JPH09301800A - Laser annealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the working time required for cleaning a laser entrance window. SOLUTION: In this device, when the cleaning of a laser entrance window 5 is required in a laser annealing process, a gate valve 20 is closed and an inert gas is supplied to a small space 21 through an inert gas supply system 22 and then, the pressure of the small space 21 is restored to the atmospheric pressure and the laser entrance window 5 is removed to clean foreign matter stuck to a laser beam transmission part of the window 5. Subsequently, a vacuum chamber 1 is fitted with the cleaned laser entrance window 5 and evacuated with a vacuum evacuation system 23 until the pressure of the small space 21 is reduced to a level almost equal to the pressure of the inside of the vacuum chamber 1 and then, the gate valve 20 is opened to resume the laser annealing. Thus, the shutdown time of the device can be shortened to improve operating efficiency of the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser annealing treatment apparatus, and more particularly to a laser annealing treatment apparatus improved so as to shorten the working time for cleaning a laser introducing window. The laser annealing apparatus of the present invention is particularly useful for forming a polycrystalline silicon thin film.

[0002]

2. Description of the Related Art FIG. 6 is a longitudinal sectional view of an essential part of an example of a conventional laser annealing apparatus. The laser annealing processing apparatus 500 includes a vacuum chamber 51 made of aluminum.
And a movable mounting table 2 which moves on a base B installed in the vacuum chamber 51 and on which an object M to be processed is mounted, and a quartz table which is mounted on a ceiling portion 51a of the vacuum chamber 51. A laser introduction window 55 in which an ultraviolet antireflection film (AR coat) is formed on both surfaces of a glass plate, an excimer laser irradiation device 6 for irradiating a laser beam R through the laser introduction window 55, and the vacuum chamber 5
1, a gate valve S2 for introducing the object M to be processed,
A gate valve S3 for leading out the object M to be processed from the vacuum chamber 1 is provided. Reference numeral 3 is a heater for heating the object M to be processed. 51b is an exhaust port for evacuation (11). 52 is an inert gas supply system. The object M to be processed has an amorphous semiconductor thin film M1 formed on an insulating substrate M2.

The laser annealing process is performed in the following procedure. (1) The gate valve S2 is opened and the unprocessed object M is processed.
Is mounted on the movable mounting table 2 and the gate valve S2 is closed. (2) The vacuum chamber 51 is evacuated (11) from the exhaust port 51b, and the inside of the vacuum chamber 51 is reduced to 10 ^-2 to 10 ^-6 To.
High vacuum of rr (or filling with nitrogen gas).
Next, the movable mounting table 2 is moved so that the laser irradiation portion P is located at the irradiation start point of the object M to be processed. Then, a laser beam R is generated from the excimer laser irradiation device 6. The laser light R is introduced into the vacuum chamber 51 through the laser introduction window 55 and is irradiated onto the surface of the object M to be processed substantially vertically. The movable mounting table 2 is moved in this state, and the amorphous semiconductor thin film M1 of the object M to be processed is irradiated with the laser irradiation portion P having a small area (for example, 0.4 mm × 150 mm).
(For example, 300 mm × 300 mm) is scanned.
Thereby, the amorphous semiconductor thin film M1 can be crystallized. (3) The gate valve S3 is opened and the processed object M that has been processed
Is taken out of the movable mounting table 2 and the gate valve S3 is closed.

When the surface of the object M to be processed is irradiated with the laser light R, a laser irradiation portion P of the object M to be processed causes ablation, and evaporated substances are generated.
This transpiration material rises substantially vertically upward as indicated by arrow J in FIG. For this reason, the evaporated substance adheres to the laser light passage portion of the laser introduction window 55 and stains the laser introduction window 55. When the laser introducing window 55 becomes more contaminated by repeating the treatment, the usable energy of the laser light R decreases, and the treatment efficiency decreases. Further, the reflected laser light reflected by the object M to be processed is re-reflected by the dirt on the laser introduction window 55, and is irradiated again to the object M to be processed, which hinders a good annealing process.

