Journal of Thermal Analysis and Calorimetry

, Volume 129, Issue 2, pp 1159–1168 | Cite as

Channel temperature measurement in hermetic packaged GaN HEMTs power switch using fast static and transient thermal methods

  • Szu-Hao Chen
  • Po-Chien Chou
  • Stone ChengEmail author


A GaN-based power device is a superior component for high-frequency and high-efficiency applications and especially for applications that involve megahertz power conversion. In this work, a fast process of static thermal resistance (R th) and transient thermal impedance (Z th) measurements are made and analyzed to determine the thermal characteristics of the channel temperature of a hermetically packaged GaN power device. Five temperature-sensitive parameters (TSPs) are measured at temperatures from 20 to 160 °C. Measurements and statistical analyses included variations with temperature of on-resistance (R on), saturation drain current (I Dsat), drain conductance (g d), threshold voltage (V th), and knee voltage (V knee). The statistical analyses revealed the relationships between the heating curve parameter (R on) and the cooling curve parameters (V knee, I Dsat, g d, and V th). The average thermal resistance values are extracted as follows: Maximum R th is 2.99 °C W−1, minimum R th is 2.92 °C W−1, and the variation among the five TSPs is <3%. Conventional optical-based techniques such as infrared (IR) and micro-Raman thermography are destructive to packaged devices. Therefore, this study developed the two reliable and fast non-destructive methods for estimating channel temperature with the following features: (1) They elucidate static and transient characteristics; (2) they involve heating and cooling; and (3) they evaluate transient thermal impedance (TTI) and safe operating area (SOA). The heating curve method has advantages over cooling curve method in terms of capturing time (40 vs. 400 s, respectively), and a lower power excitation is required to obtain the transient channel temperature response.


Junction temperature Power semiconductor device Heating curve Cooling curve Transient thermal impedance (TTI) Safe operating area (SOA) 


gd [S]

Drain conductance


Drain-to-source current

IDsat [A]

Saturated drain-to-source current

PD [W]

Power dissipation

PM [W]

Applied power for TSP measurement

Ron [ohms]

Electrical resistance of device ON

Rth [°C W−1]

Static thermal resistance

Rthjx [°C W−1]

Static thermal resistance from junction to reference point

tD [s]

Dead time

tp [s]

Pulse width

T [s]


TA [°C]

Hot chamber temperature

TC [°C]

Case temperature

TJ [°C]

Device channel temperature

TJC [°C]

Channel-to-case temperature

TJmax [°C]

Maximum junction temperature

TR [°C]

A reference temperature (e.g., room temperature)


Drain-to source voltage


Gate-to-source voltage

Vknee [V]

Knee voltage

Vth [V]

Threshold voltage

Zth [°C W−1]

Transient thermal impedance

Zthjc [°C W−1]

Transient thermal impedance from junction to case

Zthjx [°C W−1]

Transient thermal impedance from junction to reference point



This work was supported by the MOST Project 104-2221-E-009-123, Taiwan, R.O.C. The authors would like to thank Keithley team in Tektronix Taiwan for their very helpful suggestions and technical support.


