Method and system for adaptively controlling a laser-based material processing process and method and system for qualifying same

Abstract

A method and system for adaptively controlling a laser-based material processing process are provided. The system includes sensing equipment to measure a process variable or condition of at least one of a laser-based material processing system and a workpiece processed by the material processing system and to provide a corresponding measurement signal. The control system also includes a signal processor for processing the measurement signal to obtain a processed signal which initiates, at least semi-automatically, an action associated with at least one of the material processing system and the workpiece. A method and system for at least semi-automatically qualifying a laser-based material processing system which delivers laser energy to locations on or adjacent a plurality of microstructures formed on a workpiece to at least partially process the microstructures are also provided.

1 . A method for adaptively controlling a laser-based material processing process, the method comprising: 
 automatically sensing a process variable or condition of at least one of a laser-based material processing system and a workpiece processed by the system and providing a corresponding measurement signal; and    processing the measurement signal to obtain a processed signal which initiates, at least semi-automatically, an action associated with at least one of the system and the workpiece.    
     
     
         2 . The method as claimed in  claim 1 , wherein the method is an adaptive control method for human operator-in-the-loop systems and wherein the processed signal semi-automatically initiates the action.  
     
     
         3 . The method as claimed in  claim 1 , wherein the workpiece includes a semiconductive substrate and wherein the step of sensing senses at least one defect of the substrate.  
     
     
         4 . The method as claimed in  claim 1 , wherein the step of sensing is performed optically.  
     
     
         5 . The method as claimed in  claim 1 , wherein the action controls laser pulse energy delivered to a target structure on the workpiece.  
     
     
         6 . The method as claimed in  claim 1 , wherein the system delivers at least one focused laser pulse to the workpiece and the step of sensing measures at least one of average laser power, peak pulse power, pulse width, spot diameter, spot shape, spot centering, focus and wavelength.  
     
     
         7 . The method as claimed in  claim 1 , wherein the action directs or otherwise affects laser repair operations.  
     
     
         8 . The method as claimed in  claim 1 , wherein the step of sensing includes the step of imaging the workpiece at a plurality of different magnifications and wherein the step of sensing senses a condition of the workpiece at each of the plurality of different magnifications to provide corresponding measurement signals.  
     
     
         9 . The method as claimed in  claim 1 , wherein the system is a laser-based memory repair system, wherein the workpiece includes links to be cut by the system and wherein the step of sensing includes the step of obtaining images of the cut links at various locations and wherein the step of processing processes the images to perform at least one of the following: verify that correct links were cut, determine cut quality and allow a human operator of the system to classify and quantify cut quality.  
     
     
         10 . The method as claimed in  claim 1 , wherein the step of sensing is performed with an AOI subsystem to obtain image data and wherein the method further comprises the steps of: receiving reference image data and comparing the reference image data with the image data obtained with the AOI subsystem to classify defects of the workpiece.  
     
     
         11 . The method as claimed in  claim 1 , wherein the action is automatic adjustment of at least one of a temporal characteristic and a spatial characteristic of a laser pulse generated by the system.  
     
     
         12 . The method as claimed in  claim 1  further comprising: receiving a human operator-generated input and processing the input wherein the processed input and the measurement signal are processed to obtain the processed signal to thereby semi-automatically initiate the action.  
     
     
         13 . The method as claimed in  claim 1  further comprising: receiving a machine-generated input and processing the input wherein the processed input and the measurement signal are processed to obtain the processed signal to thereby automatically initiate the action.  
     
     
         14 . The method as claimed in  claim 1 , wherein the step of processing includes the steps of processing the measurement signal to obtain data and inputting the data into a pattern recognition subsystem.  
     
     
         15 . The method as claimed in  claim 14 , wherein the pattern recognition subsystem is trainable and includes a neural network.  
     
     
         16 . The method of  claim 1 , wherein the step of sensing includes measuring laser-to-link alignment with a vision subsystem to detect a systematic alignment error or change in the alignment and wherein the action includes halting laser material processing if the error or change exceeds a predetermined value.  
     
     
         17 . The method of  claim 16 , wherein the action includes execution of a diagnostic program to detect the source of the alignment error or change.  
     
