Energy-efficient, laser-based method and system for processing target material
First Claim
1. An energy-efficient, laser-based method for processing target material having a specified dimension in a microscopic region without causing undesirable changes in electrical or physical characteristics of material surrounding the target material, the method comprising:
- generating a laser pulse train utilizing a laser having a wavelength at a repetition rate wherein each of the pulses of the pulse train has a predetermined shape;
optically amplifying the pulse train without significantly changing the predetermined shape of the pulses to obtain an amplified pulse train wherein each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time; and
delivering and focusing at least a portion of the amplified pulse train into a spot on the target material wherein the rise time is fast enough to efficiently couple laser energy to the target material, the pulse duration is sufficient to process the target material and the fall time is rapid enough to prevent the undesirable changes to the material surrounding the target material.
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Accused Products
Abstract
An energy-efficient method and system for processing target material such as microstructures in a microscopic region without causing undesirable changes in electrical and/or physical characteristics of material surrounding the target material is provided. The system includes a controller for generating a processing control signal and a signal generator for generating a modulated drive waveform based on the processing control signal. The waveform has a sub-nanosecond rise time. The system also includes a gain-switched, pulsed semiconductor seed laser for generating a laser pulse train at a repetition rate. The drive waveform pumps the laser so that each pulse of the pulse train has a predetermined shape. Further, the system includes a laser amplifier for optically amplifying the pulse train to obtain an amplified pulse train without significantly changing the predetermined shape of the pulses. The amplified pulses have little distortion and have substantially the same relative temporal power distribution as the original pulse train from the laser. Each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time. The system further includes a beam delivery and focusing subsystem for delivering and focusing at least a portion of the amplified pulse train onto the target material. The rise time (less than about 1 ns) is fast enough to efficiently couple laser energy to the target material, the pulse duration (typically 2-10 ns) is sufficient to process the target material, and the fall time (a few ns) is rapid enough to prevent the undesirable changes to the material surrounding the target material.
359 Citations
83 Claims
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1. An energy-efficient, laser-based method for processing target material having a specified dimension in a microscopic region without causing undesirable changes in electrical or physical characteristics of material surrounding the target material, the method comprising:
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generating a laser pulse train utilizing a laser having a wavelength at a repetition rate wherein each of the pulses of the pulse train has a predetermined shape;
optically amplifying the pulse train without significantly changing the predetermined shape of the pulses to obtain an amplified pulse train wherein each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time; and
delivering and focusing at least a portion of the amplified pulse train into a spot on the target material wherein the rise time is fast enough to efficiently couple laser energy to the target material, the pulse duration is sufficient to process the target material and the fall time is rapid enough to prevent the undesirable changes to the material surrounding the target material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. An energy-efficient system for processing target material having a specified dimension in a microscopic region without causing undesirable changes in electrical or physical characteristics of material surrounding the target material, the system comprising:
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a controller for generating a processing control signal;
a signal generator for generating a modulated drive waveform based on the processing control signal, wherein the waveform has a sub-nanosecond rise time;
a gain-switched, pulsed seed laser having a wavelength for generating a laser pulse train at a repetition rate, the drive waveform pumping the laser so that each pulse of the pulse train has a predetermined shape;
a laser amplifier for optically amplifying the pulse train without significantly changing the predetermined shape of the pulses to obtain an amplified pulse train wherein each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time; and
a beam delivery and focusing subsystem for delivering and focusing at least a portion of the amplified pulse train into a spot on the target material wherein the rise time is fast enough to efficiently couple laser energy to the target material, the pulse duration is sufficient to process the target material, and the fall time is rapid enough to prevent the undesirable changes to the material surrounding the target material. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79)
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80. An energy-efficient, laser-based method for ablating a metal link having a specified dimension embedded in at least one passivation layer without causing undesirable changes in electrical or physical characteristics of the at least one passivation layer surrounding the metal link, the method comprising:
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generating a laser pulse train utilizing a laser having a wavelength at a repetition rate wherein each of the pulses of the pulse train has a predetermined shape;
optically amplifying the pulse train without significantly changing the predetermined shape of the pulses to obtain an amplified pulse train wherein each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time; and
delivering and focusing at least a portion of the amplified pulse train into a spot on the metal link wherein the rise time is fast enough to efficiently couple laser energy to the metal link, the pulse duration is sufficient to ablate the metal link and the fall time is rapid enough to prevent the undesirable changes to the at least one passivation layer surrounding the metal link. - View Dependent Claims (81)
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82. An energy-efficient system for ablating a metal link having a specified dimension embedded in at least one passivation layer without causing undesirable changes in electrical or physical characteristics of the at least one passivation layer surrounding the metal link, the system comprising:
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a controller for generating a processing control signal;
a signal generator for generating a modulated drive waveform based on the processing control signal, wherein the waveform has a sub-nanosecond rise time;
a gain-switched, pulsed seed laser having a wavelength for generating a laser pulse train at a repetition rate, the drive waveform pumping the laser so that each pulse of the pulse train has a predetermined shape;
a laser amplifier for optically amplifying the pulse train without significantly changing the predetermined shape of the pulses to obtain an amplified pulse train wherein each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time; and
a beam delivery and focusing subsystem for delivering and focusing at least a portion of the amplified pulse train into a spot on the metal link wherein the rise time is fast enough to efficiently couple laser energy to the metal link, the pulse duration is sufficient to ablate the metal link, and the fall time is rapid enough to prevent the undesirable changes to the at least one passivation layer surrounding the metal link. - View Dependent Claims (83)
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Specification