EXPERIMENTAL-DETERMINATION OF THRESHOLD VOLTAGE SHIFTS DUE TO QUANTUM-MECHANICAL EFFECTS IN MOS ELECTRON AND HOLE INVERSION-LAYERS

This letter reports for the first time, accurately extracted experimen tal data for the threshold voltage shift (Delta V-T) due to quantum me chanical (QM) effects in hale inversion layers in MOS devices, Additio nal experimental results are presented for QM effects in electron inve rsion layers, Compared to classical calculations, which ignore QM effe cts, these effects are found to cause a significant increase in the th reshold voltage (similar to 100 mV) in MOSFET devices with oxide thick nesses and doping levels anticipated for technologies with gate length s less than or equal to 0.25 mu m. Delta V-T has been determined from experimental devices with doping levels ranging from 5 x 10(15)-1 x 10 (18)/cm(3), and recently developed theoretical models are found to agr ee well with the results, Hn addition, an innovative technique using a two-dimensional (2-D) device simulator in conjunction with the experi mental capacitance-voltage (C-V) characteristics has been developed in order to more accurately extract various physical parameters of the M OS structure.