Simulative and Experimental Characterization of 650V GaN High Electron Mobility Transistors

Abstract

The Gallium Nitride High Electron Mobility Transistors (GaN HEMT) based on field-effect transistors came out as new promising candidates for the high-frequency high-voltage applications, due to their unique capabilities of achieving higher current density, higher breakdown voltage, higher operating temperatures and higher frequencies compared to conventional silicon (Si) transistors. In this thesis, these novel transistors will be studied to understand their material properties and their main electrical characteristics. Then, a double pulse test will be carried out to study the switching behaviour of these transistors. Since the double pulse test is a practical method of characterizing the transient performance of semiconductors transistors under hard switching. The test will be performed experimentally and in simulation under different operating conditions to have the ability to understand the difference in the transistor behaviour under these different operating points. To do so, an evaluation kit from GaN Systems will be employed, as well as a Digital Signal Processor (DSP) of Texas Instruments. A PCB will be designed as an interface between the evaluation kit and the DSP to allow the control and the communication between them. While for the simulation, it will be implemented using LTSpice software, since GaN Systems provides an LTSpice model for their devices, which allows the evaluation of the device performance. Finally, the obtained results will be presented, commented and compared to identify the particularities of these devices.