JPS644019A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce the required number of masks and to shorten a manufacturing process by a method wherein a patterning operation to form an alignment mask and another patterning operation to form a first bell region are executed simultaneously. CONSTITUTION:A silicon oxide layer 2 to be used as a film is formed on a silicon substrate 1 by a thermal oxidation method, a CVD method or the like; a first resist layer 3 to form an alignment mask and a well region is formed on the layer. Then, by a patterning operation using a mask I first openings 4 acting as alignment masks and a second opening 5 to form a first well region are made in the first resist layer 3. An impurity of, e.g., boron or the like is introduced into the silicon substrate 1 through these openings 4, 5; impurity regions 6 are formed directly under the first openings 4 and a p-well region 7 is formed directly under the second opening 5. By using this process, a mask and a resist layer which are used exclusively to form the alignment masks are not required; the process is simplified; the resist layer can be used effectively.