Effect of Annealing and Sulfur Passivation of GaAs Surface in ZnSe/GaAs Heterostructure

Abstract

We report the effect of annealing and sulfur (S) passivation of GaAs surface on the interface characteristics and interdiffusion problem in ZnSe/GaAs heterostructures whose ZnSe layers are grown by atomic layer epitaxy (ALE) and metalorganic molecular beam epitaxy (MOMBE). The photoluminescence (PL) intensity of self-activated centers created due to interdiffusion at 500°C in the conventionally grown sample is 3-14 times higher than that in the S-passivated sample. Secondary ion mass spectroscopy (SIMS) data suggest that after annealing, Ga and As concentration in the ZnSe epilayer is lower in S-passivated materials. These features suggest that heterostructures are thermally stable in S-passivated material. As a result of S-passivation, full width at half maximum (FWHM) values of X-ray rocking curves are greatly reduced and we could, without postgrowth annealing, achieve well-defined C-V characteristics of a metal/pseudoinsulating ZnSe/GaAs metal-insulator-semiconductor (MIS) diode. Sulfur passivation is an important tool for the fabrication of high-quality heterostructures of II-VI and III-V semiconductors.

Raman scattering characterization of the crystalline qualities of ZnSe films grown on S-passivated GaAs(100) substrates

“…Furthermore, it has been demonstrated that the crystalline quality of ZnSe grown on a ͑NH 4 ͒ 2 S x passivated GaAs substrate is superior than that of ordinarily treated GaAs substrate. 12,13,20 In our work, we also found that the values of FWHM, ⌫ a /⌫ b and L of samples grown on GaAs treated by 5H 2 SO 4 :H 2 O 2 :H 2 O are rather scattered, and are inferior to those obtained on S 2 Cl 2 treated substrate.…”

Growth of High Quality ZnSe Epilayer on Si (100)

“…In generally, high-temperature (HT) growth can improve quality of epilayers, since it increases step-flow growth through an increase in surface migration length [8]. However, HT growth also enhanced the inherently atomic inter-diffusion in the epilayers [9] and formed an inaccuracy structure. Therefore, a LT growth is usually preferred in order to prevent atomic interdiffusion.…”

Effect of Fe inter‐diffusion on properties of InP layers grown with addition of RE elements

“…Also after intentional diffusion of Zn, an extraordinary redistribution of Fe atoms in SI-InP has been observed [3]. The phenomenon has not been traced in the case of n-type dopants in the growth process even though inter-diffusion is inherent in epitaxy at high growth temperatures [4]. It might be thought that Fe redistribution is extremely fast in adjacent p-type material while Fe does not seem to diffuse significantly into n-type material.…”