KR20080010380A - Method and system for high-speed precise laser trimming, scan lens sysytem for use therein and electrical device produced threrby - Google Patents

Abstract

A method, system and scan lens system are provided for high-speed, laser-based, precise laser trimming at least one electrical element. The method includes generating a pulsed laser output having one or more laser pulses at a repetition rate. Each laser pulse has a pulse energy, a laser wavelength within a range of laser wavelengths, and a pulse duration. The method further includes selectively irradiating the at least one electrical element with the one or more laser pulses focused into at least one spot having a non-uniform intensity profile along a direction and a spot diameter as small as about 6 microns to about 15 microns so as to cause the one or more laser pulses to selectively remove material from the at least one element and laser trim the at least one element while avoiding substantial microcracking within the at least one element. The wavelength is short enough to produce desired short-wavelength benefits of small spot size, tight tolerance and high absorption, but not so short so as to cause microcracking.

Description

METHOD AND SYSTEM FOR HIGH-SPEED PRECISE LASER TRIMMING, SCAN LENS SYSYTEM FOR USE THEREIN AND ELECTRICAL DEVICE PRODUCED THRERBY}

                  Cross Reference to Related Applications

The application claims priority under the provisions of US Provisional Application SN 60 / 617,130, "Laser Apparatus and Method for Laser Trimming," filed Oct. 8, 2004. This application is also a division of SN 10 / 397,541 "Method and Apparatus for High-Speed Accurate Micromachining of Devices," filed March 26, 2003, and SN 10 / 108,101 "Applied Device, filed March 27, 2002. Methods and systems, methods and systems for modeling the same, and systems and apparatus for the same, and is currently published in US Patent Application No. 2002/0162973, filed on May 18, 2005. 11 / 131,668 claims "method and device for high speed accurate micromachining of an arrangement of devices". US Patent No. 6,341,029, entitled "Method and Apparatus for Shaping a Laser-Beam Intensity Profile by Dithering", assigned to the assignee of the present invention with the common inventor, is incorporated by reference in its entirety. This application is also related to US Pat. No. 6,339,604, under the "Pulse Control of Laser Devices", which is also assigned to the assignee of the present invention. The present application also relates to US Pat. No. 6,777,645 under "High Speed, Laser Based Methods and Apparatus for Treatment Materials of One or More Targets in the Field," also assigned to the assignee of the present invention.

The present invention is directed to methods and systems for high speed, accurate laser trimming, scan lens systems for use therein, and electrical devices produced thereby.

Traditionally, Nd: YAG lasers with a wavelength of 1 micron are used for trimming chip resistors. As the sizes of the resistors are smaller, the substrates are thinner, and the tolerances are tight, this wavelength hits its basic limits in terms of trim mark width, heat affected zone (i.e., HAZ), and therefore TRC and draft R of resistance. do.

It is well known that short wavelengths can result in small optical spot sizes. It is also well known that the absorption of short wavelength film materials is high. Therefore, the use of lasers with wavelengths shorter than the traditional 1 micron has the advantages of a small track width that allows for small features to be trimmed, and a small HAZ that leads to TCR drift and R drift.

United States Patents below: 5,087,987; 5,111,325; 5,404,247; 5,633,736; 5,835,280; 5,838,355; 5,969,877; 6,031,561; 6,294,778; And 6,462,306, those skilled in the art of lens design will evaluate the complexity of scan lenses designed for multiple wavelengths.

Many design variables are considered and various design compromises such as spot size, field size, scan angle, scan hole, telecentricity, and working distance are used to achieve the laser scan lens design solution for trimming applications. As a priority for high speed manipulation of microstructures over large areas, the scan lens must focus the aimed input beam and image limited laser spot diffraction over the entire field to achieve small spots over large areas of scanning. The spot must be round and uniform enough across the field to yield a uniform trim cut in the field. The lens must also provide a suitable time resolution to handle monitoring by imaging the target area selected for calibration. For the field of view through the lens, light is collected from the rough field, aimed by the scan lens and imaged on a detector using auxiliary on-axis optics. By utilizing different wavelength ranges for the target field of view and the bleaching scan lens, efficient beam combining and splitting is possible using conventional binary optical elements. Within the clock channel, good horizontal and axial color correction is required, but small amounts of horizontal color between the clock and laser channels may be accommodated in the scanning device and small amounts of axial color between the clock and laser channels may be field or auxiliary. It can be accommodated with focus adjustment of the optics. With two mirror scan heads, for example a galvanometer scan head when no pupil corrected vision is used, the scan lens must accommodate pupil manipulation resulting from separation between the two scan mirrors.

The associated lens capacity can be estimated by dividing the field size by the imaged spot size to find the number of spots per field. Conventional bleaching scan lenses for laser trimming, for example, the object used in the GSI Lumonics W670 for trimming thick films with 1.064 micron laser wavelength yields 30 micron spots over a 100 mm square field and The target is imaged on a monochrome CCD camera with conventional white light sources and a secondary camera view. The W670 device is capable of about 4667 laser spots across the diagonal of the field. Lenses of the device used for thin film trimming have smaller field sizes and smaller spot sizes. For example, a scan lens used in a GSI Lumonics W678 trim device and also with a white light capability has 12 micron spots, or about 4167 spots, over a 50 mm field. Another thin film scan lens with a laser wavelength of 1.047 microns is used in the GSI Lumonics M310 wafer trim unit, has a 6.5 micron spot over a 1 cm sq telecentric field and an emission band of about 860 nm to 900 nm for the field of view. IR LED light planes with the capability of about 2175 swabs.

To some extent, lenses or lens design forms intended for IR laser scanning, in particular IR scan lenses in the white light field of view, may be used or modified for other laser wavelengths, for example green lasers. The decrease in wavelength in principle reduces the spot size proportionately. However, considering increased lens degrees and manufacturing tolerances, this may be unachievable. For example, the green version of the W670 lens yields spots of about 20 microns compared to the 30 microns of the IR version, and the number of spots per field increases from 4667 to about 7000.

By comparison, lenses designed primarily to operate with green laser wavelengths with long wavelength viewing channels may make the most of scanning secondary wavelengths, eg 1.047 microns or 1.064 microns, resulting in a spot scaled up roughly by wavelength. It was found to yield.

The following typical US patents relate to laser trimming methods and apparatuses: 6,534,743; 6,510,605; 6,322,711; 5,796,392; 4,901,052; 4,853,671; 4,647,899; 4,511,607; And 4,429,298.

US Pat. No. 4,429,298 relates to many aspects of serpentine trimming. Basically, the serpentine register is formed of continuous plunge cuts and the final trim cut is made parallel to the register edge from the last plunge. It depicts making a plunger cut "progressively" on a register alternately from one end, with maximum and minimum plunge cut lengths, resistance threshold of plunge cuts to trim cuts, rapid cutting speed of plunge cuts, and Consider structured process flows with various resistance and cut length tests.

There is a continuing need for improved high speed, accurate trimming at all scales of operation, ranging from thick film circuits to wafer trimming.

It is an object of the present invention to provide a method and apparatus of improvement for a high speed, accurate laser trimming, a scan lens for its use and the electrical device produced thereby.

