| 摘要 |
PURPOSE:To microscopically form a transistor by a method wherein, when the well of a C-MOS type transistor is formed, an impurity layer to be used for prevention of a punch-through which is formed in the vicinity of a well boundary is formed in a self- matching manner, thereby enabling to reduce the width of the field oxide film located on the circumference of the well. CONSTITUTION:An Si3N4 film 22 is deposited on the whole surface of a high specific resistance Si substrate 21, an Al film 30 is coated thereon, a resist pattern 23 which defines a well region is provided on said Al film in such a manner that the resist pattern 23 is put aside to one side, the films 22 and 30 which are not covered by the resist pattern 23 are removed by performing an etching, and the surface of the substrate 21 is exposed. Then, a P-ion is implanted on the whole surface, an ion-implanting layer 25 to be turned to an N-well region is generated in the substrate 21, the pattern 23 is removed, and an SiO2 film is grown on the region spreading from the exposed film 30 to the layer 25 by performing a plasma CVD method. Subsequently, the stepping part of a film 27 is removed by dipping the above into the aqueous solution by hydrofluoric acid, and a P type ion implantation layer 27 to be used for prevention of a punch- through is formed along the layer 25 located in the substrate 21 utilizing the part where the stepping part is removed. |
