On the High Compositional Uniformity of Thick GaAlAs Layers Grown by Liquid Phase Electroepitaxy

Abstract

The results of electroepitaxial growth of thick GaAlAs layers on GaAs substrates are presented. It is experimentally proven that effective convective mixing of the solution volume results in the compositional uniformity of GaAlAs layers, even in spite of the high compositional non-uniformity of the material supplying the solutes (Al, As) to the solution during the growth of the layers. For the first time this allowed us to grow uniform GaAlAs layers with thicknesses up to 200-300 μm in a wide composition range from a small (5 g) amount of solution.

AlGaAs to GaAs Energy Transfer Mechanisms in AlGaAs/GaAs Structures

“…The LPEE method allows to control the Al concentration distribution during the growth. This enabled us to obtain samples with Al mole fraction increasing not only towards the substrate, as common for LPE, but also towards the surface [3]. This was the crucial point in the present study and helped us to verify the mechanisms of energy transfer from epilayer to substrate.…”

In Situ Monitoring of Electroepitaxial Growth of Thick AlGaAs Layers

“…Thick AlGaAs epitaxial layers were grown by the modified LPEE method. All the details of the growth procedure and the graphite boat configuration can be found in [1,2,4]. The total resistance of the growth system measured at the growth temperature of 800°C was 68 mΩ.…”

“…New possibilities are offered by the liquid phase electroepitaxy (LPEE)-the method in which the dc electric current passing through the solution-substrate interface is a driving force for deposition of the epitaxial layer at constant temperature. LPEE was found to be very effective for the growth of hundreds of micrometers thick and compositionally uniform AlGaAs epilayers [1,2]. Moreover, the processes occurring during the growth of such layers can be investigated in detail with the use of in situ monitoring of electroepitaxial growth.…”