Therefore, in the above laser annealing apparatus 500, the laser introducing window 5 is manufactured by the following procedure.
Clean 5 frequently. (1) Through the inert gas supply system 52, the vacuum chamber 5
An inert gas N (nitrogen gas or the like) is supplied into the inside of the vacuum chamber 1 to bring the inside of the vacuum chamber 51 to the atmospheric pressure. (2) The laser introduction window 55 is removed, and the adhering substance on the laser light transmitting portion is cleaned. (3) The laser introduction window 55 after cleaning is attached to the vacuum chamber 51. (4) Vacuuming (11) is performed again to make the vacuum chamber 1 high vacuum.

[0006]

The conventional laser annealing apparatus 500 has the following problems. (1) Only after releasing the high vacuum in the vacuum chamber 51 and returning to atmospheric pressure with an inert gas, the laser introduction window 5
Since 5 cannot be removed, it takes a long time to remove the laser introduction window 55. (2) Since it is necessary to perform vacuuming (11) again after attaching the laser introduction window 55 after cleaning to the vacuum chamber 1, it takes a long time to restart the annealing process. As a result of the above (1) and (2), the working time for cleaning the laser introduction window 55 becomes long as a whole,
The stop time of the laser annealing apparatus 500 becomes long. As a result, the operating rate of the device is lowered, and the production cost is increased. Therefore, it is an object of the present invention to provide a laser annealing treatment device capable of shortening the working time required for cleaning the laser introduction window.

[0007]

SUMMARY OF THE INVENTION In a first aspect, the present invention provides an object to be treated (M) placed in a closed container (1, 1 ').
A laser annealing device (100, 100) that irradiates a laser beam (R) from the outside through a laser introduction window (5).
200), a gate valve (20, 30) is provided immediately below the laser introduction window (5), and the closed container (1, 30) is provided by the gate valve (20, 30).
1 ') Small space (21, 3) that can communicate / block with the internal space
There is provided a laser annealing treatment apparatus (100, 200) characterized in that 1) is formed between the laser introduction window (5) and the gate valve (20, 30). The laser annealing processing apparatus of the first aspect (100, 2
00), the gate valve (2
0, 30) is opened and the object (M) to be processed is irradiated with laser light (R). When there is an opportunity to clean the laser introduction window (5), the gate valve (20, 30)
By closing and closing the small space (21, 31) with an inert gas to bring the pressure to the atmospheric pressure, the laser introduction window (5) can be removed and cleaned in a short time. Then, the laser introduction window (5) after cleaning is attached to the closed container (1, 1 '), and the small space (21, 31) is attached.
If the gate valve (20, 30) is opened after setting the atmosphere in the closed container (1, 1 ′), the annealing process can be restarted in a short time. As a result, the downtime of the device can be shortened and the operating rate of the device can be improved.

In a second aspect, the present invention relates to a laser for irradiating a processing object (M) placed in a closed container (1 ″) with a laser beam (R) from the outside through a laser introducing window (5). In the annealing device (300), a gate valve (40) is provided directly under the laser introduction window (5), and the gate valve (40) can communicate with / interrupt with the internal space of the closed container (1 ″). A small space (41) is formed between the laser introduction window (5) and the gate valve (40), and the wall (1a ″) of the closed container (1 ″) is configured as the gate valve (40). A laser annealing apparatus (300) is provided, which is shared as a part of a member. In the laser annealing apparatus (300) of the second aspect, the closed container (1 ″) is used.
Since the wall (1a ″) of the gate valve (1a ″) is shared as part of the constituent members of the gate valve (40), the thickness of the gate valve (40) in the optical axis direction of the laser beam R can be small.
The extension of the optical path length due to the interposition of the gate valve (40) can be suppressed. Moreover, since the gate valve (40) and the small space (41) do not project from the wall (1a ″), the working space for removing the laser introduction window (5) does not become narrow.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited by this.

-First Embodiment- FIG. 1 is a cross-sectional view of essential parts of a laser annealing apparatus according to a first embodiment of the present invention. This laser annealing processing apparatus 100 includes a vacuum chamber 1 made of aluminum.
And a movable mounting table 2 which moves on a base B installed in the vacuum chamber 1 and on which an object M to be processed is mounted, and a quartz table mounted on the ceiling portion 1a of the vacuum chamber 1. Between the laser introduction window 5 in which an ultraviolet ray anti-reflection film (AR coat) is formed on both surfaces of the glass plate, and the small space 21 capable of communicating / blocking with the internal space of the vacuum chamber 1 are provided between the laser introduction window 5. A gate valve 20 formed in the ceiling portion 1a, an excimer laser irradiation device 6 for irradiating the laser beam R through the laser introduction window 5, and a gate valve S2 for introducing the object M to be processed into the vacuum chamber 1. , And a gate valve S3 for leading out the object to be processed M from the vacuum chamber 1. Reference numeral 22 is an inert gas supply system to the small space 21. Reference numeral 23 is a vacuum exhaust system from the small space 21. 3 is a heater for heating the object M to be processed. 1b is an exhaust port for evacuation (11). The object M to be processed has an amorphous semiconductor thin film M1 formed on an insulating substrate M2.

