Selective plasma etching of Ge substrates for thin freestanding GaAshyphen;AlGaAs heterostructures

摘要

Selective plasma etching of Ge with a CF4/O2mixture is used to produce freestanding GaAshyphen;AlGaAs thin films. The etch rate of Ge substrates is as high as 150 mgr;m/h at temperatures of 75thinsp;deg;C under optimized conditions and with a negligible etch rate for GaAs and AlGaAs materials. This plasma etching technique, combined with a latticehyphen;matched growth of GaAshyphen;AlGaAs structures on Ge substrates, has a variety of potential device applications. The characteristics of this etch process and the photoluminescence of freestanding AlGaAshyphen;GaAs structures are presented.