High-speed, precision, laser-based method and system for processing material of one or more targets within a field
A precision, laser-based method and system for high-speed, sequential processing of material of targets within a field are disclosed that control the irradiation distribution pattern of imaged spots. For each spot, a laser beam is incident on a first anamorphic optical device and a second anamorphic optical device so that the beam is controllably modified into an elliptical irradiance pattern. The modified beam is propagated through a scanning optical system with an objective lens to image a controlled elliptical spot on the target. In one embodiment, the relative orientations of the devices along an optical axis are controlled to modify the beam irradiance pattern to obtain an elliptical shape while the absolute orientation of the devices controls the orientation of the elliptical spot.
1 - 55 . (canceled)
56 . A method of selectively removing material with a precisely controlled laser ablation threshold, the method comprising:
generating at least one laser beam along one or more propagation paths;
controllably modifying the at least one laser beam to obtain at least one modified laser beam; and
sequentially and relatively positioning the at least one modified laser beam into at least one well-focused spot to remove material wherein a precisely controlled ablation threshold allows for selective material removal and wherein the at least one well-focused spot has a set of desired spatial characteristics including an adjustable aspect ratio which are obtained by the step of controllably modifying.
57 . The method as claimed in claim 56 , wherein the method is a trimming or link blowing method.
58 . The method as claimed in claim 56 , wherein the method is a micromachining method.
59 . The method as claimed in claim 56 , wherein the aspect ratio is greater than 1.2.
60 . The method as claimed in claim 56 , wherein the step of generating is performed with a narrow pulse laser system.
61 . The method as claimed in claim 60 , wherein the narrow pulse laser system is a picosecond laser system.
62 . The method as claimed in claim 60 , wherein the narrow pulse laser system is a femtosecond laser system.
63 . The method as claimed in claim 56 , wherein the step of sequentially and relatively positioning delivers and focuses the at least one modified beam into a plurality of well-focused spots extending along a line and wherein an axis of at least one of the spots is aligned with the line.
64 . The method as claimed in claim 56 , wherein the step of controllably modifying the at least one beam includes switching the at least one beam between a plurality of optical paths.
65 . A system for selectively removing material with a precisely controlled laser ablation threshold, the system comprising:
a laser source for generating at least one laser beam along one or more propagation paths;
a controller for generating control signals;
a subsystem for controllably modifying the at least one laser beam in response to the control signals to obtain at least one modified laser beam; and
a beam delivery and focusing subsystem for sequentially and relatively positioning the at least one modified laser beam into at least one well-focused spot to remove material wherein a precisely controlled ablation threshold allows for selective material removal and wherein the at least one well-focused spot has a set of desired spatial characteristics including an adjustable aspect ratio.
66 . A high-speed, precision, laser-based method for processing material of at least one target within a field, the method comprising:
generating at least one laser beam along one or more propagation paths;
controllably modifying the at least one laser beam to obtain at least one modified laser beam; and
sequentially and relatively positioning the at least one modified laser beam into at least one well-focused spot at each target within the field to process the material of each target wherein the at least one spot has a set of desired spatial characteristics including an adjustable aspect ratio which are obtained by the step of controllably modifying.
67 . The method as claimed in claim 66 , wherein the step of sequentially and relatively positioning delivers and focuses the at least one beam into a plurality of well-focused spots extending along a laser processing path wherein the aspect ratio and orientation of each of the spots is based on predetermined dimensions of each target and target orientation.
68 . The method as claimed in claim 66 , wherein multiple targets are within the field.
69 . A high-speed, precision, laser-based method for processing material of at least one target within a field, the method comprising:
a) generating at least one laser beam along one or more propagation paths;
b) controllably modifying the at least one laser beam to obtain at least one modified laser beam;
c) relatively positioning the at least one modified laser beam into at least one well-focused spot at a target within the field to process the material of the target wherein the at least one well-focused spot has a set of desired spatial characteristics including an adjustable aspect ratio which are obtained by step b); and
d) repeating steps a) through c) for each target until the material of all targets within the field are processed.
