AlGaN microwave power HFETs on insulating SiC substrates

Gerry Sullivan, Ed Gertner, Richard Pittman, Mary Chen, Richard Pierson, Aiden Higgins, Qisheng Chen, Jin Wu Yang, R. Peter Smith, Raul Perez, Abdur Khan, Joan Redwing, Brian McDermott, Karim Boutros

Research output: Contribution to journalConference articlepeer-review


AlGaN HFETs are attractive devices for high power microwave applications. Sapphire, which is the typical substrate for AlGaN epitaxy, has a very poor thermal conductivity, and the power performance of AlGaN HFETs fabricated on sapphire substrates is severely limited due to this large thermal impedance. We report on HFETs fabricated on high thermal conductivity electrically insulating SiC substrates. Excellent RF power performance for large area devices is demonstrated. On-wafer CW measurements at 10 GHz of a 320 micron wide FET resulted in an RF power density of 2.8 Watts/mm, and measurements of a 1280 micron wide FET resulted in a total power of 2.3 Watts. On-wafer pulsed measurements, at 8 GHz, of a 1280 micron wide FET resulted in a total power of 3.9 Watts. Design of a hybrid microwave amplifier will be discussed.

Original languageEnglish (US)
Pages (from-to)471-479
Number of pages9
JournalMaterials Research Society Symposium - Proceedings
StatePublished - 1999
EventProceedings of the 1999 MRS Spring Meeting - Symposium on 'Wide-Bandgap Semiconductors for High-Power, High Frequency and High-Temperature Applications' - San Francisco, CA, USA
Duration: Apr 5 1999Apr 8 1999

All Science Journal Classification (ASJC) codes

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'AlGaN microwave power HFETs on insulating SiC substrates'. Together they form a unique fingerprint.

Cite this