Device Characteristics of Polycrystalline Si0.84Ge0.16 Thin Film Transistors Grown from Si2H6 and GeH4 Source Gases

Polycrystalline Si0.84Ge0.16 alloy film was made by solid phase crystallization (SPC) of an amorphous film deposited using Si2H6 and GeH4 source gases by low pressure chemical vapor deposition (LPCVD). The grain size of the film was about 540 nm and the preferred orientation was (111). Both n-channel and p-channel polycrystalline Si0.84Ge0.16 thin film transistors were successfully fabricated using a high temperature process. The field-effect mobilities of n- and p-channel devices were 13 and 29 cm2/Vs, which were improved to 33 and 38 cm2/Vs, respectively, after electron-cyclotron resonance (ECR) hydrogen plasma treatment.