70 . The method as claimed in claim 69 , further comprising: e) evaluating at least one of process, material and target characteristics to obtain data wherein step b) is based on the data.
71 . The method as claimed in claim 70 , wherein step d) repeats steps a) through c) and step e) for each target until the material of all targets within the field are processed.
72 . A high-speed, precision system for processing material of at least one target having predetermined dimensions and a characteristic within a field, the system comprising:
a laser source for generating at least one laser beam along one or more propagation paths and having an irradiance pattern with an aspect ratio and an orientation in a plane substantially perpendicular to the one or more propagation paths;
a controller for generating control signals including orientation control signals based on the characteristic;
a subsystem disposed in each propagation path for shaping the at least one laser beam based on the predetermined dimensions to change the aspect ratio and obtain at least one modified beam;
a second subsystem for controllably changing the orientation of the irradiance pattern based on the orientation control signals; and
a beam delivery and focusing subsystem for sequentially positioning and focusing each of the at least one modified beams into at least one well-focused spot on each target to process the material of each target.
73 . The system as claimed in claim 72 , wherein the first subsystem includes an ellipse generator and wherein the irradiance pattern of the at least one modified beam is an elliptical irradiance pattern and the at least one well-focused spot is at least one well-focused elliptical spot.
74 . The system as claimed in claim 73 , wherein the second subsystem includes a beam rotator for rotating the at least one modified beam.
75 . The system as claimed in claim 72 , wherein the processing includes semiconductor link removal, laser trimming, laser drilling or laser etching.
76 . The system as claimed in claim 72 , wherein the system compensates for system errors that would result in an out-of-round or an out-of-ellipse condition.
77 . The system as claimed in claim 72 , wherein the first subsystem includes an adaptive optical element.
78 . A method for processing at least one microstructure which is part of a multi-material device containing a plurality of microstructures, the at least one microstructure having a designated region for target material removal, the method comprising:
generating at least one laser beam;
modifying the at least one laser beam to obtain at least one modified laser beam; and
sequentially and relatively positioning the at least one modified laser beam into at least one non-round spot having a predetermined non-round energy distribution on the designated region to remove the target material in the designated region wherein the predetermined non-round energy distribution covers an area of the designated region such that energy is more efficiently coupled into the designated region for the non-round energy distribution than energy coupled into the designated region for a round energy distribution covering the same area.
79 . The method of claim 78 , wherein the at least one microstructure has a rectangular shape with a dimension less than 1 micron in a narrow dimension of the rectangular shape.
80 . The method of claim 78 , wherein the step of positioning is repeated to process a plurality of microstructures within a field with a plurality of non-round spots having a corresponding plurality of predetermined non-round energy distributions.
81 . The method of claim 80 , wherein each non-round spot has an orientation and each microstructure has an orientation and wherein the step of positioning includes aligning the orientations of the non-round spots to corresponding orientations of the microstructures.
82 . The method of claim 80 , wherein the processed microstructures are metal links of a multi-material, redundant memory device.
83 . The method of claim 78 , wherein the step of positioning includes the step of aligning an axis of the at least one non-round spot with the at least one microstructure.
84 . The method of claim 83 , wherein the step of aligning is performed automatically and wherein the step of aligning includes switching the at least one laser beam to one of a plurality of optical paths.
85 . The method of claim 84 , wherein the at least one laser beam is polarized and wherein the step of switching includes controllably modifying the polarization of the at least one laser beam.
86 . The method of claim 84 , wherein the step of switching includes controllably modifying the at least one laser beam with an anamorphic optical system.
87 . The method claim 78 , wherein the microstructures contained in the device are regularly arranged in rows and columns.
88 . The method of claim 78 , wherein the step of positioning includes the step of positioning the at least one non-round spot with a low inertia beam deflector.
