Patent ID: 6172749
Filing Date: 2001-01-09
Classification: G01B,G01N,H01L

Abstract:
A method of detecting a surface condition of a wafer, comprising the steps of:applying measuring light to a wafer from a reverse side thereof such that the measuring light undergoes total reflection from a surface of the wafer in order to produce near-field leakage light on the surface of the wafer;observing a pattern of scattered light generated by said nearfield leakage light;detecting a surface condition phenomena of the wafer based on the observed pattern of scattered light; andcomparing predetermined patterns of scattered light with the observed pattern of scattered light in order to identify the surface condition phenomenon, wherein said comparing step comprises the steps of,comparing the observed pattern of scattered light to a predetermined pattern corresponding to a fine particle on the surface of the wafer,comparing the observed pattern of scattered light to a predetermined pattern corresponding to a surface irregularity of the surface of the wafer, andcomparing the observed pattern of scattered light to a predetermined pattern corresponding to an IC pattern trench.