Effect of the plasma experimental parameters on the dose and profiles of hydrogen in-diffused into the GaN/AlGaN/GaN/Si high electron mobility transistor

Abstract

The structures of electronic devices based on GaN and its AlGaN alloys grown on foreign substrates, display a high threading dislocations concentration (TDs); 107–1011 cm-2, introducing deffects diminishing the devices predicted performances. The High Electron Mobility Transistor (HEMT) core is constituted by an AlGaN/GaN heterojunction, where the AlGaN layer, of nanometric dimensions, results on the formation of the high mobility-two-dimensional electron gas (TEG). The TEG performance might be improved by its hydrogenation, although the process can, as well, catastrophically degrade the device. Here is presented a detailed study of the effect of the hydrogenation experimental parameters: plasma power, sample temperature and duration, on its dose and distribution throughout the structure. This study found that the dose depends on the square of the plasma power, increases linearly on the hydrogenation time and slightly proportional to the sample temperature. These results shed light on how to improve the AlGaN/GaN HEMT performance.