Patent Document ID: 20100035369
Application ID: 12537296
Patent Status: 0

Claim One:
1. A method for measuring a fraction of unreacted polycrystalline silicon (polysilicon) in a sample of an integrated circuit (IC) with fully silicided (FUSI) gates, comprising the steps of: deprocessing said sample to remove nickel silicide, further comprising the steps of: exposing said sample to an oxidizing solution such that nickel in said nickel silicide is oxidized; and exposing said sample to an etching solution such that said nickel silicide is removed; generating an SEM sample image of said sample by scanning electron microscopy (SEM), such that said SEM sample image includes gate areas; acquiring a mask image from said SEM sample image in which said gate areas are easily distinguished from non-gate areas; applying said mask image to said SEM sample image to produce a masked sample image in which image information from said gate areas in said SEM sample image is included in said masked sample image and information from said non-gate areas in said SEM sample image is not included in said masked sample image; filtering and inverting a contrast of said masked sample image to produce an inverted filtered masked sample image in which regions corresponding to unreacted polysilicon are assigned a first attribute and all other regions are assigned a second attribute; and computing said fraction of unreacted polysilicon by a process further comprising the steps of: quantifying an area in said inverted filtered masked sample image with said first attribute; quantifying an area in said mask image of said gate areas; and dividing said area with said first attribute by said area of said gate areas.