Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
163 words
A method of forming a replica of an object pattern comprising transparent regions formed in an opaque background mask, said pattern comprising regions of different areas, shape and size such that when illuminated with uniform intensity light so as to produce an image of the pattern, the pattern image produced has extraneous mask induced variations in its intensity distributions due to the region configurations, said method comprising forming a compensating mask having zones of different degrees of transparency selected and arranged so that light modified by passage through said compensating mask produces a compensating image pattern having intensity variations at least partially complementary to the mask induced intensity variations in the image due to the first mask; exposing a radiation-sensitive medium to both the pattern image and the compensating image so that in the medium the mask induced intensity variations in the pattern image are at least partially compensated; and thereafter developing the medium to produce an enhanced replica of the object pattern.
Claim 2
Independent Claim
163 words
A method of forming a replica of an object pattern comprising transparent regions formed in an opaque background mask, said pattern comprising regions of different areas, shape and size such that when illuminated with uniform intensity light so as to produce an image of the pattern, the pattern image produced has extraneous mask induced variations in its intensity distributions due to the region configurations, said method comprising forming a compensating mask having zones of different degrees of transparency selected and arranged so that light modified by passage through said compensating mask produces a compensating image pattern having intensity variations at least partially complementary to the mask induced intensity variations in the image due to the first mask; exposing a radiation-sensitive medium to both the pattern image and the compensating image so that in the medium the mask induced intensity variations in the pattern image are at least partially compensated; and thereafter developing the medium to produce an enhanced replica of the object pattern.
Claim 3
Dependent Claim
16 words
A method as claimed in claim 1, comprising successively exposing the medium to the two images.
Claim 4
Dependent Claim
30 words
A method of producing a printed circuit or semi-conductor device, including forming at least one replica of an object pattern by a method as claimed in claim 1 or 2.
Claim 5
Dependent Claim
86 words
An optical projection system for projecting a desired composite image at an image plane, said system comprising a first object mask having the desired image transparency but which will result in undesirable intensity distribution at said image plane, a second, compensating mask having an image transparency that will correct for said intensity distribution at said image plane, and an optical system for projecting light through both of said transparencies to said image plane with light intensity-time exposures resulting in a desirable image at said image plane.
Claim 6
Dependent Claim
86 words
An optical projection system for projecting a desired composite image at an image plane, said system comprising a first object mask having the desired image transparency but which will result in undesirable intensity distribution at said image plane, a second, compensating mask having an image transparency that will correct for said intensity distribution at said image plane, and an optical system for projecting light through both of said transparencies to said image plane with light intensity-time exposures resulting in a desirable image at said image plane.
Claim 7
Dependent Claim
159 words
An optical projection system as claimed in claim 4-, wherein said optical system comprises an optical beam splitting member having the plane surface thereof arranged at an angle of 45° to the image plane and spaced therefrom for optical image projection thereon, one of said masks having the plane surface thereof arranged at an angle of 45° to said beam splitting member and at an angle of 90° to said image plane and aligned therewith for projecting an image onto said image plane, and the other of said masks having the plane surface thereof arranged parallel to said image plane and at an angle of 45° to said beam splitting member and aligned therewith for projecting an image through said beam splitting member and onto said image plane in registry with the image from said one mask; a source of light; and optical lens member for focusing light onto said masks for projecting the images onto said image plane.
Claim 8
Dependent Claim
34 words
An optical projection system as claimed in claim 4, wherein said other mask has the transparency thereof altered over the entire area so that the optical threshold is substantially uniform at said image plane.
Claim 9
Dependent Claim
58 words
An optical projection system as claimed in claim 4, wherein, said first mask has the lowest optical threshold for an isolated holiday, intermediate thresholds for equally divided lines and spaces, and a high threshold for an isolated opaque line, and said second mask has corresponding thresholds of inverse relationship whereby the resulting composite threshold levels are substantially equal.