SEMs for Sale

The scanning electron micrograph (SEM) shows some of my handy work in the lab. The structure was patterned using ebeam ligthography -- specifically with the Raith ebeam lithography system. Also, you should know, that instead of the traditional PMMA positive-toned resist, I used HSQ. I used HSQ in order to simply the steps required to make the hard mask. You see, after the HSQ is exposed and developed during the ebeam lithography process, that patterned HSQ is etch-mask ready. Compare HSQ with PMMA: the PMMA resist is so thin, that it could not possibly used as an etch-mask. As a result, there are a few additional steps required to transfer the PMMA resist into a suitable etch-mask.

In the SEM, the top most layer is HSQ. Notice how the HSQ etch-mask is attrited into a prism-like structure. the HSQ etch-mask attrition occurred during reactive ion etching of the underlying GaAs/AlGaAs material.