In carrying out the above and other objects of the present invention, the method is provided with at least one electrical element for high speed, laser based, accurate laser trimming. Each electrical element has at least one measurable characteristic supported on the substrate. The method includes generating a laser output of a pulse with one or more laser pulses of repetition rate. Each laser pulse has a pulse energy, a laser wavelength within a range of riser wavelengths, and a pulse duration. The method further comprises optionally at least one electrical element with one or more laser pulses focused into at least one spot and having a non-uniform concentration profile and a spot diameter of about 15 microns or less, depending on direction, wavelength, energy By selectively moving the material from at least one element f to cause a pulse duration and a spot diameter, laser trimming of the at least one element while avoiding microcracks within the at least one element. The wavelength is sufficient to yield the desired short wavelength gain of small spots and high absorption between small spots, but not so short to cause microcracks.

The pulsed laser output power of the focus corresponds to about 10-50 mw with a spot diameter of about 15 μm or less. The power can be metered in reduced spot sizes of about 15 μm or less so that the corresponding power density is sufficient to trim the element but low enough to avoid micro cracks.

Any microcracks obtained as a result of the material moving from at least the first portion of the at least one element use at least one other wavelength outside the range of laser wavelengths, from at least one element, or from the portion of the second element. Thus, it may be impractical as compared to the microcracks obtained on the moving material.

Movement of material from at least one element may be created with a trim cut having a mark width corresponding to the spot diameter.

The step of selectively irradiating with one or more pulses may be performed with at least a limiting formation of the heat affected zone.

The repetition rate may be at least 10 kilohertz.

The duration of the at least one laser pulse of the laser output may range from about 25 nanoseconds to 45 nanoseconds.

The duration of at least one laser pulse of the laser output may be less than about 30 nanoseconds.

The array of thin film electrical elements may be trimmed, and the method may further include micromechanical processing, optionally with one element in the array to change the measurable value. Optionally, the step of micromechanical machining is stopped and stopped while at least one other element of the array is selectively micromachined such that one element in the array changes the measurable characteristic. The method may further comprise optionally continuing again the stopped step of micromachining to change the measurable characteristic of an element until its value is within the desired range.

At least one element may comprise a resistor, and the at least one measurable characteristic may be at least one resistance and temperature.

The method may further comprise stopping the Michael machine tool if the measurement of the at least one measurable characteristic is within a predetermined range.

In further achieving the above and other objects of the present invention, a method is provided for laser trimming at least one electrical element having measurable characteristics. The method includes provision of a laser trimmer comprising a laser system of pulses, a beam delivery system, and a controller. When a control program is provided and executed, it causes the controller to control the system to cause one or more laser output pulses of the laser output of the pulse to avoid micro-cracks of the at least one element while laser trimming the at least one element. The laser power of the pulse is about 10 KHz recovery rate or larger and has a visible laser wavelength. The beam delivery system has an optical western system to produce a spot of focus having a non-uniform intensity aspect along the direction and has a diameter of about 15 microns or less from one or more laser output pulses. The wavelength is short enough to yield the desired short wavelength benefit of small spot size, tight tolerances and high absorption, but not so short that it will cause microcracks.

The visible laser wavelength may range from about .5 microns to about .7 microns.

The diameter may be about 6 microns to about 10 microns.

The array of thin film electrical elements may be trimmed, and the method may further include selectively micromechanical to one of the array middle elements to change the value of the measurable characteristic. Optionally, the step of micromechanical machining is stopped and stopped while at least one other element of the array is selectively micromachined such that one element in the array changes the measurable characteristic. The method may further comprise optionally continuing again the stopped step of micromachining to change the measurable characteristic of an element until its value is within the desired range.

In further achieving the above and other objects of the present invention, an apparatus is provided in which the electrical device has at least one thin electrical element trimmed by the method of the invention during at least one stage of the calculation.

 In further achieving the above and other objects of the present invention, the system is provided for accurate laser trimming of at least one electrical element of a high speed, laser foundation. Each electrical element has at least one measurable characteristic and is supported on a substrate. The system includes a laser subsystem to generate a laser output of a pulse that spans one or more laser pulses of repetition rate. Each laser pulse has a pulse energy, visible laser wavelength, and pulse duration. The beam delivery subsystem includes at least one beam deflector to receive the laser output of the pulse and position the one or more laser pulses with respect to the at least one element to be trimmed, the optical subsystem focusing the one or more laser pulses Have a visible laser wavelength in at least one spot in the field of subsystems. At least one spot has a non-uniform intensity profile and a spot diameter of 15 microns or less, depending on the direction. The controller is coupled to the beam delivery and laser subsystems to control the beam delivery and subsystems to selectively irradiate at least one element such that the daily laser output pulses are spot-sized with visible laser wavelength, laser duration, and pulse energy. The material from at least one element is selectively moved to laser trim the at least one element while avoiding virtual micro-cracks in the at least one element. The laser wavelength is short enough to yield the desired short wavelength benefits of small spot size, tight tolerances and high absorption, but not so short to cause microcracks.

The laser output power of the focused pulse may correspond to 10-50 mw with a spot diameter of about 15 μm or less. The power can be scaled to a reduced spot size so that the corresponding power density is high enough to trim the element but low enough to break the microphone crack.

The spot may be diffraction limited in nature and the non-uniform concentration profile may be a Gaussian profile along approximately the direction.

Virtual microphone cracks may also be avoided in materials that are at least in close proximity to one element.

The laser subsystem may include a solid state laser, of a frequency dual, diode pump, with a q switch.

The laser subsystem may include a frequency-switched, solid-state laser with a qswitch having a fundamental wavelength ranging from about 1.047 microns to 1.32 microns, with a visible wavelength ranging from about .5 microns to about .7 microns. It may be a wavelength of frequency double in the long visible wavelength range.

The laser wavelength may be a green laser wavelength.

The green laser wavelength may be about 532 nm.

The spot diameter may be as small as about 6 microns to about 10 microns.

The optical subsystem may include a lens that is bleached to two or more wavelengths. At least one of the wavelengths may be a visible wavelength.

The system may further include an illuminator to illuminate the substrate area with radiant energy of one or more illumination wavelengths. The protective device may be sensitive to one radiant energy of the illumination wavelength such that one of the two or more wavelengths may be the visible laser wavelength or the burning illumination wavelength.

The optical subsystem may be a telecentric optical subsystem.

The telecentric optical subsystem may include a telecentric lens.

The repetition rate may be at least 10 kilohertz.

The pulse duration of the at least one laser pulse of the laser output may be about 30 nanoseconds or less.

The controller may comprise means for controlling the position of the laser output of the pulse with respect to the at least one element.

The controller may include means for controlling the pulse energy to selectively irradiate at least one element.

The system may further include a substrate positioning device to position at least one element supported on the substrate relative to the field of the optical subsystem such that one or more laser pulses are concentrated to bring the at least one element from about 6 microns to about 15 microns. Investigate with a small spot diameter.

The optical subsystem may receive at least one laser pulse that occurs with deflection by the at least one beam deflector.

The spot diameter of focus may be as small as about 6 microns to about 10 microns at any location within the field of the optical subsystem.

The system may further include a calibration algorithm to adjust the coordinates of the material to be irradiated within the at least one element and to precisely control the dimensions of the area of material movement.

The system may further include a machine vision subsystem that includes a vision algorithm to locate or measure at least one geometrical feature of the at least one element.

The vision association may further comprise edge detection and at least one geometrical feature is edges of at least one element. Corners are used to determine the width of at least one element and to dimension the material movement.

At least one element may comprise a thin film resistor, and the at least one measurable characteristic may be at least one resistance and temperature. The system may further comprise means for prohibiting the movement of the thin plume material of the resistance device if the measurement of the at least one measurable characteristic is within a predetermined range.

