2.5 µm deep highly anisotropic GaN etch

Reactive Ion Etching

Plasmalab System 133
with loadlock for RIE

very smooth 90° profile

anisotropic etch with 90° walls
rate: 70 nm/ min (2“ wafer)
mask: photoresist
selectivity for smooth 90° walls 2 : 1
uniformity over 2" dia area: < +/- 3 %
very smooth walls

Courtesy of:
  Infineon Munich, ZT KM 4
  Dr G Franz