptor at 1000 C (SC 066) and 1100 C (SC 067) with a ramp rate of 100 C/s. The 1100 C does give a cutoff slightly higher ~5 nm, but I’m not sure if this is within the variability in different…
Below are a series of TEM micrographs showing a set of membranes produced last week. We RTPed these wafers at 700 (SC 062), 800 (SC 064) and 850 C (SC065) without the susceptor at a ramp rate of 100 C/s. The trend is increased pore size and porosity with increasing temperature which follows our intuition…
There’s been a lot of production in the last month and we’re still sorting through the data, but here is a synopsis of some key findings. All films were deposited with the AJA tool. Film reproducibility Week-to-week variation in pore morphology has never been noted explicitly due to the rapidly changing conditions we place on…
In the last few weeks, the production team has focused on making strong, stable, porous material with the AJA sputter system. In the process, we’ve RTPed a wafers over a wide range of temperatures under different deposition conditions. We found that it’s possible to make membranes that range from non-porous to highly porous along with…
Last week we attempted to mimic our standard CVC recipe in the AJA system (15 nm Si, 450 C deposition temp, 1000 C RTP). I should note that the protective oxide thickness in the AJA membrane was 20 nm (not 40 nm as it was in the CVC). Below are two images comparing the AJA…
The image below was taken with UR’s new S/TEM, the FEI Technai F20. It has the capability of resolving lattice images which should benefit the materials development effort. However, we will still rely on Karen’s TEM for most of our imaging since the throughput is higher on that tool.
Here are some high resolution TEM images from a SiMPore-UIUC collaborator. Chris says: The high resolution stuff looks pretty cool, especially the zoom-in on the 8nm pore. I the most obvious crystal planes are <111> with 0.314 nm spacing. If you look carefully, some 0.192 nm <110> planes and 0.136 nm <100> planes can also…
After much anticipation, we have confirmed that pores do form with the AJA deposition system! Below are a series of images of membranes of two different thicknesses that were annealed at several temperatures in the RTP. 1000 C RTP; 40/9/40 stack Amorphous; 40/9/40 stack 1000 C; 40/15/40 stack 800 C; 40/15/40 stack Some immediate observations:…
There’s been a flurry of activity regarding Jess’ recent discoloration post. Specifically, there is a discussion about the recent materials changes that have taken place due to the rebuilt CVC sputterer. This post is meant to supplement the ongoing materials discussion. I have noticed that films deposited post-rebuild seem to have less background texture and…
Last week, we created a series of wafers that were RTPed at four different temperatures between 900 C and 1000 C. Below is a comparison of the 900 C (left) vs. 1000 C RTP (right) wafer. We see that a difference of 100 C shifts the cutoff ~10 nm. The pores are also the roundest…