Wallis D.J.,University of Cambridge |
Wallis D.J.,Plessey Semiconductors Ltd Plessey Lighting Ltd |
Zhu D.,University of Cambridge |
Zhu D.,Plessey Semiconductors Ltd Plessey Lighting Ltd |
And 4 more authors.
Semiconductor Science and Technology | Year: 2013
A critical element for the successful growth of GaN device layers on Si is accurate control of the AlGaN buffer layers used to manage strain. Here we present a method for measuring the composition of the AlGaN buffer layers in device structures which makes use of a one-dimensional x-ray detector to provide efficient measurement of a reciprocal space map which covers the full compositional range from AlN to GaN. Combining this with a suitable x-ray reflection with low strain sensitivity it is possible to accurately determine the Al fraction of the buffer layers independent of their relaxation state. © 2013 IOP Publishing Ltd.