  1. 1.
    Chou PC, Cheng S. Performance characterization of gallium nitride HEMT cascode switch for power conditioning applications. Mater Sci Eng B. 2015;198:43–50.CrossRefGoogle Scholar
  2. 2.
    Huang X, Liu Z, Li Q, Lee FC. Evaluation and application of 600 V GaN HEMT in cascode structure. In: Proceedings of the twenty-eighth annual IEEE application power electron conference and exposition; 2013. p. 1279–1286.Google Scholar
  3. 3.
    Kikkawa T, Hosoda T, Imanishi K, Shono K, Itabashi K, Ogino T, Miyazaki Y, Mochizuki A, Kiuchi K, Kanamura M, Kamiyama M, Akiyama S, Kawasaki S, Maeda T, Asai Y, Wu Y, Smith K, Gritters J, Smith P, Chowdhury S, Dunn D, Aguilera M, Swenson B, Birkhahn R, McCarthy L, Shen L, McKay J, Clement H, Honea J, Yea S, Thor D, Lal R, Mishra U, Parikh P. 600 V JEDEC-qualified highly reliable GaN HEMTs on Si substrates. In: IEEE IEDM, San Francisco; 2014. pp. 40–43.Google Scholar
  4. 4.
    Cheng S, Chou P. Novel packaging design for high-power GaN-on-Si high electron mobility transistors (HEMTs). Int J Therm Sci. 2013;66:63–70.CrossRefGoogle Scholar
  5. 5.
    Heller ER. Simulation of life testing procedures for estimating long-term degradation and lifetime of AlGaN/GaN HEMTs. IEEE Trans Electron Devices. 2008;55:2554–60.CrossRefGoogle Scholar
  6. 6.
    Park SY, Floresca C, Chowdhury U, Jimenez JL, Lee C, Beam E, Saunier P, Balistreri T, Kim MJ. Physical degradation of GaN HEMT devices under high drain bias reliability testing. Microelectron Reliab. 2009;49(5):478–83.CrossRefGoogle Scholar
  7. 7.
    Marcon D, Kauerauf T, Medjdoub F, Das J, Van Hove M, Srivastava P, Cheng K, Leys M, Mertens R, Decoutere S, Meneghesso G, Zanoni E, Borghs G. A comprehensive reliability investigation of the voltage-, temperature- and device geometry-dependence of the gate degradation on state-of-the-art GaN-on-Si HEMTs. In: Proceedings of IEEE IEDM; 2010. p. 20.3.1–20.3.4.Google Scholar
  8. 8.
    Persson E. Practical application of 600 V GaN HEMTs in power electronics. In: Proceedings of IEEE application power electron conference and exposition (APEC); 2015.Google Scholar
  9. 9.
    Hodge MD, Vetury R, Shealy JB. Fundamental failure mechanisms limiting maximum voltage operation in AlGaN/GaNHEMTs. In: Proceedings of IEEE IRPS; 2012 pp. 3D.2.1–3D.2.6.Google Scholar
  10. 10.
    Sarua A, Ji H, Kuball M, Uren MJ, Martin T, Hilton KP, Balmer RS. Integrated micro-Raman/infrared thermography probe for monitoring self-heating in AlGaN/GaN transistor structures. IEEE Trans Electron Devices. 2006;53(10):2438–47.CrossRefGoogle Scholar
  11. 11.
    Ahamd I, Kasisomayajula V, Holtz M, Berg JM, Kurtz SR, Tigges CP, Allerman AA, Baca AG. Self-heating study of an AlGaN/GaN-based heterostructure field-effect transistor using ultraviolet micro-Raman scattering. Appl Phys Lett. 2005;86(17):173–503.Google Scholar
  12. 12.
    Darwish AM, Bayba AJ, Hung HA. Utilizing diode characteristics for GaN HEMT channel temperature prediction. IEEE Trans Microw Theory Tech. 2008;56(12):3188–92.CrossRefGoogle Scholar
  13. 13.
    Guangchen Z, Shiwei F, Peifeng H, et al. Channel temperature measurement of AlGaN/GaN HEMTs by forward Schottky characteristics. Chin Phys Lett. 2011;28(1):017201.CrossRefGoogle Scholar
  14. 14.
    Joh J, del Alamo JA, Chowdhury U, Chou T-M, Tserng H-Q, Jimenez JL. Measurement of channel temperature in GaN high-electron mobility transistors. IEEE Trans Electron Devices. 2009;56:2895–901.CrossRefGoogle Scholar
  15. 15.
    Chen S, Chou P, Cheng S. Evaluation of thermal performance of packaged GaN HEMT cascode power switch by transient thermal testing. Appl Therm Eng. 2016;98(1):1003–12.CrossRefGoogle Scholar
  16. 16.
    Darwish AM, Huebschman BD, Viveiros E, Hung HA. Dependence of GaN HEMT millimeter-wave performance on temperature. IEEE Trans Microw Theory Tech. 2009;57(12):3205–11.CrossRefGoogle Scholar
  17. 17.
    Darwish AM, Huebschman B, Viveiros E, Hung HA. The dependence of GaN HEMT’s frequency figure of merit on temperature, presented at the IEEE international microwave symposium, Boston; 2009.Google Scholar
  18. 18.
    Worman J, Ma Y. eGaN® FET safe operating area. Application Note: AN014, Efficient power conversion corporation (EPC); 2012.Google Scholar
  19. 19.
    Parikh P, Wu Y, Mishra U, Shen L, Birkhahn R, Swenson B, Gritters J, Barr R, McCarthy L, Honea J, Yea S, Smith K, Smith P, Dunn D, McKay J, Clement H, Kikkawa T, Hosoda T, Asai Y, Imanishi K, Shono K. Commercialization of 600 V GaN HEMTs. In: 2014 SSDM, Tsukuba; 2014.Google Scholar
  20. 20.
    Szabo P, Rencz M, Farkas G, Poppe A. Short time die attach characterization of LEDs for in-line testing application. In: 2006 electronics packaging technology conference, Singapore; 2006. p. 360–36.Google Scholar
  21. 21.
    Farkas G. Thermal transient characterization of semiconductor devices with programmed powering. In: Proceedings of 29th SEMI-THERM symposium; 2013. p. 248–255.Google Scholar
  22. 22.
    Siegal B. An Introduction to diode thermal measurements. In: An introduction to diode thermal measurements. Thermal Engineering Associates, Inc. Santa Clara, CA, USA. 2009. Accessed 15 Jul 2016.
  23. 23.
    Chinthavali M, Ning P, Cui Y., Tolbert LM. Investigation on the parallel operation of discrete SiC BJTs and JFETs. In: Proceedings of the 2011 twenty-sixth annual IEEE applied power electronics conference and exposition (APEC); 2011. p. 1076–1083.Google Scholar
  24. 24.
    Chou P, Cheng S, Chen S. Evaluation of thermal performance of all-GaN power module in parallel operation. Appl Therm Eng. 2014;70(1):593–9.CrossRefGoogle Scholar
  25. 25.
    Farkas G, Purak T, Toth G. Thermal transient measurement of insulated gate devices using the thermal properties of the channel resistance and parasitic elements. In: Proceedings of the 20th THERMINIC, London; 2014. p. 24–26.Google Scholar
  26. 26.
    Meresse D, Harmand S, Grine A. Thermal diffusivity identification by 2nd derivative analysis of transient temperature profile. J Therm Anal Calorim. 2016;124:1193–208.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2017

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringNational Chiao-Tung UniversityHsinchuTaiwan

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