The laser annealing process is performed in the following procedure.
As shown in FIG. 2, the gate valve 20 is open. (1) The gate valve S2 is opened and the unprocessed object M is processed.
Is mounted on the movable mounting table 2 and the gate valve S2 is closed. (2) Vacuuming from the exhaust port 1b of the vacuum chamber 1 (1
1) Then, the inside of the vacuum chamber 1 is set to a high vacuum of 10 ⁻² to 10 ⁻⁶ Torr (or filled with nitrogen gas). next,
The movable mounting table 2 is moved so that the laser irradiation portion P is located at the irradiation start point of the object M to be processed. Then, a laser beam R is generated from the excimer laser irradiation device 6. The laser light R is introduced into the vacuum chamber 1 through the laser introduction window 5 and is irradiated onto the surface of the object M to be processed substantially vertically. In this state, the movable mounting table 2 is moved to scan the entire surface (for example, 300 mm × 300 mm) of the amorphous semiconductor thin film M1 of the processing target M with the laser irradiation portion P having a small area (for example, 0.4 mm × 150 mm). . Thereby, the amorphous semiconductor thin film M1 can be crystallized. Since the small space 21 communicates with the internal space of the vacuum chamber 1, the small space 21 also has a high vacuum. (3) The gate valve S3 is opened and the processed object M that has been processed
Is taken out of the movable mounting table 2 and the gate valve S3 is closed.

When the object M to be processed is heated by the heater 3, the gate valve 20 is closed, the object M is heated to a target temperature, and then the gate valve 20 is opened to irradiate the laser beam R. Is preferred. This is to prevent the evaporated substance from being generated from the object M to be processed during the heating by the heater 3, and thus prevent the evaporated substance from adhering to the laser introduction window 5.

When the annealing process is performed, a part of the amorphous semiconductor thin film M1 is ablated, and the evaporated substance rises vertically above the laser irradiation portion P and adheres to the laser introduction window 5. While the annealing process is repeated, the laser introduction window 5 becomes dirty and the energy of the introduced laser light R decreases. Further, the reflected laser light reflected by the object M to be processed is re-reflected due to the dirt on the laser introduction window 5, and is again irradiated to the object M to be processed, which hinders a good annealing process.

Therefore, in the laser annealing apparatus 100, the laser introducing window 5 is frequently cleaned by the following procedure. (1) As shown in (a) of FIG. 3, the gate valve 20 is closed, and the inert gas N (such as nitrogen gas) is supplied to the small space 21 through the inert gas supply system 22 to make the small space 21 large. Set to atmospheric pressure. In the figure, the reason why the internal space of the vacuum chamber 1 is hatched differently from the small space 21 is as follows.
This is because the internal space of the vacuum chamber 1 remains in high vacuum. (2) As shown in FIG. 3B, the laser introduction window 5
Remove. Then, the adhering substance on the laser light transmitting portion of the laser introducing window 5 is cleaned. At this time, the gate valve 22 remains closed. (3) As shown in FIG. 3C, the laser introducing window 5 after cleaning is attached to the vacuum chamber 1. (4) As shown in FIG. 3D, the vacuum evacuation system 23 evacuates the small space 21 until the atmospheric pressure becomes almost the same as that in the vacuum chamber 1. (5) As shown in FIG. 3E, the gate valve 20 is opened. As a result, the small space 21 has the same high vacuum as the vacuum chamber 1.

According to the laser annealing apparatus 100 according to the first embodiment, only the small space 21 is opened to the atmospheric pressure and vacuumed while the inside of the vacuum chamber 1 is maintained at a high vacuum, and the laser introduction window is opened. 5 can be attached and detached. Therefore, the down time of the laser annealing processing apparatus 100 can be shortened, and the operating rate of the laser annealing processing apparatus 100 can be improved.

