JP2000031082A - Laser annealer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure good annealing by improving a laser annealer. SOLUTION: A gas supply valve 1 for supplying nitrogen gas into a chamber 14 foe performing laser anneal and a gas supply pipe 3 conducting with a gas supply pump 2 are introduced and a diffusion filter 5 is disposed in the vicinity of an air outlet 4. Since nitrogen gas flow introduced into the chamber 14 is diffused and nitrogen density is made uniform in the chamber 14, reactive substance removing effect is made constant in the chamber 14 and an element on a substrate 19 to be processed employing a film formed by laser anneal has uniform characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laser annealing apparatus for forming a good semiconductor film on a substrate.

[0002]

2. Description of the Related Art In recent years, in a semiconductor device manufacturing process, laser annealing has been performed on a semiconductor film on a substrate to promote activation or to crystallize an amorphous film. In particular, when manufacturing a liquid crystal display (LCD) using a substrate having a low heat-resistant limit temperature,
Polysilicon (p-) obtained by crystallizing amorphous silicon (a-Si) on a substrate by laser annealing
When Si) is used, not only a switching element in the display pixel portion but also a peripheral driver portion for driving the display pixel portion can be integrally formed on the same substrate. Laser annealing technology has become an indispensable element in mass production of such a driver built-in LCD.

FIG. 2 shows the structure of such a laser annealing apparatus. (51) is a laser oscillation source composed of a laser medium, a resonance system, etc., and (52) is a light shield (5).
7) an optical system in which a lens (55), a mirror (56) and the like are installed, (53) a final irradiation part of a laser beam,
(54) a chamber in which laser annealing is performed;
(58) is a mounting table for supporting the substrate (59) on which a-Si to be laser-annealed is formed.

The laser light generated by the laser oscillation source (51) is shaped into a predetermined irradiated area by an optical system (52), and is irradiated from an irradiation section (53) into a chamber (54). You. The chamber (54) is maintained at a predetermined pressure and temperature optimum for laser annealing. Chamber (5
In 4), the support table (5) on which the substrate to be processed (59) is mounted is placed.
8) is moved in a fixed direction and scans while passing through the laser irradiation area, and laser annealing is performed on the entire surface.

[0005]

When crystallization of a-Si (59) is performed in the laser annealing process, various other physicochemical reactions are accompanied by the crystallization, and thus, the crystallization of a-Si (59) is performed. The characteristics of the device using the p-Si film fluctuate. Therefore, it is preferable that the inside of the chamber (54) be set in a vacuum atmosphere to remove elements that easily cause a physicochemical reaction. However, if a chamber (54) capable of withstanding such a vacuum state and an exhaust / air supply facility are provided, the apparatus becomes expensive. In addition, it takes a long time to evacuate the substrate (59) in and out.

An object of the present invention is to provide a laser
It is an object of the present invention to provide an apparatus capable of preventing unnecessary physicochemical reactions from occurring and performing laser annealing at a low manufacturing cost.

[0007]

SUMMARY OF THE INVENTION The present invention achieves this object and comprises a laser oscillation source for generating a laser beam and a plurality of optical components for shaping the laser beam emitted from the laser oscillation source. In a laser annealing apparatus having an optical system and a processing chamber having a mounting table that supports an object to be laser-annealed at a position irradiated with the laser beam sent from the optical system, the processing chamber includes:
It is configured to include an introduction pipe for introducing an inert gas into the inside, and gas diffusion means for diffusing the inert gas.

[0008] Thus, since the processing chamber is replaced with the inert gas, it is possible to prevent a physicochemical reaction other than the laser annealing. Further, since there is no need to evacuate the processing chamber, an increase in manufacturing cost can be avoided.

[0009]

FIG. 1 is a configuration diagram of a laser annealing apparatus according to an embodiment of the present invention. (11) is a laser oscillation source composed of a laser medium, a resonance system, etc., (1)
2) a lens (15) in a light shield (17),
An optical system provided with a mirror (16) and the like; (13) a final irradiation part of a laser beam; (14) a chamber in which laser annealing is performed; and (18) an a-Si to be laser-annealed. A mounting table for supporting the substrate to be processed (19).

The chamber (14) is an airtight chamber, which is an air supply system comprising an air supply valve (1), an air supply pump (2) and an air supply pipe (3) communicating therewith, and an exhaust valve (5), an exhaust pump An exhaust system including (6) and an exhaust pipe (7) is provided. (5) is a diffusion filter according to the present invention formed in a shower head shape, and is attached to the outlet (4) of the air supply pipe (3) introduced into the chamber (14).

With this configuration, during the laser annealing process,
The air supply valve (1) and the exhaust valve (5) are opened, and, for example, nitrogen as an inert gas is introduced into the chamber (14) and discharged from the exhaust system. At this time, the inside of the chamber (14) is kept at substantially the same pressure as the atmospheric pressure. That is, during the laser annealing process, the chamber (14) is constantly being replaced by the nitrogen flow. For this reason, since the laser annealing is always performed in an inert nitrogen atmosphere, a physicochemical reaction does not occur due to the laser energy. Further, even if a reactive substance activated by the laser annealing treatment is generated, it is removed by the nitrogen flow.

In particular, in the present invention, the supplied nitrogen gas stream is diffused and introduced into the chamber (14) for the diffusion filter (5) provided at the outlet (4). This is for the following reason. If,
When the nitrogen flow is vigorously introduced into the chamber (14), a variation in the nitrogen density occurs in the chamber (14),
The removal effect of the reactive substance by the nitrogen flow is high for the substrate (1
9) It depends on the position above. Therefore, the characteristics of the device using the p-Si film obtained by the laser annealing vary on the substrate, which adversely affects the operation of the entire device including such a device. Therefore, in the present invention, by providing the diffusion filter (5) at the outlet (4), the nitrogen flow introduced into the chamber (14) is diffused, and the flow of nitrogen is made uniform, whereby the reactivity is increased. The effect of removing substances is made uniform on the substrate to be processed (19),
The characteristics of the obtained device are stabilized.

[0013]

As is apparent from the above description, the laser annealing apparatus of the present invention has improved the laser annealing atmosphere without increasing the apparatus cost, and has realized laser annealing for obtaining uniform characteristics.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a laser annealing apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional laser annealing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air supply valve 2 Air supply pump 3 Air supply pipe 4 Outlet 5 Diffusion filter 11 Laser oscillation source 12 Optical system 13 Irradiation unit 14 Chamber 15 Lens 16 Mirror 17 Light shield 18 Mounting table 19 Substrate to be processed 20 Window

Continued on the front page (72) Inventor Yoshihiro Morimoto 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term (reference) in Sanyo Electric Co., Ltd. 2H092 JA28 KA04 KA05 MA30 MA35 NA24 NA27

Claims (1)

[Claims] 1. A laser oscillation source for generating a laser beam, an optical system comprising a plurality of optical components, and shaping a laser beam emitted from the laser oscillation source, and a laser beam emitted from the optical system being irradiated with the laser beam. In a laser annealing apparatus having a processing chamber provided with a mounting table that supports an object to be laser-annealed at a position, the processing chamber has an air supply means for introducing an inert gas into the inside thereof, and A laser annealing apparatus comprising: a diffusion unit for diffusing an inert gas.