The material of the substrate may be a semiconductor or ceramic.

 At least one element may comprise an element of a thin film.

The arrangement of the electrical elements of the thin film may be trimmed with the system. The controller may include means for selectively micromachining the array elements to change the value of the measurable characteristic and means for inhibiting selective micromachining while selective micromachining is prohibited. The controller is further adapted to selectively micromechanize at least one other array element to change the value of the measurable characteristic and to continue the selective micromachining to change the measurable characteristic of the array element until its value is within the desired range. It may further comprise means.

The system may further include a user interface and a software program coupled to the interface and the controller. The software program may be adapted to accept yeast target values for at least one element and to limit the electrical output applied to the at least one element based on the values.

Potential damage to at least one element may be avoided.

In further achieving the above and other objects of the present invention, there is provided a bleaching scan lens system for use in a laser based micromachining system. The laser based micromachining system has a scan field with a laser spot size of 20 microns or less and a viewing channel with a bandwidth of at least 40 nm. Scan lens system continuously from a side of incident micro-machining laser beam: negative optical power, index of refraction (n ₁₎ and the Abbe elements of the first with a dispersion number (v ₁₎ (L ₁₎ and the index of refraction ( n ₂ ) and the Abe dispersion number (v ₂ ) n ₁ <n ₂ And multiple lens elements comprising a pair containing a _second element L ₂ having v ₁ > v ₂ to meet the requirements of spot size, field size and viewing channel bandwidth.

The pair may be a charcoal phase pair having a carburized surface. The charcoal surface may be spaced apart from the incident micromachining laser beam.

L ₁ May be an element on one side only. L ₂ may be a convex element.

L ₁ And L ₂ may be second and third elements of the plurality of lens elements. The plurality of lens elements may consist of at least six lens elements.

The above and other objects, features, and advantages of the present invention will be readily apparent from the following detailed description, when taken in conjunction with the accompanying drawings, of the best mode for carrying out the invention.

1A-1B are schematic diagrams illustrating current flow lines before and after laser trimming, respectively;

1C is a chart illustrating the effect of various cut formats on various trim parameters;

2A is a schematic diagram of an arrangement of chip resistors arranged in columns and rows and illustrates the results of using laser trimming steps in accordance with an embodiment of the invention;

FIG. 2B is a block diagram flow chart further defining trimming steps corresponding to FIG. 2A;

3 is a block diagram flow chart further defining the trimming operations of FIGS. 2A and 2B in the system of the present invention;

4A is a schematic diagram of an arrangement of chip resistors arranged in columns and rows and illustrates the results of using laser trimming steps in accordance with an embodiment of the present invention;

4B is a block diagram flow chart further defining trimming steps corresponding to FIG. 4A;

5 is a block diagram flow chart further defining the trimming operations of FIGS. 4A and 4B in the system of the present invention;

6A is a schematic diagram of a laser trimming apparatus that may be used in one embodiment of the present invention;

FIG. 6B is a schematic diagram of a resistance device having geometrical characteristics to be measured, in particular the corners of the resistance device, using the data obtained with the device of FIG. 6A;

FIG. 7 is a graph showing the time versus position of the laser beam during scanning of the resistor arrangement in one embodiment, such that a rapid scan with a solid deflector may optionally form the cut of FIG. 2 or FIG. Is added as an electromechanical linear;

8 is a schematic diagram of a system for delivering multi-directional beams to at least one resistor to increase trim speed;

9 is a schematic diagram of a system for providing redundant beams to at least one resistor of a laser trimming device;

FIG. 10 is an electron micrograph (reproduced from FIG. 11 of U.S.P.N. 6,534,743) showing microcracks formed on the substrate of the resistance device trimmed by a Gaussian beam produced by a UV laser;

11 is a picture of a thin film resistor processed by a green laser;

     12 is a plot of the mark width of 6-7 microns achieved by a green laser with newly designed optics;

13 is a picture of a chip resistor trimmed by a green laser; And

14 is a 3D layout view of an 8 micron Green / IR scan lens for use in one embodiment of the laser system of the present invention.

high speed serpentine Trim  fair

In resistor trimming, the cuts are directed to the current flow through the resistive material along the resistive path. Fine control and adjustment of the cut size and shape change the resistance to a desired value, as shown in FIGS. 1A-1C. Typically, chip resistors are arranged in rows and columns on a substrate. 2A shows an arrangement in which the rows of resistors R1, R2, ... RN are to be processed. The probe arrangement, which sleeps the probe 200 and is depicted by arrows in FIG. 2A, is brought into contact 202 with the conductors in the row of storage devices. The matrix switch addresses the contact for the first pair of conductors (e.g., contact across R1) and a series of cuts and measurements are made to vary the wgkd between the pair of conductors to a desired value. When the trimming of the resistors is completed, the matrix switches to the contact of the second set of elements of the next row (e.g. R2) and the trimming process is repeated. All rows of resistors R1 ... RN If this is trimmed, the contact is broken between the contacts and the probe array. The substrate is then positioned with respect to another row, the probe is brought into contact, and the second row is treated in the same way as the previous row.

Trimming of the serpentine thin film resistors involves a laser that processes the cut to create cuts in the region of the resistive material between the conductors, as described, for example, in FIG. 1C. Interposed cuts are directed to the current flow through the resistive material along the serpentine path that wraps around the cuts. This geometry allows for a wide range of resistances that would result in the film / conductor arrangement of the section being zoned. The approach shown above will process a series of serpentine cuts with the measuring steps of the resistor site and move it to the next resistor.

Referring to FIG. 2A, the initial laser position for a cut is depicted as 205 and the beam positioning device is directed to the beam along a straight path through the resistor material. According to the present invention, the new paradigm trims differently to the first resistor device (eg, trim cut 204 of R1) and measures the resistance. If the resistance is below a predetermined threshold, similar equal straight trims are made across the other resistors R2 ... RN of the row. A perfectly identical straight trim along the row is described as 210 in FIG. 2 and the corresponding block 220 is further defined in FIG. 2B. In at least one embodiment of the present invention, a subset of resistors may be measured to calculate the thin film concentration across the substrate, but one measurement may be sufficient if the thin film is a known concentration.

The next same straight group of cuts along the row of resistors is further defined in block 221 of FIG. 2B, by means as shown by 211 of FIG. 2A, so that resistor RN is trimmed for the first time. The process is repeated as shown in 212-213 of FIG. 2A and correspondingly further defined in blocks 222-223 of FIG. 2B. If the measurement shows that the threshold has crossed, the trimming of column R1..RN continues the measurement of each resistor to trim the value before switching to the next resistor (depicted by block 224 to 214).

Limiting the number of measurements and maintaining a common straight trim trajectory both increase the trim rate.

The flowchart of FIG. 3 also defines the steps corresponding to FIGS. 2A-2B and additional processing steps used in the trimming system (eg, indexing and filling).

In at least one embodiment, the cutting steps may be performed based on certain information. For example, for certain resistor types, the first series of elements may be based on certain aspects of the resistor (eg, geometry) and / or known film characteristics (eg, before the resistance is measured). Sheet resistance) may be continuously cut. Likewise, the number of bar measurement cuts may be determined within the run mode of the first resistor device (including for example at least one measurement, or interaction measurements). In the lower run mode, interactive measurements are made. The number of cuts in the beetle is determined based on the measurements and the material properties. In at least one embodiment the number of non-measured cuts may be suitable.

