Advanced in Gallium Nitride materials and structures for power electronics

摘要

Gallium Nitride and related group III-Nitride semiconductors have emerged over the past decade as a materials platform for electronic and optoelectronic devices in solid-state lighting (blue, green, white LEDs), optical data storage (blue laser diodes), radar and communications (heterojunction field effect transistors).[1] Owing to the technological challenge of synthesizing large area bulk substrates, the Gallium Nitride (GaN) used for these semiconductor devices has primarily been heteroepitaxially deposited on dissimilar substrates such as Silicon Carbide, Silicon or sapphire. The accommodation of mismatch between the epitaxy and substrate has resulted in a high density of dislocations and related defects, with an areal density on the order of 10⁸-10¹⁰ cm^-2, influencing the device relevant physical properties in the GaN such as: thermal conductivity, critical breakdown field, mobility and carrier concentration.