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A controlled, switched laser system for vaporizing a target structure on a substrate includes a diode-pumped, solid-state laser for producing a laser output, a controllable switch for controlling the on/off state and power level of the laser, and a wavelength shifter. The wavelength shifter shifts t

A controlled, switched laser system for vaporizing a target structure on a substrate includes a diode-pumped, solid-state laser for producing a laser output, a controllable switch for controlling the on/off state and power level of the laser, and a wavelength shifter. The wavelength shifter shifts the wavelength of the laser output from a conventional wavelength to a wavelength beyond the absorption edge of the substrate but shorter than 1.2 μm in order to obtain a decrease in absorption of the laser output by the substrate due to the shift in the wavelength of the laser output. The wavelength shifter is removably insertable into the switched laser system so as to enable the switched laser system to operate at the conventional wavelength and at the wavelength beyond the absorption edge of the substrate. Heating of the substrate and hence damage to the substrate is limited due to the wavelength being beyond the absorption edge of the substrate. Good depth of focus of the laser beam output is maintained relative to spot size of the laser beam output due to the wavelength being less than about 1.2 μm.

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1. A laser-based method of vaporizing and removing a target link structure on a semiconductor wafer comprising the steps of:providing a target link structure supported on a silicon substrate, the substrate being part of a semiconductor memory device;producing a laser beam having a pulse width less t

