不同有源层厚度的多晶硅薄膜晶体管特性研究

Characteristics of polysilicon thin film transistor with different active layer thickness

多晶硅薄膜晶体管(poly-Si TFT)因较非晶硅薄膜晶体管(a-Si TFT)相比具有更高的场效应迁移率而成为目前显示界研究的热点。在制备多晶硅薄膜及其TFT器件的过程中,发现不同厚度的多晶硅薄膜具有不同的电学特性。经分析,不同厚度的多晶硅薄膜有源层TFT器件也势必表现出不同的器件电学特性。为此,制备3种多晶硅薄膜有源层厚度的TFT器件,比较且优化器件的各种电学特性—场迁移率、阈值电压、亚阈值幅摆、电流开关比等,最后确定TFT器件有源层的最佳厚度。

Poly-Si TFT has become the hot topic in the field of display currently due to higher field-effect mobility than that of a-Si TFT.During the fabrication of polycrystalline silicon thin film and its TFT devices,it is observed that polycrystalline silicon thin film showes different electrical properties.After analysis,we consider that polysilicon thin film TFT devices with different active layer thickness are bound to show different electrical properties of devices.Therefore,we prepared three kinds of TFT devices with different polycrystalline silicon thin film active layer thickness,After comparing and optimizing various electrical properties of the device,such as field mobility,threshold voltage,subthreshold swing increase,current ratio,and gate voltage induced drain leakage,the optimum active layer thickness of the TFT device was determined.