Methods and systems for precisely relatively positioning a waist of a pulsed laser beam and method and system for controlling energy delivered to a target structure
First Claim
1. A method for thermal-based laser processing a multilayer, multi-material memory device including a silicon substrate and a target metal link microstructure surrounded by materials having dissimilar thermal and/or optical properties, the method comprising:
- generating a single multi-stage temporally shaped laser pulse, said laser pulse having a selected pulse width and a temporal shape, said temporal shape comprising a fast leading edge and a fast fall time, respectively, relative to a q-switched pulse shape having the selected pulse width;
irradiating and overfilling the target link with the single temporally shaped laser pulse; and
removing at least a portion of the link with a thermal-based process without creating undesirable changes to other structures or the substrate with the single temporally shaped laser pulse;
wherein each pulse stage is characterized by a controlled amplitude and temporal shape, and a duration comprising a respective portion of the overall pulse width, andwherein the single temporally shaped laser pulse comprises a higher power first portion and a lower power second portion.
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Accused Products
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.
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Citations
47 Claims
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1. A method for thermal-based laser processing a multilayer, multi-material memory device including a silicon substrate and a target metal link microstructure surrounded by materials having dissimilar thermal and/or optical properties, the method comprising:
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generating a single multi-stage temporally shaped laser pulse, said laser pulse having a selected pulse width and a temporal shape, said temporal shape comprising a fast leading edge and a fast fall time, respectively, relative to a q-switched pulse shape having the selected pulse width; irradiating and overfilling the target link with the single temporally shaped laser pulse; and removing at least a portion of the link with a thermal-based process without creating undesirable changes to other structures or the substrate with the single temporally shaped laser pulse; wherein each pulse stage is characterized by a controlled amplitude and temporal shape, and a duration comprising a respective portion of the overall pulse width, and wherein the single temporally shaped laser pulse comprises a higher power first portion and a lower power second portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for thermal based laser processing a multilayer, multi-material memory device including a silicon substrate and a microstructure surrounded by materials having dissimilar thermal and/or optical properties, the method comprising:
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generating a single temporally shaped laser pulse; controlling pulse amplitude of the shaped pulse, wherein the predetermined pulse shape has multiple stages, the pulse amplitude providing a pulse width and a pulse shape having a fast rising edge and a high energy density followed by a reduced power and a fast fall time relative to a q-switched pulse shape having the selected pulse width; and irradiating an area less than 20 square microns with the irradiance on the target structure at greater than about 109 watts per square centimeter and at least 60% of the energy required to open the link completely with a single pulse, whereby energy is efficiently coupled into the link, at least a portion of the link is removed and damage to the substrate is avoided. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A method for thermal-based laser processing a multilayer, multi-material memory device including a silicon substrate and a target metal link microstructure surrounded by materials having dissimilar thermal and/or optical properties, the method comprising:
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generating laser radiation comprising a single pulse having a temporal pulse shape, said temporal pulse shape having a rise time fast enough to efficiently couple laser energy into the target, a duration sufficient to cleanly remove a portion of the target structure, and a fall time fast enough to avoid undesirable damage relative to a q-switched pulse shape, said temporal pulse shape further comprising a portion with high peak power followed by a second portion with lower power; and irradiating the microstructure with the laser radiation; wherein the temporal pulse shape is controlled over portions each having a duration less than 1 ns. - View Dependent Claims (37)
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38. The method as claimed in 36 further comprising:
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generating a q-switched laser pulse; and shaping the q-switched laser pulse amplitude to generate the temporal pulse shape by applying a shaped modulation pulse voltage to a high-speed electro-optic modulator. - View Dependent Claims (39)
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40. The method as claimed in 4 wherein the delay is a programmable delay.
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41. The method as claimed in 4 wherein the delay controls peak to peak spacing of combined pulses.
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42. The method as claimed in 41 wherein at least one pulse has a duration of greater than a few picoseconds to several nanoseconds.
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43. The method as claimed in 4 wherein the delayed portion temporal pulse shape is a fast rising, square pulse.
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44. The method as claimed in 1 wherein surrounding material comprises underlying layers, overlying layers or adjacent material.
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45. The method as claimed in 1 wherein surrounding material comprises silicon dioxide, silicon nitride, a dielectric, an insulator or a high transmission material.
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46. The method as claimed in 1 wherein the metal is one of gold, aluminum, titanium, platinum, and copper.
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47. A method for thermal-based laser processing a multilayer, multi-material memory device including a silicon substrate and a target metal link microstructure, the method comprising:
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selecting a multi-stage temporal pulse shape based on physical properties of the target link microstructure; automatically generating a laser output comprising a single pulse having the selected temporal pulse shape with a controlled amplitude and temporal shape; irradiating and overfilling the link with the laser output; and removing at least a portion of the link in a thermal process without creating undesirable changes to other structures or the substrate.
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Specification