SiO2层上沉积的纳米多晶硅薄膜及其特性

采用低压化学气相沉积(LPCVD)系统以高纯SiH4为气源,在p型10.16 cm<100>晶向单晶硅衬底SiO2层上制备纳米多晶硅薄膜,薄膜沉积温度为620℃,沉积薄膜厚度分别为30 nm、63 nm和98 nm.对不同薄膜厚度的纳米多晶硅薄膜分别在700℃、800℃和900℃下进行高温真空退火.通过X射线衍射(XRD)、Raman光谱、扫描电子显微镜(SEM)和原子力显微镜(AFM)对SiO2层上沉积的纳米多晶硅薄膜进行特性测试和表征,随着薄膜厚度的增加,沉积态薄膜结晶显著增强,择优取向为<111>晶向.通过HP4145B型半导体参数分析仪对沉积态掺硼纳米多晶硅薄膜电阻I-V特性测试发现,随着薄膜厚度的增加,薄膜电阻率减小,载流子迁移率增大.

Deposition and Characteristics of Nano-Polysilicon Thin Films on SiO2 Layer

With low pressure chemical vapor deposition（LPCVD） method and high-purity SiH4 as gas source,nano-polysilicon thin films were fabricated on SiO2 layer of p-type 10.16 cm 100 crystal silicon substrate.The deposition temperature of nano-polysilicon thin films was 620 ℃ and the deposition thicknesses of the thin films were 30 nm,63 nm and 98 nm respectively.The nano-polysilicon thin films with different thicknesses were annealed in vacuum at high temperatures of 700 ℃,800 ℃ and 900 ℃ respectively.The nano-polysilicon thin films deposited on SiO2 layer were tested and characterized by X-ray diffraction（XRD）,Raman spectroscopy,field emission scanning electron microscopy（SEM） and atomic force microscope（AFM）,and results indicate that with the increase of the deposited thin films thickness,crystallization of the thin films is significantly enhanced and the excellent orientation is 111.The I-V characteristics of the deposited nano-polysilicon thin films with B doping were measured by HP4145B type semiconductor parameter analysis device,which verifies that conductivity of the thin films decreases and mobility of the carriers increases with the increase of thin film thickness.