Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
237 words
The method of electrically characterizing the performance of a photolithographic exposure tool comprising the steps of: providing a substrate standard, against which said tool may be characterized, having a substantially non-conductive surface in which a first relief image pattern is defined by first and second levels on the surface of said substrate, applying a layer of selectively etchable material over the surface of the substrate, forming a second relief image pattern in said layer of selectively etchable material to expose at least portions of said first and second levels, said second relief pattern being substantially defined by imagewise expose in the exposure tool to be characterized, said first relief image pattern defining and establishing at least one edge of said second pattern to thereby determine the alignment of that second relief pattern with respect to said standard, depositing a layer of conductive material over said second relief image pattern and exposed areas of said substrate, said first relief image pattern bifurcating said deposited layer of conductive material, removing the remaining portions of said selectively etchable material and overlying portions of said conductive layer, and measuring an electrical characteristic of at least two different portions of said bifurcated conductive layer remaining on one of said first and second levels, the measured characteristic being representative of the extent to which said photolithographic tool-exposed second relief image is aligned with and bifurcated by said first relief image in said substrate.
Claim 2
Independent Claim
237 words
The method of electrically characterizing the performance of a photolithographic exposure tool comprising the steps of: providing a substrate standard, against which said tool may be characterized, having a substantially non-conductive surface in which a first relief image pattern is defined by first and second levels on the surface of said substrate, applying a layer of selectively etchable material over the surface of the substrate, forming a second relief image pattern in said layer of selectively etchable material to expose at least portions of said first and second levels, said second relief pattern being substantially defined by imagewise expose in the exposure tool to be characterized, said first relief image pattern defining and establishing at least one edge of said second pattern to thereby determine the alignment of that second relief pattern with respect to said standard, depositing a layer of conductive material over said second relief image pattern and exposed areas of said substrate, said first relief image pattern bifurcating said deposited layer of conductive material, removing the remaining portions of said selectively etchable material and overlying portions of said conductive layer, and measuring an electrical characteristic of at least two different portions of said bifurcated conductive layer remaining on one of said first and second levels, the measured characteristic being representative of the extent to which said photolithographic tool-exposed second relief image is aligned with and bifurcated by said first relief image in said substrate.
Claim 3
Dependent Claim
113 words
The method of claim 1 wherein said measurement comprises: causing a current to flow through said conductive layer, measuring the voltages between at least three selected points on said layer, and determining the distance the pattern is shifted from the center of the first image relief pattern where, said distance is: ##EQU3## where I is the applied current, ρ is the sheet resistance, L 1 is the distance between first two of said selected points, L 2 is the distance between a second two of said selected points, V 1 is the measured voltage between said first two selected points and V 2 is the measured voltage between said second two selected points.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein said substrate is formed of silicon and said non-conductive surface is silicon oxide formed thereon and said first relief image pattern is etched into said non-conductive surface.
Claim 5
Dependent Claim
33 words
The method of claim 3 wherein said selectively etchable material is a photoresist and said second relief image pattern is formed therein by exposing said photoresist to light and developing said exposed photoresist.
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein said conductive material is deposited by evaporation.
Claim 7
Dependent Claim
13 words
The method of claim 4 wherein said conductive material is deposited by sputtering.
Claim 8
Dependent Claim
75 words
A standard against which a photolithographic exposure tool can be characterized comprising: a substrate having a substantially planar surface in which a first relief image pattern is defined with first and second levels and over which a second relief image pattern is established such that said first relief image pattern defines and establishes at least one edge of said second pattern to thereby determine the alignment of that second pattern with respect to said standard.
Claim 9
Dependent Claim
75 words
A standard against which a photolithographic exposure tool can be characterized comprising: a substrate having a substantially planar surface in which a first relief image pattern is defined with first and second levels and over which a second relief image pattern is established such that said first relief image pattern defines and establishes at least one edge of said second pattern to thereby determine the alignment of that second pattern with respect to said standard.