For example, cuts in the net may be made without measuring. Referring to FIG. 4A, the initial state 410 is described, which is in contact with the heat 202 as in FIG. 2A of the probes. Referring to FIG. 4B, the state of four seconds is further defined at block 420. For example, FIGS. 4A-4B illustrate an embodiment of a trimming process in which the initial four cuts 411 are made without making any measurements. As shown in FIG. 4B, when the block 421 is measured up, a predetermined number of cuts (eg, four) are defined based on at least one trim value or state. The scan passage to complete the four cuts is depicted as 405. The first resistor R1 in the next column is trimmed at 406 to determine when the target value is reached. If not reached, the other resistors R2..RN are cut (eg without measurement) as depicted at 412.

The next process is repeated to begin trimming 407 of the RN and is further defined by block 423 by cutting to R1 of R [N-1] as shown in the next 413. Therefore, with each change in the direction of R1 or RN, the remaining resistors R2..RN or R [N-1] ... R1 are cut, respectively, if the target value is not reached. The final step comes after either R1 or RN reaches the target value. Each resistor device is burned, connected and trimmed and further defined by block 424, described at 414.

The flowchart of FIG. 5 also defines the steps corresponding to FIGS. 4A-4B and additional steps used in the trimming system (including, for example, pasting and unloading).

In one embodiment, the predetermined information is obtained using interaction measures, so that trim values are provided. The values may be specified by an operator, a process engineer, or another obtained. The software provides the ability to specify or use Yetrim target values so that the test voltage and / or current of the application is controlled. This feature is useful to avoid voltages sufficient to damage components over a wide range of resistance changes associated with serpentine trimming. When using the rapid resistor measurement system in an embodiment of the present invention, the voltage applied to the resistor for measurement is reduced to limit latent damage to the resistor through rectification during a low resistance cut of four seconds. Since the continuous cuts are made to increase the resistance, the measurement voltage is increased.

The typical trim and cut sequences of FIGS. 2A and 2B and 4A and 4B may be adjusted to allow for changes in material properties and other process variables and tolerances.

For example, in at least one embodiment of the present invention, additional steps may be utilized if the measurement trim cut reaches a target value and the length is within a predetermined margin of the maximum allowable cut length. Within the margin, a change in material properties may leave some short trim cuts of the target value and may require additional cuts.

In the first mode, trim cuts are made in series in a row of elements and the position of the elements that do not reach the ride value is saved. With continuous trim cuts, the elements remaining in the saved positions are trimmed to the target value.

In the second mode, the cut length is reduced to prevent the target value from being reached based on the length of the first element trimmed to the value and the non-measured cuts are processed to complete the row. Continuous trim cuts bring all elements into a row to revive the target value.

In the third mode, the length of at least one preceding cut on the element is modified to prevent successive cuts from falling into the margin state. In at least one embodiment, additional steps may be utilized if the value of the measurement trim cut is within a predetermined margin of the target value. Changes in material properties, in margin, may leave some element beyond the target value using sufficient unmeasured cuts.

In the first mode, trim cuts are made in series of elements and the positions of the elements that do not reach the target value are saved. With the continuous trim cuts, the other elements of the saved position are trimmed to the target value.

In the second mode, based on the value measured at the first element, the cut length is reduced to prevent the target value from being reached so that the non-measured cuts are processed to complete the row. Continuous trim cuts bring all the elements of the row to the target value.

In a third mode, the length of at least one preceding cut on the element is changed to prevent the successive cuts from falling into the margin.

Experimental data indicates an improvement in throughput by cutting all resistors in the row as shown in FIGS. 2-4 as opposed to the conventional single resistor trim method. Instead of examples, the approximate results are shown in the table below.

The total trim rate increases with the number of thermal resistors, fewer measurements, and the reduction time for the final (i.e. fine) trimming.

In addition, each resistor has an additional time to recover from the energy of laser generation. The continuation of the cuts may be determined to manage the temperature change in the element (eg, the maximum element temperature decrease during cutting). For example, referring to FIG. 4A, the sequence 405 may be reversed so that a set of cuts is initiated near the center of the element and progress to the end of the element approaching the lead and probe. Other orders, appropriate orders may be used (eg some order of non-adjacent cuts has an advantage for thermal management). Preferably, the second element may be cut prior to the addition step of the measurement. The range of resistance change for serpentine cuts varies from an amount of about 1 grade (eg 10X) to a typical (100X) amount of grade 2, and about 500X with current material.

laser Trim  Systems

In at least one embodiment of the invention, the laser trimming system may first be calibrated using the method described in US Pat. No. 4,918,284, "Laser Trimming Device Calibration." The '284 patent controls the laser beam positioning mechanism to move the laser beam to the desired nominal laser position on the substrate area, engraves a mark (e.g. line cutting) in the middle to establish the actual laser position, and the actual laser position. It teaches to calibrate the laser trimming device by scanning the inscribed mark to find the and comparing the actual nominal position with the desired nominal position. Preferably, the laser beam acts on one wavelength and the mark is scanned with a detector that acts on a different wavelength. The finder looks at the field covering the portion of the total substrate area and estimates the position of the mark in the field. The '284 patent also teaches determining where the beam position is with respect to the view of the camera field.

Other calibration methods may be used alone or in combination with the '284 method. For example, US Pat. No. 6,501,061 "Laser Calibration Apparatus and Method" discloses a method of determining scanner coordinates for precisely positioning a focused laser beam. The intensive laser beam is scanned by a laser scanner over the relevant area (eg, a hole) on the working surface. The location of the focused laser beam is detected by a photodetector at certain spans of time or when a space or focused laser balm appears through a hole in the work surface. The detection position of the concentrated laser beam is used to generate beam position data versus scanner position based on the position of the laser screener at the time the concentrated laser beam is detected. The beam position data versus screener position is used to determine the scan position coordinates corresponding to the center of the hole or the desired position of the focused laser beam.

The order for system calibration preferably includes calibration of many other system components, with at least one substrate having the devices to be trimmed loaded in the trim location.

With reference to FIG. 6A, an improved laser trimming system, partially incorporated from the '284 patent, is provided with a laser beam 603 along the optical path 604 and through the laser beam positioning mechanism 605 to the substrate region 606. Silver may include an infrared laser 602, typically having a wavelength from about 1.047 microns to 1.32 microns output. To apply to the trimming of thin film arrays, a preferred wavelength of about .532 microns may be obtained by doubling the output frequency of the IR laser using various techniques known in the art and commercially available.

The laser beam positioning mechanism 605 preferably includes a pair of mirrors and is attached to respective galvanometers 607 and 608 (available from the assignee of the present invention, respectively). The beam positioning mechanism 605 directs the laser beam to the substrate on the field through the lens 609 (which may be telecentric or non-telecentric, preferably bleached to both wavelengths). The X-Y galvanometer mirror system may provide the angular range of the entire substrate if sufficient precision is maintained. If not, various positioning mechanisms may be used to provide relative motion between the substrate and the laser beam. For example, a two axis precision step and repeat translator, outlined at 617, may be used to position the substrate in a field of galvanometer based on mirror systems 607, 608 (eg, in the X-Y plane). The laser beam positioning mechanism 605 provides two-dimensional denture determination of the laser beam 603 beyond the substrate region 606 by moving the laser beam 603 along two predetermined axes. Each mirror and associated galvanometers 607 and 608 move the beam along its respective x or y axis under the control of the computer 610. The lighting devices 611 may be halogen light or light emitted from diodes to produce visible light to illuminate the substrate region 606.

