Hello dear friends,

I am making some movable devices on a 500 micron PMMA substrate. Now I need to
release these movable parts by RIE ecthing from the back side of the PMMA. The
thickness
of movable parts is only 50 micron. I need to remove 450 micron PMMA. So I hope
the
etching rate be around 5um/min. I tried O2 and O2+FS6 several times. The etching
rate
was only 0.4um/min. Can any one give me some help? Thank you very much.

Yongjun Zhao
Institute for Mircomanufacturing
Louisiana Tech University