| 摘要 |
PURPOSE:To save one etching process by a method wherein, after an impurity is implanted into a part from which the part of a silicon nitride film formed on a substrate is removed by photoetching, a thick oxide film is formed on that part and the other impurity is implanted into the other part. CONSTITUTION:On the surface of a thin silicon oxide film 103 formed on a semiconductor substrate 102, a silicon nitride film 101 is formed. After a part of the silicon nitride film 101 is removed by photoetching, impurity ions 105 are implanted. Then a thick oxide film 106 is formed on a part where the silicon nitride film does not exist. At that time, in accordance with oxidation conditions, the implanted impurity ions 105 are diffused by heat to form an impurity diffused layer 107. Then, after the silicon nitride film 101 is removed, impurity ions 108 are implanted. With this constitution, different impurity diffused layers 107 and 109 can be formed by one photoetching process in a self- alignment manner.
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