Comparison of ratio of gate length to gate-drain distance influences on source access resistance of AlGaN/AlN/GaN HFETs at different temperatures.

In this work, two AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) with different ratios of gate length (L G) to gate-drain distance (L GD) were used to compare the effects of ratio of L G to L GD on the source access resistance (R GS) at 300 K , 350 K , and 400 K. The results showed that the ratio of L G to L GD had a significant effect on R GS at the above-mentioned each temperature, which can be attributed to the polarization Coulomb field (PCF) scattering. In addition, the effects of the ratio of L G to L GD on R GS in the two AlGaN/AlN/GaN HFETs prepared in this work were different at different temperatures. This indicated that elevated-temperature performance of AlGaN/AlN/GaN HFETs can be improved by optimizing the ratio of L G to L GD based on PCF scattering. [Display omitted] • The effects of the ratio of L G to L GD on R GS in AlGaN/AlN/GaN HFETs are investigated at different temperatures. • It is found that the ratio of L G to L GD has a significant effect on R GS at each testing temperature. • PCF scattering is responsible for the effects of the ratio of L G to L GD on R GS. • R GS can be modulated by optimizing the ratio of L G to L GD based on PCF scattering. [ABSTRACT FROM AUTHOR]