Study on the Point‐Contact Gate AlGaN/GaN High Electron Mobility Transistor with 0.1 μm Gate Length

The current collapse has been one of the most challenging problems in AlGaN/GaN high electron mobility transistors (HEMTs). In recent years, the virtual gate effect has been the most widely accepted cause of the current collapse effect. To effectively improve the current collapse effect and reduce the influence of the virtual gate effect on the device, a point‐contact gate AlGaN/GaN HEMT structure is proposed in this article. Tests show that the device has high transconductance, high cut‐off frequency, and good transfer, output, and breakdown characteristics. The maximum saturation drain current is 18 mA mm−1, the maximum transconductance is 200 mS mm−1, the breakdown voltage is 994 V, the maximum current gain is about 190 dB, and the cut‐off frequency is up to 206 GHz when the gate length and width are 0.1 μm × 0.001 μm. The experimental analysis shows that the point‐contact gate AlGaN/GaN HEMT structure shortens the gate length, thereby improving the virtual gate effect and effectively suppressing the current collapse effect, increasing the breakdown voltage of the device, and further improving the device performance, which lays the foundation for the future research of AlGaN/GaN HEMT. A point‐contact gate structure high electron mobility transistor with a gate length and width of 0.1 μm × 0.01 μm is demonstrated. When the drain voltage is 300 V, the on‐state resistance increase ratio is only 8.93%, indicating that this structure can effectively suppress the current collapse effect. Additionally, this structure can improve the radio frequency and breakdown characteristics of the device.