| 摘要 |
PURPOSE:To form an insulating layer to the lower section of a plate for a charge storage cell, and to prevent reaching to the end of a depletion layer in the lower section of the cell by a diffusion of pair-produced charges in an silicon substrate by implanting oxygen ions into the semiconductor substrate in the lower section of the plate. CONSTITUTION:A channel stopper is implanted to the surface of a P-type silicon substrate 1, and a field oxide film 13 is shaped. Oxygen ions 14 are implanted to depth of approximately 0.4mum from the surface of the P-type silicon substrate 1 forming a charge storage cell, and annealed in a furnace at 1100 deg.C. An insulating layer 5 in 0.4mum is shaped through the annealing while an silicon layer in the surface brought to an amorphous state by implanting oxygen ions displays complete crystallizability by in-phase growth. As ions are implanted to form an N-type lower-side plate 4 in the charge storage cell, and a firm insulating layer 3 and an upper-side plate 2 consisting of polycrystalline silicon in the upper section of the layer 3 are shaped. The insulating layer 5 is formed, thus inhibiting spread to the side of the P-type silicon substrate 1 of a depletion layer shaped on the lower side of the charge storage cell. |
