Effects of Combined Gate and Ohmic Recess on GaN HEMTs

Publication date: Available online 23 April 2016 Source:Perspectives in Science Author(s): Sunil Kumar, Vimal Kumar Agrawal AlGaN/GaN, because of their superior material properties are most suitable semiconductor material for High Electron Mobility Transistors (HEMTs). In this work we investigated the hidden physics behind these materials and studied the effect of recess technology in AlGaN/GaN HEMTs. The device under investigation is simulated for different recess depth using Silvaco-Atlas TCAD. Recess technology improves the performance of AlGaN/GaN HEMTs. We considered three kind of recess technology gate, ohmic and combination of gate and ohmic. Gate recess improves transconductance gm but it reduces the drain current Id of the device under investigation. Ohmic recess improves the transconductance gm but it introduces leakage current Ig in the device. In order to use AlGaN/GaN for high voltage operation, both the transconductance and the drain current should be reasonably high which is obtained by combining both gate and ohmic recess technology. A good balance in transconductance and drain current is achieved by combining both gate and ohmic recess without any leakage current.

Source: Perspectives in Science - April 23, 2016 Category: Science Source Type: research