Patent ID: 8987013
Filing Date: 2015-03-24
Classification: G01R,H01L

Abstract:
1. A method of inspecting misalignment of a polysilicon gate, comprising the following steps in the sequence set forth: providing a test wafer and defining a plurality of first active areas and a plurality of second active areas on the test wafer, wherein the plurality of first active areas and the plurality of second active areas horizontally extend in a first direction and each adjacent two of the plurality of first active areas and the plurality of second active areas are isolated from each other by an isolation structure; implanting P-type ions without using a photoresist mask to form a P-well in each of the plurality of first active areas and the plurality of second active areas; forming a plurality of first polysilicon gates above a surface of the test wafer, wherein the plurality of first polysilicon gates horizontally extend in a second direction perpendicular to the first direction and each has a first end above one of the plurality of first active areas and a second end above a corresponding one of the plurality of second active areas; implanting N-type ions without using a photoresist mask to form an N-type implantation region in each P-well; forming one or more first contact electrodes on each N-type implantation region of the plurality of first active areas and forming one or more second contact electrodes on each N-type implantation region of the plurality of second active areas; and performing electrical defect inspection on each first contact electrode and on each second contact electrode using an advanced electron beam inspection tool in a positive mode, wherein if both a first contact electrode near a first end of one of the plurality of first polysilicon gates and a second contact electrode near a second end of said one of the plurality of first polysilicon gates appear bright in an image generated from the advanced electron beam inspection tool, and the bright first contact electrode and the bright second contact electrode are on a same side of said one of the plurality of first polysilicon gates, then said one of the plurality of first polysilicon gates is identified as misaligned.