Defect detection method of semiconductor wafer patterns

Claim 1

A method of detecting essentially opaque defects in an image pattern on a reticle used to define an additional layer on an image die, which is one of a plurality of mutiple reproduced dice in a substrate, the defects resulting from contamination of the image pattern on the reticle, the image die being compared to a reference die which is another of the plurality of multiple reproduced dice in the substrate; the method comprising the steps of: forming the image on the reticle from stored data: applying a photo-sensitive resist to the substrate over at least the image die and the reference die; exposing the photo-sensitive resist on the image die to the reticle image pattern; blanket exposing the resist on the reference die to exclude additional layer; developing the exposed photo-sensitive resist; dividing each of the dice into pixels; and recording the light levels from equally illuminated corresponding pixels of the image die and the reference die; the method characterized by: utilizing the stored design data to exclude from inspection the areas defining the image pattern: comparing the recorded levels from said reference die with those from said image die of the non-excluded areas; and detecting a defect whenever the two levels differ by a predefined amount.

Claim 2

A method of detecting essentially opaque defects in an image pattern on a reticle used to define an additional layer on an image die, which is one of a plurality of mutiple reproduced dice in a substrate, the defects resulting from contamination of the image pattern on the reticle, the image die being compared to a reference die which is another of the plurality of multiple reproduced dice in the substrate; the method comprising the steps of: forming the image on the reticle from stored data: applying a photo-sensitive resist to the substrate over at least the image die and the reference die; exposing the photo-sensitive resist on the image die to the reticle image pattern; blanket exposing the resist on the reference die to exclude additional layer; developing the exposed photo-sensitive resist; dividing each of the dice into pixels; and recording the light levels from equally illuminated corresponding pixels of the image die and the reference die; the method characterized by: utilizing the stored design data to exclude from inspection the areas defining the image pattern: comparing the recorded levels from said reference die with those from said image die of the non-excluded areas; and detecting a defect whenever the two levels differ by a predefined amount.