钝化处理对Al2O3/InP MOS电容界面特性的影响

制备了Al/Al_2O_3/InP金属氧化物半导体(MOS)电容,分别采用氮等离子体钝化工艺和硫钝化工艺处理InP表面。研究了在150、200和300 K温度下样品的界面特性和漏电特性。实验结果表明,硫钝化工艺能够有效地降低快界面态,在150 K下测试得到最小界面态密度为1.6×10¹⁰ cm^-2·eV^-1。与硫钝化工艺对比,随测试温度升高,氮等离子体钝化工艺可以有效减少边界陷阱,边界陷阱密度从1.1×10¹² cm^-2·V^-1降低至5.9×10¹¹ cm^-2·V^-1,同时减少了陷阱辅助隧穿电流。氮等离子体钝化工艺和硫钝化工艺分别在降低边界陷阱和快界面态方面有一定优势,为改善器件界面的可靠性提供了依据。

Effects of Passivation Process on the Interface Properties of Al_2O_3/InP MOS Capacitors

Al/Al2O3/InP metal oxide semiconductor ( MOS) capacitors were prepared, and InP surfaces were treated by the nitrogen plasma passivation and sulfur passivation process, respectively. The interface characteristics and leakage current of the samples were investigated at temperatures of 150, 200 and 300 K. The experimental results show that the fast interface states can be effectively reduced by the sulfur passivation process. The minimum interface state density of 1.6×10^10cm^-2·eV^-1 is obtained at 150 K. Compared with the sulfur passivation process , the border traps can be effectively reduced by the nitrogen plasma passivation process with the increase of the test temperature. The border trap density decreases from 1. 1×10^12 to 5. 9×10^11cm^-2 ? V^-1 , while the trap-assisted tunneling current is reduced. Nitrogen plasma passivation and sulfur passivation process have advantages in reducing border traps and fast in terface states which provide a basis for improving the reliability of the device interface.