Development of a glass-bonded compliant substrate

The critical thickness limitation for lattice-mismatched heteroepitaxial gr owth could potentially be removed by the use of a compliant substrate. This work presents initial results for the development of a compliant substrate consisting of a similar to 10 nm GaAs layer (template layer) bonded to a G aAs "handle wafer" through a borosilicate-glass. The glass concentration is chosen to have a moderate viscosity at the temperature used during lattice -mismatched growth. Compliant substrates using 30 and 50 mol% B2O3 glass as the bonding layer were used in the growth of 2 mu m of In0.40Ga0.60As (sim ilar to 3.1% lattice mismatch to GaAs). X-ray diffraction demonstrated that epitaxy was achieved between the growth and template layer. Optical micros copy, atomic force microscopy, and scanning electron microscopy were also u sed to characterize both the initial borosilicate-glass-bonded compliant su bstrate as well as the grown structures. (C) 1998 Elsevier Science B.V. All rights reserved.