硅基不同晶面上的空穴迁移率研究

Hole Mobility Measured on Silicon with Different Crystalline Orientations

近年来,金属氧化物半导体场效应晶体管(MOSFET)的特征尺寸减小并进入纳米尺度,为了改善器件的短沟道效应,器件由原来的平面结构改为立体结构。而在立体结构器件中,沟道由不同于传统Si(100)晶面的Si晶面所组成。因此,为了了解不同Si晶面上器件反型层空穴迁移率的变化情况,在不同晶面Si衬底上分别制作了pMOSFET,并研究了器件的空穴迁移率。采用Split C-V方法测试了Si(100),(110),(111)和(112)晶面上器件的空穴迁移率。结果表明,Si(110)晶面上的空穴迁移率最大,Si(112)晶面上<111>沟道方向空穴迁移率比(110)晶面上空穴迁移率小,而略大于(100)和(111)晶面上的空穴迁移率,(100)晶面上的空穴迁移率最小。

The feature size of the metal oxide semiconductor field effect transistors （MOSFETs） decreases and has reached the nanometer scale in recent years. In order to improve the short channel effects （ SCE）, MOSFETs are evolved from a planar structure to a three-dimensional structure. However, in the three-dimensional structure, the channels are often composed by two or three silicon surfaces with different crystalline orientations from the conventional （100） silicon orientation. Therefore, in order to understand the impact of different crystalline orientations on hole mobility in inversion layers on silicon, pMOSFETs were fabricated on silicon substrates with various crystalline orientations and were characterized. Hole mobility was measured using the split C-V test method in pMOSFETs on （ 100）, （110） , （111） and （112） silicon substrates. Hole mobility of （110） silicon is found to be the largest. Hole mobility in 〈 111 〉 channel direction on （112） silicon is smaller than that on （110） substrate and slightly larger than that on （100） and （ 111 ） silicon substrates. The hole mobility on （100） silicon is found to be the smallest.