There is provided a technique for improving the flatness at the surface of members embedded in a plurality of recesses without resulting in an increase in the time required for the manufacturing processes. According to this technique, the dummy patterns can be placed up to the area near the boundary BL between the element forming region DA and dummy region FA by placing the first dummy pattern DP.sub.1 of relatively wider area and the second dummy pattern DP.sub.2 of relatively small area in the dummy region FA. Thereby, the flatness of the surface of the silicon oxide film embedded within the isolation groove can be improved over the entire part of the dummy region FA. Moreover, an increase of the mask data can be controlled when the first dummy patterns DP.sub.1 occupy a relatively wide region among the dummy region FA.
This application is a Continuation Application of U.S. application Ser. No. 11/430,983, filed May 10, 2006 now U.S. Pat. No. 7,411,302, which, in turn, is a Continuation of U.S. application Ser. No. 10/748,139, filed Dec. 31, 2003, now U.S. Pat. No. 7,071,560, and which, in turn, is a Divisional of U.S. application Ser. No. 09/985,309, filed Nov. 2, 2001, now U.S. Pat. No. 6,693,315; and the entire disclosures of which are incorporated herein by reference.
