Phase-Locked Epitaxy Using RHEED Intensity Oscillation

Abstract

Long lasting RHEED oscillations during MBE growth of GaAs and Al x Ga1-x As are observed. Using these oscillations, accurate measurements of GaAs, Al x Ga1-x As growth rates and the Al mole fraction x were performed during the growths. The phase of the RHEED oscillations was analyzed by computer and molecular beam shutters were operated at a particular phase. This computer controlled phase-locked epitaxy (PLE) was applied to grow precisely defined (GaAs)2(AlAs)2 bi-layer superlattices. Raman scattering spectra showed split lines characteristic of superlattices. This PLE method is invulnerable to molecular beam fluctuations.

Valence Band Mixing in GaAs/AlGaAs Quantum Wells Adjacent to Self-Assembled InAlAs Antidots

“…For MBE of III-V semiconductors, the growth rate is controlled by the group III elements. In addition, when two or more group III elements are simultaneously supplied, their growth rates are additive [29,30]. By observing the specular beam intensity oscillations during the growths of GaAs and AlAs, we calibrated Ga and Al fluxes so that the deposition rates of Ga and Al are about f GaAs = 1 and f AlAs = 0 43 monolayer (ML)/s.…”

Principles of Molecular Beam Epitaxy

“…This can be useful for very high-temperature growth of AlGaAs, or for materials such as InGaAs and InAlAs, where the In tends to desorb at lower temperatures than Ga or Al. PLE takes advantage of the knowledge of ML completion to grow extremely perfect interfaces [61,62]. At temperatures >650 C, the desorption of Ga and As can no longer be ignored, and a decrease in the growth rate, visible as an increased period in RHEED oscillations, is observed.…”

High-resolution transmission electron microscopy of AlAs-GaAs semiconductor superlattices

“…Several techniques for forming atomically flat interfaces [1][2][3][4] have been proposed, and the growth interruption technique during MBE growth is a wellknown example [2,3]. Fig.…”

“…Thus, many studies have been carried out to achieve high-quality AlAs (A1GaAs)-GaAs superlattices [1][2][3][4]. For example, AlAs-GaAs interfaces grown by recent thin-film growth techniques, such as molecular beam epitaxy (MBE), are generally abrupt but have a roughness several monolayers high.…”