Tuning substrate/resist contrast to maximize defect inspection sensitivity for ultra-thin resist in DUV lithography
First Claim
1. A method for enhancing the contrast between oxide film and ultra-thin resists on a semiconductor wafer in DUV lithography for use with a wafer defect inspection system in order to maximize defect inspection sensitivity, said method comprising the steps of:
- providing a semiconductor wafer having a standard oxide film thickness of about 1600 Å and
a standard ultra-thin resist thickness of 1000 Å
or less;
fixing said ultra-thin resist thickness; and
varying the thickness of the oxide film in order to obtain a reflectivity of the ultra-thin resist which is different from the reflectivity of the oxide film so as to produce a high contrast therebetween.
1 Assignment
0 Petitions
Accused Products
Abstract
There is provided a method for enhancing the contrast between oxide film and ultra-thin resists in deep-ultraviolet lithography for use with a wafer defect inspection system in order to maximize defect inspection sensitivity. This is achieved by varying the thickness of the oxide film for a given ultra-thin resist thickness so as to produce a high contrast. As a result, defect inspection of the ultra-thin resist pattern is easily obtained. In a second embodiment, the ultra-thin resist thickness is varied for a given oxide film thickness. In a third embodiment, both the oxide film and the ultra-thin resist thicknesses are varied simultaneously so as to obtain an optimum contrast.
-
Citations
6 Claims
-
1. A method for enhancing the contrast between oxide film and ultra-thin resists on a semiconductor wafer in DUV lithography for use with a wafer defect inspection system in order to maximize defect inspection sensitivity, said method comprising the steps of:
-
providing a semiconductor wafer having a standard oxide film thickness of about 1600 Å and
a standard ultra-thin resist thickness of 1000 Å
or less;
fixing said ultra-thin resist thickness; and
varying the thickness of the oxide film in order to obtain a reflectivity of the ultra-thin resist which is different from the reflectivity of the oxide film so as to produce a high contrast therebetween. - View Dependent Claims (2, 3, 4)
-
-
5. A method for enhancing the contrast between oxide film and ultra-thin resists on a semiconductor wafer in DUV lithography for use with a wafer defect inspection system in order to maximize defect inspection sensitivity, said method comprising the steps of:
-
providing a semiconductor wafer having a standard oxide film thickness of about 1600 Å and
a standard ultra-thin resist thickness of 1000 Å
or less;
fixing said oxide film thickness; and
varying the thickness of the ultra-thin resist in order to obtain a reflectivity of the ultra-thin resist which is different from the reflectivity of the oxide film so as to produce a high contrast therebetween.
-
-
6. A method for enhancing the contrast between oxide film and ultra-thin resists on a semiconductor wafer in DUV lithography for use with a wafer defect inspection system in order to maximize defect inspection sensitivity, said method comprising the steps of:
-
providing a semiconductor wafer having a standard oxide film thickness of about 1600 Å and
a standard ultra-thin resist thickness of 1000 Å
or less;
varying said ultra-thin resist thickness; and
varying simultaneously the thickness of the oxide film in order to obtain a reflectivity of the ultra-thin resist which is different from the reflectivity of the oxide film so as to produce a high contrast therebetween.
-
Specification