A beam splitter 612 (partially reflective mirror) is located in the light path 604 toward the light energy reflected back along the path from the substrate region 606 to the discovery device 614. The discovery device 614 includes a camera 615, which may be a digital CCD camera, or may be associated with a frame grabber 616 (or a digital frame buffer provided in the camera) to receive video input from the television camera 615. The pixel data representing the two-dimensional image of the portion of the substrate region 606 is converted into numerical values to obtain. The pixel data is stored in the memory of the frame grabber 616 or transmitted, for example, by a high speed link directly to the computer 610 for processing.

The beam positioning subsystem may contain computer controlled optical subsystem for adjusting the laser spot size and / or other optical components, such as auto focusing the laser spot at the location of the substrate.

In applying the invention to thin film trimming of resistor arrays, at least one thin film array is supported by a substrate. The calibration data obtained above is preferably in combination with an automated machine vision calculation scheme by positioning the elements of the array (e.g., resistor R1) to measure the position of at least one geometrical feature of element 620 of FIG. 6B. Is used. For example, the feature is one of the horizontal edges 621 (e.g., edges parallel to the X direction) and the vertical edges found by analysis of pixel data in memory using a number of obtainable edge finding schemes ( 622 (eg, edges parallel to the Y direction). The edges may include a composite edge measurement along the entire perimeter of the resistor, a sample of the edges, and many resistors in the array. The width of the resistor device may then be determined and used to define the cutting length, typically as a width of a predetermined percentage. Preferably, the corner information is obtained automatically and used as calibration data, for example to control the length of each cut in the column R1 ... RN. Other methods of measurement may also be used in suitable, for example, image calibration or blob discovery methods.

The correction is applied to one or more points along the cut. In at least one embodiment, the starting point of at least one cut is to be corrected with calibration data.

Preferably, the grinding and starting points of the plurality of cuts of FIGS. 2 and 4 are corrected.

Most preferably, the grinding and starting point of all cuts in FIGS. 2A and 4A are corrected.

In one embodiment, the first resistor (eg R1 or RN) is calibrated and the corresponding correction is applied to all resistors in the column (eg R1, .. RN).

Complete automation is preferred. However, a semi-automatic way of operator interference may be used, for example a galvanometer is placed so that the array elements 620 are in the field, the next beams are arranged continuously in interaction with the elements and on the display 630 by the operator. An intensive profile (or derivative or intensive) is observed.

The use of correction information in adjusting the coordinates within the array area is valuable for improving the accuracy of laser beam positioning without lowering throughput. The measurements of the storage width and alignment data are useful for controlling the length of the cut and correcting deviations from the linearity and non-orthogonality of the array relative to the scanner X, Y coordinate system. The use of calibration data for geometric correction is particularly well suited for use in laser trimming systems with one or more linear translation steps. Geometric correction does not require replacement and other useful system design features, including fsitter lens linearity, linear beam correction, and the like. System tolerance stack-up may generally be used to determine tradeoffs between the number of cut calibration positions based on the expected placement error. In particular, when spreading the beam linearly into a large space beyond many resistors, only one is calibrated and aligned. For example, if the space between resistors is relatively large, a single cut is calibrated and aligned. Errors incurred in placement are expected in factors that will be partially mitigated by system design, fsitter linearity, linear spread compensation, and the like. It is anticipated that the closely isolated cuts of the intersecting fans will have a small error compared to the fans on the axis.

Throughput Improvements-Optical Techniques

In at least one embodiment of the present invention, throughput may be further improved by increasing the effective scan fineness using one or more of the techniques below.

Further increase in processing speed with trims in the same straight line can be achieved with faster jumps across trim gaps between rows of resistors. One such gap is shown in FIG. 2A. Referring to FIG. 7, in at least one of the present inventions, a single axis acoustic-optical beam deflector (AOBD) superimposes a sawtooth line scan pattern 701 as galvanometer scans cross a row at a constant speed 702. . The AOBD scans of the retraction movement 703 and between the trims during trimming provide a quick jump to the next cut. This allows the galvanometer to scan at a constant speed and minimizes the contribution of jumps to the total processing time.

The use of acoustic-optic beam deflectors in combination with galvanometers for speed improvement is well known in the art. For example, US Pat. No. 5,837,962 describes an improved apparatus for heating, dissolving, vaporizing or cutting a workpiece. Two-dimensional acoustic-optical deflectors provided for five factors of improvement in display speed.

US Pat. No. 6,341,029, which is incorporated by reference in its entirety, shows in Figure 5 an embodiment with several components that may be used in a complete system when implementing the invention in a retraction mode for increasing speed. In the '029 patent, acousto-optic deflectors and galvanometers, in conjunction with a controller, show jitter CW beams for the laser pattern. See also Section 3, Line 47 and Section 4 of the '029 Patent for additional details related to system configuration.

The arrangement of the '029 patent may be readily adapted using available techniques to provide for modifications of the optical components and the scan control profiles are preferably additional hardware calibration procedures to implement the retreating scanning technique of the present invention. Have

In another embodiment of the invention, collinear trims on serpentine resistors may be achieved in a parallel shape with multiple spots along the rows. A device of developing squeaking or other multi-beam calculations is used to create a spot array such that two or more spots are formed and aligned with the resistor pitch along the row. For example, U. S. Patent No. 5,521, 628 discloses the use of marking a diffractive lens simultaneously in multiple parts. The multiple beams may be generated from a more powerful laser source, or may be low output beams combined from multiple sources. The scan system scans multiple beams and forms spots through a common lens that simultaneously crosses multiple resistors. The trim process is similar to the single supot method with two or more cuts in parallel during nonmeasured cutting steps. When the threshold is reached, the system converts each resistor in single spot mode to trim the values in succession.

Likewise, collinear trims on serpentine resistors may be achieved in a parallel style with multiple spots formed on the target to make parallel cuts. A device of developing squeaking or other multi-beam calculations is used to create a spot arrangement so that two or more spots are formed, the spots being elements at predetermined intervals between the cuts. If a predetermined number of cuts are then executed (eg, as shown in FIG. 4A), in one embodiment, the number of passes can be reduced to 50% (eg: single in each direction). Pass). This embodiment may be most useful if resistance process changes and tolerances are well established. The diffraction grating may be in an optically translated path to selectively form multiple spots or a single number spot.

Published US Patent Application 2002/0162973 discloses a method and system for creating multiple spots for processing semiconductor links for memory repair. Various modifications to the lens system and the deflector system may be used to generate multiple spots for use in the present invention.

In one embodiment, a single laser pulse is used to trim up to two resistors at a time (eg, not one or two cuts). Referring to FIG. 8, two spots 801, 802 are formed by spatially dividing a single aimed laser beam 803 on two cuts in two split beams of light 804, 805. do. Fine tuning of different frequencies controls spot separation. The use of an acoustic-optical device for spatially separating beams in material processing applications is well known in the art. For example, Japanese Patent Summary JP 53152662 shows one arrangement for drilling holes in a microscope using a multi-frequency deflector with selectable frequencies f1 ... fN.

