Method for inspecting pattern defects

A method for inspecting pattern defects, the method comprising:

• forming groups of a plurality of patterns over an underlying layer, the plurality of patterns being electrically isolated from each other;
• charging the plurality of patterns by scanning only a part of a first group of the plurality of patterns with an electron beam to find a defect;
• obtaining an intensity of secondary electrons emitted from the scanned part of the first group of the plurality of patterns;
• searching one or more of the plurality of patterns in the first group only the part of which are scanned and which show an intensity of the secondary electrons different from others of the plurality of patterns only the part of which are scanned in the first group, by comparing the intensity of the secondary electrons of the first group of the plurality of patterns with each other;
• when one of the plurality of patterns showing the intensity of the secondary electrons different from others of the plurality of patterns is found, obtaining a location of the one of the plurality of patterns;
• and
• scanning a part of a second group of the plurality of pattern with the electron beam to find a defect, wherein:
• during the scanning the part of the first group of the plurality of patterns, the electron beam does not scan the defect, the plurality of patterns comprise line-and-space patterns having a plurality of line patterns disposed spaced apart from each other, and the plurality of line patterns are more conductive than the underlying layer,
• scanning only the part of the first group of the plurality of patterns with an electron beam is performed in a skipped manner, and
• the skipped manner includes performing an odd line-pattern scanning and performing an even line-pattern scanning, wherein the odd line-pattern scanning and the even line-pattern scanning are performed along a same path within the part of the first group of the plurality of patterns.

A test device for detecting a defect, comprising:

• an underlying layer disposed over a substrate;
• a plurality of line patterns electrically isolated from each other disposed over the underlying layer;
• and
• a frame pattern surrounding the plurality of line patterns and electrically isolated from the plurality of line patterns, wherein:
• the plurality of line patterns and the frame pattern are more conductive than the underlying layer, and
• the plurality of line patterns includes at least one of a defect that is a broken line pattern or a defect that is a bridge of adjacent line patterns.