JP2892415B

PURPOSE:To improve electric characteristic without increasing a contact resistance by forming a P type layer by diffusing boron from a BSG pattern containing high concentration of boron, forming an N type layer with the pattern as a mask material, and forming the P type and N type layers in a self-alignment manner. CONSTITUTION:After a P type implantation layer 17 is formed, boron in a BSG pattern 16 is diffused in a semiconductor substrate 11 directly under the pattern 16 to form a P type layer 19, and a P type layer 18 is simultaneously formed. Then, with a polysilicon film 13 and the pattern 16 as mask materials arsenic is implanted into a P-type layer made of the layers 19 and 18 by an ion implanting method, and annealed to form an N type layer 20. Then, the pattern 16 is removed by etching, an intermediate insulating film 21 is formed, a contact hole 22 is so opened as to reach the part of the layer 20 and the layer 18 in an opening 14, and a source electrode 23 of metal is formed via the hole 22. Thus, a contact is satisfactorily obtained to improve electric characteristics.