COMPUTER SIMULATION METHOD OF SILICON OXIDATION

A simulation method of Si oxidation is provided, which decreases the simulation time. A diffusion equation of oxidant is solved at individual nodes in a SiO.sub.2 region to calculate the surface concentration of the oxidant at the Si/SiO.sub.2 interface, resulting in the first value of the surface concentration of the oxidant at each of the nodes in the present time step. Then, the first value of the surface concentration of the oxidant at each of the nodes in the SiO.sub.2 region is adjusted to generate the second value of the surface concentration of the oxidant at each of the nodes in the SiO.sub.2 region in the present time step. Also, the second value of the surface concentration of the oxidant in the present time step is set as zero with respect to one of the nodes where the thickness increase of the SiO.sub.2 region has a value equal to or less than the specific small value. Simultaneously with this, the first value of the surface concentration of the oxidant is stored for a next time step. The stored first value of the surface concentration of the oxidant is added to a first value of the surface concentration of the oxidant obtained in the next time step, thereby producing a second value of the surface concentration of the oxidant in the next time step. The second value of the surface concentration of the oxidant is used in calculation of the thickness increase of the SiO.sub.2 region.