A P-channel poly-Si/Si1-xGex/Si sandwiched conductivity modulated thin-film transistor

A p-channel poly-Si/Si1-xGex/Si sandwiched conductivity modulated thin-film transistor (CMTFT) is proposed and demonstrated in this paper for the firs t time. This structure uses a poly-Si/Si1-xGex/Si sandwiched structure as t he active layer to avoid the poor interface between the gate oxide and the poly-Si1-xGex material. Also an offset region placed beta een the channel a nd the drain is used to reduce the Leakage current. Furthermore, the concep t of conductivity modulation in the offset region is used to provide high o n-state current. Results show that this structure provides high on-state cu rrent as well as low leakage current as compared to that of conventional of fset drain TFT's, The on-state current of the structure is 1.3-3 orders of magnitude higher than that of a conventional offset drain TFT at a gate vol tage of -24 V and drain voltage ranging from -15 to -5 V while maintaining comparable leakage current.