| 摘要 |
PURPOSE:To grow a crystal having specified characteristics in a gaseous phase with the doping amount as the functions of a position and time, by obtaining the doping amount corresponding to the desired distribution from the equation of the impurity distribution at the time of crystal growth and at the time of high temperature. CONSTITUTION:P type impurities and N type impurities are offset each other in a substrate. In order to have the desired impurity distribution by doping in the gaseous phase, the extra amount of the reverse conductive type impurities with respect to the substrate is doped to offset the amount of solid diffusion from the substrate and the selfdiffusion. The impurities diffused into the growing layer from the substrate is finally evaporated from the surface. The impurity distribution by the solid diffusion from the substrate can be expressed as the functions of the thickness of the growth x and the growing time t. If the impurity concentration in the gaseous phase is controlled, the impurity concentration in the inside of the growing layer can be controlled. When the concentration or the conductive type of the impurity gas in the gaseous phase are changed according to the desired program depending on the time schedule, the impurity concentration at the surface and inside of the growing layer becomes the function of the time, and the epitaxial layer with desired characteristics can be obtained. |
