JP3175002B2 - Laser annealing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a laser annealing apparatus used in a semiconductor manufacturing technique, and more particularly to a process chamber which is a chamber for annealing a processing substrate and a method for forming an internal atmosphere thereof.

[0002]

2. Description of the Related Art In semiconductor manufacturing technology, it is often necessary to anneal a silicon wafer. Here, "annealing" refers to annealing a silicon wafer by heat treatment at a high temperature. Such annealing
It is used to electrically activate the ion-implanted impurities, or to neutralize and inactivate the charge to remove instability.

[0003] An annealing apparatus is called an annealing apparatus. One of the annealing devices is a laser annealing device. This laser annealing apparatus is an apparatus for irradiating an amorphous silicon thin film with laser light pulse-oscillated from an excimer laser apparatus to perform polycrystallization. That is, when high-energy laser light is applied to the amorphous silicon thin film, the laser light is absorbed by the amorphous silicon thin film, instantaneously becomes a molten state, and recrystallization occurs. As a result, the amorphous silicon thin film becomes polycrystalline. This technique is used, for example, for producing a polycrystalline silicon thin film for forming a thin film transistor (TFT) of a liquid crystal panel.

A conventional laser annealing apparatus will be described with reference to FIG. The illustrated laser annealing apparatus has four chambers, namely, process chamber 1
0 ', load chamber 20', unload chamber 3
0 'and the transfer chamber 40'.

[0005] A processing substrate (not shown) is accommodated in a process chamber 10 '. The laser annealing device further includes a laser device 50 for irradiating a processing substrate in the process chamber 10 'with a laser beam. A process window 11 for transmitting a laser beam is provided on the upper surface of the process chamber 10 '. The laser light emitted from the laser device 50 is applied to the processing substrate in the process chamber 10 ′ via the optical system 60 and the process window 11.

[0006] The load chamber 20 'includes a loader (not shown) for transferring a processing substrate into the process chamber 10'. The unload chamber 30 'includes an unloader (not shown) for unloading the processing substrate in the process chamber 10'. The transfer chamber 40 '
Robot (not shown) for transferring processing substrates between process chamber 10 ', loader and unloader
including.

[0007] Dry pumps 12 ', 22', 32 'and 42', which are a kind of vacuum pump, are attached to the process chamber 10 ', the load chamber 20', the unload chamber 30 'and the transfer chamber 40', respectively. The interior of each chamber can be evacuated. The entrance (not shown) of the process chamber 10 'and the entrance (not shown) of the transfer chamber 40' are connected via a gate valve 70 '. An outlet (not shown) of the load chamber 20 'and an inlet (not shown) of the transfer chamber 40' are connected via a gate valve 80 '. The inlet (not shown) of the unload chamber 30 'and the outlet (not shown) of the transfer chamber 40' are connected via a gate valve 90 '. The process chamber 10 'includes a motor 10
0 is attached, and the processing substrate in the process chamber 10 'can be moved in a predetermined horizontal direction.

Next, the process chamber 10 'will be described with reference to FIG. A rail 13 is laid on the lower surface of the inner wall of the process chamber 10 '. A stage 14 is provided along the rail 13 so as to be slidable in a predetermined horizontal direction (left-right direction in the drawing) via a slide 15. A processing substrate 17 is mounted on the stage 14 via pins 16. The stage 14 is connected to a motor 100 via a lead screw 101, a bellows 102 and a rod 103. That is,
The rotation of the motor 100 is converted into the predetermined horizontal linear motion by the combination of the lead screw 101 and the rod 103, and the stage 14 is slid along the predetermined horizontal direction. The bellows 102 is for shielding a vacuum and the atmosphere. Process chamber 1
A turbo molecular pump 18 'is attached to 0'.

On the other hand, the laser light emitted from the laser device 50 (FIG. 3) is made to have an elongated cross section by an optical system 60 such as a homogenizer, and then passes through a process window 11 to a process chamber 10 '. It is irradiated on the processing substrate 17 in the inside.

By the way, during the processing by the laser annealing, the processing substrate 17 is instantaneously brought into a molten state as described above. Therefore, it is necessary to prevent oxidation of the processing substrate 17. Therefore, the inside of the process chamber 10 ′
It is necessary to make the atmosphere non-oxidizable. As an atmosphere in which oxidation cannot be performed, the process chamber 10 ′ may be set in a vacuum state or an atmosphere of an inert gas such as nitrogen gas (N ₂ ). Here, a chamber whose inside is in a vacuum state is called a vacuum chamber, and a chamber whose inside is filled with an N ₂ gas is called an N ₂ chamber.

[0011] 'When using a vacuum chamber or N ₂ chamber, in order to increase productivity, the load chamber 20' the process chamber 10, the unload chamber 3
The inside of the transfer chamber 40 'and the inside of the transfer chamber 40' must have the same atmosphere as the process chamber 10 '.

