Semiconductor device and manufacturing method thereof
First Claim
1. A method of manufacturing a semiconductor device having a memory cell region and a peripheral region, comprising the steps of:
- forming an alignment mark for positioning made of a conductive material, in said peripheral region;
forming a first insulating film so as to cover said alignment mark and extend to said memory cell region;
forming a second insulating film on said first insulating film;
forming a third insulating film on said second insulating film, said third insulating film having a low etching rate in relation to a first etchant for said first insulating film;
forming an opening portion so as to extend through said third and second insulating films up to said first insulating film;
forming a spacer on the side wall of said opening portion, said spacer having a low etching rate in relation to said first etchant for said first insulating film;
forming a first contact hole so as to extend through said first insulating film, using said third insulating film and said spacer as masks;
filling said opening portion and said first contact hole with a first conductive material to form a contact plug; and
selectively removing said third insulating film using a second etchant whose etching rate to said second insulating film is low.
3 Assignments
0 Petitions
Accused Products
Abstract
A semiconductor device comprises a first insulating film formed over a semiconductor substrate, a second insulating film formed on the first insulating film, a contact plug made of a conductive material vertically penetrating the first and second insulating films and extending on the second insulating film, and a conductor film in contact with the upper surface of the contact plug and part of the second insulating film. This construction makes it possible to form minute via-holes in a mass-production line without increasing parasitic capacity, increasing the number of manufacturing steps, and generating defects.
25 Citations
8 Claims
-
1. A method of manufacturing a semiconductor device having a memory cell region and a peripheral region, comprising the steps of:
-
forming an alignment mark for positioning made of a conductive material, in said peripheral region; forming a first insulating film so as to cover said alignment mark and extend to said memory cell region; forming a second insulating film on said first insulating film; forming a third insulating film on said second insulating film, said third insulating film having a low etching rate in relation to a first etchant for said first insulating film; forming an opening portion so as to extend through said third and second insulating films up to said first insulating film; forming a spacer on the side wall of said opening portion, said spacer having a low etching rate in relation to said first etchant for said first insulating film; forming a first contact hole so as to extend through said first insulating film, using said third insulating film and said spacer as masks; filling said opening portion and said first contact hole with a first conductive material to form a contact plug; and selectively removing said third insulating film using a second etchant whose etching rate to said second insulating film is low. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
Specification