Gan Epitaxial Development, Devices Reliability and Modeling( I )

Main project aims to achieve a high-power converter system using a wide bandgap element (GaN HEMT) with surface-mount packaged components and integration to achieve high efficiency and high power density goals. The implementation of the plan is closely cooperating with the industry, and has close cooperation with epitaxial companies, manufacturing companies, power component companies, and system application companies. At present, GaN power device-related technology has been successfully run on six-inch production wafers, and successfully developed 650V / 106 mΩ and 100V / 74 mΩ power devices, and E- / D-mode 100V logic devices. The sub-project 1 established a SPICE model for the development of the converters in the sub-project 3 which completed the high-frequency LLC resonant DC / DC converter. The output power is 1 kW, the switching frequency is 1.5 MHz, and the power density reaches 40.1 W / cm3, meeting international standards. The new two-year target, sub-project 1 still provides novel epitaxial wafers for sub-project 2, including 6-inch silicon wafers and other epitaxial wafers with high heat dissipation. Sub-project 2 continued to develop improved GaN HEMTs and GaN SBDs, as well as vertical high-current GaN SBDs and GaN FETs. The converter of sub-project 3 uses the SPICE model of sub-project 1 to design to achieve the integration goal. In the integration part, the driving circuit is integrated with the power transistors. With 190 W as the application target, it can achieve a high power density ( 60W / cm3) at a switching speed of 1 - 1.5 MHz. The original overall goal (package components) is now one of the international benchmarks. It is hoped that two years later, it will further increase its power density to a world record. The sub-project 1 has a target planning in three directions, namely the epitaxial development of GaN materials, reliability analysis, and device model. In addition to providing new epitaxial wafers for sub-project 2, including epitaxial wafers on 6-inch silicon wafers and other high heat dissipation substrates. The epitaxial technology of novel structures and materials will also be explored to assist our industry players in breaking the patents of foreign competitors, pursuing better device characteristics, and solving the current reliability issues of GaN HEMTs. In the reliability analysis, the leakage current and breakdown voltage are studied, the dynamic on-resistance after off-state, the stability under high positive gate bias voltage / temperature, and the phenomenon of the breakdown of the drain. Finally, a SPICE model is established to study the parasitic inductance effect. The model includes static I-V and C-V characteristic curves, dynamic double pulse test characteristics, I-V thermal effect characteristics, and stray inductance effects of packaged components.