     
         18 . A control system for adaptively controlling a laser-based material processing process, the system comprising: 
 sensing equipment to measure a process variable or condition of at least one of a laser-based material process system and a workpiece processed by the material processing system and to provide a corresponding measurement signal; and    a signal processor for processing the measurement signal to obtain a processed signal which initiates, at least semi-automatically, an action associated with at least one of the material processing system and the workpiece.    
     
     
         19 . The control system as claimed in  claim 18 , wherein the control system is a human-in-the-loop system and wherein the processed signal semi-automatically initiates the action.  
     
     
         20 . The control system as claimed in  claim 18 , wherein the workpiece includes a semiconductive substrate and wherein the sensing equipment senses at least one defect of the substrate.  
     
     
         21 . The control system as claimed in  claim 18 , wherein the sensing equipment includes optical sensing equipment.  
     
     
         22 . The control system as claimed in  claim 18 , wherein the action controls laser pulse energy delivered to a target structure on the workpiece.  
     
     
         23 . The control system as claimed in  claim 18 , wherein the material processing system delivers at least one focused laser pulse to the workpiece and the sensing equipment measures at least one of average laser power, peak pulse power, pulse width, spot diameter, spot shape, spot centering, focus and wavelength.  
     
     
         24 . The control system as claimed in  claim 18 , wherein the action directs or otherwise affects laser repair operations.  
     
     
         25 . The control system as claimed in  claim 18 , wherein the sensing equipment includes an imager for imaging the workpiece at a plurality of different magnifications and wherein the sensing equipment measures a condition of the workpiece at each of the plurality of different magnifications to provide corresponding measurement signals.  
     
     
         26 . The control system as claimed in  claim 18 , wherein the material processing system is a laser-based memory repair system, wherein the workpiece includes links to be cut by the system and wherein the sensing equipment obtains images of the cut links at various locations and wherein the signal processor processes the images to perform at least one of the following: verify that correct links were cut, determine cut quality and allow an operator of the repair system to classify and quantify cut quality.  
     
     
         27 . The control system as claimed in  claim 18 , wherein the sensing equipment includes an AOI subsystem to obtain image data and wherein the control system further comprises means for receiving reference image data and means for comparing the reference image data with the image data obtained with the AOI subsystem to classify defects of the workpiece.  
     
     
         28 . The control system as claimed in  claim 18 , wherein the action is automatic adjustment of at least one of a temporal characteristic and a spatial characteristic of a laser pulse generated by the material processing system.  
     
     
         29 . The control system as claimed in  claim 18  further comprising a user interface for receiving a human operator-generated input and a processor for processing the input wherein the processed input and the measurement signal are processed to obtain the processed signal to thereby semi-automatically initiate the action.  
     
     
         30 . The control system as claimed in  claim 18  further comprising means for receiving a machine-generated input and a processor for processing the input wherein the processed input and the measurement signal are processed to obtain the processed signal to thereby automatically initiate the action.  
     
     
         31 . The control system as claimed in  claim 18 , wherein the signal processor processes the measurement signal to obtain data and wherein the control system includes a pattern recognition subsystem which receives the data.  
     
     
         32 . The control system as claimed in  claim 31 , wherein the pattern recognition subsystem is trainable and includes a neural network.  
     
     
         33 . The control system as claimed in  claim 18 , wherein the sensing equipment includes a vision subsystem for measuring laser-to-link alignment to detect a systematic alignment error or change in the alignment and wherein the action includes halting laser material processing if the error or change exceeds a predetermined value.  
     
     
         34 . The control system as claimed in  claim 33 , wherein the action includes execution of a diagnostic program to detect the source of the alignment error or change.  
     
     
         35 . A method for at least semi-automatically qualifying a laser-based material processing process, the method comprising: 
 using a laser-based material processing system to deliver laser energy to locations on or adjacent a plurality of microstructures formed on a workpiece to at least partially process the microstructures;    automatically sensing a process variable or condition of at least one of the system and the at least partially processed microstructures and areas of the workpiece adjacent the at least partially processed microstructures and providing corresponding measurement signals; and    processing the measurement signals to obtain a processed signal which, at least semi-automatically, initiates qualification of the process.    
     
