Patent ID: 7773840

Claim:
A method for etching laser layers of a wafer when forming a sloped junction region to passive amorphous silicon waveguides, comprising: etching an InGaAs cap portion with H 2 SO 4 :H 2 O 2 :H 2 O; etching a first InP layer with HCl:H 3 PO 4 ; rinsing said wafer with NH 4 OH:H 2 O; reactive ion etching an InGaAsP layer with a gas mixture, wherein said reactive ion etching forms a plasma polymer deposited on said wafer; removing said plasma polymer in an O 2 plasma; etching a second InP layer with HCl:H 3 PO 4 ; rinsing said wafer with NH 4 OH:H 2 O after etching said second InP portion; reactive ion etching a second InGaAsP layer and a third InP layer with said gas mixture, wherein said reactive ion etching forms a second plasma polymer deposited on said wafer; removing said second plasma polymer in an O 2 plasma; and etching a final InP layer with HCl:H 3 PO 4 .