Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
182 words
An X-Y-ϑ stage assembly (10;230;260), characterized by a base (18); an X-Y-ϑ stage (11;231), respectively, movable along orthogonal X and Y axes and rotatable about an orthogonal third axis in ϑ-direction; drive means (14) for moving the X-Y-ϑ stage; and first, second and third interferometers (72,74,76; 72',74',76';292,294,296), the first, second and third interferometers being utilized for providing first, second and third signals, respectively, indicative of distances (X,Y1,Y2; M1,M2,N;U,V,W) to first, second and third X-Y-ϑ stage mounted retroreflectors (78,80,82;78',80', 82';262,264,266) for indicating the location of the X-Y-ϑ stage along the X and Y axes and in the ϑ-direction, the first, second and third interferometers being mounted upon first and second or first, second and third transport means (100,106;242,244;304,308,312) which are responsive to first circuit means (228;228') for providing optical coupling between the interferometers and the retroreflectors; and second circuit means (132;256;333) for causing the X-Y-ϑ stage to move to a preselected position along the X and Y axes and in the ϑ-direction at preselected velocities in response to values and time rates of change of values of the first, second and third signals.
Claim 2
Dependent Claim
182 words
An X-Y-ϑ stage assembly (10;230;260), characterized by a base (18); an X-Y-ϑ stage (11;231), respectively, movable along orthogonal X and Y axes and rotatable about an orthogonal third axis in ϑ-direction; drive means (14) for moving the X-Y-ϑ stage; and first, second and third interferometers (72,74,76; 72',74',76';292,294,296), the first, second and third interferometers being utilized for providing first, second and third signals, respectively, indicative of distances (X,Y1,Y2; M1,M2,N;U,V,W) to first, second and third X-Y-ϑ stage mounted retroreflectors (78,80,82;78',80', 82';262,264,266) for indicating the location of the X-Y-ϑ stage along the X and Y axes and in the ϑ-direction, the first, second and third interferometers being mounted upon first and second or first, second and third transport means (100,106;242,244;304,308,312) which are responsive to first circuit means (228;228') for providing optical coupling between the interferometers and the retroreflectors; and second circuit means (132;256;333) for causing the X-Y-ϑ stage to move to a preselected position along the X and Y axes and in the ϑ-direction at preselected velocities in response to values and time rates of change of values of the first, second and third signals.
Claim 3
Dependent Claim
45 words
An assembly as in claim 1, characterized in that the transport means (100,106) are movable along orthogonal surfaces (104,110), respectively, to define the X and Y axes, respectively, for the X-Y-ϑ stage assembly (10) by utilizing the orthogonal surfaces as a metrological standard of orthogonality.
Claim 4
Dependent Claim
59 words
An X-Y-ϑ stage assembly (230) as in claim 1, characterized in that the transport means (242,244) are movable along angularly spaced guideways (250,254) to define a Y axis that bisects the angle between the guideways, and a precisely orthogonal X axis for the X-Y-stage assembly (230) by utilizing the sine and cosine, respectively, of half the angle between them.
Claim 5
Dependent Claim
143 words
An X-Y-ϑ stage assembly (260) as in claim 1, characterized in that the transport means (304,308,312) are movable about fourth, fifth and sixth axes, respectively, wherein the fourth, fifth and sixth axes are each parallel to the third axis, and further wherein the second circuit means (333) is utilized for repetitively calculating values and time rates of change in values of the distances (U,V,W) in response to the preselected position and preselected velocities along the orthogonal X and Y axes and in the ϑ-direction and is further utilized for repetitively calculating additional signals utilized by the drive means (14) for moving the X-Y-ϑ stage (261) in response to error signals resulting from differences between the calculated values and time rates of change in values of the distances (U,V,W) and the actual values and time rates of change in values of the distances (U,V,W).
Claim 6
Dependent Claim
31 words
An assembly as in one of claims 1 to 4, characterized in that the stage element (12) is movable by an X-, Y-, ϑ-linear motor (14) relative to the base (18).
Claim 7
Dependent Claim
29 words
An assembly as in one of claims 1 to 5, characterized in that the stage element (12) is supported by means of gas bearings (16) on said base (18).
Claim 8
Dependent Claim
15 words
An assembly as in claim 6, characterized in that three gas bearings (16) are provided.
Claim 9
Dependent Claim
38 words
Use of an assembly as claimed in one of claims 1 to 7 to step and position a semiconductive wafer (13) which is held on the stage element (12) under an imaging lens of a step- and repeat-camera.