1. A reticle substrate comprising a pair of main surfaces opposing each other, two pairs of side faces that are right to the main surfaces and that are opposed in pair to each other, and chamfered surfaces between the main surfaces and the side faces, wherein:
at least one of the main surfaces has a flatness not greater than 0.5 \u03bcm on a flatness measuring area which is laid inside of an intermediate area of 3 mm located within a boundary between the at least one main surface and the chamfered surface;
the boundary between the at least one main surface and the chamfered surface has a maximum height between \u22121 and 0 \u03bcm (excluding 0 \u03bcm) from a reference surface determined in relation to the flatness measuring area disposed inside of the intermediate area; and
the intermediate area between the flatness measuring area and the chamfered surface is declined or lowered from the flatness measuring area towards the chamfered surface.
2. A mask blank comprising a thin film for a transfer pattern, on the at least one of the main surfaces of the reticle substrate according to claim 1.
3. The mask blank according to claim 2, wherein the thin film has a film stress of 0.5 Gpa or less.
4. The mask blank according to claim 2 or 3, wherein the flatness is not greater than 0.5 \u03bcm on a flatness measuring area of the main surface on which the thin film is formed, with the intermediate area of 3 mm which is laid inwardly from the boundary between the main surface and the chamfered surface and which is exempted from the flatness measuring area, while the boundary between the main surface and the chamfered surface has the maximum height between \u22121 and 0 \u03bcm from the reference surface determined in relation to the flatness measuring area laid inside of the intermediate area; and
wherein:
the intermediate area between the flatness measuring area and the chamfered surface is lowered from the flatness measuring area towards the chamfered surface.
5. A method for manufacturing the reticle substrate according to claim 1, characterized by the steps of:
grinding and precisely polishing a main surface of a reticle substrate;
thereafter measuring a surface configuration of the main surface on an area that includes a substrate peripheral portion to be supported by a substrate-holding member of an exposure apparatus; and
modifying the surface configuration of the main surface on the basis of a result of the measurement so that the surface configuration of the main surface becomes a desired shape, by finding that an area of the main surface is convex relative to an optionally determined reference plane, by providing, on the area, a pressure higher than the other areas onto polishing pads of a polishing apparatus, with a polishing liquid being supplied towards the polishing pads, and by moving the reticle substrate relative to the polishing pads.
6. The method for manufacturing the reticle substrate according to claim 5, wherein the above-mentioned precisely polishing step comprises:
a roughly polishing process of removing surface defects of the substrate while maintaining the flatness obtained in the grinding process by using a relatively large abrasive grain; and
a mirror-polishing process of polishing the surface of the substrate for mirror finish by using a relatively small abrasive grain.
7. A method for manufacturing the mask blank by forming a thin film as a transfer pattern on a main surface of the reticle substrate manufactured by the method according to claim 5 or 6.
8. The method for manufacturing the mask blank according to claim 7, comprising:
a heating process of suppressing that change of the maximum height from the reference plane which appears during or after the forming of the thin film, at the boundary between the main surface and the chamfered surface, the heating process being carried out before and after the forming of the thin film.
9. A reticle substrate comprising a pair of main surfaces opposing each other, two pairs of side faces right to the main surfaces wherein the two side faces of each pair opposing each other, and chamfered surfaces between the main surfaces and the side faces, wherein:
at least one of the main surfaces has a flatness not greater than 0.5 \u03bcm on a flatness measuring area which is laid inside of an intermediate area of 3 mm located within a boundary between the main surface and the chamfered surface;
while a boundary between the flatness-measuring area and a flatness non-measuring area has a maximum height between \u22121 and 0 \u03bcm from a reference surface determined in relation to the flatness measuring area laid inside of the intermediate area; and
wherein:
the intermediate area between the flatness measuring area and the chamfered surface is lowered from the flatness measuring area towards the chamfered surface.
10. A mask blank comprising a thin film functioning as a transfer pattern formed on at least one of the main surfaces of the reticle substrate according to claim 9.
11. The mask blank according to claim 10, wherein the thin film has a film stress of 0.5 Gpa or less.
12. The mask blank according to claim 10 or 11, wherein the flatness is not greater than 0.5 \u03bcm on a flatness measuring area of the main surface on which the thin film is formed, with the intermediate area of 3 mm which is laid inwardly from the boundary between the main surface and the chamfered surface and which is exempted from the flatness measuring area, while the boundary between the flatness measuring area and the flatness non-measuring area has the maximum height between \u22121 and 0 \u03bcm from the reference surface determined in relation to the flatness measuring area laid inside of the intermediate area; and
wherein:
the intermediate area between the flatness measuring area and the chamfered surface is lowered from the flatness measuring area towards the chamfered surface.
