Characteristics of P-channel polysilicon conductivity modulated thin-film transistors

A p-channel polysilicon conductivity modulated thin-film transistor (CMTFT) is demonstrated and experimentally characterized. The transistor uses the concept of conductivity modulation in the offset region to obtain a signifi cant reduction in on-state resistance, The conductivity modulation is achie ved by injecting minority carriers (electrons) into the offset region throu gh a diode added to the drain, Experimental results show that the conductiv ity modulation in the p-channel device is as effective as that in the n-cha nnel device, This structure can provide 1.5 to 2 orders of magnitude higher on-state current than that of the conventional offset drainthin-film trans istor (TFT) at drain voltage ranging from - 15 V to -5 V while still mainta ining low leakage current and simplicity in device operation. The p-channel CMTFT can be combined with the n-channel CMTFT to form CMOS high-voltage d rivers, which is very suitable for use in fully integrated large-area elect ronic applications.