Recessed gate GaN MESFETs fabricated by the photoelectrochemical etching process

Won Sang Lee, Yoon Ho Choi, Ki Woong Chung, Moo Whan Shin, Dong Chan Moon

Research output: Contribution to journalConference articlepeer-review


A new photo-electrochemical etching method was developed and used to fabricate GaN MESFETs. The etching process uses photoresist for masking illumination and the etchant is KOH based. The etching rate with 1.0 mol% of KOH for n-GaN is as high as 1600 angstrom/min under the Hg illumination of 35 mW/cm2. The MESFET saturates at VDS = 4 V and pinches off at VGS = -3 V. The maximum drain current of the device is 230 mA/mm at 300 K and the value is remained almost same for 500 K operation. The characteristic frequencies, fT and fmax, are 6.35 GHz and 10.25 GHz, respectively. Insensitivity of the device performance to temperature was attributed to the defect-related high activation energy of dopants for ionization and band-bending at the subgrain boundaries in GaN thin films.

Original languageEnglish
Pages (from-to)481-487
Number of pages7
JournalMaterials Research Society Symposium - Proceedings
Publication statusPublished - 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: 1999 Apr 51999 Apr 8

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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