13. A method for manufacturing the reticle substrate according to claim 9, characterized by the steps of:
grinding and precisely polishing a main surface of a reticle substrate;
thereafter measuring a surface configuration of the main surface on an area that includes a substrate peripheral portion to be supported by a substrate-holding member of an exposure apparatus; and
modifying the surface configuration of the main surface on the basis of a result of the measurement so that the surface configuration of the main surface becomes a desired shape, by finding that an area of the main surface is convex relative to an optionally determined reference plane, by providing, on the area, a pressure higher than the other areas onto polishing pads of a polishing apparatus, with a polishing liquid being supplied towards the polishing pads, and by moving the reticle substrate relative to the polishing pads.
14. The method for manufacturing the reticle substrate according to claim 13, wherein the above-mentioned precisely polishing step comprises:
a roughly polishing process of removing surface defects of the substrate while maintaining the flatness obtained in the grinding process by using a relatively large abrasive grain; and
a mirror-polishing process of polishing the surface of the substrate for mirror finish by using a relatively small abrasive grain.
15. A method for manufacturing the mask blank by forming a thin film as a transfer pattern on a main surface of the reticle substrate manufactured by the method according to claim 13 or 14.
16. The method for manufacturing the mask blank according to claim 15, comprising:
a heating process of suppressing that change of the maximum height from the reference plane which appears during or after the forming of the thin film, at the boundary between the main surface and the chamfered surface, the heating process being carried out before and after the forming of the thin film.
17. The reticle substrate according to claim 1, wherein:
the flatness measuring area has a flatness not greater than 0.25 \u03bcm while the boundary between the main surface and the chamfered area has a maximum height between \u22120.5 \u03bcm and 0 \u03bcm relative to the reference surface.
18. The reticle substrate according to claim 9, wherein:
the flatness measuring area has a flatness not greater than 0.25 \u03bcm while a boundary between the flatness measuring area and the flatness non-measuring area has a maximum height between \u22120.5 \u03bcm and 0 \u03bcm relative to the reference surface.
19. The method for manufacturing the reticle substrate according to claim 5, wherein the modifying step is carried out so that a desired relationship could be accomplished between a flatness of the flatness measuring area and a declined degree of the intermediate between the flatness measuring area and the chamfered area.
20. The method for manufacturing the reticle substrate according to claim 13, wherein the modifying step is carried out so that a desired relationship could be accomplished between a flatness of the flatness measuring area and a declined degree of the intermediate between the flatness measuring area and the chamfered area.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An adjustable manhole installation comprising:
a first generally tubular member having an outer surface, and a first plurality of cooperative height-adjusting engagement elements spaced apart on its external circumference and fixed on the outer surface;
a second generally tubular member, having an internal diameter greater than the external diameter of the first generally tubular member such that the first member fits concentrically within the second member, the second member further having an interior surface having a second complimentary plurality of cooperative height-adjusting engagement elements spaced apart on its internal circumference and fixed thereon for cooperative engagement with the first plurality of engagement elements;
the first generally tubular member being held generally concentrically within the second generally tubular member by the engagement of the first plurality of height-adjusting engagement elements with the second plurality of height-adjusting engagement elements.
2. The adjustable manhole installation of claim 1 wherein the first and second generally tubular members each comprises a top rim, and when the first tubular member is held concentrically within the second tubular member, the top rim of the first tubular member extends higher than the top rim of the second tubular member.
3. The adjustable manhole installation of claim 1 wherein the first tubular member is of a shorter length than the second tubular member.
4. The adjustable manhole installation of claim 1 wherein the tubular members are comprised of cast iron.
5. The adjustable manhole installation of claim 4 wherein each of the plurality of engagement elements of the tubular members is fixed to a tubular member by fasteners.
6. The adjustable manhole installation of claim 4 wherein each engagement element is cast simultaneously with the tubular member in a unitary casting.
7. The adjustable manhole installation of claim 1 wherein the tubular members are comprised of cast concrete.
8. The adjustable manhole installation of claim 7 wherein each of the plurality of engagement elements of the tubular members is fixed to a tubular member by fasteners.
9. The adjustable manhole installation of claim 7 wherein each engagement element is cast simultaneously with the tubular member in a unitary casting.
10. The adjustable manhole installation of claim 1 wherein each engagement element is affixed to a tubular shaped member with an adhesive.
11. The adjustable manhole installation of claim 1 wherein each engagement element comprises a thin flange formed into a series of steps and risers.
12. The adjustable manhole installation of claim 1 wherein each engagement element comprises a block element placed into a stair-shaped formation.
13. The adjustable manhole installation of claim 1 wherein each engagement element comprises a thin generally horizontal flange and each tubular member has a series of thin generally horizontal flanges, each series of flanges being spaced generally in parallel orientation generally vertically on the cooperating walls of the respective tubular members in a manner similar to the rungs of a ladder such that at least one of the flanges of the series of flanges on the first tubular member engages at least one of the flanges of the series of flanges on the second tubular member.
