A Study on the First‐Derivative Output Properties of GaN Static Induction Transistor with Submicrometer Fin Width

Abstract

The first derivative of output curves of a Schottky‐junction vertical channel GaN static induction transistor (SIT) with a submicrometer‐sized fin is studied to understand its fundamental electrical properties. It is found that the derivative of output curves increases with the increase in drain voltage (Vds) in ohmic region because of the raised potential minima in the channel, which is not seen in SITs with a relatively long fin width. The influence of the gate voltages (Vgs) and Vds on electric potential in the channel is demonstrated by evaluating the contribution of Vgs and Vds, expressed through two coefficients α and β. The ratio of α to β increases up to 31.1 from 16.3 with decrease in the fin width from 0.9 to 0.5 μm, showing a higher dependency of the potential minima on Vgs and the fin width. The voltage gain expressed by α/β is 14.9 dB for the GaN SIT with a fin width of 0.5 μm.