-Second Embodiment- FIG. 4 is a cross-sectional view of essential parts of a laser annealing apparatus according to a second embodiment of the present invention. In this laser annealing apparatus 200, the gate valve 30 is provided directly above the ceiling portion 1a ′ of the vacuum chamber 1 ′, and the small space portion 31 is formed above the gate valve 30 ′ according to the first embodiment. Different from 100. The second
According to the laser annealing apparatus 200 according to the embodiment described above, the inert gas supply system 22 and the vacuum exhaust system 23 to the small space 31 can be directly led to the outside world, and the assembly process of the apparatus can be simplified. I can.

-Third Embodiment- FIG. 5 is a cross-sectional view of essential parts of a laser annealing apparatus according to a third embodiment of the present invention. In this laser annealing apparatus 300, a gate valve 40 is internally provided in a ceiling portion 1a ″ of a vacuum chamber 1 ″, and the ceiling portion 1a ″ is shared as a part of a constituent member of the gate valve 40, and the ceiling portion 1a ″ is provided. The small space 41 is formed inside the laser annealing apparatus 100 according to the first embodiment. According to the laser annealing apparatus 300 of the third embodiment, since the ceiling portion 1a ″ can be used as a support member for the mechanical opening / closing portion of the gate valve 40, the direction of the optical axis of the laser beam R of the gate valve 40 can be used. Therefore, it is possible to suppress the extension of the optical path length due to the interposition of the gate valve 40. Further, since the gate valve 40 and the small space 41 do not project from the ceiling portion 1a ″, the laser introduction window 5 is provided. The work space for attaching and detaching is not narrowed.

[0018]

According to the laser annealing apparatus of the present invention, the laser introducing window can be attached and detached by opening and vacuuming only a small space to the atmospheric pressure while maintaining a high vacuum in the closed container. . Therefore, the down time of the laser annealing apparatus can be shortened and the operating rate of the laser annealing apparatus can be improved. Further, if the wall of the closed container is shared as a part of the constituent members of the gate valve, the extension of the optical path length can be suppressed. In addition, the working space for attaching and detaching the laser introduction window does not become narrow.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts of a laser annealing apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an open state of a gate valve.

FIG. 3 is an explanatory diagram of attachment and detachment of a laser introduction window.

FIG. 4 is a cross-sectional view of essential parts of a laser annealing apparatus according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of essential parts of a laser annealing apparatus according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of essential parts of an example of a conventional laser annealing apparatus.

[Explanation of symbols]

 100, 200, 300 Laser annealing apparatus 1, 1 ', 1 "Vacuum chamber 1a, 1a', 1a" Ceiling part 1b Exhaust port 2 Moving stage 3 Heater 5 Laser introduction window 6 Excimer laser irradiation device 20, 30, 40 Gate valve 21, 31, 41 Small space 22 Inert gas supply system 23 Vacuum exhaust system B Base M Object to be processed M1 Amorphous semiconductor thin film M2 Insulating substrate P Laser irradiation part R Laser light S2, S3 Gate valve

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C30B 29/06 C30B 29/06 Z H01S 3/02 H01S 3/02 (72) Inventor Miki Sawai Yotsukaido City, Chiba Prefecture Takanodai 1-chome 3 Japan Steel Works

Claims (2)

[Claims] 1. A laser annealing apparatus (100, 100) for irradiating a processing object (M) placed in a closed container (1, 1 ′) with a laser beam (R) from the outside through a laser introducing window (5). 200), a gate valve (2) is provided directly below the laser introduction window (5).
0, 30) and the gate valve (20,
A small space (21, 31) capable of communicating / blocking with the internal space of the closed container (1, 1 ') is formed between the laser introduction window (5) and the gate valve (20, 30) by 30). A laser annealing apparatus (100, 200) characterized by the above. 2. A laser annealing treatment device (3) for irradiating a treatment object (M) placed in a closed container (1 ″) with laser light (R) from outside through a laser introduction window (5).
00), a gate valve (4) is provided directly below the laser introduction window (5).
0) is provided, and a small space (41) capable of communicating / blocking with the internal space of the closed container (1 ″) by the gate valve (40) is provided with the laser introduction window (5) and the gate valve (40). Formed between the closed containers (1 ")
The laser annealing treatment apparatus (300), wherein the wall (1a ″) of the gate valve (1a ″) is shared as a part of the constituent members of the gate valve (40).