Diamond Field Effect Transistors With MoO3Gate Dielectric

Abstract

We report the first attempt of the diamond MOSFETs with MoO3 dielectric directly deposited on H-diamond surface preserving atmospheric-adsorbate-induced 2DHG. The transistors with 4- $\mu \text{m}$ gate show a transconductance of 29 mS/mm and an ON-resistance of $75.25~\Omega \cdot \text {mm}$ at $\vert V_{\text {GS}} - V_{\text {TH}}\vert = 2.2$ V, respectively. The effective mobility is extracted to be 108 cm2/(Vs) from the relationship between the ON-resistance and $\vert V_{\text {GS}}- V_{\text {TH}}\vert $ . The relatively high transconductance among the reported diamond MOSFETs with the same gate length could be attributed to the quite low ON-resistance. The evaluated high mobility indicates good interface characteristics between diamond and MoO3. However, the saturation drain current is limited at 33 mA/mm by the forward gate breakdown at $\text{V}_{\text {GS}}$ of around −2 V.