Complementary p- and n-channel quantum-well MI3SFET's

Heterostructure design and device fabrication techniques for vertically integrated p- and n-channel quantum-well FETs are described, and the operation of FETs fabricated on a p/n double-quantum-well heterostructure is demonstrated. The dependence of parasitic resistance and gate leakage on heterostructure layer parameters and device geometry is examined in experiments. Contact and n⁺ sheet resistances as low as 0.2 Ω-mm and 385 Ω/2b, respectively, and peak transconductance values of 300 mS/mm are achieved in the best 1.5-μm n-FETs at 77 K. p-FETs fabricated on a double-quantum-well heterostructure by Zn diffusion show contact and p⁺ sheet resistances of approximately 0.5 Ω-mm and 200 Ω/2b, respectively, with peak transconductance of 80 mS/mm for 1.5-μm gates at 77 K. Gate leakage is sufficiently low in both p- and n-FETs to allow high-speed complementary logic and memory at supply voltages of 1.1 V.