Characterization of semiconductor resist material during processing

Claim 1

A method for evaluating the quality of a semiconductor resist material produced by a softbake process, that contains a solute and a solvent and that is deposited as a substantially planar film on a substrate, the method comprising the steps of: determining the absorption a=1-e - α.sbsp.o L .sbsp.o (L o =single pass optical path length in the film of interest, if any) and absorption coefficient (αL) o of the substrate surface before the coat process begins, through a measurement of Total Reflectivity of the substrate surface for a predetermined wavelength λ, predetermined incidence angle θ 1 and known index of refraction of the substrate; depositing a resist film on the substrate at an estimated predetermined thickness; determining the thickness of the resist film through a measurement of Total Reflectivity of the resist film at each of a sequence of one or more predetermined wavelengths λ 1 , λ 2 , . . . , λ r at a sequence of one or more predetermined film incidence angles θ 1 ,1, θ 1 ,2, . . . , θ 1 ,s (with r+s≧3); determining the absorption of a=1-e - αL of the resist film after the coat process and before completion of the softbake process through a measurement of Total Reflectivity of the resist film for a predetermined wavelength λ, predetermined film incidence angle θ 1 , and predetermined film thickness h; forming the quantity Δ=αL-(αL) o for each of the sequenmce of combinations of substrate and resist film deposited thereon; comparing the value of Δ for each such combination with a predetermined target value Δ t ; performing the softbake process for each such combination; forming the quantity ρ=h/Δ for each of the sequence of combinations of substrate and resist film deposited thereon; and comparing the value of ρ for each such combination with a predetermined target value ρ t .

Claim 2

A method for evaluating the quality of a semiconductor resist material produced by a softbake process, that contains a solute and a solvent and that is deposited as a substantially planar film on a substrate, the method comprising the steps of: determining the absorption a=1-e - α.sbsp.o L .sbsp.o (L o =single pass optical path length in the film of interest, if any) and absorption coefficient (αL) o of the substrate surface before the coat process begins, through a measurement of Total Reflectivity of the substrate surface for a predetermined wavelength λ, predetermined incidence angle θ 1 and known index of refraction of the substrate; depositing a resist film on the substrate at an estimated predetermined thickness; determining the thickness of the resist film through a measurement of Total Reflectivity of the resist film at each of a sequence of one or more predetermined wavelengths λ 1 , λ 2 , . . . , λ r at a sequence of one or more predetermined film incidence angles θ 1 ,1, θ 1 ,2, . . . , θ 1 ,s (with r+s≧3); determining the absorption of a=1-e - αL of the resist film after the coat process and before completion of the softbake process through a measurement of Total Reflectivity of the resist film for a predetermined wavelength λ, predetermined film incidence angle θ 1 , and predetermined film thickness h; forming the quantity Δ=αL-(αL) o for each of the sequenmce of combinations of substrate and resist film deposited thereon; comparing the value of Δ for each such combination with a predetermined target value Δ t ; performing the softbake process for each such combination; forming the quantity ρ=h/Δ for each of the sequence of combinations of substrate and resist film deposited thereon; and comparing the value of ρ for each such combination with a predetermined target value ρ t .

Claim 7

A method for evaluating the quality of a semiconductor resist material, produced by a softbake process, that contains a solute and a solvent and that is deposited as a substantially planar film on a substrate, the method comprising the steps of: determining the absorption a=1-e - α.sbsp.o L .sbsp.o (L o =single pass optical path length in the film of interest, if any) and absorption coefficient (αL) o of the substrate surface before the coat process begins, through a measurement of Total Transmissivity of the substrate surface for a predetermined wavelength λ, predetermined incidence angle θ 1 and known index of refraction of the substrate; depositing a resist film on the substrate at an estimated predetermined thickness; determining the thickness of the resist film through a measurement of Total Reflectivity of the resist film at each of a sequence of one or more predetermined wavelengths λ 1 , λ 2 , . . . , λ r at a sequence of one or more predetermined film incidence angles θ 1 ,1, θ 1 ,2, . . . θ 1 ,s (with r+s≧3); determining the absorption a=1-e - αL of the resist film after the coat process and before completion of the softbake process through a measurement of Total Transmissivity of the resist film for a predetermined wavelength λ, predetermined film incidence angle θ 1 , and predetermined film thickness h; forming the quantity Δ=αL-(αL) o for each of the sequence of combinations of substrate and resist film deposited thereon; comparing the value of Δ for each such combination with a predetermined target value Δ t ; performing the softbake process for each such combination; forming the quantity ρ=h/Δ for each of the sequence of combinations of substrate and resist film deposited thereon; and comparing the value of ρ for each such combination with a predetermined target value ρ t .

Claim 8

A method for evaluating the quality of a semiconductor resist material, produced by a softbake process, that contains a solute and a solvent and that is deposited as a substantially planar film on a substrate, the method comprising the steps of: determining the absorption a=1-e - α.sbsp.o L .sbsp.o (L o =single pass optical path length in the film of interest, if any) and absorption coefficient (αL) o of the substrate surface before the coat process begins, through a measurement of Total Transmissivity of the substrate surface for a predetermined wavelength λ, predetermined incidence angle θ 1 and known index of refraction of the substrate; depositing a resist film on the substrate at an estimated predetermined thickness; determining the thickness of the resist film through a measurement of Total Reflectivity of the resist film at each of a sequence of one or more predetermined wavelengths λ 1 , λ 2 , . . . , λ r at a sequence of one or more predetermined film incidence angles θ 1 ,1, θ 1 ,2, . . . θ 1 ,s (with r+s≧3); determining the absorption a=1-e - αL of the resist film after the coat process and before completion of the softbake process through a measurement of Total Transmissivity of the resist film for a predetermined wavelength λ, predetermined film incidence angle θ 1 , and predetermined film thickness h; forming the quantity Δ=αL-(αL) o for each of the sequence of combinations of substrate and resist film deposited thereon; comparing the value of Δ for each such combination with a predetermined target value Δ t ; performing the softbake process for each such combination; forming the quantity ρ=h/Δ for each of the sequence of combinations of substrate and resist film deposited thereon; and comparing the value of ρ for each such combination with a predetermined target value ρ t .