Precise and efficient ex situ technique for determining compositions and growth rates in molecular-beam epitaxy grown semiconductor alloys

A technique based on the principle of coupling an evanescent wave via a pri sm into a semiconductor thin him has been used to determine simultaneously the composition and the thickness of II-VI semiconductor ternary alloys. Th is approach, which determines the indices of refraction n with high precisi on (at least 0.1%), and also concurrently determines the epilayer thickness es with an uncertainty of less than 0.5%, has been applied to a series of m olecular-beam epitaxy grown ternary alloy families; Zn1-xCdxSe, Zn1-xMgxSe, Zn1-xBxSe, Zn1-xMnxSe, and ZnSe1-xTex. The composition determined by x-ray measurements allow one to generate a calibration between it and the alloy composition, which is used subsequently to derive the alloy composition of the ternary specimen by measuring only its value of ra. Since the: prism co upler method also determines the thickness of the film, the growth rates ar e also obtained concurrently. (C) 2000 American Vacuum Society. [S0734-211X (00)08303-7].