2 µm deep highly
anisotropic GaN etch

ICP - RIE technology

Plasmalab System 100
with loadlock and ICP source

transition photoresist mask/ GaN

Plasmalab 80 Plus
Plasmalab System 100/ 133

Inductive Coupled Plasma ICP - RIE*
Cl based process
*original work by ECR, see:
http://www.oxfordplasma.de/technols/rie_ecr.htm

anisotropic etch with 90° walls
rate: 110 nm/ min (2“ wafer)
mask: photoresist
selectivity for smooth 90° walls 2 : 1
uniformity over 2" dia area: < +/- 3 %
very smooth walls

Courtesy of:
  Munich, ZT KM 4
  Dr G Franz

signals by mass spectrometry
(differentially pumped)

signals by optical emission
rate, Ga signal and H2O vs time