The laser 806 of FIG. 8 is pulsed at a predetermined repetition rate. The laser beam passes through an intermediate optic that forms an intermediate image of the laser beam waist into the acousto-optic modulator (AOM) aperture. Operating in Bragg tissue, AOM 808 is preferably used to control the energy of each laser bin by controllably generating two slightly divergent collimated primary diffraction laser beams. AOM is driven by two frequencies, f1 and f2 (f1 = f0 + df, f2 = f0-df, where df is a small percentage of the original RF coral frequency f0). The angle between the two beams is approximately equal to the Bragg angle with f0 times 2 (df / f0). The AOM controls the energy of the angle of the laser beams by two frequency components, a single amplitude of f1 and f2 in the RF signal 812 to make adjustments to the beam crosslink.

After exiting the AOM 808, the beams pass through the light beam rotation control module 809 to rotate the 90 degree beams toward the beam at X or Y. Although many methods of rotation are well known as described in connection with US Patent Publication No. 2002/0170898, in one embodiment a prism is used for this rotation.

The beam then passes through a set of optics to place the beam waist and a set of beam sizes that matches the actual lens 810. The zoom optics also change the angle between the two beams so that the angle between the two beams leaving the AOM must be adjusted with respect to the zoom setting to result in desirable spot separation in the focal plane. The laser beams then enter a real lens 810 providing a pair of spots 801, 802 focused on two resistors. Two spots. Separated by a distance equal to the focal length of the lens 810 multiplying the angle between the two beams. Retracting and parallel methods can be combined for collinear trimming on serpentine resistors. For example, chestnuts are scanned by AOBD, split into the next pair, and scanned across the field. Two adjacent resistors are trimmed at the same time so the jump is from resistor N to resistor N = 2 to the next pair or resistors.

Alternatively, or with a two-dimensional deflector, the pair of spots may be calculated in a direction orthogonal to the serpentine scan direction. For example, with relatively simple control and programming of a one-dimensional AOBD, the deflector may be used to simultaneously calculate (with adequate output power control) at least two of the beams of the net used to make a cut of the net as shown in FIG. 4A. have. As such, the scan time for cuts may be reduced by 50%. As a result of the programmable bias, the AODB may take precedence over the deployment grid. Multiple spots may also be as crude as needed to produce fine trims.

9 schematically illustrates an exemplary embodiment of an improved laser trimming system with module 901 from FIG. 8 added for retracting scanning, parallel processing, or a combination thereof. For example, the signal 902 from the computer 610 may be used to control the AOBD or other solid deflector 808 of one or more axes, and the beam rotation module 809, if ready. Module 901 may include relay optics 807 and other beam forming components. Preferably, at least one AOBD is used to provide a great flexibility and ease of use, for example to provide a digital RF generator that provides a signal 812 from the computer 610.

Moreover, techniques for forming elongated elliptical spots can be employed in the present invention to further increase the quality of the processing speed. Improvements in the trimming rate associated with spot formation are described in published US patent application 2002/0170898 to the simultaneous application.

Many other design alternatives may be used in at least one embodiment of the invention to enhance system implementation and ease of use. For example, substitutions include but are not limited to the following.

1. The system may be prepared for spot size and / or focus adjustment of computer control. U. S. Patent No. 6,483, 071 to the assignee of the present invention describes an optical subsystem for both spot size control and dynamic focus for memory repairs of laser foundations.

2. Another alternative is the control of beam energy with a variable beam attenuator. The attenuator may be an acoustic optical deflector (or modulator). Neutral filters or polarizer-based attenuators may be used, whether manually adjusted or automatically adjusted. US Pat. No. 6,518,540 shows, for example purposes, a suitable variable attenuator with a rotating half waveplate and polarizing sensitive beam splitter.

3. The pulse width may be changed using methods known to those skilled in the art, with the understanding that the energy of the laser of q conversion will vary at a repetition rate, especially at high repetition rates. For dynamic trimming, measurements may be made between the pulses, prioritizing to maintain a substantially constant pulse energy. The method for controlling pulse energy is disclosed in the 6,339,694 patent, which reduces the change in energy at the target so that the trimming speed is reduced (e.g. larger laser time space), when the resistance value reaches a predetermined target value. Corresponds to the periods of measurement.

4. In at least one embodiment, the frequency double, YAG laser of the diode pump is used to trim the resistor arrangement. The output wavelength of 532 nm results in zones of low drift, the absence of micro cracks, and insignificant thermal effects when compared to other wavelengths. Pulse widths of about 25-45 ns may be prioritized below typical 30 ns. The preferred maximum laser repetition rate will be at least 10 KHz. Much less than typical for thin film systems, the pulse width provides for thin film material movement at relatively high repetition rates. Preferably, multiple spots may be provided since the maximum available pulse energy at reduced pulse widths and high repetition rates will allow losses associated with diffractive optics (eg grating or AOBD).

5. The laser may be focused on the spot size of the approximate, diffraction limit. The spot size is typically less than about 30 microns, or less than about 20 microns with a preferred spot size, and the most preferred spot size in the range of about 6-15 microns, for example 10-15 microns, is typical. would.

6. In the described embodiments of the invention, the xiamenite cuts are described as a series of parallel cuts. However, it will be appreciated that the application of the present invention is not limited to forming parallel cuts. Trimming or micromachining for calculating a plurality of non-cross cuts with a reduced number of measurements is considered within the scope of the invention.

7. In addition, embodiments of the invention are not limited to thin film resistor measurements, but may be applied to other micromachined applications where physical properties are measurable. The measurement is not limited to electrical measurements, but may be a temperature that monitors (eg, with an infrared sensor) a stress, vibration, or other characteristic.

As described herein, comparative application studies were conducted using three types of lasers: conventional IR laser 1.064 μm, green laser 0.532 μm, and UV laser 0.355 μm. The results of the study clearly indicated that green lasers gave better results than lasers of the same or achieved TRC drift and resistance tolerances. However, samples treated with UV lasers are easy to have micro cracks in the cut, as indicated in FIG. 10.

For example purposes, a laser output of pulses of about 30 mW was applied to the resistor over a spot size of about 13 microns on the surface. The wavelength was .532 microns. Good results, in particular the absence of micro cracks, were provided at the green wavelength. Laser operation may be performed within the range of about 10 mw to 50 mw over a 13 micron spot diameter.

The corresponding output density (watts / cm ² ) is a function of the spot size, and the laser output power in the pulse may be appropriately determined as the spot size is deformed. For example, the laser power mW with a pulse may be reduced by four times if the spot size is 6 microns.

Although wavelengths of .532 microns have shown good results, other wavelengths may be utilized. Although old, embodiments of the invention avoid wavelengths that are virtually short enough to cause microcracks.

Mark widths as small as 6 microns are achieved with the novel optics shown in FIG. Typically, a mark width of approximately 12 microns can handle chip sizes below 0402 and 0201. FIG. 13 shows a 0402 resistor treated with a green laser.

Michael cracks in cuts by the UV laser may extend inside the film causing R and TRC drifts. It brings more volunteers and is published on the new 0402 and 0201 chip resistors due to the use of thinner substrates. Microcracks result in multiplying breakdown failures of the substrate. Thus, if the laser wavelength becomes too short, for example into the UV region, the UV treatment is subject to the shortcomings of microcracks and their cracking (i.e. dragging of R and TCR due to cracking and their growth in the film material). It is clear that there is instability caused by.

Beam homogenization of UV beams is proposed (US Pat. No. 6,534,743). According to this patent, the number of microcracks is reduced but the microcracks are not completely excluded.

In addition, UV lasers are inherently less stable due to the need for two nonlinear crystals than one. Other drawbacks of UV lasers for resist trimming include process instability, including substrate damage and sensitivity to beam profile.

