Methods and systems for processing a device, methods and systems for modeling same and the device

Abstract

A method and system for locally processing a predetermined microstructure formed on a substrate without causing undesirable changes in electrical or physical characteristics of the substrate or other structures formed on the substrate are provided. The method includes providing information based on a model of laser pulse interactions with the predetermined microstructure, the substrate and the other structures. At least one characteristic of at least one pulse is determined based on the information. A pulsed laser beam is generated including the at least one pulse. The method further includes irradiating the at least one pulse having the at least one determined characteristic into a spot on the predetermined microstructure. The at least one determined characteristic and other characteristics of the at least one pulse are sufficient to locally process the predetermined microstructure without causing the undesirable changes.

1 - 144 . (canceled)  
   
   
       145 . A method of laser processing a multi-level, multi-material device including a substrate, a microstructure and a multi-layer stack, the stack having inner layers which separate the microstructure from the substrate, the method comprising: 
 a) generating a pulsed laser beam having a predetermined wavelength and including at least one laser pulse having a predetermined characteristic comprising at least one of a temporal shape and spatial shape;    b) relatively positioning the microstructure and a waist of the laser beam in three-dimensional space based on at least a position measurement obtained at a reference location wherein the position measurement is used to obtain a prediction of a common location of the microstructure and the beam waist; and    c) irradiating the microstructure with the at least one laser pulse based on the predicted common location at a time wherein the beam waist and the microstructure substantially coincide, wherein the microstructure is cleanly removed with substantially maximum pulse energy density at the microstructure and wherein an undesirable change to the inner layers of the stack and substrate is avoided.    
   
   
       146 . The method of  claim 145 , wherein pulse energy density at the substrate is less than a damage threshold of the substrate and wherein the maximum pulse energy density at the microstructure is greater than the damage threshold of the substrate.  
   
   
       147 . The method of  claim 145 , wherein peak pulse energy density at the substrate is less than about 1/10 of the maximum pulse energy density at the microstructure.  
   
   
       148 . The method of  claim 145  further comprising: 
 (1) obtaining information identifying microstructures designated for removal;    (2) measuring a first set of reference locations to obtain three-dimensional reference data;    (3) generating a trajectory based on at least the three-dimensional reference data to predict a plurality of beam waist and microstructure locations; and    (4) updating the prediction during the step of relatively positioning based on updated position information, the updated position information being obtained during the step of relatively positioning.    
   
   
       149 . A system of laser processing a multi-level, multi-material device including a substrate, a microstructure and a multi-layer stack, the stack having inner layers which separate the microstructure from the substrate, the system comprising: 
 means for generating a pulsed laser beam having a predetermined wavelength and including at least one laser pulse having a predetermined characteristic comprising at least one of a temporal shape and spatial shape;    means for relatively positioning the microstructure and a waist of the laser beam in three-dimensional space based on at least a position measurement obtained at a reference location wherein the position measurement is used to obtain a prediction of a common location of the microstructure and the beam waist; and    means for irradiating the microstructure with the at least one laser pulse based on the predicted common location at a time wherein the beam waist and the microstructure substantially coincide, wherein the microstructure is cleanly removed with substantially maximum pulse energy density at the microstructure and wherein an undesirable change to the inner layers of the stack and substrate is avoided.    
   
   
       150 . A method of laser processing a multi-level, multi-material device including a substrate, a microstructure and a multi-layer stack, the stack having inner dielectric layers which separate the microstructure from the substrate, the method comprising: 
 generating a pulsed laser beam having a predetermined wavelength and including at least one laser pulse wherein at least reflections of the laser beam by the layers of the stack substantially reduce pulse energy density at the substrate relative to at least one other wavelength; and    processing the microstructure with the at least one laser pulse wherein pulse energy density at the microstructure is sufficient to remove the microstructure while avoiding damage to the substrate and the inner layers of the stack.    
   
   
       151 . A method of laser processing a multi-level, multi-material device including a substrate, a microstructure and a multi-layer stack, the stack having inner layers which separate the microstructure from the substrate, the method comprising: 
 generating a pulsed laser beam having a predetermined wavelength and including at least one laser pulse having a predetermined characteristic wherein: a) the predetermined wavelength is below an absorption edge of the substrate; and b) wherein the at least one pulse has duration less than about 10 nanoseconds, and a repetition rate of 10 KHz or higher;    relatively positioning the microstructure and a waist of the laser beam in three-dimensional space based on at least a position measurement obtained at a reference location wherein the position measurement is used to obtain a prediction of a common location of the microstructure and the beam waist; and    irradiating the microstructure with the at least one laser pulse based on the predicted common location at a time wherein the beam waist and the microstructure substantially coincide, wherein the microstructure is cleanly removed with substantially maximum pulse energy density at the microstructure and wherein an undesirable change to the inner layers of the stack and substrate is avoided.    
   
   
       152 . The method of  claim 151 , wherein the predetermined characteristic includes a q-switched pulse shape.  
   
   
       153 . A method of laser processing a multi-material device including a silicon substrate, a metal link, and a multi-layer stack, the stack having at least one dielectric layer over the metal link and at least one inner dielectric layer which separates the metal link from the silicon substrate, the method comprising: 
 generating a pulsed laser beam having a predetermined visible or near UV wavelength less than an absorption edge of the silicon substrate and long enough to sufficiently tolerate variations of at least one of the thickness and reflectance of a layer of the device, or variations over a batch of devices, the silicon substrate having a relatively high absorption coefficient at the predetermined wavelength and the at least one dielectric layer having a low absorption coefficient at the predetermined wavelength; and    processing the metal link with the at least one laser pulse wherein pulse energy density, over an approximate diffraction limited beam waist at the metal link, is sufficient to remove the metal link while avoiding damage to the silicon substrate and damage to adjacent links.    
   
   
       154 . The method of  claim 153 , wherein the pulsed laser beam has a pulse duration less than about 10 nanoseconds, and wherein pulses are generated at a repetition rate of 10 KHz or higher.  
   
   
       155 . The method of  claim 153 , wherein the method further comprises: 
 measuring at least one of a thickness and reflectance of a layer to determine a variation; and    determining an adjustment of at least one of pulse energy and pulse power based on the measurement.    
   
   
       156 . The method of  claim 153 , wherein the visible wavelength is a green wavelength.  
   
   
       157 . The method of  claim 153 , wherein the predetermined wavelength is a near UV wavelength above the absorption edge of the stack.  
   
   
       158 . The method of  claim 153 , wherein the pulsed laser beam has a pre-determined spatial characteristic that includes an irradiance profile at a controlled three-dimensional beam waist position.  
   
   
       159 . The method of  claim 153 , wherein a dimension of the beam waist is about 1.5 microns or finer at the metal link.  
   
   
       160 . A system of laser processing a multi-material device including a silicon substrate, a metal link, and a multi-layer stack, the stack having at least one dielectric layer over the metal link and at least one inner dielectric layer which separates the metal link from the silicon substrate, the system comprising: 
 means for generating a pulsed laser beam having a predetermined visible or near UV wavelength less than an absorption edge of the silicon substrate and long enough to sufficiently tolerate variations in the thickness of at least one of the thickness and reflectance of a layer of the device, or variations or over a batch of devices, the silicon substrate having a relatively high absorption coefficient at the predetermined wavelength and the at least one dielectric layer having a low absorption coefficient at the predetermined wavelength; and    means for processing the metal link with the at least one laser pulse wherein pulse energy density, over an approximate diffraction limited beam waist at the metal link, is sufficient to remove the metal link while avoiding damage to the silicon substrate and damage to adjacent links.