MEASUREMENT OF DIFFUSION LAYER DEPTH

摘要

PURPOSE:To measure the depth of a diffusion layer accurately by chemical and electrical methods utilizing V-grooves formed by mesa-etching of silicon. CONSTITUTION:An oxide film 13 is formed on a silicon substrate 11 in which a diffusion layer 12 is formed and a plurality of apertures 14 are formed. Each aperture 14 has a different width. The substrate 11 is etched using the oxide film 13 as a mask to form U-grooves 15. Then electrodes 16 are formed and continuity or discontinuity of the diffusion layer 12 is checked at both sides of each V-groove 15. Therefore, when continuity or discontinuity of the diffusion layer 12 is checked at the sides of the most shallow V-groove 15 and checked successively in the order of the depth of the V-grooves 15, if the checked results change from continuity to discontinuity, the depth of the diffusion layer 12 is measured as the intermediate value between the depth of the V-groove 15 at that time and the depth of the V-groove 15 one step before. The depth of each V-groove 15 can be calculated with high accuracy from the measured dimensions of the apertures so that the depth of the diffusion layer 12 can be measured accurately by utilizing the depth of each V-groove 15.