Abstract

Selective-area embedded regrowth of III–V semiconductors by molecular beam epitaxy enables the seamless integration of metals and dielectrics into crystalline material for novel design of optoelectronic devices. This study evaluates the deposition selectivity of alternative dielectric mask materials Al₂O3, TiO2, and HfO2, films with preferable spectral responses but higher surface reactivity. It finds that Al₂O₃ exhibits promising selective growth characteristics within typical GaAs growth temperatures, HfO₂ demonstrates high non-selectivity dominated by Ga adsorption on the mask at temperatures up to 650 °C, and TiO₂ is reactive during deposition. Surface modification with a thin SiO₂ capping layer improves selective growth on Si₃N₄ and TiO₂ films, and sub-1 nm SiO₂ caps significantly change selectivity on Al₂O3, decoupling selective-growth behavior from optical response.

Abstract

Selective-area embedded regrowth of III–V semiconductors by molecular beam epitaxy enables the seamless integration of metals and dielectrics into crystalline material for novel design of optoelectronic devices. This study evaluates the deposition selectivity of alternative dielectric mask materials Al₂O3, TiO2, and HfO2, films with preferable spectral responses but higher surface reactivity. It finds that Al₂O₃ exhibits promising selective growth characteristics within typical GaAs growth temperatures, HfO₂ demonstrates high non-selectivity dominated by Ga adsorption on the mask at temperatures up to 650 °C, and TiO₂ is reactive during deposition. Surface modification with a thin SiO₂ capping layer improves selective growth on Si₃N₄ and TiO₂ films, and sub-1 nm SiO₂ caps significantly change selectivity on Al₂O3, decoupling selective-growth behavior from optical response.

Abstract

Selective-area embedded regrowth of III–V semiconductors by molecular beam epitaxy enables the seamless integration of metals and dielectrics into crystalline material for novel design of optoelectronic devices. This study evaluates the deposition selectivity of alternative dielectric mask materials Al₂O3, TiO2, and HfO2, films with preferable spectral responses but higher surface reactivity. It finds that Al₂O₃ exhibits promising selective growth characteristics within typical GaAs growth temperatures, HfO₂ demonstrates high non-selectivity dominated by Ga adsorption on the mask at temperatures up to 650 °C, and TiO₂ is reactive during deposition. Surface modification with a thin SiO₂ capping layer improves selective growth on Si₃N₄ and TiO₂ films, and sub-1 nm SiO₂ caps significantly change selectivity on Al₂O3, decoupling selective-growth behavior from optical response.

Abstract

Selective-area embedded regrowth of III–V semiconductors by molecular beam epitaxy enables the seamless integration of metals and dielectrics into crystalline material for novel design of optoelectronic devices. This study evaluates the deposition selectivity of alternative dielectric mask materials Al₂O3, TiO2, and HfO2, films with preferable spectral responses but higher surface reactivity. It finds that Al₂O₃ exhibits promising selective growth characteristics within typical GaAs growth temperatures, HfO₂ demonstrates high non-selectivity dominated by Ga adsorption on the mask at temperatures up to 650 °C, and TiO₂ is reactive during deposition. Surface modification with a thin SiO₂ capping layer improves selective growth on Si₃N₄ and TiO₂ films, and sub-1 nm SiO₂ caps significantly change selectivity on Al₂O3, decoupling selective-growth behavior from optical response.