Last week the rotation stage broke in the middle of a deposition. The wafer came out looking very non-uniform, and judging by the color of the film there was at least a 10 nm gradient. Since I’m not sure when the motor stopped, it’s hard to say if the underlying oxide is non-uniform as well,…
Last week, a RTP temperature series was performed on 15 nm Si membranes with 20 nm and 40 nm oxide layers. The purpose of this study was to 1. evaluate the effect of a thicker oxide on pinhole density and 2. identify a dependence of morphology on oxide thickness. Below are two graphs summarizing the…
Initial studies into the mechanical properties of pnc-Si were carried out using the “bulge test”. With JP’s help, we’ve collected a large amount of pressure-displacement measurements. This technique has been used to investigate thin film membranes suspended over windows of different geometries e.g. Vlassak. In this study, we measure the deflection of a pressurized membrane…
A temperature series was performed last week over seven wafers annealed inside the susceptor (15 nm silicon). The objective was to determine if the current configuration of target materials would show pore tunability over the temperatures of interest (900 – 1100 C). Below is a series of TEM micrographs and their corresponding histograms. At the…
Last week, we ran several wafers with a silicon target from Refining Systems (Las Vegas). In addition to the source material being different, the target bond was a silver elastomer vs. the typical indium bond that AJA uses. Below is a TEM micrograph of a comparison between the RS silicon and AJA silicon. Both these…
Recently, SiMPore has been exploring alternate ways for depositing our film stack. We’ve finished our initial testing of a plasma-enhanced chemical vapor deposited film by Rogue Valley (OR), and it appears that the pore formation process is inhibited with the standard 1000 C RTP 100 C/s anneal. The most striking difference (besides the difference in…
We haven’t talked much about the optical properties of pnc-Si, but I thought it would be good to share some of the index and dispersion data I’ve collected using the ellipsometer. Below are plots of index of refraction (n) and extinction coefficient (k) vesus energy. The index is a measure of the optical density. The…
In the last month, we’ve run several sets of 15 nm pnc-Si wafers over a range of RTP temperatures. Below is a chart that illustrates the current pore size control we have by tuning annealing temp. The 900 C, 950 C, and 1000 C samples were from wafers SC 231, SC 314, and SC 316,…
Last Friday, Chris and I met with Dave Glocker from Isoflux Inc., an expert in physcial vapor deposition. Specifically, we wanted to get advice on the recent problems we’ve had with the AJA tool. Arcing from Lesker targets We recently decided to try new oxide targets from Lesker because the last batch of AJA targets…
I had some old carbonized samples kicking around and decided to do some high res TEM yesterday to see what a completely occluded pore looked like. Below is an image showing a blocked pore and adjacent Si nanocrystal. Inside the pore, you can see concentric “rings” of carbon atoms i.e. graphene sheets? Here is a…