Device Characteristics of HEMT Structures based on Backgate Contact Method

This paper presents a novel technique to obtain device characteristics of high electron mobility transistors (HEMT) structures based on the backgate contact method, thus avoiding the need for complete gate formation. The gate contact was prepared on the back side of the substrate. Measurements performed on various HEMT structures shows typical transistor characteristics. Significant changes in drain- source current as a function of backgate voltage bias was observed for different HEMT structures. Increasing the channel thickness from 8 to 26 nm shows an increase in the threshold voltage of the transistor and a noticeable variation in drain-source current. This result leads to an effective and novel technique for the determination of sample quality prior to the further fabrication process to obtain the complete device.