LPCVD制备多晶硅薄膜的性能

Performances of Polysilicon Films Prepared by LPCVD

对低压化学气相沉积(LPCVD)制备多晶硅薄膜的生长工艺与钝化性能进行研究,重点分析了沉积温度、硅烷体积流量和沉积时间对薄膜生长和钝化性能的影响。在590~635℃沉积温度内,多晶硅薄膜生长速率与沉积温度近似呈线性关系,钝化性能随着沉积温度的增加先变优再变差;在250~1150 cm^(3)/min硅烷体积流量内,多晶硅薄膜的生长速率与硅烷体积流量基本呈线性关系,当硅烷体积流量为1150 cm^(3)/min时,钝化性能明显变差;随着多晶硅薄膜厚度增加,钝化性能先变优后稳定。使用优化后的工艺制备多晶硅薄膜样品并对其进行测试,测试结果表明样品的隐性开路电压为749 mV,饱和电流密度为1.46 fA/cm^(2),钝化性能最佳。

The growth process and passivation performances of polysilicon films prepared by low pressure chemical vapor deposition(LPCVD)were studied,and the effects of deposition temperature,SiH_(4) volume flow and deposition time on film growth and passivation performance were emphatically analyzed.Within the deposition temperature range of 590-635℃,the growth rate of polysilicon films is approximately linear with deposition temperature,and the passivation performance first becomes better and then worse with the increase of deposition temperature.When the SiH_(4) volume flow is in the range of 250-1150 cm^(3)/min,the growth rate of polysilicon films is basically linear with SiH_(4) volume flow.When the SiH_(4) volume flow is 1150 cm^(3)/min,the passivation performance becomes worse obviously.With the increase of the polysilicon film thickness,the passivation performance becomes better and then stable.Polysilicon film samples were prepared with the optimized process and tested.The test results indicate that the sample shows the best passivation performance with a recessive open circuit voltage of 749 mV and a saturation current density of 1.46 fA/cm^(2).