Etch pits and dislocations of Ga1−xAlxAs liquid phase epitaxial layers

Abstract

The etch pits of Ga1−xAlxAs are revealed by the etchant (H2O/H2O2/CH3COOH/HF) and it is verified that these etch pits correspond faithfully to dislocations using x-ray transmission topographs. The shapes of dislocation etch pits which are revealed by the etchant (1 H2O/1 H2O2/2 CH3COOH/0.5 HF) are either conical on the (100) face of Ga1−xAlxAs with x≳0.1 or pyramidal on the (100) face of Ga1−xAlxAs with x=0.05.

The Detection of Structural Defects in GaAs by Electrochemical Etching

“…Recently, the composition and width of the SiO2-Si interface, formed by thermal oxidation of <10O> and <111> oriented Si surfaces were characterized by analysis of x-ray photoelectron spectroscopy (XPS) data (5)(6)(7)(8). Changes in Si chemical bonding at this interfacial region were derived from XPS spectra (5,8).…”

“…Recently, the composition and width of the SiO2-Si interface, formed by thermal oxidation of <10O> and <111> oriented Si surfaces were characterized by analysis of x-ray photoelectron spectroscopy (XPS) data (5)(6)(7)(8). Changes in Si chemical bonding at this interfacial region were derived from XPS spectra (5,8). Although the detection limit of x-ray photoelectron spectroscopy is approximately 1013 cm -2 and does not provide a means for direct observation of the sites responsible for Qss, the XPS findings do provide a new picture of the transition region within which these electrical instabilities must be understood.…”

Direct Observation of Dislocations in Ga1 − x Al x As ‐ GaAs Grown by the LPE Method

“…The depth resolution is estimated to be about 5% of the sputtered film thickness, or 50A for the typical 1000A oxide films. The secondary ion yields of C1 + in SiO2 are less than a factor of 3 greater than in silicon, while the sputter rates in Si and SiO2 differ by not more'than 10% under these measurement conditions (12). No evidence for charging effects on the C1 species due to the sputter etcn proceaure was indicated.…”

“…The characteristics of the samples are summarized in Table I, where melt-back of the substrate has been employed for sample II by a temperature rise of 3.8~ X-ray topographs are obtained under conditions of anomalous transmission (#t : 12-14) by a double crystal Lang technique using monochromatic divergent radiation made by a curved (111) Ge crystal (10). Cu-Kal radiation and Ilford L4 50 It has been reported that the etchant (H20/H202/ CH~COOH/HF) is a dislocation etchant for Gal-xAlzAs epitaxial layers (12). Molten KOH is a good dislocation etchant for (001) GaAs (13,14).…”

The Effect of Dislocations in Ga1 − x Al x As : Si Light‐Emitting Diodes

“…Although the examination for dark spots was unsuccessful, the application of a defect-revealing etchant for dislocations was a most fruitful enterprise. There are a variety of etchants that produce dislocation etch pits in (100) GaAs, among which are the ammonium hydroxide anodic (AHA) etchant ( 9), the A-B etchant (10), an iodine-based etchant (11), and the H202-HF-acetic acid etchant (12). The etchant used in this study, however, was molten KOH, first suggested by Grabmaier and Watson (13).…”