Experimental and theoretical characteristics of MOS transistors non uniformly doped by SILOX technique

Most existing theories for nonuniformly doped MOS transistors are related to the extreme cases of doped layers which are large or small with respect to the semiconductor surface space-charge layer. The theoretical part of the present paper Introduces a general one-dimensional analytical model, that takes the complete doping profile of the substrate into account and allows the evaluation of the principal characteristics of MOS transistors having a single type net impurity concentration profile. The second part of the paper describes the fabrication technology and presents experimental results for n-channel MGS transistors nonuniformly doped by means of the SILOX technique. The experimental data are compared with calculated results.