Group III-Sb compound semiconductors are promising materials for future CMOS circuits. Especially, In1-xGaxSb is considered as a complimentary p-type channel material to n-type In1-xGaxAs MOSFET due to the superior hole transport properties and similar chemical properties in III-Sb’s to those of InGaAs. The heteroepitaxial growth of In1-xGaxSb on Si substrate has significant advantage for volume fabrication of III-V ICs. However large lattice mismatch between InGaSb and Si results in many growth-related defects (micro twins, threading dislocations and antiphase domain boundaries); these defects also act as deep acceptor levels. Accordingly, unintentional doping in InGaSb films causes additional scattering, increase junction leakages and affects the interface properties. In this paper, we studied the correlations between of defects and hole carrier densities in GaSb and strained In1-xGaxSb quantum well layers by using various designs of metamorphic superlattice buffers.

A new in-situ technique to reduce threading dislocation density (TDD) within sub- micron growth is demonstrated by using metal-organic vapor-phase epitaxy (MOVPE). We achieved drastic reduction of TDD of AlGaN buffer on SiC substrate by inserting highly-Si- incorporated AlGaN/undoped AlGaN superlattice (SL). TDD of AlGaN was decreased from 2×1010 to 7×107 cm−2 by inserting the SL with the total growth thickness of 0.8νm. Si incorporation in AlGaN SL was estimated to be 1.2×1020 cm−3. This technique is exactly in- situ process without complicated fabrication processes, and the surface is kept flat throughout the total growth. This method is especially useful on SiC wafer in order to prevent cracks with thin growth layer. We confirmed the similar effects for GaN and AlGaN buffer on sapphire substrates.