| 摘要 |
PURPOSE:To make a drain size to small and to make a CCD to be formed in high density when an overflow drain to constitute a solid-state image sensing device is to be formed by a method wherein an insulating film is adhered on a semiconductor substrate, an Si film containing impurities to constitute a solid phase diffusion source is provided thereon, and heat treatment is performed to make impurities to be diffused through the insulating film. CONSTITUTION:An SiO2 film 32 is adhered on a P type semiconductor substrate 31, a polycrystalline Si film 33 containing As atoms is made to grow thereon, a photo resist film 34 is applied thereon, and the film is made to remain only on the region to form the overflow drain by the photoetching method. At this time, a positive photo resist is used for the film 34, and breadth of the remaining film 34 is formed as smaller than mask size L. Then the Si layer 33 is made to remain only at the lower part of the film 34 by etching to make the other part to be removed, and heat treatment is performed to make impurities in the layer 33 to be diffused in the substrate 31 through the film 32 to make and N<++> type layer 35 to constitute the drain to be generated. Accordingly diffusion in the lateral direction of the layer 35 is not generated, the layer 35 having minute size can be obtained, and density of drawing element is increased to enhance sensitivity. |
