Threshold Voltage Adjustment by Varying Ge Content in SiGe p-Channel for Single Metal Shared Gate Complementary FET (CFET).

We have demonstrated the method of threshold voltage (V) adjustment by controlling Ge content in the SiGe p-channel of N1 complementary field-effect transistor (CFET) for conquering the work function metal (WFM) filling issue on highly scaled MOSFET. Single WFM shared gate N1 CFET was used to study and emphasize the V tunability of the proposed Ge content method. The result reveals that the Ge mole fraction influences V of 5 mV/Ge%, and a close result can also be obtained from the energy band configuration of SiGe. Additionally, the single WFM shared gate N1 CFET inverter with V adjusted by the Ge content method presents a well-designed voltage transfer curve, and its inverter transient response is also presented. Furthermore, the designed CFET inverter is used to construct a well-behaved 6T-SRAM with a large SNM of ~120 mV at V of 0.5 V.