Caractérisation et simulation des transistors HEMTs de la filière InAlN/GaN

Abstract

High Electron Mobility Transistor (HEMTs) based on III-N semiconductors have become the most important candidates for power applications because of their very promising performance. The objective of this thesis is to study the function of the HEMT transistor based on In0.18Al0.82N/AlN/GaN. In summary, the AEC1388 plate present an average performance while the AEC1561 plate present better performance. The InAlN/GaN HEMT transistors, shows a more interesting performance than the AlGaN/GaN HEMT . The performance of the InAlN/GaN HEMTs are very promising for high-frequency and high power applications. The output characteristics Ids = (Vds) show the presence of the self-heating effect in the transistor, the latter has a saturation current (Idsmax = 0.177A). On the other hand, the Kinck effect is not present. A comparison of the electrical characteristics of two different technologies of HEMT transistors, In0.18Al0.82N/AlN/GaN (plate AEC1561) and Al0.24Ga0.76N/GaN (plate AEC1388) showed that the AEC1388 plate exhibits average performances while that the AEC1561 plate still suffers from the lack of maturity of the manufacturing processes. Based on the comparison of the simulated Igs(Vgs) characteristic of the AEC1561 plate with the experimental characteristic, the dominant mechanisms are the tunneling effect predominant over almost the entire polarization range and the effect of the leakage current observable for the weak tensions. An analytical simulation of the output characteristics Ids (Vds) showed that a small molar fraction (x%), a small thickness of the InAlN layer (d), a large grid width (Wg) and a short drain-source length (Lds) will optimize the good operation of the InAlN/AlN/GaN-based transistor. A good Schottky contact is essential for the HEMT transistor to work properly, research in this area must be emphasized for the InAlN/AlN/GaN structure.