Photosensitive coating material for a substrate

Abstract

A radiation-sensitive coating material, in addition to a base polymer, has a solvent and a radiation-active substance which forms an acid on irradiation by light (including energetic electrons or ions), a fluorescent substance which alters its fluorescence property subject to a change in the acid content of its surroundings. In a process for exposing a substrate coated with the coating material at least one sensor in the exposure chamber of the exposure apparatus measures the intensity of the change in fluorescence spectrum as a function of time during the exposure operation. From the course of intensity at the time of an individual line of the fluorescence spectrum or the intensity integrated over a wavelength interval it is possible to determine the endpoint of the exposure operation by way of electronic algorithms. Deviations from experimentally determined ideal curves of the intensity course provide information on erroneous functions in the course of coating material application and exposure.

1 . A photosensitive coating material for coating a substrate, comprising: 
 a base polymer;    a solvent;    a photoactive substance forming an acid upon irradiation with light; and    a fluorescent substance surrounded by at least one material and having a fluorescence property, the fluorescence property of said fluorescent substance changing in dependence on an acid fraction present in said at least one material.    
   
   
       2 . The photosensitive coating material according to  claim 1 , wherein the fluorescence property designates a spectrum of the light re-emitted by said fluorescent substance.  
   
   
       3 . The photosensitive coating material according to  claim 1 , wherein the fluorescence property designates an intensity of the light re-emitted by said fluorescent substance.  
   
   
       4 . The photosensitive coating material according to  claim 1  implemented as a chemically amplified coating material.  
   
   
       5 . The photosensitive coating material according to  claim 1  configured as a coating material sensitive for wavelengths of less than 157 nanometers.  
   
   
       6 . The photosensitive coating material according to  claim 1  formed with molecular chains, and wherein said photoactive substance and said fluorescent substance are parts of common molecular chains.  
   
   
       7 . A radiation-sensitive coating material for coating a substrate, comprising: 
 a base polymer;    a solvent;    a radiation-active substance forming an acid upon irradiation with energetic radiation; and    a fluorescent substance having a fluorescence property, said fluorescent substance changing a fluorescence in dependence on an acid fraction present in a material surrounding said fluorescent substance.