Correlation Between Two-Dimensional Electron Gas Mobility and Crystal Quality in AlGaN/GaN High-Electron-Mobility Transistor Structure Grown on 4H-SiC.

We investigated the correlation between the crystal quality and two-dimensional electron gas (2DEG) mobility of an AlGaN/GaN high-electron-mobility transistor (HEMT) structure grown by metal-organic chemical vapor deposition. For the structure with an AlN nucleation layer grown at 1100 °C, the 2DEG mobility and sheet carrier density were 1627 cm²/V·s and 3.23 × 10¹³ cm⁻², respectively, at room temperature.

GaN Epitaxial Layer Grown with Conductive Al(x)Ga(1-x)N Buffer Layer on SiC Substrate Using Metal Organic Chemical Vapor Deposition.

This study investigated GaN epitaxial layer growth with a conductive Al(x)Ga(1-x)N buffer layer on n-type 4H-SiC by high-temperature metalorganic chemical vapor deposition (HT-MOCVD). The Al composition of the Al(x)Ga(1-x)N buffer was varied from 0% to 100%. In terms of the crystal quality of the GaN layer, 79% Al was the optimal composition of the Al(x)Ga(1-x)N buffer layer in our experiment.

High Quality Al-Polar AIN Growth on (0001) Sapphire Using Polarity-Selective Thermal Etching by High Temperature Metalorganic Chemical Vapor Deposition.

In this study, we suggest a polarity-selective in-situ thermal etching and re-growth process for the fabrication of high quality Al terminated AIN epilayers by high temperature metalorganic chemical vapor deposition. Mixed-polar AIN layers grown on a thin (5 nm) buffer layer at a high temperature (950 degrees C) exhibited high crystalline quality. Surface morphologies of in-situ thermally etched AIN layers depended on the grain size and distance between grains.

Fabrication of AIN Nano-Structures Using Polarity Control by High Temperature Metalorganic Chemical Vapor Deposition.

This study investigates the crystallographic polarity transition of AIN layers grown by high temperature metalorganic chemical vapor deposition (HT-MOCVD), with varying trimethylaluminum (TMAI) pre-flow rates. AIN layers grown without TMAI pre-flow had a mixed polarity, consisting of Al- and N-polarity, and exhibited a rough surface. With an increasing rate of TMAI pre-flow, the AIN layer was changed to an Al-polarity, with a smooth surface morphology.