Thermal modeling and measurement of AlGaN-GaN HFETs built on sapphire and SiC substrates

Jeong Park, Moo Whan Shin, Chin C. Lee

Research output: Contribution to journalArticlepeer-review

51 Citations (Scopus)


In this paper, we present thermal modeling and measurement results of AlGaN-GaN heterojunction field effect transistors fabricated on sapphire and SiC substrates, respectively. The device structures are identical except for the substrate material used to grow the AlGaN-GaN hetrostructure. One objective is to study the effect of substrate material on the thermal and electrical performance of the resulting devices. To compute the temperature profiles, in-house PAMICE code developed for a three-dimensional structure was used. To measure the temperatures on the chip surface, nematic liquid crystal thermography was used. This technique is nondestructive and can be performed in realtime during device operation. It has submicrometer spatial resolution and ±1 °C temperature accuracy. The measured temperatures agree well with the calculated ones. The relationship between the measured temperature and power is almost linear for both types of devices. The junction-to-case thermal resistance of the device fabricated on sapphire substrate is 4.4 times that of the device built on SiC substrate.

Original languageEnglish
Pages (from-to)1753-1759
Number of pages7
JournalIEEE Transactions on Electron Devices
Issue number11
Publication statusPublished - 2004 Nov

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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