Delta-doped complementary heterostructure FETs with high Y-value pseudomorphic In/sub 1/Ga/sub 1-y/As channels for ultra-low-power digital IC applications

The authors report on the device and circuit performance of delta-doped complementary heterostructure insulated gate field effect transistors (C-HIGFETs) which make use of a high InAs mole fraction (y-value) pseudomorphic In/sub y/Ga/sub 1-y/As channel along with a sub-channel delta-doped Si layer to adjust the n-HIGFET and p-HIGFET threshold voltages. Results are presented showing that increasing the y value of the In/sub y/Ga/sub 1-y/As channel up to y=0.25 enhances both the n-HIGFET and the p-HIGFET device performance, as evidenced by the high transconductance values (i.e., G/sub m-n/>300 mS/mm and G/sub m-p/>70 mS/mm, respectively) for 1- mu m gate length devices. The authors present results from In/sub y/Ga/sub 1-y/As channel (y=0.25) C-HIGFET ring oscillators with less than 4- mu W/gate standby-power consumption. These C-HIGFET ring oscillators exhibit gate delays as low as 143 ps at a standby-power of 40 mu W/gate and a switching-power-delay product of 250 fJ. The authors also report on the first fully functional delta-doped C-HIGFET 1 K*4 SRAM operating at a 284-MHz clock frequency and consuming only 183 mW.<>