Study and Optimization of Field Limiting Rings for 10kV SiC Insulated Gate Bipolar Transistor

A 10kV-level silicon carbide (SiC) insulated gate bipolar transistor (IGBT) with field limiting rings (FLRs) is designed and simulated with Sentaurus TCAD, the detailed optimization method and comparisons are presented in this paper. Linearly varying spacing between rings is introduced to SiC IGBT and adjustment is performed on width of rings, the final structure achieves a breakdown voltage over 12kV with a termination length of 164.5 µm , which is 69.93% lower than that of conventional structure with a fixed ring spacing. Moreover, the final design can decrease the sensitivity to the interface charges, the tolerance to positive surface charges exceeds 8 × 10 11 cm − 2 , which is 3.5 times that of the conventional structure. Besides, double pulse measurements prove no degradation of conduction and switching characteristics.

Optimization of Insulated Gate Bipolar Transistor System to Maximize Heat Dissipation

An electric motor, a battery and an inverter are the key components of any hybrid vehicle. The most commonly used switching device in the electric power conversion system is Insulated Gate Bipolar Transistor (IGBT) modules. Heat sinks with their fins are optimized to provide the maximum heat flow to the surrounding and Pure copper is used as it has high thermal conductivity with reasonable heat resistance. This helps to decrease the temperature of the IGBT and heat will spread to the fins. Parallel forced air cooling is utilised to give maximum possible heat removal rate. Further experimentation was done on a IGBT using an Inverter circuit and it was analyzed on ANSYS software and it was observed that the results obtained by numerical method and experimental method are approximately same.

Investigation of Base Transport Mechanism in Silicon-Germanium Heterojunction Bipolar Transistor Operating over Wide Temperature Range

A high breakdown voltage silicon-germanium heterojunction bipolar transistor operated over a wide temperature range from 300 K to 10 K has been investigated. The measured Gummel characteristics illustrate that the collector current and base current both shift to the higher voltage as the temperature decreases. The fT/fmax are extracted to be 23/40 GHz at 300K, 28/40 GHz at 90 K, and 25/37GHz at 10K, respectively. The effective amplification range becomes narrow as the temperature decreases. And the ideality factor of base current in the low current region is shown to be temperature-dependent and its value is much larger than 2 at cryogenic temperatures. This phenomenon indicates that the base current is not only contributed by drift, diffusion, and Shockley-Read-Hall recombination, but also by trap-assisted tunneling. The Hurkx local trap-assisted tunneling has been used to analyze the non-ideal base transport mechanism. And a calibrated TCAD device model is developed to further verify this non-ideal transport mechanism.