The data shown here teach that there is no benefit to using UV lasers in trimming these chip devices. Green lasers are accomplished as marks and TCR in as little as lasers can. 11 shows the part processed by the green laser,

With this new possibility of 6 micron marks, there is no doubt that the green laser wavelength is short enough to handle any many chip resistors from optical points in terms of small spot size.

Thus, green leisures with Gaussian beam shapes have all the benefits of UV lasers without the risks associated with UV laser processing such as micro cracks and susceptibility.

The preferred wavelength should be small enough to yield the desired benefits of shorter wavelengths, such as smaller spot sizes, tight tolerances and high absorption, but not too short to cause micro cracks.

Various embodiments of the present invention will also generally avoid substantial increases in material and running costs, process instability, complexity and instability. For purposes of example, the benefits of the present invention stem from the optical component hardware of association for escape of UV wavelengths (short to cause actual microcracks) and third harmonic generation. In addition, auxiliary beam shaped optics for calculating uniform spot distributions are not needed when implementing embodiments of the present invention.

Therefore, an object in one embodiment of the present invention is the use of a green laser for trimming.

Some of the features of this embodiment are:

   1. Achieves the high absorption required for smaller spot sizes and smaller chip sizes,

     Laser to avoid the possibility of causing micro cracks and damage to the substrate

     Use of green laser to trim.

  2. New for green wavelengths as a means to realize green laser processing potential

     Use of designed optics. The optics are taken below with FIG.

     It is explained in detail.

  3. High precision beam spraying system as a means to realize green laser processing potential

     The use of.

  4. Measure the subsystem as a means to realize the green laser processing potential

     The use of a trim system to test.

For thin film hybrid systems, about 25 to spot side with green laser, smaller spots of less than 20 microns, preferably spot sizes less than 12 microns, most preferably 8 microns or about 7000 spots across field diameter has a scan field surrounding a scan area of mm × 50 mm; At least 40 nm, preferably 100 nm. And most preferably it has a viewing channel with a bed width of> 100 nm. The viewing channel may be part of a white spectrum of about 550 nm subphase selected with a band pass or high pass optical filter. The viewing channel may be selected by the emission spectrum of the LED illuminator. Across the field to a scanning lens yielding an 8 micron green spot at 532 nm.

 It is also desirable to calculate at 1.064 microns of about 17 microns across the field.

The lens form below was found to be effective in order to meet the requirements of a scan area of 17 micron spot of 25 mm x 50 mm, 8 micron spot 532 nm, 1.064 nm with selected viewing channel.

It goes without saying that elements that are described as having flat surfaces and that may be roughly flat surfaces, or roughly flat surfaces with curved surfaces with relatively long radii, do not contribute to substantial light output.

Multi-element colorless scanning lenses continue to contain from the side of incident light:

n ₂ <n ₃

n ₂ > n ₃ being

Preferred solution (shown in Figure 14)

First both concave element L1

First cemented bi-lens comprising planar concave and both convex elements L2, L3, cemented surface concave away from incident light

A second cemented bi-lens comprising planar concave and both convex elements L4, L5,

Cement bonded surface concave away from incident light

First subconcave-convex lens element L6 concave toward the incident light

First both convex elements L7

Triplet  solution

Move Airspace L5 / L6 to create triplets:

First both concave element L1

First cemented bi-lens comprising planar concave and both convex elements L2, L3, cemented surface concave away from incident light

Flat concave, both convex elements, first cemented triplet comprising subconvex lens elements L4, L5, L6, the first cemented surface recess is away from incident light

First both convex elements L7

6 element solution

6 moves L5 to create an element design

First both concave element L1

First cemented bi-lens comprising planar concave and both convex elements L2, L3, cemented surface concave away from incident light

First planar convex element L4

First subconcave-convex lens element L6 concave toward the incident light

First both convex elements L7

Preferably L2 is an anomalous dispersion glass, for example KzFSN4.

An exponential anomaly

L1 n ₁ > 1.58 n ₁ <40

L2 1.85> n ₂ > 1.5 n ₂ <50

L3 n ₃ > 1.58 n ₃ <40

L4 n ₄ > 1.61 n ₄ <35

L5 1.85> n ₅ > 1.5 n ₅ <40

L6 n ₆ > 1.61 n ₆ <35

L7 1.85> n ₇ > 1.5 n ₇ <40

Effective focal length 110 mmm

Incident pupil diameter 13.8 mm

Input beam 1 / e ² 13.8 mm

After working distance 150mm

Cutting wavelength (s) 532 nm, 1.064 μm

Spot size 1 / e ² At .532 μm, 8 μm

Spot size 1 / e ² 17 μm at a diameter of 1.064 μm

Field angle 15 °

Field size 25 mm × 50 mm

Telecentricity <3 °

Spot roundness ≥90%

Penetrating lens Viewing  Having green / IR Sken  lens

Glass data

Index distribution

L1 1.65 33.8

L2 1.61 44.3 or later

L3 1.88 25.4

L4 1.81 25.4

L5 1.69 53.3

L6 1.81 25.4

L7 1.61 56.9

Preferred lenses can be made by several optical manufacturers including special optics inks, according to the following product specifications.

Reds  Standard or product specification

While embodiments of the invention have been illustrated and described, these embodiments are not intended to illustrate and describe all possible forms of the invention. Moreover, the terminology used herein is for the purpose of description and not of limitation, and various changes may be made without departing from the spirit and scope of the invention.

Claims (52)

