Patent•
Laser irradiation apparatus and laser irradiation method
15 Jun 2005-
TL;DR: In this paper, a laser irradiation apparatus for homogenously crystallized films is described, where the energy intensity of an irradiation beam in forward and backward directions of the irradiation is varied in accordance with the scanning direction.
Abstract: It is an object of the present invention to provide a laser irradiation apparatus which can manufacture a homogenously crystallized film by varying the energy intensity of an irradiation beam in forward and backward directions of the irradiation. A laser irradiation apparatus of the present invention comprises a laser oscillator and means for varying beam intensity wherein a laser beam is obliquely incident into the irradiation surface, the laser beam is scanned relative to the irradiation surface, and the beam intensity is varied in accordance with the scanning direction. Further, the laser oscillator is a continuous wave solid-state laser, gas laser, or metal laser. A pulsed laser having a repetition frequency of 10 MHz or more can also be used.
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Patent•
27 Nov 2002
TL;DR: In this article, the uniformity of laser annealing can be improved by the minimum number of homogenizers, which is shown to be the case in the case of linear laser light.
Abstract: There are disposed two homogenizers for controlling an irradiation energy density in the longitudinal direction of a laser light transformed into a linear one which is inputtted into the surface to be irradiated. Also, there is disposed one homogenizer for controlling an irradiation energy density in a width direction of the linear laser light. According to this, the uniformity of laser annealing can be improved by the minimum number of homogenizers.
259 citations
Patent•
25 Feb 2004
TL;DR: In this paper, a fundamental wave is used without putting laser light into a non linear optical element, and laser annealing is conducted by irradiating a semiconductor thin film with pulsed laser light having a high repetition rate.
Abstract: In conducting laser annealing using a CW laser or a quasi-CW laser, productivity is not high as compared with an excimer laser and thus, it is necessary to further enhance productivity. According to the present invention, a fundamental wave is used without putting laser light into a non linear optical element, and laser annealing is conducted by irradiating a semiconductor thin film with pulsed laser light having a high repetition rate. A laser oscillator having a high output power can be used for laser annealing, since a non linear optical element is not used and thus light is not converted to a harmonic. Therefore, the width of a region having large grain crystals that is formed by scanning once can be increased, and thus the productivity can be enhanced dramatically.
188 citations
Patent•
05 Mar 2010
TL;DR: In this article, the amorphous silicon film is formed using silane gas diluted with hydrogen and crystallization is attained in the crystallization process even with the continuous formation of the base film through the polysilicon film in the single film forming chamber.
Abstract: At present, a forming process of a base film through an amorphous silicon film is conducted in respective film forming chambers in order to obtain satisfactory films. When continuous formation of the base film through the amorphous silicon film is performed in a single film forming chamber with the above film formation condition, crystallization is not sufficiently attained in a crystallization process. By forming the amorphous silicon film using silane gas diluted with hydrogen, crystallization is sufficiently attained in the crystallization process even with the continuous formation of the base film through the amorphous silicon film in the single film forming chamber.
185 citations
Patent•
01 Dec 2003
TL;DR: In this paper, the authors present an apparatus for use in a laser processing process, characterized by that it is provided with an internal sample holder and a device which functions as a heating means of the sample, a window made of a material sufficiently transparent to transmit a laser beam, a chamber comprising a vacuum evacuation device, a device for introducing a reactive gas containing an impurity element, a laser apparatus operating in a pulsed mode to irradiate a laserbeam to said chamber, and a means to move said chamber synchronously with the laser irradiation.
Abstract: A process for laser processing an article, which comprises: heating the intended article to be doped with an impurity to a temperature not higher than the melting point thereof, said article being made from a material selected from a semiconductor, a metal, an insulator, and a combination thereof; and irradiating a laser beam to the article in a reactive gas atmosphere containing said impurity, thereby allowing the impurity to physically or chemically diffuse into, combine with, or intrude into said article. The present invention also provides an apparatus for use in a laser processing process, characterized by that it is provided with an internal sample holder and a device which functions as a heating means of the sample, a window made of a material sufficiently transparent to transmit a laser beam, a chamber comprising a vacuum evacuation device and a device for introducing a reactive gas containing an impurity element, a laser apparatus operating in a pulsed mode to irradiate a laser beam to said chamber, and a means to move said chamber synchronously with the laser irradiation.
