Method and apparatus for positioning patterns of a photographic mask on the surface of a wafer on the basis of backside patterns of the wafer

Claim 3

A method as claimed in claim 1, in which said angle of incidence of the illumination light for said metal-plated patterns of said wafer is adjusted to the angle at which the image of said metal-plated patterns of said wafer is most clearly observed.

Claim 4

Apparatus for positioning patterns of a photographic mask on the top surface of a wafer with reference to metal-plated patterns on the underside of said wafer, comprising a pair of object lenses disposed in a face-to-face relation and aligned along a common extended axis, means for supporting a patterned mask on the top side of said underside patterned wafer and for disposing said mask and wafer at an intervening position between said aligned object lenses, first and second reflection mirror means disposed on the image side and transverse to the optical axis of each of said object lenses for respectively reflecting the projecting images from said object lenses, semi-transparent mirror means for combining said images from said object lenses, an eyepiece lens for enlarging the combined image from said semi-transparent mirror means, a first light source projecting a light beam for illuminating said photographic mask along the optical axis of the object lens which faces the mask, second light source means spaced from said optical axis of the other object lens which faces the wafer for directly illuminating said wafer underside patterns, and means for adjusting the relative position of said photographic mask on said wafer, said adjusting means having means for temporarily fixing said photographic mask on said wafer in a contacting condition.

Claim 5

Apparatus for positioning patterns of a photographic mask on the top surface of a wafer with reference to metal-plated patterns on the underside of said wafer, comprising a pair of object lenses disposed in a face-to-face relation and aligned along a common extended axis, means for supporting a patterned mask on the top side of said underside patterned wafer and for disposing said mask and wafer at an intervening position between said aligned object lenses, first and second reflection mirror means disposed on the image side and transverse to the optical axis of each of said object lenses for respectively reflecting the projecting images from said object lenses, semi-transparent mirror means for combining said images from said object lenses, an eyepiece lens for enlarging the combined image from said semi-transparent mirror means, a first light source projecting a light beam for illuminating said photographic mask along the optical axis of the object lens which faces the mask, second light source means spaced from said optical axis of the other object lens which faces the wafer for directly illuminating said wafer underside patterns, and means for adjusting the relative position of said photographic mask on said wafer, said adjusting means having means for temporarily fixing said photographic mask on said wafer in a contacting condition.

Claim 6

Apparatus as claimed in claim 3, further comprising means for adjusting the position of said second light source means.

Claim 7

Apparatus as claimed in claim 3, in which said means for disposing the underside patterned wafer at an interveining position between said object lenses includes a glass plate for receiving said wafer thereon.

Claim 8

Apparatus as claimed in claim 3, wherein said second light source means for said wafer underside patterns comprises at least one lamp spaced from said common axis of said object lenses.

Claim 9

Apparatus as claimed in claim 3, further comprising means for removing said wafer and mask from their intervening position between said object lenses, wHile said photographic mask is temporarily fixed to said wafer by said adjusting means removing said wafer and mask from their intervening position between said object lenses.

Claim 10

Appparatus as claimed in claim 3, wherein said second light source means for said wafer underside portions is a circular lamp.

Claim 11

Apparatus for positioning patterns of a phototgraphic mask on the top surface of a wafer with reference to metal-plated patterns on the underside of the wafer, comprising left and right pairs of upper and lower object lenses, said lenses of each respective pair disposed in a face-to-face aligned position and arranged side by side with the other said pair of lenses with an equal space between the lenses of each said pair, means for supporting a patterned mask on the top side of an underside-patterned wafer and for disposing said mask and wafer at an intermediate position in said space between the lenses of said pairs of lenses, a first means for illuminating said patterned mask along optical axes of said right and left upper object lenses, a second illuminating means disposed off said optical axes of said right and left lower object lenses for directly illuminating the underside of said patterned wafer, means for projecting images from said object lenses, means for combining said images from each respective pair of said object lenses, means for adjusting the relative position of said photographic mask on said wafer, a pair of eyepiece lenses, means for collecting said combined images in the visual field of said eyepiece lenses so that the left half area of said visual field of each eyepiece lens receives the combined image of said left pair of object lenses, while the right half area of said visual fiedl of each eyepiece lens recives the combined image of said right pair of object lenses.

Claim 12

Apparatus for positioning patterns of a phototgraphic mask on the top surface of a wafer with reference to metal-plated patterns on the underside of the wafer, comprising left and right pairs of upper and lower object lenses, said lenses of each respective pair disposed in a face-to-face aligned position and arranged side by side with the other said pair of lenses with an equal space between the lenses of each said pair, means for supporting a patterned mask on the top side of an underside-patterned wafer and for disposing said mask and wafer at an intermediate position in said space between the lenses of said pairs of lenses, a first means for illuminating said patterned mask along optical axes of said right and left upper object lenses, a second illuminating means disposed off said optical axes of said right and left lower object lenses for directly illuminating the underside of said patterned wafer, means for projecting images from said object lenses, means for combining said images from each respective pair of said object lenses, means for adjusting the relative position of said photographic mask on said wafer, a pair of eyepiece lenses, means for collecting said combined images in the visual field of said eyepiece lenses so that the left half area of said visual field of each eyepiece lens receives the combined image of said left pair of object lenses, while the right half area of said visual fiedl of each eyepiece lens recives the combined image of said right pair of object lenses.

Claim 13

Apparatus as claimed in claim 9, in which said collecting means comprises a first common prism means disposed at a position for reflecting images from said object lenses so that the images from said right object lenses are reflected toward the right hand side while the images from said left object lenses are reflected toward the left hand side, a second common prism means disposed at a position for refelcting images from said first common prism means toward said eyepiece lenses so that said images reflected by said second common prism means are in the visible field of each of said eyepiece lenses, means for reflecting the images reflected by said first common prism means towards said second prism means, and means for separately reflecting the respective left and right combined images reflected by said second common prism means towards said eyepiece lenses.

Claim 14

Apparatus as claimed in claim 10, in which said means for separately reflecting said respective combined left and right images reflected from said second common prism means towards said eyepiece lenses includes two semi-reflecting mirrors positioned side-by-side.

Claim 15

Apparatus as claimed in claim 9, in which said adjusting means includes means for temporarily fixing said photographic mask to said wafer in an aligned position, and further comprising means for moving said adjusting means to remove said mask and wafer from their intervening position between said object lenses.