Method for dose calculation of photolithography projection printers through bleaching of photo-active compound in a photoresist

Claim 1

A method for selecting the exposure speed of a photoresist-coated surface comprising the steps of: (a) coating a plurality of quartz wafers with a photoresist layer, and covering a portion of the coated surfaces of said quartz wafers with an optically opaque material; (b) subjecting said wafers to a plurality of exposure speeds to ultraviolet light on a photolithography production instrument; (c) determining relative percent photoactive compound bleached values by measuring and comparing the absorbance of the exposed and unexposed portions of each of said wafers; (d) plotting a curve of relative percent photoactive compound bleached values against said exposure speeds; and (e) setting an exposure speed of a photolithography instrument by determining from the curve the exposure speed corresponding to any desired relative percent photoactive compound bleached value.

Claim 2

A method for selecting the exposure speed of a photoresist-coated surface comprising the steps of: (a) coating a plurality of quartz wafers with a photoresist layer, and covering a portion of the coated surfaces of said quartz wafers with an optically opaque material; (b) subjecting said wafers to a plurality of exposure speeds to ultraviolet light on a photolithography production instrument; (c) determining relative percent photoactive compound bleached values by measuring and comparing the absorbance of the exposed and unexposed portions of each of said wafers; (d) plotting a curve of relative percent photoactive compound bleached values against said exposure speeds; and (e) setting an exposure speed of a photolithography instrument by determining from the curve the exposure speed corresponding to any desired relative percent photoactive compound bleached value.

Claim 3

A method for quantitatively determining the exposure dose associated with any exposure speed of a patterning exposure tool comprising: (a) constructing a curve by: (i) coating a plurality of quartz wafers with a photoresist layer, and covering a portion of the coated surfaces of said quartz wafers with an optically opaque material; (ii) subjecting said wafers to exposure to ultraviolet light at a plurality of exposure speeds on a photolithography production instrument; (iii) determining relative percent photoactive compound bleached values by measuring and comparing the absorbance of the exposed and unexposed portions of each of said wafers; (iv) plotting a curve of relative percent photoactive compound bleached values against said exposure speeds; and (b) constructing a calibration curve by the further steps of: (i) coating a plurality of quartz wafers with a photoresist layer, and covering a portion of the coated surfaces of said quartz wafers with an optically opaque material; (ii) subjecting said wafers to exposure to ultraviolet light at a plurality of known wavelengths and dosages; (iii) measuring the optical absorbance of exposed and unexposed portions of each of said wafers, and determining the relative percent photoactive compound bleached for each of said wafers by comparing the optical absorbance of the exposed and unexposed portions of each of said wafers; (iv) plotting said relative percent photoactive compound bleached values against said dose measured values; and (c) determining the exposure dose at any said exposure speeds by determining the relative percent photoactive compound bleached at any exposure speed from the first curve and determining the exposure dose corresponding to that relative percent photoactive compound bleached value from the calibration curve.

Claim 4

A method for quantitatively determining the exposure dose associated with any exposure speed of a patterning exposure tool comprising: (a) constructing a curve by: (i) coating a plurality of quartz wafers with a photoresist layer, and covering a portion of the coated surfaces of said quartz wafers with an optically opaque material; (ii) subjecting said wafers to exposure to ultraviolet light at a plurality of exposure speeds on a photolithography production instrument; (iii) determining relative percent photoactive compound bleached values by measuring and comparing the absorbance of the exposed and unexposed portions of each of said wafers; (iv) plotting a curve of relative percent photoactive compound bleached values against said exposure speeds; and (b) constructing a calibration curve by the further steps of: (i) coating a plurality of quartz wafers with a photoresist layer, and covering a portion of the coated surfaces of said quartz wafers with an optically opaque material; (ii) subjecting said wafers to exposure to ultraviolet light at a plurality of known wavelengths and dosages; (iii) measuring the optical absorbance of exposed and unexposed portions of each of said wafers, and determining the relative percent photoactive compound bleached for each of said wafers by comparing the optical absorbance of the exposed and unexposed portions of each of said wafers; (iv) plotting said relative percent photoactive compound bleached values against said dose measured values; and (c) determining the exposure dose at any said exposure speeds by determining the relative percent photoactive compound bleached at any exposure speed from the first curve and determining the exposure dose corresponding to that relative percent photoactive compound bleached value from the calibration curve.