We present a critical review of the strategies used in the fabrication of mismatched semiconductor heterostructures. By using simple concepts derived from the Matthews model of misfit relief, we show how the relaxation of single layers and complex structures may be analysed and predicted. These techniques allow a broad view of the processes that take place in the relaxation of strained layers. This is followed by a discussion of how the relative misfits and thicknesses of different layers in a heterostructure may influence the behaviour and distribution of dislocations in the structure. Finally, we describe the historical development and status of the experimental work and development that has been carried out in this area.

Plastic relaxation and relaxed buffer layers for semiconductor epitaxy

The nature and behavior of antiphase boundaries in GaAs/Si heterostructures using GaP, GaP/GaAsP, and GaAsP/GaAs strained‐layer superlattices as intermediate layers have been studied by transmission electron microscopy. The antiphase domains are found to be very complicated three‐dimensional polygons consisting of several subboundaries in different orientations. Self‐annihilation of antiphase domains during crystal growth of GaAs on (001) 0.4° off or (001) 2° off Si substrates is directly observed for the first time through plan‐view and cross‐sectional observations. Based on these findings, a mechanism of annihilation of these domains is presented.

Direct evidence for self‐annihilation of antiphase domains in GaAs/Si heterostructures

GaAs was grown on a Si substrate by metalorganic chemical vapor deposition using GaAs/GaAsP strained‐layer superlattice (SLS) intermediate layers. The dislocation density decreases at the interface between GaAs and the SLS, but does not decrease in the SLS. When a GaAs/GaAsP SLS is used as the intermediate layer, part of the threading dislocation propagates into the top GaAs layer because of the lattice mismatch of GaAs and SLS. The low etch pit density of (3–5)×105 cm−2 was obtained by using the intermediate layer of a GaAs/GaAsP SLS and an AlAs/GaAs superlattice with thermal cycle annealing.

Low etch pit density GaAs on Si grown by metalorganic chemical vapor deposition

Relaxed lattice-mismatched growth of III–V semiconductors

Heteroepitaxial technologies on Si for high-efficiency solar cells

MOCVD growth and characterization of GaAs and GaP grown on Si substrates

GaP crystals are grown on Si substrates by MOCVD. Double crystal X-ray diffraction indicates that the crystal quality of GaP layers greatly improves when AsH3 is supplied before growth. The FWHM of (400) diffraction peak of the GaP layer decreases as the thickness increases and the best FWHM of 112.5 arcs is obtained at a thickness of 5 μm. The GaP/Si interface is characterized using secondary ion mass spectroscopy (SIMS) to demonstrate the effect of AsH3.

K. Uchida

Papers

MOCVD growth and characterization of GaAs and GaP grown on Si substrates

High Quality GaP Growth on Si Substrates By Mocvd