ANALYSIS OF THE MOS-TRANSISTOR BASED ON THE SELF-CONSISTENT SOLUTION TO THE SCHRODINGER AND POISSON EQUATIONS AND ON THE LOCAL MOBILITY MODEL

The effects of carrier energy quantization in the semiconductor surfac e region on performance of the metal-oxide-semiconductor (MOS) transis tor are theoretically considered by comparison of results of a self-co nsistent solution to the Schrodinger and Poisson equations and the res ults of the classical description. The gate voltage dependencies of th e surface potential and inversion layer charge density are compared. U sing the local mobility model the relations between the electron effec tive mobility and the electric effective field obtained from the both descriptions are for the first time compared. The accuracy of the comm only used triangular well approximation is examined. This approximatio n is used for calculation of the transistor current-voltage (I-V) char acteristics. Simulations are performed for MOS transistors with ultrat hin oxides and highly doped substrates, in accordance,vith the state o f the art of today's VLSI/ULSI technology.