| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technology for preventing degradation in superposition precision in a photoengraving process. <P>SOLUTION: A groove 7 used as an alignment mark and grooves 17 and 27 constituting an element isolation structure are formed in a surface 80. A substrate 1 is prepared in which a polysilicon film 3 is so formed on the surface 80 as to avoid the grooves 7, 17, and 27. The grooves 7, 17, and 27 are filled with an insulating film 30. The insulating film 30 is selectively etched so that the insulating film 30 in the groove 7 is partially removed while the insulating film 30 on a side surface 81 and a bottom surface 82 of the groove 7 is left out. The polysilicon film 3 is selectively etched using the insulating film 30 in the groove 7 as a protection film. Since the insulating film 30 in the groove 7 is used as a protection film, the shape of the groove 7 is not changed even if the substrate 1 is etched. Thus, the precision in superposition in a photoengraving process is prevented from degrading. <P>COPYRIGHT: (C)2003,JPO</p> |
