US 2004/0171237 A1 · Laser irradiation method, laser irradiation apparatus, and method for manufacturing semiconductor device

Abstract

When the CW laser oscillator is employed in the manufacturing process of the semiconductor device, it is expected to obtain the device of high performance. However, the CW oscillator provides only a small beam spot and forms an inferior crystalline region when it is scanned on the semiconductor film. It is necessary to minimize such an inferior crystalline region because it gives a problem in terms of high integration of the semiconductor element. In view of the problem, the present invention is to form a long crystalline region as suppressing the formation of the inferior crystalline region by irradiating the fundamental wave with the harmonic supplementarily (refer to FIG. 1). The present invention also includes a constitution in which a part having high energy density in the fundamental wave is irradiated to a part having low energy density in the harmonic

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Drawings

Claims17

Dependent claims

A laser irradiation apparatus comprising;

a first laser oscillator outputting a first laser beam having a wavelength not longer than that of visible light;
means for shaping the first laser beam into an elongated beam on a surface to be irradiated wherein the elongated beam has at least a first portion and a second portion, said first portion having a lower energy density than the second portion;
a second laser oscillator outputting a second laser beam of a fundamental wave;
means for irradiating the second laser beam to the first portion of the elongated beam having the lower energy density;
means for moving the surface to be irradiated in a first direction relatively to the first laser beam and the second laser beam;
and
means for moving the surface to be irradiated in a second direction relatively to the first laser beam and the second laser beam.

4 more elements

A laser irradiation method comprising the steps of;

shaping a first laser beam having a wavelength not longer than that of visible light into an elongated beam on a surface to be irradiated;
irradiating the surface with the elongated beam wherein an irradiation area of the elongated beam on the surface has at least a first portion and a second portion, said first portion having a lower energy density than said second portion;
irradiating the surface with a second laser beam concurrently with the elongated beam wherein an irradiation area of the second laser beam on the surface has at least a first portion and a second portion having a higher energy density than the first portion, said second laser beam having a fundamental wave,
wherein the irradiation of the elongated beam and the second laser beam is performed in such a manner that the second portion of the irradiation area of the second laser beam overlaps at least the first portion of the irradiation area of the elongated beam while moving the surface relatively to the elongated beam and the second laser beam in a first direction.

1 more element

A method of manufacturing a semiconductor device comprising the steps of;

forming a non-single crystalline semiconductor film over a substrate;
shaping a first laser beam emitted from a first laser oscillator into an elongated beam on a surface to be irradiated wherein the first laser beam has a wavelength not longer than that of visible light;
irradiating the non-single crystalline semiconductor film with the elongated beam wherein an irradiation area of the elongated beam has at least a first portion and a second portion, said first portion having a lower energy density than the second portion;
irradiating the non-single crystalline semiconductor film with a second laser beam emitted from a second laser oscillator, said second laser beam having a fundamental wave wherein the irradiation of the second laser beam is performed concurrently with the irradiation of the elongated beam in such a manner that an irradiation area of the second laser beam overlaps at least the first portion of the irradiation area of the elongated beam;
and
moving the substrate relatively to the elongated beam and the second laser beam in a first direction, thereby, forming a crystal grain region in the non-single crystalline semiconductor film;
and
moving the substrate in a second direction relatively to the elongated beam and the second laser beam.

5 more elements

A method of manufacturing a semiconductor device comprising the steps of;

forming a non-single crystalline semiconductor film over a substrate,
shaping a first laser beam emitted from a first laser oscillator into an elongated beam on a surface to be irradiated wherein the first laser beam has a wavelength not longer than that of visible light;
irradiating the non-single crystalline semiconductor film with the elongated beam wherein an irradiation area of the elongated beam has at least a first portion and a second portion, said first portion having a lower energy density than the second portion;
irradiating the non-single crystalline semiconductor film with a second laser beam emitted from a second laser oscillator outputting a fundamental wave wherein an irradiation area of the second laser beam has at least a first portion and a second portion, said second portion having a higher energy density than the first portion;
forming a crystal grain region while moving the substrate in a first direction relatively to the elongated beam and the second laser beam;
moving the substrate in a second direction relatively to the elongated beam and the second laser beam,
wherein the irradiation of the elongated beam and the second laser beam is performed in such a manner that the second portion of the irradiation area of the second laser beam overlaps at least the first portion of the irradiation area of the elongated laser beam.

