Models for the self-heating evaluation of a gallium nitride-based high electron mobility transistor

Abstract

We propose a novel model approach for temperature evaluation in the channel region of a InAlN/AlN/gallium nitride high electron mobility transistor (HEMT) due to self-heating effects. The heat transfer in a HEMT device has been investigated experimentally by the nearby temperature sensor and compared by theoretical models solved by both numerical and analytical methods. The average temperature of the channel area of almost 160 °C for dissipated power of 2 W was determined using the drain-source current variation analysis. The electrical and thermal behavioral numerical model under quasi-static conditions have been used to describe the HEMT device. In contrast, the one-dimensional thermal model for analytical evaluation has been proposed as an alternative approach. Surprisingly, the experimental results verified not only the validity of precise numerical simulation but also the simplified analytical model that makes it a reliable tool even for complex electronic devices.

Theoretical and Experimental Substractions of Device Temperature Determination Utilizing I-V Characterization Applied on AlGaN/GaN HEMT

“…This approximation is found to be sufficient, although further V DS and I DS time dependence investigations for t < t 0 are recommended. The trapping time constants of at least one order higher than ~10 −7 s allow the calculation of the isothermal time dependence utilizing (14).…”

“…Temperature dependent thermal resistance and thermal capacity result in a ∆T A * deviation from ∆T 0 . Quasi-static state methods, utilizing the T 0 variation, allows for the calculation of dT A and ∆T A * [9,14].…”

“…The top ohmic drain/source and gate contacts were created via standard Au-based metallization. A gated transmission line model (GTLM) HEMT with a width of w ≈ 100 µm, a gate with a length of d G ≈ 0.15 µm, asource to gate gap of length d GS ≈ 0.75 µm and the drain to gate gap of length d GS ≈ 1.5 µm was investigated [14]. The device is placed in an open package located on the Al thermal chuck and maintainedat a constant temperature.…”

“…Interpolated thermal and isothermal parts of dI DS /dV DS vs. V DS at T 0 ≈ 25 • C are depicted in Figure 5. Moreover, the dissipated power contribution dP * = V DS ∆I * , caused by dT 0 for low V DS negligible in comparison with dP = V DS dI DS + I DS dV DS caused by dV DS , results in the simplified formula for differential thermal resistance R A0 (T 0 ) calculation [14] utilizing (12):…”

“…Increasing V DS results in different R A0 values at a defined T 0, which is partially caused by spatially distributed electrical parameters of the active device area such as the g M dV THE /dV DS variation. The approximation R A0 ≈ k RA (T 0 − T 00 ) + R 00 , T 00 ≈ 25 • C, k RA ≈ 0.2 W −1 , R 00 ≈ 57.0 K/W at the defined T 0 was utilized to calculate T A in a recurrent way [14] as illustrated in Figure 7. In [8] the major contribution of the thermal I DS section is assigned to the serial source area resistance increase, caused by self-heating in a saturation regime for AlGaN/GaN HEMT.…”