Details

Autor(en) / Beteiligte

• Chung-Han Lin
• Merz, T. A.
• Doutt, D. R.
• Jungwoo Joh
• del Alamo, J. A.
• Mishra, U. K.
• Brillson, L. J.

Titel

Strain and Temperature Dependence of Defect Formation at AlGaN/GaN High-Electron-Mobility Transistors on a Nanometer Scale

Ist Teil von

• IEEE transactions on electron devices, 2012-10, Vol.59 (10), p.2667-2674

Ort / Verlag

New York, NY: IEEE

Erscheinungsjahr

2012

Quelle

IEEE Xplore

Beschreibungen/Notizen

• We use depth-resolved cathodoluminescence spectroscopy (DRCLS), Kelvin probe force microscopy (KPFM), and surface photovoltage spectroscopy (SPS) on a nanometer scale to map the temperature, strain, and defects inside GaN high-electron-mobility transistors. DRCLS maps temperature at localized depths, particularly within the 2-D electron gas region during device operation. KPFM maps surface electric potential across the device, revealing lower potential patches that decrease rapidly with increasing off-state stress. CL spectra acquired at these patches exhibit defect emissions that increase with both on- and off-state stresses and that increase with decreasing surface potential. SPS also reveals features of deep level gap states generated after device operation that reduce near-band-edge emission and increase surface band bending. Our nanoscale measurements are consistent with defect generation by inverse piezoelectric field-induced stress at the gate edge on the drain side at high voltage.