1. A method of trimming an electrical device using a precision laser based on a high speed laser on at least one electrical device supported on a substrate, having at least one measurable property, Generating a pulsed laser having one or more laser pulses at a repetition rate; Selectively irradiate one or more electrical elements with one or more laser pulses focused on one or more spots of about 15 microns or less, with non-uniform intensity profiles along one direction, to determine wavelength, energy, pulse duration and spot diameter Selectively irradiating the one or more devices while removing material from the one or more devices with one or more laser pulses having the microcracking within the one or more devices, the wavelength being small spot size, tight tolerances and high absorption And short but not causing microcracking to produce desirable wavelength characteristics. The method of claim 2, The focused pulsed laser power corresponds to about 10-50 mw over a range of spot diameters of less than about 15 μm, and this power appears as a reduced spot size of less than about 15 μm, so that the corresponding power density can trim the device. Enough, but low enough to prevent microcracking. According to claim 1, Microcracking obtained as a result of removing material from at least a first portion of one or more devices compares to microcracking obtained when removing material from one or more devices or a portion of a second device using one or more other wavelengths outside the laser wavelength range. Characterized in that the method. The method of claim 1, The removal of material from the one or more devices is characterized by forming a trim cut having a kerf width corresponding to the spot diameter. The method of claim 1, Optionally irradiating with one or more laser pulses limits the formation of a heat affected zone. The method of claim 1, And the repetition rate is at least 10 kilohertz. The method of claim 1, Wherein the pulse duration of the one or more laser outputs of the laser output ranges from about 25 nanoseconds to 45 nanoseconds. The method of claim 1, Wherein the pulse duration of the one or more laser pulses of the laser output is less than about 30 nanoseconds. The method of claim 1, The array of thin film electrical elements is tripped and this method Selectively machining one element of the array to change the value of the measurable characteristic; Optionally stopping machining and optionally machining one or more other elements of the array to change the value of the measurable characteristic while the selectively machining step is stopped; And resuming a stationary step that is optionally mechanically operable to change the measurable characteristic of one device until the measurable value is within the desired range. The method of claim 9, At least one device comprises a resistance and at least one measurable characteristic is at least one resistance and a temperature. The method of claim 9, If the measurement of the one or more measurable characteristics is within a predetermined range, stopping the machining. A method of laser trimming one or more electrical elements having measurable characteristics, Providing a laser trimmer comprising a pulsed laser system, a beam delivery system and a controller; In execution, the control system is controlled by a controller, the system providing a control program that causes the one or more laser pulses of the pulsed laser output to trip one or more devices while preventing microcracking of the one or more devices, The pulsed laser power has a repetition rate of about 10 kilohertz or more, has a visible laser wavelength, The beam delivery system has a non-uniform intensity profile along one direction, and has an optical subsystem to generate a focused spot of about 15 microns in diameter from one or more laser output pulses, with a wavelength of small spot size, tight tolerances and A method of trimming an electrical element, characterized in that it is short enough to produce the desired short wavelength characteristics of high absorption but not short enough to cause microcracking. The method of claim 12, And a visible laser wavelength of about 5 microns to about 7 microns. The method of claim 12, Wherein the diameter is as small as about 6 microns to about 10 microns. The method of claim 12, The array of thin film electrical elements is tripped and this method Selectively machining one element of the array to change the value of the measurable characteristic; Optionally stopping machining and selectively machining one or more other elements of the array to change the value of the measurable characteristic while the selectively machining step is stopped; And resuming a stationary step that is optionally mechanically operable to change the measurable characteristic of one device until the measurable value is within the desired range. At least one thin film electrical element trimmed by the method of claim 1 during at least one step of producing the apparatus. An electrical device having at least one thin film electrical element tripped by the method of claim 12 during at least one step of producing the device. A system for precision laser trimming on a high speed basis of one or more electrical elements supported on a substrate having one or more measurable characteristics, Having a laser subsystem for generating a pulsed laser output with one or more laser pulses at a repetition rate, Each of these pulses has a pulse energy, visible laser wavelength and pulse duration; A beam delivery subsystem comprising one or more beam deflectors that receive pulsed laser output and position one or more laser pulses relative to one or more devices to trim; It also has an optical subsystem for focusing one or more laser pulses having visible laser wavelengths to one or more spots in the field of the optical subsystem, At least one spot has an optical subsystem having a non-uniform intensity profile along one direction and a spot diameter of about 15 microns or less; In addition, one or more laser output pulses having visible laser wavelength, pulse duration, pulse energy, and spot diameter can be beam delivered to selectively remove material from one or more devices and trip one or more devices while preventing microcracking in one or more devices. And a controller coupled to the subsystem and the laser subsystem to selectively irradiate one or more devices. The method of claim 18, The focused pulsed laser power corresponds to about 10-50 mw over a range of spot diameters of less than about 15 μm, and this power appears as a reduced spot size of less than about 15 μm, so that the corresponding power density is sufficient to trim the device. However, the system characterized by being low in preventing microcracking. The method of claim 18, The spot is limited in diffraction and the non-uniform intensity profile is approximately Gaussian profile along the direction. The method of claim 18, Microcracking is prevented in a material proximate one or more devices. The method of claim 18, And the laser subsystem is a q-switched, frequency-amplified, diode amplified semiconductor laser. The method of claim 8, The laser subsystem includes a q-switched, frequency-amplified, diode-amplified semiconductor laser having a fundamental wavelength in the range of about 1.047 microns to 1.32 microns. The method of claim 18, The laser wavelength is a green laser wavelength. The method of claim 24, And the green laser wavelength is about 532 nm. The method of claim 18, The spot diameter is as small as about 6 microns to about 10 microns. The method of claim 18, The optical subsystem includes a lens that is color shaded at two or more wavelengths, wherein the one or more wavelengths are visible wavelengths. An illuminator for illuminating the substrate region with radiant energy having one or more illumination wavelengths; And a detection device having sensitivity to radiation energy having at least one illumination wavelength, wherein one of the at least two wavelengths is a visible laser wavelength and the other is an illumination wavelength. The method of claim 18, The optical subsystem is a telecentric optical subsystem. The method of claim 29. The telecentric optical subsystem includes a telecentric lens. The method of claim 18, The repetition rate is at least 10 kilohertz. The method of claim 18, And wherein the pulse duration of the one or more laser pulses of the laser output ranges from about 25 nanoseconds to about 45 nanoseconds. The method of claim 18, And wherein the pulse duration of the one or more laser pulses of the laser output is about 30 nanoseconds or less. Under 18, And the controller comprises means for controlling the position of the pulsed laser output relative to the one or more devices. The method of claim 18, Means for controlling pulse energy to selectively irradiate one or more devices. The method of claim 18, Wherein the one or more laser pulses are focused to irradiate one or more devices with a spot diameter as small as about 6 microns to about 15 microns. The method of claim 18, And the optical subsystem receives one or more laser pulses after deflection by one or more beam deflectors. The method of claim 36, The focused spot diameter is as small as about 6 microns to about 10 microns at any location within the field of the optical subsystem. The method of claim 18, And a calibration algorithm that adjusts the coordinates of the material to be radiated within the one or more devices to precisely control the size of the area of material removal. The method of claim 18, And a machine vision algorithm comprising a vision algorithm to locate or measure one or more geometrical components of the one or more elements. The method of claim 40, Wherein the at least one geometry is an edge of one or more devices, the edge being used to determine the width of the one or more devices to define the material removal size. The method of claim 18, The at least one device is a thin film resistor, the at least one measurable characteristic is at least one resistance and temperature, and the system further comprises means for stopping removal of the thin film material of the resistor when the measurement of the at least one measurable characteristic is within a predetermined range. System comprising a. The method of claim 18, The material of the substrate is a semiconductor. The method of claim 18, And the material of the substrate is ceramic. The method of claim 18, The at least one device comprises a thin film device. The method of claim 18, The array of thin film electrical elements trips to the system, and the controller Means for selectively micromachining the array element to change the measurable characteristic; Means for stopping optional micromachining while the optional micromachining stops; Means for selectively micromachining one or more other array elements to change the value of the measurable characteristic; And means for resuming selective micromachining to alter the measurable characteristic of the device in the array until the measurable characteristic value is within the desired range. The method of claim 18, It further includes a user interface, a software program connected to the user interface, and a controller, the software program accepting pre-trip target values for one or more devices to limit the electrical output applied to one or more devices based on these values. System characterized in that. The method of claim 47, Wherein the potential damage to one or more devices is prevented. 10. A saximium scan lens system for use in a laser based micromachining system having a scan field having a laser spot size of 20 microns and a viewing channel having a bandwidth of at least 40 nm, comprising multiple lens elements comprising a double line. Incident micromachining laser beam from the side, A first element L ₁ having negative optical power, refractive index n ₁ and Abbe dispersion number v ₁ ; A second element (L ₂ ) having a refractive index (n ₂ ) and an Abbe dispersion number (v ₂ ), Colorimetric lens, characterized in that n ₁ &lt; n ₂ and v ₁ &gt; v ₂ to meet the requirements of spot size, field size and viewing channel bandwidth. The method of claim 49, The double line is a reinforcement double line having a reinforcing surface, and the reinforcing surface is concave from the incident machining laser beam. 51. The method of claim 50, L ₁ is a concave element of flat, L ₂ is achromatic lens, characterized in that the double concave element. 51. The method of claim 50, L ₁ and L ₂ is the second and third elements of the multi-element lens and then the lens elements are achromatic lens, characterized in that six or more lens elements.

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