Laser process with controlled polarization

Abstract

A laser system includes a laser configured to provide a laser beam and a laser delivery assembly including a waveplate. The laser delivery assembly is positioned to receive the laser beam from the laser and direct the laser beam toward a substrate to facilitate forming a separation line within the substrate along a process path. An instantaneous direction of the process path relative to a direction of a crystalline plane of the substrate defines a process path angle. The laser delivery assembly is configured to selectively rotate at least one of the waveplate or the substrate to control a polarization angle of the laser beam based on (i) an instantaneous direction of polarization of the laser beam and (ii) the process path angle.

1 . A laser system comprising:
 a laser configured to provide a laser beam; and   a laser delivery assembly including a waveplate;   wherein the laser delivery assembly is positioned to receive the laser beam from the laser and direct the laser beam toward a substrate to facilitate forming a separation line within the substrate along a process path;   wherein an instantaneous direction of the process path relative to a direction of a crystalline plane of the substrate defines a process path angle; and   wherein the laser delivery assembly is configured to selectively rotate at least one of the waveplate or the substrate to control a polarization angle of the laser beam based on (i) an instantaneous direction of polarization of the laser beam and (ii) the process path angle.   
     
     
         2 . The laser system of  claim 1 , wherein the laser delivery assembly is configured to selectively rotate the at least one of the waveplate or the substrate such that the polarization angle and the process path angle are the same along at least a portion of the process path such that the instantaneous direction of the process path and the instantaneous direction of polarization are parallel. 
     
     
         3 . The laser system of  claim 1 , wherein the laser delivery assembly is configured to selectively rotate the at least one of the waveplate or the substrate such that the polarization angle and the process path angle are different along at least a portion of the process path such that the instantaneous direction of the process path and the instantaneous direction of polarization are non-parallel. 
     
     
         4 . The laser system of  claim 1 , wherein the separation line includes a plurality of laser-induced channels positioned at a plurality of spaced apart locations. 
     
     
         5 . The laser system of  claim 4 , wherein the laser system is configured to selectively rotate the at least one of the waveplate or the substrate based on (i) the instantaneous direction of polarization of the laser beam and (ii) the process path angle of the instantaneous direction of the process path relative to the direction of the crystalline plane of the substrate to prevent the formation of microcracks between adjacent laser-induced channels. 
     
     
         6 . The laser system of  claim 4 , wherein the laser system is configured to selectively rotate the at least one of the waveplate or the substrate based on (i) the instantaneous direction of polarization of the laser beam and (ii) the process path angle of the instantaneous direction of the process path relative to the direction of the crystalline plane of the substrate to cause the formation of microcracks between adjacent laser-induced channels. 
     
     
         7 . The laser system of  claim 1 , wherein the laser delivery assembly includes a motion device positioned to facilitate rotating the waveplate. 
     
     
         8 . The laser system of  claim 1 , wherein the laser delivery assembly includes a base configured to support the substrate, wherein the base is at least one of a movable base or a stationary base. 
     
     
         9 . The laser system of  claim 1 , wherein the substrate is at least partially transparent to the laser beam. 
     
     
         10 . A laser system comprising:
 a laser delivery assembly including a waveplate;   wherein the laser delivery assembly is positioned to receive a laser beam from a laser and direct the laser beam toward a substrate to facilitate forming a separation line within the substrate along a process path;   wherein an instantaneous direction of the process path relative to a direction of a crystalline plane of the substrate defines a process path angle; and   wherein the laser delivery assembly is configured to selectively rotate at least one of the waveplate or the substrate to control a polarization angle of the laser beam based on (i) an instantaneous direction of polarization of the laser beam and (ii) the process path angle.   
     
     
         11 . The laser system of  claim 10 , wherein the laser delivery assembly is configured to selectively rotate the at least one of the waveplate or the substrate such that the polarization angle and the process path angle are the same along at least a portion of the process path such that the instantaneous direction of the process path and the instantaneous direction of polarization are parallel. 
     
     
         12 . The laser system of  claim 10 , wherein the laser delivery assembly is configured to selectively rotate the at least one of the waveplate or the substrate such that the polarization angle and the process path angle are different along at least a portion of the process path such that the instantaneous direction of the process path and the instantaneous direction of polarization are non-parallel. 
     
     
         13 . The laser system of  claim 10 , wherein the substrate is at least partially transparent to the laser beam. 
     
     
         14 . The laser system of  claim 10 , wherein the separation line includes a plurality of laser-induced channels positioned at a plurality of spaced apart locations. 
     
     
         15 . The laser system of  claim 14 , wherein the laser system is configured to selectively rotate the at least one of the waveplate or the substrate based on (i) the instantaneous direction of polarization of the laser beam and (ii) the process path angle to prevent the formation of microcracks between adjacent laser-induced channels. 
     
     
         16 . The laser system of  claim 14 , wherein the laser system is configured to selectively rotate the at least one of the waveplate or the substrate based on (i) the instantaneous direction of polarization of the laser beam and (ii) the process path angle to cause the formation of microcracks between adjacent laser-induced channels. 
     
     
         17 . The laser system of  claim 10 , wherein the laser delivery assembly includes a base configured to support the substrate, wherein the base is at least one of a movable base or a stationary base. 
     
     
         18 . The laser system of  claim 10 , wherein the laser delivery assembly includes a motion device positioned to facilitate selectively rotating the waveplate. 
     
     
         19 . A laser system comprising:
 a laser; and   a laser delivery assembly including a waveplate;   wherein the laser delivery assembly is positioned to receive a laser beam from the laser and direct the laser beam toward a substrate to facilitate forming a separation line within the substrate along a process path; and   wherein the laser delivery assembly is configured to selectively rotate at least one of the waveplate or the substrate to control a polarization angle of the laser beam based on (i) an instantaneous direction of polarization of the laser beam, (ii) an instantaneous direction of the process path, and (iii) a direction of a crystalline plane of the substrate.   
     
     
         20 . The laser system of  claim 19 , wherein the separation line includes a plurality of laser-induced channels positioned at a plurality of spaced apart locations, and wherein the laser delivery assembly is configured to selectively rotate the at least one of the waveplate or the substrate to (i) selectively prevent the formation of microcracks between adjacent laser-induced channels and (ii) selectively cause the formation of the microcracks between the adjacent laser-induced channels.