Method and apparatus for forming patterned photoresist layer

Abstract

A method for forming a patterned photoresist layer aligned with a predetermined layer is described. A photoresist layer is formed on a substrate and then exposed. The overlay offset between the exposed portions of the photoresist layer and the predetermined layer is measured for determining whether the exposed portions of the photoresist layer are aligned with the predetermined layer. A development step is performed when the exposed portions of the photoresist layer are found to align with the predetermined layer. An apparatus for forming a patterned photoresist layer is also described, which utilizes the aforementioned method and has a mechanism capable of feeding back the overlay offset in real time for reducing the cycle time and the rework time in the lithography process.

1 - 7 . (canceled)  
   
   
       8 . An apparatus for forming a patterned photoresist layer, being used to form a patterned photoresist layer aligned with a predetermined wafer layer and comprising: 
 a photoresist coating tool for coating a photoresist layer on a substrate;    an exposure/overlay-measurement tool for exposing the photoresist layer to form a latent image therein and for measuring an overlay offset between the latent image and the predetermined layer;    a development tool for developing the photoresist layer; and    a substrate carrying tool connected between the photoresist coating tool, the exposure/overlay-measurement tool and the development tool.    
   
   
       9 . The apparatus of  claim 8 , further comprising a photoresist removal tool that is connected with the exposure/overlay-measurement tool via the substrate carrying tool.  
   
   
       10 . The apparatus of  claim 9 , wherein the photoresist removal tool is connected with the photoresist coating tool via the substrate carrying tool.  
   
   
       11 . The apparatus of  claim 9 , wherein the substrate carrying tool carries the substrate to the photoresist removal tool or the development tool according to the overlay offset value.  
   
   
       12 . The apparatus of  claim 8 , wherein the exposure/overlay-measurement tool comprises: 
 an exposure module for forming a latent image in the photoresist layer; and    an overlay measurement module for measuring the overlay offset between the latent image and the predetermined layer and for feeding back a control signal generated based on the overlay offset to the exposure module.    
   
   
       13 . The apparatus of  claim 12 , wherein the exposure module comprises: 
 an exposure light source disposed over the substrate; and    a photomask disposed between the exposure light source and the substrate.    
   
   
       14 . The apparatus of  claim 12 , wherein the overlay measurement module comprises: 
 a laser light source for scanning the latent image in the photoresist layer;    a signal reception device for receiving a test signal generated from the laser scanning that contains information of the overlay offset; and    a signal feedback device for generating the control signal based on the test signal and for feeding back the control signal to the exposure module.