Page 22 - PEN eBook July 2022
P. 22
SEMICONDUCTORS
POWERUP
PROCEEDINGS
Agenda
https://www.powerup-expo.com/en/english-schedule
Speakers
GaN Epi Wafer
https://www.powerup-expo.com/en/speakers-and-panelists
Manufacturing for
High-Voltage GaN Devices
By Satya Dixit, board member and advisor at Future Semiconductor Business
Gallium nitride has become the de facto material in third-generation semiconductors. However,
making GaN wafers in the quality you need and the thermal resistance you desire are challenges
that fabs are still trying to overcome.
The mismatch of lattice constant and thermal expansion coefficient between GaN epi layers and
substrates such as silicon, sapphire, and silicon carbide lead to the dislocation and cracking of epi
layers.
A common method for thermal management is using substrates with high thermal conductivity,
such as SiC or diamond, as the heatsink. However, both the lattice mismatch and the coefficient
of thermal expansion mismatch between GaN and SiC/diamond make the heteroepitaxy very
challenging. Furthermore, the conventional nucleation layer exhibits low thermal conductivity due
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