PURPOSE: To reduce contact resistance by a method wherein impurities are introduced into the contact resion on the surface of a substrate, and after a heat treatment has been conducted, the area in the vicinity of the surface is removed by etching, and electrode metal is formed in such a manner that the density of activated impurities can be increased sufficiently.
CONSTITUTION: After a field oxide film has been formed on a P-type silicon substrate, arsenic ions are implanted into an isolated element region, and a heat treatment is conducted in a dry nitrogen atmosphere. The arsenic ions are diffused by the heat treatment, and a high density region 4 is formed. Subsequently, the surface of the semiconductor substrate is etched by the mixed solution of fluoric acid, acetic acid and nitric acid. A silicon oxide film is deposited by a CVD method, and a contact hole is perforated. Lastly, an aluminum electrode film 3 is deposited in the above-mentioned connection hole using a sputtering method, and an electrode wiring is formed. As a result, a contact having low contact resistance can be formed using the region having the maximum carrier density as a contact interface.
MURAKOSHI ATSUSHI
KASHIWAGI MASAHIRO