89 . The method of claim 78 , wherein the step of positioning includes the step of positioning the at least one non-round spot with a movable translation stage.
90 . A system for processing at least one microstructure which is part of a multi-material device containing a plurality of microstructures, the at least one microstructure having a designated region for target material removal, the system comprising:
means for generating at least one laser beam;
means for modifying the at least one laser beam to obtain at least one modified laser beam; and
means for sequentially and relatively positioning the at least one modified laser beam into at least one non-round spot having a predetermined non-round energy distribution on the designated region to remove the target material in the designated region wherein the predetermined non-round energy distribution covers an area of the designed region such that energy is more efficiently coupled into the designated region for the non-round energy distribution than energy coupled into the designated region for a round energy distribution covering the same area.
91 . The system of claim 90 , wherein the predetermined non-round energy distribution includes pre-specified characteristics including an aspect ratio, a focused spot size, an orientation, depth of focus and a focused irradiance distribution.
92 . A method of selectively removing material with a precisely controlled laser ablation threshold, the method comprising:
generating a laser beam along a propagation path;
controllably modifying the laser beam to obtain a modified laser beam; and
sequentially and relatively positioning the modified laser beam into at least one elongated irradiance pattern having a predetermined linear energy distribution to remove material wherein a precisely controlled ablation threshold allows for selective material removal and wherein the at least one elongated irradiance pattern has a set of desired spatial characteristics including an adjustable aspect ratio which are obtained by the step of controllably modifying.
93 . The method as claimed in claim 92 , wherein the step of sequentially and relatively positioning delivers and focuses the modified beam into a plurality of elongated irradiance patterns extending along a row or column of the material.
94 . The method as claimed in claim 92 , wherein the linear energy distribution is a series of overlapping spots forming a line.
95 . The method as claimed in claim 92 , wherein the step of controllably modifying the laser beam includes deflecting the laser beam between a plurality of optical paths.
96 . The method of claim 92 , wherein the step of controllably modifying the laser beam includes the step of switching the beam with an acousto-optic deflector.
97 . A system for selectively removing material with a precisely controlled laser ablation threshold, the system comprising:
a laser source for generating a laser beam along a propagation path;
a controller for generating control signals;
a subsystem for controllably modifying the laser beam in response to the control signals to obtain a modified laser beam; and
a beam delivery and focusing subsystem for sequentially and relatively positioning the modified laser beam into at least one elongated irradiance pattern having a linear energy distribution to remove material wherein a precisely controlled ablation threshold allows for selective material removal and wherein the at least one elongated irradiance pattern has a set of desired spatial characteristics including an adjustable aspect ratio.
98 . A method for processing at least one microstructure which is part of a multi-material device containing a plurality of microstructures, the at least one microstructure having a designated region for target material removal by selectively removing material with a precisely controlled laser ablation threshold, the method comprising:
generating a laser beam along a propagation path;
controllably modifying the laser beam to obtain a modified laser beam; and
sequentially and relatively positioning the modified laser beam into a plurality of overlapping well-focused spots extending along one or more parallel lines to remove material wherein the overlapping well-focused spots along one line is an elongated irradiance pattern having a major axis and a minor axis wherein along the major axis the elongated irradiance pattern is aligned with the microstructure and wherein a precisely controlled ablation threshold allows for selective material removal and wherein the elongated irradiance pattern has a set of desired spatial characteristics including an adjustable aspect ratio which are obtained by the step of controllably modifying.
99 . A high-speed, precision, laser-based method for processing material of at least one target within a field, the method comprising:
generating a laser beam along a propagation path;
controllably modifying the laser beam by switching between multiple beam paths to obtain modified laser beam; and
sequentially and relatively positioning the modified laser beam into at least one well-focused spot at the at least one target within the field to process the material of the at least one target wherein the at least one well-focused spot has a set of desired spatial characteristics including the alignment of an axis to a target which are obtained by the step of controllably modifying.