Patent ID: 7906351
Filing Date: 2011-03-15
Classification: C09K,G01N,H01L

Abstract:
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: 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: