AlxGa1-xN/GaN MISHEMTs With a Common Gold-Free Metal-Stack for Source/Drain/Gate

作者：Tham W H^*; Bera L K; Ang D S; Dolmanan S B; Bhat T N; Tripathy S

来源：IEEE Electron Device Letters, 2015, 36(12): 1291-1294.

DOI：10.1109/LED.2015.2491362

• GaN-on-Si
• gold-free CMOS-compatible HEMT/MISHEMT
• single metal
• self-aligned
• low-temperature process

A low-temperature fabrication of AlxGa1-xN/GaN MISHEMTs on a 200-mm GaN-on-Si substrate using a common metal stack (Ti/Al/NiV) for concurrent source, drain, and gate formation is demonstrated. An ohmic contact resistance of 0.8 Omega-mm and a specific contact resistivity of 6x10(-6) Omega-cm(2) are achieved at an annealing temperature of 500 degrees C. The fabricated MISHEMTs have excellent electrical characteristics: an I-ON/I-OFF ratio of nine decades (due to subnanoampere OFF-state leakage current up to a -15 V gate bias), and a subthreshold swing of 80 mV/decade (by virtue of a relatively low Al0.23Ga0.77N/GaN interface-trap density on the order of 1011 cm(-2)eV(-1)). The demonstrated approach is thus a promising alternative toward the gold-free GaN-on-Si integration.

• 出版日期2015-12
• 单位南阳理工学院