AlGaN/GaN MOS-HEMT with stack gate HfO₂/Al₂O ₃ structure grown by atomic layer deposition

• 摘要：

  We have developed a novel AlGaN/GaN metal-oxide-semiconductor high electron mobility transistor (MOS-HEMT) using stack gate HfO₂/Al ₂O₃ structure grown by atomic layer deposition (ALD). The stack gate consists of a thin Hf0₂ (30Å) gate dielectric and a thin A1₂O₃ (20Å) interfacial passivation layer (TPL). For the 50Å stack gate, no measurable C-V hysteresis and smaller threshold voltage shift were observed, indicating that a high quaity interface can be achieved using a A1₂O₃ IPL on AlGaN substrate. Good surface passivation effects of the A1₂O₃ IPL have also been confirmed by pulsed gate measurements. Devices with 1-μm gate lengths exhibit a cutoff frequency (f_T) of 12GHz and a maximum frequency of oscillation (f_MAx) of 34GHz. The gate leakage current is at least six orders of magnitude lower than that of the reference HEMTs at positive gate bias.

• 作者：

  Yuan Zheng Yue;跃 郝;进成 张

• 刊名：

• 在线出版时间：

  2008