Pore tunability with susceptor in RTP
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 lower temperatures, 900, 925, and 950 C, there is a low density of smaller pores. There appears to be a region of linear increase in size and porosity. The porosity increases further at 1050 C, but the cut-off remains similar to the 1000 C sample. At 1100 C, the cut-off is pushed to 35 nm. Here is a plot showing the trend in porosity and mean diameter.
Finally, a plot showing the pore density vs. radii.
In conclusion, we are able to achieve a range of cut-offs and porosities using the susceptor. The porosity/diameter vs. temperature dependence seems to be linear in the 925 – 1050 C range, but saturates at higher temperatures.