Thin oxide thickness extrapolation from capacitance-voltage measurements

Five oxide-thickness extrapolation algorithms, all based on the same model (metal gate, negligible interface traps, no quantum effects), are compared to determine their accuracy. Three sets of parameters are used: (acceptor impurity concentration, oxide thickness, and temperature): (10(16) cm(-3), 250 Angstrom, 300 K), (5 x 10(17) cm(-3), 250 Angstrom, 300 K), and (5 x 10(17) cm(-3), 50 Angstrom, 150 K). Demonstration examples show that a new extrapolation method, which includes Fermi-Dirac statistics, gives the most accurate results, while the widely-used C-o similar or equal to C-g (measured at the power supply voltage) is the least accurate. The effect of polycrystalline silicon gate is also illustrated.