Fig xA a Drain ndash source

III–V field effect transistors (FETs) have great potential for high performance low power consumption logic circuits on Si substrates due to their high mobility and low bandgap characteristics [1], [2] and [3]. While the developments on the n-channel devices for complementary circuits have been successful in the last few years, the progress on p-channel devices is rather limited. Antimonide-based heterostructure is one of the promising candidates for p-channel devices since exciting results, hole mobility of 1500 cm2/V s with sheet concentration of 7×1011 cm−2, have been demonstrated on InGaSb/Al(Ga)Sb QW structures [4]. The antimonide heterostructure is also favored because the lattice constant of the stained InGaSb layer is close to that of InAs. This makes the BRL 44408 with InAs n-channel FETs for complementary circuits much easier since they can share the same buffer layer on Si. Up to date, high hole mobility InGaSb/Al(Ga)Sb p-channel devices have been demonstrated on GaAs substrates, but the reports of III–V p-channel devices on Si substrates remain few [5], [6] and [7]. In 2012, Takei et al. demonstrated the integration of InGaSb/AlSb p-channel FETs on Si substrates using epitaxial layer transfer technology [8]. An InAs/InGaSb/InAs structure was grown on a GaSb substrate by molecular beam epitaxy (MBE), and then transferred onto a Si substrate by polydimethylsiloxane. A maximum effective hole mobility of ~820 cm2/V s at room temperature was achieved. The placement issue of this approach has to be overcome before renin can be utilized for mass production. In 2014, Madisetti et al. reported their studies on the metal-oxide-semiconductor (MOS) capacitors of InGaSb-QW structure, which was directly grown on a Si-on-insulator substrate with a metamorphic buffer layer by MBE. Although a lot of defects including twins were observed in the buffer layer, the InGaSb/AlSb QWs exhibited a maximum hole mobility of 632 cm2/V s with a sheet hole density of 7.6×1011 cm−2, and sheet resistance over 12,000 Ω/sq [9]. In this work, InGaSb p-channel QW FETs were grown on Si by MBE and characterized. Hole mobility as high as 770 cm2/V s with sheet resistance of 8100 Ω/sq at room temperature was obtained by modifying the growth temperature of QW. The effects of twins on the transport properties were also investigated.