Effect of Non-Uniform Doing on Gate C-V Characteristics of MOSFETS

Abstract

The goal of this thesis is to determine the effects that the actual physical structure of a metal􀃽oxide·semiconductor (MOS) capacitor. A semi-classical numerical model is presented to investigate the effect of non-uniform substrate doping on gate C-V characteristics of MOSFETs. Poisson's equation is solved numerically neglecting quantum mechanical effects. Maximum surface potential is considered as equa! to 2¢F' Calculated gate C- V characteristic for step doping profi Ie and Gaus sian doping profile are compared with C- V for uniformly doped substrates. It is observed that non-uniform doping has great influence in C􀃾V characteristics ofMOSFETs in weak accumulation and depletion r egime. It also affects the threshold voltage.