1. A laser-based method of vaporizing and removing a target link structure on a semiconductor wafer comprising the steps of:providing a target link structure supported on a silicon substrate, the substrate being part of a semiconductor memory device;producing a laser beam having a pulse width less than about 8 nanoseconds, an operating repetition rate of 10 kilohertz or higher, and a wavelength less than 1.2 microns;generating computer-controlled timing signals synchronized with position of the laser beam relative to the target link structure;controllably switching an optical switch based on the timing signals so as to transmit an output pulse of the laser beam to the target link structure on demand, the output pulse rate being controlled by controlling the optical switch;focusing the output pulse onto the target link structure into a spot diameter;whereby the spot size and depth of focus is improved relative to a longer wavelength greater than 1.2 microns, and the output pulse width limits damage to the substrate. 2. The method of claim 1 further comprising the step of mounting the device on a movable stage. 3. The method of claim 1 wherein the movable stage is a step and repeat stage. 4. The method of claim 2 wherein the target link structure comprises metal. 5. The method of claim 1 wherein a maximum processing rate exceeding 10,000 target link structures per second is achievable with a repetition rate of greater than 10 KHz. 6. The method of claim 1 wherein the step of generating computer-controlled timing signals includes correlating the timing signals with the position of the laser beam and the target link structure during relative motion between the laser beam and the target link structure. 7. The method of claim 6 further comprising positioning the beam with a galvanometer, and synchronizing the timing signals with the galvanometer positions. 8. The method of claim 1 wherein the optical switch is disposed in an optical path and is positioned beyond the laser cavity and external to the laser cavity. 9. The method of claim 1 wherein the output pulse width is less than 5 nanoseconds. 10. The method of claim 1 wherein the correlating step further comprises providing accuracy of better than 0.3 microns between the laser beam and the target link structure. 11. The method of claim 1 wherein the step of controllably switching the optical switch further comprises controlling an acousto-optic modulator to prevent an output beam from reaching a target link structure except when desired, and controlling an acousto-optic optic modulator to set the output power to a desired level. 12. A laser-based method of vaporizing and removing a target link structure on a semiconductor wafer comprising the steps of:providing a target link structure supported on a silicon substrate, the substrate being part of a semiconductor memory deviceproducing a laser beam having a pulse width less than about 8 nanoseconds, an operating repetition rate of 5 kHz or higher, at a first laser wavelength;generating computer-controlled timing signals synchronized with position of the laser beam relative to the target link structure;shifting the first laser wavelength to a second laser wavelength, the second wavelength being less than 1.2 microns;controllably switching an optical switch based on the timing signals so as to transmit an output pulse of the laser beam to the target link structure on demand, the output pulse rate and pulse spacing being controlled by the controlling the optical switch;focusing the laser output pulse onto the target link structure into a spot diameter, the output pulse having a wavelength less than 1.2 microns and a pulse width less than about 8 nanoseconds;whereby the spot size and depth of focus is improved relative to a longer wavelength greater than 1.2 microns, and the output pulse width limits damage to the substrate. 13. The method of claim 12 further comprising the step of mounting the device on a movable stage. 14. The method of claim 13 wherein the movable stage is a step and repeat stage. 15. The method of claim 12 wherein the target link structure comprises metal. 16. The method of claim 12 wherein a maximum processing rate exceeding 10,000 target link structures per second is achievable with a repetition rate of greater than 10 KHz. 17. The method of claim 12 wherein the step of generating computer-controlled timing signals includes correlating the timing signals with the position of the laser beam and the target link structure during relative motion between the laser beam and the target link structure. 18. The method of claim 12 wherein the optical switch is disposed in an optical path between a wafer and a laser, and is positioned beyond the laser cavity and external to the laser cavity. 19. The method of claim 12 wherein one of the first and second wavelengths is beyond the absorption edge of the silicon substrate and one of the first and second wavelengths is not beyond the absorption edge of the substrate. 20. The method of claim 19 wherein the wavelength less than the absorption edge is less than about 1.12 microns. 21. The method of claim 20 wherein the wavelength less than the absorption edge is about 1.047 microns. 22. The method of claim 20 wherein the wavelength less than the absorption edge is about 1.064 microns. 23. The method of claim 15 wherein both the first and second wavelengths are less than 1.2 microns. 24. The method of claim 15 further comprising positioning the beam with a galvanometer, and synchronizing the timing signals with the galvanometer positions. 25. The method of claim 15 wherein the output pulse width is less than 5 nanoseconds. 26. The method of claim 15 wherein the correlating step further comprises providing accuracy of better than 0.3 microns between the laser beam and the target link structure. 27. The method of claim 15 wherein the step of controllably switching the optical switch further comprises controlling an acousto-optic modulator to prevent an output beam from reaching a target link structure except when desired, and controlling an acousto-optic optic modulator to set the output power to a desired level. 28. A method of vaporizing and removing a target link structure on a silicon substrate, comprising the steps of:providing a controlled, switched laser system comprising a diode-pumped, solid-state laser assembly and a controllable switch for controlling the on/off state and power level of the laser assembly;producing a laser beam output having an output pulse width less than about 8 nanoseconds at an operating repetition rate of about 5 kilohertz or higher, and a wavelength shorter than 1.2 microns; anddirecting the laser beam output at the target link structure on the silicon substrate to vaporize and remove the target link structure;whereby heating of the silicon substrate and hence damage to the silicon substrate is limited due to the output pulse width being less than about 8 nanoseconds. 29. A laser system for vaporizing and removing a target link structure on a semiconductor wafer, comprising:a laser assembly configured to produce a laser beam having a pulse width less than about 8 nanoseconds, an operating repetition rate of 10 kilohertz or higher, and a wavelength of less than 1.2 microns;a computer programmed to control timing signals synchronized with position of the laser beam relative to a target link structure supported on a silicon substrate, the substrate being part of a semiconductor memory device; andan optical switch that is controllably switchable based on the timing signals so as to transmit an output pulse of the laser beam to the target link structure on demand, the output pulse rate being controllable by controlling the optical switch, the laser assembly being configured to focus the output pulse onto the target link structure into a spot diameter;whereby the spot size and depth of focus is improved relative to a longer wavelength greater than 1.2 microns, and the output pu lse width limits damage to the substrate. 30. A laser system for vaporizing and removing a target link structure on a semiconductor wafer, comprising:a laser assembly configured to produce a laser beam having a pulse width less than about 8 nanoseconds, an operating repetition rate of 10 kilohertz or higher, and a first wavelength, and configured to shift the first laser wavelength to a second laser wavelength, the second wavelength being less than 1.2 microns;a computer programmed to control timing signals synchronized with position of the laser beam relative to a target link structure supported on a silicon substrate, the substrate being part of a semiconductor memory device; andan optical switch that is controllably switchable based on the timing signals so as to transmit an output pulse of the laser beam to the target link structure on demand, the output pulse rate being controllable by controlling the optical switch, the laser assembly being configured to focus the output pulse onto the target link structure into a spot diameter;whereby the spot size and depth of focus is improved relative to a longer wavelength greater than 1.2 microns, and the output pulse width limits damage to the substrate. 31. A controlled, switched laser system for vaporizing and removing a target link structure on a silicon substrate, comprising:a diode-pumped, solid-state laser assembly;a controllable switch for controlling the on/off state and power level of the laser assembly; anda computer programmed to control the laser assembly to cause the laser assembly to produce a laser beam output having an output pulse width less than about 8 nanoseconds at an operating repetition rate of 5 kilohertz or higher, and a wavelength shorter than 1.2 microns, the computer being programmed to cause the laser beam output to be directed at the target link structure on the silicon substrate to vaporize and remove the target link structure;whereby heating of the silicon substrate and hence damage to the silicon substrate is limited due to the output pulse width being less than about 8 nanoseconds.