Development of hydrogenated diamond triple-gate fin-type MOSFETs

摘要

Thanks to its extraordinary intrinsic properties, wide bandgap semiconductor diamond is promising to fabricate electronic devices for low power-loss, high-power, high-frequency, and high-temperature applications. Recently, hydrogenated diamond (H-diamond) surface channel based metal-oxide-semiconductor field-effect transistors (MOSFETs) have been developed greatly. However, lack of large-area commercially available wafers hinders them for future practical applications. To resolve this issue, we have tried to downscale device size and to enhance electrical properties of the H-diamond MOSFETs to meet requirement of small area wafers. The triple-gate fin-type H-diamond MOSFET has been fabricated successfully . Since holes in the fin channel can travel at both planar and lateral sides, current output and extrinsic transconductance of the fin-type MOSFET are much higher than those of the planar-type MOSFET at the same device area. However, some issues for the triple-gate fin-type H-diamond MOSFETs still exist. Fabrication process of them is quite complicated, leading to degradation of electrical properties and difficulty to repeat the experiment by other researchers. Additionally, ratio between height of lateral side and width of planar side for each fin is only 0.57, which means that the advantage of fin channel is not fully utilized. In this study, we have simplified the fabrication process for the triple-gate fin-type H-diamond MOSFETs and increased the ratio between height of lateral side and width of planar side for each fin to be 1.45 for further enhancing device current output at the same device area.