Monolithic High-Mobility InAs on Oxide Grown at Low Temperature

Abstract

We demonstrate high electron mobility single-crystal InAs mesas monolithically integrated on amorphous dielectric substrates at a growth temperature of 300 °C. Critically, a room temperature mobility of ∼5800 cm 2 /(V s) was measured, the highest mobility reported for any thin-film semiconductor material system directly grown on a nonepitaxial substrate. Detailed modeling of the scattering mechanisms in the grown material indicates that the mobility is limited by surface roughness scattering, not the intrinsic material quality. We project that reducing the RMS surface roughness of the InAs from 1.8 to 1 nm would produce materials with room temperature mobilities of >10000 cm 2 /(V s), and RMS roughness of 0.5 nm would result in mobility of ∼20000 cm 2 /(V s), essentially identical with epitaxially grown materials. These results pave the way for growth of high-mobility materials directly onto the back end of silicon CMOS wafers and other nonepitaxial substrates such as glass, as well as polymers for flexible electronics.

Selective electrodeposition of indium microstructures on silicon and their conversion into InAs and InSb semiconductors

“…E-beam evaporated indium was used for the fabrication of large (> 100 µm) high-mobility InAs and InP crystals at 580 °C and 560 °C, respectively, on a Si/SiO 2 /MoO x substrate [13]. This approach was further modified for the fabrication of optoelectronic grade InP and InAs on Si-based substrates [14][15][16]. However, the templated liquid phase In process operates in a narrow design window due to geometrical stability constraints of the confined liquid, and no epitaxial relation between crystals and substrates was obtained.…”

“…To surpass this limitation, we propose the concept of template-assisted electrodeposition of In directly on a silicon substrate and its saturation with V-element. The process combines features of rapid melt growth in crucibles (RMG) [17,18] and templated liquid phase growth [15]. The former can achieve epitaxial crystallization of III-Vs on Si but is plagued by unintentional Si doping and Si precipitation stemming from the dissolution of the Si interface during annealing.…”