4 more elements

Dependencies are inferred from the claim text.

Description18,058 words

Summary4,542 words

#1. Field of the Invention

#The present invention relates to a laser irradiation method and a laser irradiation apparatus for performing the laser irradiation (the laser irradiation apparatus includes a laser oscillator and an optical system to guide a laser beam emitted from the laser oscillator to an object to be irradiated). In addition, the present invention relates to a method for manufacturing a semiconductor device comprising a step of the laser irradiation process. It is noted that the semiconductor device described here includes a general device that can be operated by utilizing the semiconductor characteristic. And thereby an electro-optical device such as a liquid crystal display device, a light-emitting device or the like, and an electronic device having such an electro-optical device as its component are also included in the semiconductor device.

#2. Description of the Related Art

Brief description of the drawings20 figures

#In the accompanying drawings:

#FIGS. 1A and 1B are drawings to show a irradiation track of a beam spot;

#FIG. 2 is a drawing to explain an embodiment mode 1;

Detailed description13,203 words

#[Embodiment Mode 1]

#The embodiment mode 1 of the present invention is explained with reference to FIG. 2. This embodiment mode explains an example in which long beams 205 and 206 are formed to irradiate a surface of a semiconductor film 204.

#First of all, an LD pumped laser oscillator 201 with an output of 10 W (Nd: YVO4 laser, CW, the second harmonic (532 nm)) is prepared. The laser oscillator 201 generates in TEM00 mode, and includes LBO crystal in its resonator to convert the laser beam into the second harmonic. The harmonic is not limited to the second harmonic but the second harmonic is superior to the other higher harmonics in terms of the conversion efficiency. The beam diameter is 2.25 mm. The divergence angle is approximately 0.3 mrad. The traveling direction of the laser beam is changed by a 45° reflecting mirror 202 so as to have an angle of φ from the vertical direction. Next, the laser beam is made incident at an angle φ into a planoconvex lens 203 having a focal length of 20 mm whose plane portion corresponds to a horizontal plane. The angle φ may be changed appropriately, and it is set to 20° in this embodiment mode. The semiconductor film 204 is set on a surface to be irradiated in parallel with the horizontal plane. The semiconductor film 204 is formed over a surface of a glass substrate. A distance between the semiconductor film 204 and the planoconvex lens 203 is set about 20 mm, and the distance is adjusted so as to form the long beam 205 elongated in a direction as parallel as possible to the incidence plane on the semiconductor film 204. The accuracy of fine adjustment is about 50 μm. This forms the long beam 205 whose shape is similar to an ellipse having a major axis of 500 μm and a minor axis of 20 μm.

Facts

Application

10/787,120Filed 27 Feb 2004

Priority

JP 2003-05469528 Feb 2003

Published

2 Sep 2004

Term ends

Not estimatedThe source records don’t support an estimate.

Classification15 codes

B23K 26/0732
Shaping the laser spot: into a rectangular shape
B23K 26/0736
Shaping the laser spot: into an oval shape, e.g. elliptic shape
H10D 86/0229
Comprising crystallisation of amorphous, microcrystalline or polycrystalline semiconductor materials: characterised by control of the annealing or…
H10P 14/2922
Materials: being non-crystalline insulating materials, e.g. glass or polymers

Laser irradiation method, laser irradiation apparatus, and method for manufacturing semiconductor device

Life of this patent

Laser irradiation method, laser irradiation apparatus, and method for manufacturing semiconductor device

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims17

Description18,058 words

Drawings

Classification15 codes

Life of this patent

Description18,058 words