Method for mask and substrate alignment

Abstract

Methods and apparatuses for aligning masks with substrates are provided. A method can include receiving a carrier having a substrate disposed thereon at an alignment stage of an alignment module, transferring a mask from a mask cassette of a mask stocker of the alignment module to a position over the alignment stage, and positioning the mask on the carrier. The method also includes acquiring one or more images of the mask and the substrate, where the mask contains one or more alignment holes passing through the mask and the substrate contains one or more alignment elements disposed on an upper surface of the substrate, analyzing the one or more images to determine one or more differences between one or more alignment holes of the mask and one or more alignment elements of the substrate, and aligning the mask with the substrate based on the differences.

What is claimed is: 
     
         1 . A method for aligning a mask with a substrate, comprising:
 receiving a carrier having the substrate disposed on a surface of the carrier at an alignment stage of an alignment module, wherein the substrate comprises an alignment element disposed on an upper surface of the substrate;   transferring, via a transfer robot, the mask from a mask cassette of a mask stocker of the alignment module to a position over the alignment stage, wherein the mask comprises an alignment hole passing through the mask, and wherein the alignment hole has a diameter of about 50 μm to about 2,000 μm; and   positioning the mask on the carrier.   
     
     
         2 . The method of  claim 1 , further comprising:
 acquiring one or more images of the mask and the substrate;   analyzing the one or more images to determine one or more differences between the alignment hole and the alignment element; and   aligning the mask with the substrate based on the one or more differences.   
     
     
         3 . The method of  claim 2 , wherein aligning the mask with the substrate further comprises moving the alignment stage to adjust a position of the substrate with respect to the mask. 
     
     
         4 . The method of  claim 3 , wherein aligning the mask with the substrate further comprises aligning the alignment hole with the alignment element. 
     
     
         5 . The method of  claim 4 , wherein aligning the mask with the substrate further comprises aligning two or more alignment holes with two or more alignment elements, each alignment hole is aligned with a respective alignment element. 
     
     
         6 . The method of  claim 4 , wherein the alignment hole has a diameter of about 250 μm to about 750 μm. 
     
     
         7 . The method of  claim 4 , wherein the diameter of the alignment hole is greater than the diameter of the alignment element. 
     
     
         8 . The method of  claim 4 , wherein the alignment hole is radially positioned between a pattern in the mask and a substrate exclusion zone of the substrate. 
     
     
         9 . The method of  claim 1 , wherein the alignment element comprises a marking, a dot, a pattern, a line, an edge, a corner, or combinations thereof. 
     
     
         10 . The method of  claim 1 , wherein the alignment element has a diameter of about 50 μm to about 2,000 μm. 
     
     
         11 . The method of  claim 1 , wherein the alignment element comprises a pattern and has a diameter of about 250 μm to about 750 μm. 
     
     
         12 . The method of  claim 1 , further comprising:
 receiving the carrier carrying the substrate and the mask at the alignment stage;   catching the mask with the transfer robot; and   moving the alignment stage vertically away from the transfer robot to disengage the mask from the carrier.   
     
     
         13 . A method for aligning a mask with a substrate, comprising:
 receiving a carrier having the substrate disposed on a surface of the carrier at an alignment stage of an alignment module;   transferring the mask from a mask cassette of a mask stocker of the alignment module to a position over the alignment stage;   positioning the mask on the carrier;   acquiring one or more images of the mask and the substrate, wherein the mask comprises one or more alignment holes passing through the mask and the substrate comprises one or more alignment elements disposed on an upper surface of the substrate, wherein the alignment hole has a diameter of about 50 μm to about 2,000 μm, and wherein the diameter of the alignment hole is greater than the diameter of the alignment element;   analyzing the one or more images to determine one or more differences between one or more alignment holes of the mask and one or more alignment elements on the substrate; and   aligning the mask with the substrate based on the one or more differences.   
     
     
         14 . The method of  claim 13 , wherein the alignment element comprises a marking, a dot, a pattern, a line, an edge, a corner, or combinations thereof, and wherein the alignment element has a diameter of about 50 μm to about 2,000 μm. 
     
     
         15 . The method of  claim 13 , wherein the alignment element comprises a pattern and has a diameter of about 250 μm to about 750 μm. 
     
     
         16 . An alignment module for aligning a mask with a substrate, comprising:
 a mask stocker configured house a mask cassette configured to store a plurality of masks;   an alignment stage configured to support a carrier and a substrate;   a transfer robot configured to transfer a mask of the plurality of masks from the mask stocker to the alignment stage and position the mask over the substrate; and   a controller configured to control the system to:
 receive the carrier having the substrate disposed on a surface of the carrier at the alignment stage of the alignment module, wherein the substrate comprises an alignment element disposed on an upper surface of the substrate; 
 transfer, via the transfer robot, the mask from a mask cassette of a mask stocker of the alignment module to a position over the alignment stage, wherein the mask comprises an alignment hole passing through the mask, and wherein the alignment hole has a diameter of about 50 μm to about 2,000 μm; 
 position the mask on the carrier by moving the alignment stage vertically toward the transfer robot to position the mask on the carrier; 
 acquire one or more images of the mask and the substrate; 
 analyzing the one or more images to determine one or more differences between the alignment hole and the alignment element; and 
 align the mask with the substrate based on the one or more differences by moving the alignment stage to adjust a position of the substrate with respect to the mask. 
   
     
     
         17 . The alignment module of  claim 16 , wherein each alignment hole has a diameter of about 100 μm to about 1,000 μm, and wherein the mask is aligned with the substrate by respectively aligning each alignment hole with each alignment element. 
     
     
         18 . The alignment module of  claim 16 , wherein the mask comprises three or more alignment holes and the substrate comprises three or more alignment elements. 
     
     
         19 . The alignment module of  claim 16 , wherein the alignment element comprises a marking, a dot, a pattern, a line, an edge, a corner, or combinations thereof. 
     
     
         20 . The alignment module of  claim 16 , wherein the alignment element has a diameter of about 50 μm to about 2,000 μm.