An improved passive inductor microwave performance on gallium nitride substrates using ion implantation technology

Recently, gallium nitride (GaN) substrates have been widely used in high-power monolithic microwave integrated circuit applications, which work because of the high breakdown voltage associated with the wider energy band-gap. The objective of this article is to investigate the spiral inductors that have been used to implant various ions on GaN substrates, demonstrated separately by N⁺, Mg⁺ and O⁺. The measured substrate resistance (R_sub) results were 85Σ and 360Σ for undoped GaN substrates and N⁺ doped substrates, respectively. This ion implantation technology could substantially improve the substrate resistance and provide a higher quality factor value (Q-value) for spiral inductors. The low parasitic effect extracted by the scattering parameter (S-parameter) for various substrates indicated that the spiral inductor value can be applied stably at high frequency. Consequently, the high GaN substrate quality adopting high-isolation ion implantation technology, demonstrates its huge potential for high-power and high-efficiency amplifier applications.