Control of InGaAs facets using metal modulation epitaxy (MME)

TL;DR

This paper investigates how metal modulation epitaxy (MME) can control faceting and improve the quality of InGaAs growth during epitaxy, enabling better nanoscale device fabrication.

Contribution

It demonstrates that MME produces smooth, gap-free InGaAs growth and elucidates how flux variations influence facet formation and growth morphology.

Findings

MME yields smooth, gap-free InGaAs growth.

Higher As fluxes induce {111} facet formation.

Self-aligned FETs show reduced channel resistance.

Abstract

Control of faceting during epitaxy is critical for nanoscale devices. This work identifies the origins of gaps and different facets during regrowth of InGaAs adjacent to patterned features. Molecular beam epitaxy (MBE) near SiO2 or SiNx led to gaps, roughness, or polycrystalline growth, but metal modulated epitaxy (MME) produced smooth and gap-free "rising tide" (001) growth filling up to the mask. The resulting self-aligned FETs were dominated by FET channel resistance rather than source-drain access resistance. Higher As fluxes led first to conformal growth, then pronounced {111} facets sloping up away from the mask.