Patent•
Beam shaping and projection imaging with solid state uv gaussian beam to form vias
26 May 2000-
TL;DR: In this article, a diode-pumped solid-state laser (52) of a laser system (50) provides ultraviolet Gaussian output (54) that is converted by a diffractive optical element (90) into shaped output (94) having a uniform irradiance profile.
Abstract: A diode-pumped, solid-state laser (52) of a laser system (50) provides ultraviolet Gaussian output (54) that is converted by a diffractive optical element (90) into shaped output (94) having a uniform irradiance profile. A high percentage of the shaped output (94) is focused through an aperture of a mask (98) to provide imaged shaped output (118). The laser system (50) facilitates a method for increasing the throughput of a via drilling process over that available with an analogous clipped Gaussian laser system. This method is particularly advantageous for drilling blind vias (20b) that have better edge, bottom, and taper qualities than those produced by a clipped Gaussian laser system. An alternative laser system (150) employs a pair of beam diverting galvanometer mirrors (152, 154) that directs the Gaussian output around a shaped imaging system (70) that includes a diffractive optical element (90) and a mask (98). Laser system (150) provides a user with the option of using either a Gaussian output or an imaged shaped output (118).
Citations
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Patent•
26 Mar 2003TL;DR: In this article, a method and system for high-speed, precise micromachining an array of devices are disclosed wherein improved process throughput and accuracy, such as resistor trimming accuracy, are provided.
Abstract: A method and system for high-speed, precise micromachining an array of devices are disclosed wherein improved process throughput and accuracy, such as resistor trimming accuracy, are provided. The number of resistance measurements are limited by using non-measurement cuts, using non-sequential collinear cutting, using spot fan-out parallel cutting, and using a retrograde scanning technique for faster collinear cuts. Non-sequential cutting is also used to manage thermal effects and calibrated cuts are used for improved accuracy. Test voltage is controlled to avoid resistor damage.
73Â citations
Patent•
25 May 2006TL;DR: In this paper, a stack of material layers, a minimum laser ablation threshold based on laser pulse width is determined for each of the layers, and a beam of one or more laser pulses is generated having a fluence in a range between the selected laser threshold and approximately ten times the selected threshold.
Abstract: Systems and methods are provided for scribing wafers with short laser pulses so as to reduce the ablation threshold of target material. In a stack of material layers, a minimum laser ablation threshold based on laser pulse width is determined for each of the layers. The highest of the minimum laser ablation thresholds is selected and a beam of one or more laser pulses is generated having a fluence in a range between the selected laser ablation threshold and approximately ten times the selected laser ablation threshold. In one embodiment, a laser pulse width in a range of approximately 0.1 picosecond to approximately 1000 picoseconds is used. In addition, or in other embodiments, a high pulse repetition frequency is selected to increase the scribing speed. In one embodiment, the pulse repetition frequency is in a range between approximately 100 kHz and approximately 100 MHz.
66Â citations
Patent•
18 Jan 2001
TL;DR: In this article, the authors proposed a method for patterned sequential lateral solidification of a substrate surface, avoiding the need for demagnification to avoid mask damage from fluence sufficient to overcome the threshold for sequential lateral softening, while using the high throughput of a common stage presenting both 1:1 mask and substrate simultaneously for patterning.
Abstract: Apparatus and method for patterned sequential lateral solidification of a substrate surface, avoiding the need for demagnification to avoid mask damage from fluence sufficient to overcome the threshold for sequential lateral solidification, while using the high throughput of a common stage presenting both 1:1 mask and substrate simultaneously for patterning. The radiation source provides imaging beam and non-imaging beam, each of fluence below the threshold of sequential lateral solidification, but with aggregate fluence above the threshold. The imaging beam path includes a relatively delicate 1:1 mask and 1:1 projection subsystem, with optical elements including a final fold mirror proximate to the substrate surface, put the below-threshold mask pattern on the substrate surface. The non-imaging beam bypasses the delicate elements of imaging beam path, passing through or around the final fold mirror, to impinge on the substrate surface at the same location. Where the radiation patterns of the masked imaging beam and non-imaging beam coincide, their aggregate fluence exceeds the threshold for sequential lateral solidification. The dual selection provides pattern without damage to delicate optical elements.
63Â citations
Patent•
31 Jan 2007TL;DR: In this paper, laser-based methods and systems for removing one or more target link structures of a circuit fabricated on a substrate includes generating a pulsed laser output at a predetermined wavelength less than an absorption edge of the substrate are provided.
