Method for detecting a void
View Patent ↗Methods for detecting a void in an element portion of a semiconductor device having an element portion and a void detection structure are disclosed. As a part of the method, an insulating film is formed on a substrate, a plurality of holes is formed in the insulating film, and a metal portion is formed on the insulating film to fill the plurality of holes. The metal portion is polished until the insulating film is exposed and a recessed portion is formed in the void detection structure. It is determined if a void exists in the element portion of the semiconductor device by determining whether or not a void is exposed at a surface of the recessed portion of the void detection structure.
1. A method for detecting a void in an element portion of a semiconductor device having an element portion and a void detection structure, comprising the steps of:
forming an insulating film on a substrate;
forming a plurality of holes in the insulating film;
forming a metal portion on the insulating film to fill the plurality of holes;
polishing the metal portion until the insulating film is exposed and a recessed portion is formed in the void detection structure; and
determining if a void exists in the element portion of the semiconductor device by determining whether or not a void is exposed at a surface of the recessed portion of the void detection structure.
2. The method of claim 1 , wherein in the step of forming a plurality of holes, the plurality of holes are formed so that an area occupancy of a total area viewed from the top of a plurality of holes in the void detection structure to an area viewed from the top of the void detection structure becomes larger than that of the area viewed from the top of a plurality of holes in the element portion to the area viewed from the top of the element portion.
3. The method of claim 1 , wherein in the step of forming a plurality of holes, the plurality of the holes are formed so that each cross-sectional shape of a plurality of holes of the void detection structure is the same as that of a plurality of holes of the element portion.
4. The method of claim 1 , wherein in the step of forming a plurality of holes, a plurality of holes are formed in the void detection structure in a line pattern or a dotted pattern.
5. The method of claim 1 , wherein the insulating film includes an inter-layer insulating film, and the metal portion includes a via plug.
6. The method of claim 1 , wherein the insulating film includes an inter-layer insulating film, and the metal portion includes an interconnection layer and a via plug.
7. The method of claim 1 , wherein the insulating film is formed of SiO 2 and the metal portion is formed of Cu.