Influence of GaAs surface stoichiometry on the interface state density of as-grown epitaxial ZnSe/epitaxial GaAs heterostructures

Abstract

Epitaxial ZnSe/epitaxial GaAs interfaces have been formed by molecular beam expitaxy and evaluated by several techniques including capacitance-voltage measurements. In the study reported here, the GaAs surface stoichiometry was systematically varied prior to the nucleation of ZnSe. A dramatic reduction of interface state density occurred when the GaAs epilayer was made As deficient. The resulting interface state densities of as-grown structures are comparable to values obtained with (Al,Ga)As/GaAs interfaces.

Cation variations at semiconductor interfaces: ZnSe(001)/GaAs(001) superlattices

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] The ZnSe/GaAs system, with only a small lattice mismatch ͑0.27% at room temperature͒, provides a model for studying the interplay between bond strength and electronic effects with relatively little strain contribution. Both phenomena are sensitive to factors such as lattice mismatch, interface bond strength, and electronic charge balance.…”

GaAs homojunction interfacial workfunction internal photoemission (HIWIP) far-infrared detectors

“…This kind of noise is related to the presence of interface localized states [8]. The interface states N is has been estimated [9] ) reported for MBE grown Be-doped p-type GaAs [10].…”

(001) GaAs substrate preparation for direct ZnSe heteroepitaxy

“…Much work has been devoted to the study of the nucleation of ZnSe on GaAs. [3][4][5][6][7] The best results so far are obtained by starting the growth on a GaAs homoepitaxial buffer layer. 8 By decreasing the defect density down to mid-10 3 cm Ϫ2 , 100-h lifetime laser diodes have been obtained 9 revealing the importance of the optimization of the heterointerface.…”

“…3,4 The current understanding is that the growth starts in a two-dimensional ͑2D͒ mode on an Asstabilized surface, while it starts in a three-dimensional ͑3D͒ mode on a Ga-stabilized surface. [3][4][5] The use of a GaAs buffer layer thus gives the best results since, in addition of providing a very smooth surface, its stoichiometry can be precisely controlled by a proper adjustment of the fluxes in the III-V growth chamber. A contrario, it is admitted that the growth invariably starts in a 3D mode on a bare substrate.…”