14. The adjustable manhole installation of claim 1 wherein each engagement element comprises gear-teeth-shaped support elements, which engage each other in a manner similar to the meshing of gears in a machine.
15. An adjustable manhole installation comprising:
a first generally tubular member having an outer surface, and a first plurality of stair-shaped elements spaced apart on its external circumference and fixed on the outer surface;
a second generally tubular member having an internal diameter greater than the external diameter of the first generally tubular member such that the first member fits concentrically within the second member, the second member further having an interior surface having a second complimentary plurality of stair-shaped elements spaced apart on its internal circumference and fixed thereon for cooperative engagement with the first plurality of stair-shaped elements;
the first generally tubular member being held generally concentrically within the second generally tubular member by the engagement of the first plurality of stair-shaped elements with the second plurality of stair-shaped elements.
16. The adjustable manhole installation of claim 15 wherein the first and second generally tubular members each comprises a top rim, and when the first tubular member is held concentrically within the second tubular member, the top rim of the first tubular member extends higher than the top rim of the second tubular member.
17. The adjustable manhole installation of claim 15 wherein the first tubular member is of a shorter length than the second tubular member.
18. The adjustable manhole installation of claim 15 wherein the tubular members are comprised of cast iron.
19. The adjustable manhole installation of claim 18 wherein each of the plurality of stair-shaped elements of the tubular members is fixed to a tubular member by fasteners.
20. The adjustable manhole installation of claim 18 wherein the respective stair-shaped elements and generally tubular members are a unitary casting.
21. The adjustable manhole installation of claim 15 wherein each stair-shaped element is affixed to a tubular shaped member with an adhesive.
22. The adjustable manhole installation of claim 15 wherein each stair-shaped element comprises a thin flange formed into a series of steps and risers.
23. An adjustable manhole installation comprising:
a first generally tubular member having an outer surface, and a first plurality of block-shaped supports arranged in a stair-shaped formation spaced apart on its external circumference and fixed on the outer surface;
a second generally tubular member having an internal diameter greater than the external diameter of the first generally tubular member such that the first member fits concentrically within the second member, the second member further having an interior surface having a second complimentary plurality of block-shaped supports spaced apart on its internal circumference and fixed thereon for cooperative engagement with the first plurality of block-shaped supports;
the first generally tubular member being held generally concentrically within the second generally tubular member by the engagement of the first plurality of block-shaped supports with the second plurality of block-shaped supports.
24. The adjustable manhole installation of claim 23 wherein the first and second generally tubular members each comprises a top rim, the second tubular member being adjustable relative to the second tubular member such that the top rim of the second tubular member is moveable relative to the top rim of the first tubular member.
25. An adjustable manhole installation for use at and below the surface of the ground or a road surface, comprising:
a first tubular member having a top surface, an outer surface and a first series of stair-shaped elements about its outer surface;
a second tubular member having an internal diameter greater than the external diameter of the first tubular member, further having an interior surface and a corresponding second series of stair-shaped elements about the interior surface;
the first tubular member fitting generally concentrically within the second tubular member so that the first series of stair-shaped elements engages the second series of stair-shaped elements such that the first tubular member can be set at a desired height relative to the ground or road surface;
the first tubular member being adjustable, within the second tubular member such that the second tubular member can be raised or lowered, within the first tubular member, relative to the ground or road surface, in graduated steps.
26. The manhole installation of claim 25 wherein the first and second tubular members are constructed of cast iron and the stair-shaped elements are cast integrally with the tubular members.
27. The manhole installation of claim 25 wherein the first and second tubular members each comprise several series of stair-shaped elements such that the stair-shaped elements are substantially about the entire inner circumference of the first tubular member and the outer circumference of the second tubular member.
28. A method of adjusting a manhole installation to level its opening with a ground or road surface, including the steps of:
providing a manhole installation having a first tubular member having an interior surface, and a second tubular member having a smaller diameter than the diameter of the first tubular member and an exterior surface;
providing a plurality of stair-shaped support elements, spaced apart, on both the interior surface of the first tubular member and the exterior surface of the second tubular member;
placing the second tubular member within the first tubular member at a desired height within the first tubular member; and,
rotating the second tubular member, within the first tubular member, to cooperatively engage the stair-shaped elements of the first tubular member with the stair-shaped elements of the second tubular member.
29. The method of adjusting a manhole installation of claim 28, including the step of lifting and rotating the second tubular member, within the first tubular member, engaging the stair shaped support elements of the second tubular member with different stair shaped support elements of the first tubular member such that a new desirable height for the second tubular member is set, when the ground surface level has been changed.
30. The method of adjusting a manhole installation of claim 28, including the step of providing a top rim on the second tubular member such that the top rim is placed at the ground surface level.