Enhancement of ultraviolet laser ablation and etching organic solids
Patent 4925523 Issued on May 15, 1990. Estimated Expiration Date: July 17, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
216/66, Using ion beam, ultraviolet, or visible light216/62, Irradiating, ion implanting, alloying, diffusing, or chemically reacting the substrate prior to etching to change properties of substrate toward the etchant219/121.69, Methods219/121.76Multiple beams
A method and apparatus are described which enhance the ablative effect of a UV laser. The ablative effect of a pulsed UV laser is enhanced using a second, longer wavelength pulsed laser. Each pulse of the first laser is followed by or combined with a pulse from the second laser. The etch depth per pulse is controlled by varying the time between pulses from the first and second lasers. The maximum etch depth per pulse occurs at a time separation which is a function of the substrate being etched. The first laser wavelength is selected to be within the absorption spectrum of the unexcited surface molecules of the substrate, while the wavelength of the second laser is selected to be within the absorption spectrum of the surface molecules excited by the incident radiation of the first laser.
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July 17, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