Abstract: Laser-based methods and systems for removing one or more target link structures of a circuit fabricated on a substrate includes generating a pulsed laser output at a predetermined wavelength less than an absorption edge of the substrate are provided The laser output includes at least one pulse having a pulse duration in the range of about 10 picoseconds to less than 1 nanosecond, the pulse duration being within a thermal laser processing range The method also includes delivering and focusing the laser output onto the target link structure The focused laser output has sufficient power density at a location within the target link structure to reduce the reflectivity of the target link structure and efficiently couple the focused laser output into the target link structure to remove the target link structure without damaging the substrate
63Â citations
Patent•
21 Sep 2011
TL;DR: In this paper, a first laser output was applied to the material, and then a second laser was used to singulate the material in such a way that surfaces created by the singulation of the material were substantially free from defects.
Abstract: Systems and methods for material singulation. According to some embodiments, methods for material singulation may include applying a first laser output to the material, the first laser output causing a modification of a material property of the material when exposed to the first laser output; and applying a second laser output to the material that was exposed to the first laser output to cause singulation of the material in such a way that surfaces created by the singulation of the material are substantially free from defects.
54Â citations
References
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TL;DR: In this paper, the authors introduce phase filters having a predetermined phase function into optical coherent systems in such a manner that the local phase variations influence light from local object areas, where the object distribution is multiplied by the phase function so that its spectrum at the frequency plane constitutes the desired transformation.
Abstract: Geometrical image modifications such as coordinate transformations and local translation, inversion, reflection, stretching which require space-variant optical coherent systems are provided by introducing phase filters having a predetermined phase function into optical coherent systems in such a manner that the local phase variations influence light from local object areas. In one embodiment, the object distribution is multiplied by the phase function so that its spectrum at the frequency plane constitutes the desired transformation. In a second embodiment, the aforementioned concept is applied to produce a transformation in an image plane. The phase filters, in a preferred embodiment, comprise computer generated holograms.
311Â citations
Patent•
06 Jul 1995TL;DR: In this paper, the output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light for forming vias (72, 74) in multi-layered targets (40).
Abstract: The output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light (62) for forming vias (72, 74) in multi-layered targets (40). The parameters of the output pulses (62) are selected to facilitate substantially clean, simultaneous or sequential drilling or via formation in a wide variety of materials such as metals, organic dielectrics, and reinforcement materials having different thermal absorption characteristics in response to ultraviolet light. These parameters typically include at least two of the following criteria: high average power of greater than about 100 milliwatts measured over the beam spot area, a temporal pulse width shorter than about 100 nanoseconds, a spot diameter of less than about 50 microns, and a repetition rate of greater than about one kilohertz. The laser system (10) and method circumvent conventional depth of cut saturation limitations and can achieve an increased depth of cut per pulse in a target (40) formed of either single- or multi-layered material.
258Â citations
Patent•
17 May 1996TL;DR: In this article, the output of a continuously pumped, Q-switched, Nd:YAG laser is converted to provide ultraviolet light for forming vias in targets (40) having metallic layers (64,68) and a dielectric layer (66).
Abstract: The output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light (62) for forming vias (72, 74) in targets (40) having metallic layers (64,68) and a dielectric layer (66) The invention employs a first laser output of high power density to ablate the metallic layer and a second laser output of a lower power density to ablate the dielectric layer The parameters of the output pulses (62) are selected to facilitate substantially clean, sequential drilling or via formation These parameters typically include at least two of the following criteria: power density first above and then below the ablation threshold of the conductor, wavelength less than 400 nm, a temporal pulse width shorter than about 100 nanoseconds, and a repetition rate of greater than about one kilohertz The ability to generate ultraviolet light output pulses at two power densities facilitates the formation of depthwise self-limiting blind vias in multilayer targets, such as a target composed of a layer dielectric material covered on either surface by a layer of metal
154Â citations
Patent•
17 Nov 1981
TL;DR: An optical beam homogenizer divides and redirects an incident beam to provide uniform irradiation to a plane surface as mentioned in this paper, which is useful for metal hardening, semiconductor annealing, or other materials processing applications.
Abstract: An optical beam homogenizer divides and redirects an incident beam to provide uniform irradiation to a plane surface. The beam homogenizer is particularly useful in an apparatus and method for uniform laser irradiation of materials. The apparatus comprises a laser, a beam homogenizer, and a support for the material being irradiated. Depending on the system parameters, the apparatus is useful for metal hardening, semiconductor annealing, or other materials processing applications.
152Â citations
TL;DR: A versatile, rapidly convergent, iterative algorithm is presented for the construction of kinoform phase plates for tailoring the far-field intensity distribution of laser beams that contains more than 95% of the incident energy inside a desired region and is relatively insensitive to beam aberrations.
Abstract: A versatile, rapidly convergent, iterative algorithm is presented for the construction of kinoform phase plates for tailoring the far-field intensity distribution of laser beams The method consists of repeated Fourier transforming between the near-field and the far-field planes with constraints imposed in each plane For application to inertial confinement fusion, the converged far-field pattern contains more than 95% of the incident energy inside a desired region and is relatively insensitive to beam aberrations
141Â citations