Thermal characterization of DC and small-signal parameters of 150 nm and 250 nm gate-length AlGaN/GaN HEMTs grown on a SiC substrate

Abstract

This paper investigated the temperature effects on the performance of the AlGaN/GaN high electron mobility transistor (HEMT) with a 150 nm and 250 nm gate length on a SiC substrate over a temperature range of −40 to 150°C including experimental characterization, modelling and analysis by on-wafer measurements up to 50 GHz. All the DC and small signal parameter variations with ambient temperature on the same set of devices have been reported for the first time. The temperature coefficient of all the DC and small signal parameters as well as f t and f max were reported. Some of the extracted equivalent circuit parameters with the theoretical data of the evolution of electrical parameters and the relevant physical equations involved have been compared using the same biasing condition for further accuracy. The theoretical results are shown to be consistent with the extracted data. Some results are also experimentally verified with previous works cited in the paper. The results provide some valuable insights for the underlying physics of the device parameters affected by temperature.

Investigation of Self-Heating Effect on DC and RF Performances in AlGaN/GaN HEMTs on CVD-Diamond

“…However, a small increase in drain resistance (R d ) was also observed at higher V D . Similar behaviour of extrinsic parameters with temperature has been reported in the published work [18]. The extracted C g (C gs + C gd ) at different V D was shown in Figure 8(a).…”

Gallium Nitride (GaN) High-Electron-Mobility Transistors with Thick Copper Metallization Featuring a Power Density of 8.2 W/mm for Ka-Band Applications

“…With a two-port network, the small signal model of the AlGaN/GaN HEMT device can be depicted as in Figure 3 [17,18]. Utilizing the y-parameter analysis, the drain-source current (I DS ) and the transconductance (G m ) of the device can be derived as:…”

An ambient temperature dependent small signal model of GaN HEMT using method of curve fitting

“…From Table 10, it has been observed that proposed method is more general as instead of an assumed linear function, it uses curve fitting method involving polynomials. Except for Reference 20, none of the referred works in discussion have quantified the deviation in predicted and measured values of the extrinsic and intrinsic parameters. Even in comparison to the method reported in Reference 20, error % is better indicating comparability with the method.…”

“…Except for Reference 20, none of the referred works in discussion have quantified the deviation in predicted and measured values of the extrinsic and intrinsic parameters. Even in comparison to the method reported in Reference 20, error % is better indicating comparability with the method. Hence, the proposed method is more general and hence can be applied to devices across technology.…”

“…According to their findings performance of GaN based HEMT degrades with rise in ambient temperature. Thermal characterization of DC and small signal parameters of 150 nm and 250 nm gate length AlGaN/GaN HEMTs grown on SiC substrate have been considered in Reference 20. Based on physical dimensions and bias conditions, ambient temperature effect has been mathematically modeled.…”