Improved performance of back-gate MoS2 transistors by NH3-plasma treating high-k gate dielectrics

• 来源期刊: 中国物理B（英文版）
• 关键词: MoS2 transistor high-k dielectric NH3-plasma treatment oxygen vacancy mobility
• 年，卷（期）: 2019,（12）
• 页码范围: 387-394
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab50fe

摘要

NH3-plasma treatment is used to improve the quality of the gate dielectric and interface.Al2O3 is adopted as a buffer layer between HfO2 and MoS2 to decrease the interface-state density.Four groups of MOS capacitors and back-gate transistors with different gate dielectrics are fabricated and their C-V and I-V characteristics are compared.It is found that the Al2O3/HfO2 back-gate transistor with NH3-plasma treatment shows the best electrical performance:high on-off current ratio of 1.53 × 107,higher field-effect mobility of 26.51 cm2/V.s,and lower subthreshold swing of 145 mV/dec.These are attributed to the improvements of the gate dielectric and interface qualities by the NH3-plasma treatment and the addition of Al2O3 as a buffer layer.