Monolithic Integration of Inductive Components in a GaN-on-Si Technology

This work presents the results for monolithic integration of inductive components into a GaN-on-Si heterojunction technology. A design flow for integrated spiral inductors with simple formulas is introduced. A special feature is the thermal analysis for calculating the current carrying capability, which is indispensable for use in DC-DC converters. Based on this design flow, a spiral inductor with the inductor parameters of 12.6 nH, 1.6 Omega, approx. 1 A, and 45 nJ/mm2 was designed, measured, and verified as an example. The heat distribution of the spiral inductor was examined with the help of infrared images. This spiral inductor is compared with other on-chip inductors. Furthermore, a Figure-of-Merit has been adopted to review the application in DC-DC converters as Power System on Chip (PwrSoC) and to show the recent limit of this technology.