     
         36 . The method as claimed in  claim 35 , wherein the system comprises a laser-based link cutting system, wherein the microstructures include a plurality of links having a pitch and wherein the processed signal represents effective spot size of the laser energy at the locations.  
     
     
         37 . The method as claimed in  claim 35 , wherein the workpiece is a test workpiece.  
     
     
         38 . The method as claimed in  claim 35 , wherein the step of sensing is performed optically.  
     
     
         39 . The method as claimed in  claim 35 , wherein the step of sensing is performed with an AOI subsystem to obtain image data.  
     
     
         40 . The method as claimed in  claim 35 , wherein the laser energy is delivered in the form of laser pulses and wherein the processed signal initiates, at least semi-automatically, adjusting at least one of temporal and spacial characteristic of the laser pulses.  
     
     
         41 . The method as claimed in  claim 35 , wherein the laser energy is delivered in the form of focused laser pulses and wherein the processed signal initiates, at least semi-automatically, adjusting at least one of average laser power, peak pulse power, pulse width, spot-diameter, spot shape, spot centering, focus and wavelength.  
     
     
         42 . The method as claimed in  claim 35  further comprising: receiving a human operator-generated input and processing the input wherein the processed input and the measurement signals are processed to obtain the processed signal to thereby semi-automatically initiate qualification of the process.  
     
     
         43 . The method as claimed in  claim 35  further comprising: receiving a machine-generated input and processing the input wherein the processed input and the measurement signals are processed to obtain the processed signal to thereby automatically initiate qualification of the process.  
     
     
         44 . The method as claimed in  claim 35 , wherein the method is an adaptive qualifying method for a human operator-in-the-loop system and wherein the processed signal semi-automatically initiates qualification of the process.  
     
     
         45 . A system for at least semi-automatically qualifying a laser-based material processing system which delivers laser energy to locations on or adjacent a plurality of microstructures formed on a workpiece to at least partially process the microstructures, the qualifying system comprising: 
 sensing equipment to measure a process variable or condition of at least one of the material processing system and the at least partially processed microstructures and areas of the workpiece adjacent the at least partially processed microstructures and to provide corresponding measurement signals; and    a signal processor for processing the measurement signals to obtain a processed signal which qualifies, at least semi-automatically, the material processing system.    
     
     
         46 . The qualifying system as claimed in  claim 45 , wherein the material processing system comprises a laser-based link cutting system and wherein the microstructures include a plurality of links having a pitch.  
     
     
         47 . The qualifying system as claimed in  claim 45 , wherein the workpiece is a test workpiece.  
     
     
         48 . The qualifying system as claimed in  claim 45 , wherein the sensing equipment includes optical sensing equipment.  
     
     
         49 . The qualifying system as claimed in  claim 45 , wherein the sensing equipment includes an AOI subsystem to obtain image data.  
     
     
         50 . The qualifying system as claimed in  claim 45 , wherein the laser energy is delivered in the form of laser pulses and wherein the processed signal initiates, at least semi-automatically, adjusting at least one of temporal and spacial characteristic of the laser pulses.  
     
     
         51 . The qualifying system as claimed in  claim 45 , wherein the laser energy is delivered in the form of focused laser pulses and wherein the processed signal initiates, at least semi-automatically, adjusting at least one of average laser power, peak pulse power, pulse width, spot-diameter, spot shape, spot centering, focus and wavelength.  
     
     
         52 . The qualifying system as claimed in  claim 45  further comprising: 
 a user interface for receiving a human operator-generated input; and    a processor for processing the input wherein the processed input and the measurement signals are processed to obtain the processed signal to thereby semi-automatically initiate qualification of the material processing system.    
     
     
         53 . The qualifying system as claimed in  claim 45  further comprising: 
 means for receiving a machine-generated input; and    a processor for processing the input wherein the processed input and the measurement signals are processed to obtain the processed signal to thereby automatically initiate qualification of the material processing system.    
     
     
         54 . The qualifying system as claimed in  claim 45 , wherein the qualifying system is a human operator-in-the-loop system and wherein the processed signal semi-automatically initiates qualification of the material processing system.