Large pores in thick membranes
There has been some experimentation recently on trying to form very large pores in thick membranes. We have found that a high temperature anneal (1000 C) along with a fast ramp rate (100 C/s) w/o the susceptor can create these large voids.
It seems that the distribution widens as we push the cut-off up. The gaps in the histogram might be due to a low sampling size. I will image at lower magnifications next time to see if there is a difference…
Lower ramp rates inside the susceptor (10 C/s & 50 C/s) yielded low porosity, irregularly shaped pores.
SC 191 – 30 nm Si – 10 C/s in susceptor
SC 164 – 30 nm Si – 50 C/s in susceptor
