Single-interface and quantum-well heterostructure MISFETs

The physical operation of heterostructure metal-insulator-semiconductor field-effect transistors (H-MISFETs) is described and compared with that of more familiar heterostructure FETs. Undoped, doped-channel, and quantum-well MISFETs based on AlGaAs-GaAs heterostructures are examined. The focus is on quantum-well MISFETs, which differ most from more conventional devices. Results are presented of experiments and simulations carried out to study the physical mechanisms related to charge control, gate leakage, device geometry, short-channel effects, buffer leakage, and electron trapping in the devices, and the advantages of other III-V materials systems are described. The potential advantages of H-MISFETs are discussed in terms of particular circuit applications