Details

Autor(en) / Beteiligte

• Cheney, David

Titel

(Invited) AlGaN/GaN HEMT Reliability and Trap Detection Using Optical Pumping

Ist Teil von

• ECS transactions, 2014, Vol.61 (4), p.197-204

Erscheinungsjahr

2014

Beschreibungen/Notizen

• Changes in the drain current that correspond to charge trap energies in the band-gap of AlGaN/GaN High Electron Mobility Transistors (HEMTs) were measured when illuminated by below band-gap light. The energy of the applied wavelength of light affects the trapping and de-trapping of carriers within the band-gap, providing an indicator of trap densities. These changes were compared on HEMTs with gate lengths of 0.14 & 0.17 µm, before and after electrically stressing under on-state (V G = 0 V), off-state (V G =-5 V), and typical operating conditions (V G = -2V) indicating a change in trap density as a result of electrical stressing. Changes in trap densities were minimal after both off-state and on-state stressing but significant trap creation in the range E C ¬-0.4-0.6 eV were observed in HEMTs exhibiting gradual degradation during stressing. Energy levels corresponding to these values in the literature have been suggested to correlate Ga N and N Ga substitutional defects, as well as Ga I interstitials.