163 citations
Patent•
27 Feb 2001
TL;DR: In this article, moisture is intentionally included in an atmosphere in irradiating laser beam to the semiconductor film by which a temperature holding layer comprising water vapor is formed on the surface of the semiconducting material, and the laser annealing operation can be performed effectively.
Abstract: In order to promote an effect of laser annealing in respect of a semiconductor film, moisture is intentionally included in an atmosphere in irradiating laser beam to the semiconductor film by which a temperature holding layer comprising water vapor is formed on the surface of the semiconductor film in irradiating the laser beam and the laser annealing operation can be performed effectively.
147 citations
References
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Patent•
27 Nov 2002
TL;DR: In this article, the uniformity of laser annealing can be improved by the minimum number of homogenizers, which is shown to be the case in the case of linear laser light.
Abstract: There are disposed two homogenizers for controlling an irradiation energy density in the longitudinal direction of a laser light transformed into a linear one which is inputtted into the surface to be irradiated. Also, there is disposed one homogenizer for controlling an irradiation energy density in a width direction of the linear laser light. According to this, the uniformity of laser annealing can be improved by the minimum number of homogenizers.
259 citations
Patent•
08 Sep 1986
TL;DR: In this article, a beam forming arrangement is used to correct an asymmetric beam cross-section, a first relay telescope, a beam dimensional control system and a second relay telescope.
Abstract: Laser apparatus for eroding a surface comprises means to select and control the shape and size of the area irradiated by each pulse of laser energy without varying the energy density of the beam. By varying the size of the irradiated area between pulses, some regions of the surface may be eroded more than others and so the surface may be reprofiled. The method and apparatus are suitable, inter alia, for removing corneal ulcers and reprofiling the cornea to remove refractive errors and also for reprofiling optical elements. In one embodiment the beam from the laser enters an optical system housed in an articulated arm and terminating in an eyepiece having a suction cup for attachment to an eye. The optical system includes a beam forming arrangement to correct an asymmetric beam cross-section, a first relay telescope, a beam dimensional control system and a second relay telescope. The beam dimension control system has a stop with a shaped window or a shaped stop portion and movable axially along a converging or diverging beam portion. An alternative beam dimension control system has a stop with a shaped window and positioned between coupled zoom systems. Mirrors, adjustable slits and refractive systems may also be used. The laser is preferably an ArF Excimer laser. The apparatus may include a measurement device to measure the surface profile, and a feedback control system to control the laser operation in accordance with the measured and desired profiles.
232 citations
Patent•
07 Jun 2002TL;DR: In this paper, a long cut path is divided into short segments, from about 10 µm to 1 mm, and the laser output is scanned within a first short segment for a predetermined number of passes before being moved to and scanned within another short segment (122) for a certain time interval.
Abstract: UV laser cutting throughput through silicon and like materials is improved by dividing a long cut path (112) into short segments (122), from about 10 µm to 1 mm. The laser output (32) is scanned within a first short segment (122) for a predetermined number of passes before being moved to and scanned within a second short segment (122) for a predetermined number of passes. The bite size, segment size (126), and segment overlap (136) can be manipulated to minimize the amount and type of trench backfill. Real-time monitoring is employed to reduce rescanning portions of the cut path (112) where the cut is already completed. Polarization direction of the laser output (32) is also correlated with the cutting direction to further enhance throughput. This technique can be employed to cut a variety of materials with a variety of different lasers and wavelengths.
208 citations
Patent•
26 May 2000TL;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).
191 citations
Patent•
25 Feb 2004
TL;DR: In this paper, a fundamental wave is used without putting laser light into a non linear optical element, and laser annealing is conducted by irradiating a semiconductor thin film with pulsed laser light having a high repetition rate.
Abstract: In conducting laser annealing using a CW laser or a quasi-CW laser, productivity is not high as compared with an excimer laser and thus, it is necessary to further enhance productivity. According to the present invention, a fundamental wave is used without putting laser light into a non linear optical element, and laser annealing is conducted by irradiating a semiconductor thin film with pulsed laser light having a high repetition rate. A laser oscillator having a high output power can be used for laser annealing, since a non linear optical element is not used and thus light is not converted to a harmonic. Therefore, the width of a region having large grain crystals that is formed by scanning once can be increased, and thus the productivity can be enhanced dramatically.
188 citations