Endpoint detection for CH4/H2 reactive ion etching of InGaAsP heterostructures by mass spectrometry

Abstract

Mass spectrometry has been shown to be a suitable tool for endpoint detection during etching of InGaAsP heterostructures in a reactive plasma of CH4/H2. Among the volatile etching products PH4+ can be detected with the highest sensitivity and discrimination. A depth resolution of 5 nm could be obtained