Cutoff frequency increase of gate recessed AlGaN/GaN MISHFETs with amorphous AlN insulator

• DOI: 10.1063/5.0252024
• Publication Date: 2025-02-20T15:45:52Z
• Authors: Peter Kordoš; Dagmar Gregušová; Martin Mikulics; Hilde Helen Hardt...
• Keywords: Physics; QC1-999; info:eu-repo/classification/ddc/530; 530

The RF performance of gate recessed MISHFET devices with an amorphous AlN layer was investigated by small-signal (S-parameter) measurements. They reveal current gain and unilateral power gain cutoff frequencies of 125 and 138 GHz, respectively. These device parameters were achieved for gate recessed MISHFET devices after applying a selective “step by step” etching T-gate formation procedure. The results indicate that the combination of an amorphous AlN dielectric layer with the gate recessed AlGaN/GaN MISHFET structures affects the RF performance in devices prepared for high frequency operation advantageously.