Semiconductor Energy Laboratory Co., Ltd.

Ihi Corporation

Ryusuke Kawakami

Miyuki Masaki

Norihito Kawaguchi

Kenichiro Nishida

Atsushi Yoshinouchi

Masaru Morita

Kenichirou Nishida

Jun Izawa

A laser annealing method for executing laser annealing by irradiating a semiconductor film formed on a surface of a substrate with a laser beam, the method including the steps of, generating a linearly polarized rectangular laser beam whose cross section perpendicular to an advancing direction is a rectangle with an electric field directed toward a long-side direction of the rectangle or an elliptically polarized rectangular laser beam having a major axis directed toward a long-side direction, causing the rectangular laser beam to be introduced to the surface of the substrate, and setting a wavelength of the rectangular laser beam to a length which is about a desired size of a crystal grain in a standing wave direction.

Laser annealing method and device

Disclosed are a laser annealing method and apparatus capable of forming a crystalline semiconductor thin film on the entire surface of a substrate without sacrificing the uniformity of crystallinity in a seam portion in a long-axis direction of laser light, the crystalline semiconductor thin film having good properties and high uniformity to an extent that the seam portion is not visually recognizable. During the irradiation of a linear beam, portions corresponding to the edges of the linear beam are shielded by a maskwhich is disposed on the optical path of a laser light, and the maskis operated so that the amount of shielding is periodically increased and decreased.

Laser annealing method and apparatus

A laser annealing apparatus is provided that is capable of reducing irradiation unevenness of laser light caused by a refraction phenomenon of the laser light due to fluctuation in the temperature of inert gas. The laser annealing apparatus includes a gas supply unit for supplying inert gas G to at least a laser irradiation area of a workpiece, and a gas temperature controller for regulating the temperature of the inert gas G. The gas temperature controller controls the temperature of the inert gas G supplied to the laser irradiation area so as to decrease a temperature difference between the temperature of the inert gas G and the atmospheric temperature of a space (a room R) that is disposed outside the supply area of the inert gas so the temperature controlled inert gas surrounds the optical path of the laser light.

Laser annealing apparatus

The energy distribution in the short-side direction of a rectangular laser beam applied to an amorphous semiconductor film (amorphous silicon film) is uniformized. It is possible to the energy distribution in the short-side direction of the rectangular laser beam by the use of a cylindrical lens array or a light guide and concentrating optical systems or by the use of an optical system including a diffracting optical element. Accordingly, since the effective energy range of a laser beam applied to the amorphous semiconductor film is widened and the transport speed of a substrate can be enhanced as much, it is possible to improve the processing ability of the laser annealing.

Laser annealing method and laser annealing device

In the case of a lens array type homogenizer optical system, the incident angle and intensity of a laser beamentering a large-sized lens (long-axis condenser lens) of a long-axis condensing optical system, which is provided on the rear side, are changed for every shot by performing laser irradiation while long-axis lens arraysandare reciprocated in a direction corresponding to a long axial direction of a linear beam (X-direction). Therefore, vertical stripes are significantly reduced. Further, the incident angle and intensity of a laser beamentering a large-sized lens (projection lens) of a short-axis condensing optical system, which is provided on the rear side, are changed for every shot by performing laser irradiation while short-axis lens arraysandare reciprocated in a direction corresponding to a short axial direction of a linear beam (Y-direction). Therefore, horizontal stripes are significantly reduced.

A method for making a sample for evaluation of laser irradiation position and evaluating the sample, and an apparatus which is switchable between a first mode of modification of semiconductor and a second mode of making and evaluating the sample. Specifically, a sample is made by irradiating a semiconductor substrate for evaluation with a pulse laser beam while the semiconductor substrate is moved for evaluation at an evaluation speed higher than a modifying treatment speed, each relative positional information between pulse-irradiated regions in the sample is extracted, and stability of the each relative positional information between pulse-irradiated regions is evaluated. The evaluation speed is such a speed that separates the pulse-irradiated regions on the sample from each other in a moving direction.

Making method of sample for evaluation of laser irradiation position and making apparatus thereof and evaluation method of stability of laser irradiation position and evaluation apparatus thereof

In laser annealing using a solid state laser, a focus position of a minor axial direction of a rectangular beam is easily corrected depending on positional variation of a laser irradiated portion of a semiconductor film. By using a minor-axis condenser lenscondensing incident light in a minor axial direction and a projection lensprojecting light, which comes from the minor-axis condenser lens, onto a surface of a semiconductor film, laser beamis condensed on the surface of the semiconductor filmin the minor axial direction of a rectangular beam. The positional variation of a vertical direction of the semiconductor filmin a laser irradiated portion of the semiconductor filmis detected by a positional variation detector, and the minor-axis condenser lensis moved in an optical axis direction based on a value of the detection.

Laser annealing method and laser annealing apparatus

The irradiation unevenness caused by drift occurring in a beam short-axis direction is reduced without adding a new beam shaping unit and affecting the propagation characteristic of a beam in an optical resonator. A position deviation detector for detecting a position deviation of a laser beam before passing through a beam shaping optical system, an angle deviation detector for detecting an angle deviation of the laser beam before passing through the beam shaping optical system, a deflection mirror for deflecting the laser beam, which is disposed in an optical path between a laser and an object (substrate), and a mirror controller for controlling orientation of the deflection mirror, based on detection data obtained using the position deviation detector and the angle deviation detector so as to eliminate the position deviation from a reference irradiation position in the short-axis direction of a linear beam on a surface to be irradiated.

Laser annealing apparatus and method

The energy distribution in the short-side direction of a rectangular laser beam applied to an amorphous semiconductor film (amorphous silicon film) is uniformized. It is possible to the energy distribution in the short-side direction of the rectangular laser beam by the use of a cylindrical lens arrayor a light guideand concentrating optical systemsandor by the use of an optical system including a diffracting optical element. Accordingly, since the effective energy range of a laser beam applied to the amorphous semiconductor film is widened and the transport speed of a substratecan be enhanced as much, it is possible to improve the processing ability of the laser annealing.

A laser irradiation apparatus is provided in which the occurrence of adverse effects on an object to be irradiated with a laser beam due to the difference in the polarization state between pulsed laser beams can be prevented or significantly reduced when the pulsed laser beams emitted from two laser light sources are guided to pass through the same optical path for irradiation of an object to be irradiated with the pulsed laser beams. The laser irradiation apparatus is provided with a first laser light source, a second laser light source, an optical path combining optical memberwhich guides the pulsed laser beams emitted from the first laser light sourceand the second laser light sourceto pass through the same optical path, and a polarization control memberwhich controls polarization state of the pulsed laser beam from the optical path combining optical member. The polarization control memberincludes a first polarization control portionand a second polarization control portionthrough which beam components of the pulsed laser beam pass. The polarization states of the beam components that have passed through the first polarization control portionand the beam components that have passed through the second polarization control portionbecome different from each other. The beam components in different polarization states are superimposed on each other on a surface to be irradiated with the laser beam of the object to be irradiated with the laser beam.

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Tokyo, Japan

Ryusuke Kawakami