Positive type photosensitive resin composition and method for forming resist pattern

Abstract

A liquid or a solid positive type photosensitive resin composition is herein disclosed which is used under the irradiation circumstance of a safelight having a maximum wavelength within the range of 500 to 620 nm, wherein an absorbancy of an unexposed film formed from this composition is 0.5 or less within the range of the maximum wavelength ±30 nm selected from the range of the maximum wavelength of the safelight; and a method for forming a resist pattern is also disclosed which comprises (1) a step of applying a positive type photosensitive resin composition onto a substrate to form a photosensitive film thereon, (2) a step of exposing the photosensitive film so as to obtain a desired pattern, and (3) a step of performing a developing treatment to form a resist pattern, wherein at least one step of the steps (1) to (3) is carried out under the irradiation circumstance of the safelight having a high spectral luminous efficiency in which the maximum wavelength of an emission spectrum of a light source is within the range of 500 to 620 nm.

What is claimed is:  
     
         1 . A liquid or a solid positive type photosensitive resin composition which is used under the irradiation circumstance of a safelight having a maximum wavelength within the range of 500 to 620 nm, wherein an absorbancy of an unexposed film formed from this composition is 0.5 or less within the range of the maximum wavelength ±30 nm selected from the range of the maximum wavelength of the safelight.  
     
     
         2 . The positive type photosensitive resin composition according to    claim 1    which comprises a resin and a light acid generator for generating an acid radical by an active energy ray as essential components, the resin and the light acid generator being chemically bonded, or the resin and the light acid generator being mixed.  
     
     
         3 . The positive type photosensitive resin composition according to    claim 1    wherein the safelight is given from a discharge lamp containing sodium as a main component (which consists mainly of a D-ray having a light wavelength of 589 nm).  
     
     
         4 . A method for forming a resist pattern which comprises: 
 (1) a step of applying a positive type photosensitive resin composition onto a substrate to form a photosensitive film thereon,    (2) a step of exposing the photosensitive film formed on the substrate to a laser beam directly or through a mask film so that a desired resist pattern (an image) may be obtained on the photosensitive film, and    (3) a step of subjecting the resist film to a developing treatment to form the resist pattern on the substrate, wherein an absorbancy of an unexposed film formed from the positive type photosensitive resin composition is 0.5 or less within the range of a maximum wavelength ±30 nm selected in the range of the maximum wavelength of a safelight; and at least one step of the steps (1) to (3) is carried out under the irradiation circumstance of the safelight having a high spectral luminous efficiency in which the maximum wavelength of an emission spectrum of a light source is within the range of 500 to 620 nm.    
     
     
         5 . The method for forming the resist pattern according to    claim 4    wherein the safelight is given from a discharge lamp containing sodium as a main component (which consists mainly of a D-ray having a light wavelength of 589 nm).