In order to use the chamber as a vacuum chamber, the inside of the chamber may be evacuated by a vacuum pump. Even when the chamber is used as an N ₂ chamber, the inside of the chamber is once filled with N ₂ gas after a low vacuum state.

[0013]

As described above, in the conventional laser annealing apparatus, the process chamber 1
0 ', load chamber 20', unload chamber 3
0 'and the inside of the transfer chamber 40' must be evacuated, and a vacuum pump (dry pump) 1
2 ', 22', 32 'and 42' are essential components. As a result, the conventional laser annealing apparatus has a disadvantage that it is expensive. Also, or the inside of the chamber in a vacuum state, or, once, since they must be in an N ₂ atmosphere to a vacuum state, it takes time to the chamber in a predetermined atmosphere, the disadvantage is not improved productivity is there. Further, since the inside of the chamber must be evacuated, the wall thickness (wall thickness) of the chamber must be increased. Further, since the inside of the process chamber 10 'must be evacuated, in addition to the process chamber 10',
It also requires a load chamber 20 ', an unload chamber 30' and a transfer chamber 40 '.

Accordingly, an object of the present invention is to provide a laser annealing device which is inexpensive and can improve productivity.

Another object of the present invention is to provide a laser annealing apparatus that can eliminate chambers other than the process chamber.

[0016]

According to the present invention, the process chamber is set to an inert gas atmosphere by filling only the inert gas without evacuating the process chamber. And a method for forming an atmosphere in the process chamber.

In the method for forming an atmosphere in the process chamber, for example, nitrogen gas can be used as the inert gas. In that case, it is preferable that the nitrogen gas is filled in the process chamber by introducing nitrogen gas from the upper portion of the process chamber and discharging air in the process chamber from the lower portion of the process chamber. Further, it is preferable that the pressure in the process chamber be slightly higher than the atmospheric pressure. Further, only when the processing substrate is carried into and out of the process chamber, the entrance of the process chamber may be opened by a simple gate valve. Further, it is preferable that the partition between the inside atmosphere of the process chamber and the outside air at the entrance and exit of the process chamber be performed by a curtain of an inert gas or a curtain of an ionized inert gas.

Further, according to the present invention, in a process chamber in which the inside needs to be an inert gas atmosphere,
A process chamber is provided, comprising a filling means for filling the process chamber with an inert gas without evacuating the process chamber.

In the process chamber, the active gas is, for example, nitrogen gas. Preferably, the filling means includes means for introducing nitrogen gas from the upper part of the process chamber and means for discharging air in the process chamber from the lower part of the process chamber. Preferably, the filling means further includes means for setting the pressure in the process chamber to be slightly higher than the atmospheric pressure. Further, it is desirable to further include a simple gate valve for opening the entrance of the process chamber only when the processing substrate is transferred and unloaded to and from the process chamber. In addition, it is desirable that a curtain of an inert gas or a curtain of an ionized inert gas be formed at the entrance and exit of the process chamber to further include a partition unit that separates the internal atmosphere of the process chamber from the outside air.

Further, according to the present invention, a process chamber having an inert gas atmosphere therein, a laser device for irradiating a processing substrate in the processing chamber with laser light, and a processing substrate for loading the processing substrate into the processing chamber. Loader and
In a laser annealing apparatus including an unloader for unloading a processing substrate in a process chamber, and a robot for transferring a processing substrate between the process chamber, the loader, and the unloader, without evacuation of the inside of the process chamber And a laser annealing apparatus characterized by comprising a filling means for filling an inert gas into a process chamber.

In the laser annealing apparatus, the inert gas is, for example, a nitrogen gas. Preferably, the filling means includes means for introducing nitrogen gas from the upper part of the process chamber and means for discharging air in the process chamber from the lower part of the process chamber.
The filling means preferably further includes means for setting the pressure in the process chamber to be slightly higher than the atmospheric pressure. It is preferable to further include a partitioning unit that separates an internal atmosphere of the process chamber from outside air at an entrance and exit of the process chamber. The partition means may be a simple gate valve for opening the entrance of the process chamber only when the processing substrate is transported and unloaded to and from the process chamber, or may be a curtain of an inert gas or an ionized gas at the entrance of the process chamber. Means for forming a curtain of active gas may be used. Before carrying the processing substrate into the process chamber, it is desirable to further include dust removing means for removing dust attached to the processing substrate. As such a dust removing means, for example, a means for forming a curtain of an inert gas at the outlet of the loader to blow off dust on the processing substrate can be used. Before carrying the processing substrate into the process chamber, it is preferable to further include static electricity removing means for removing static electricity from the processing substrate. As such static electricity removing means, for example, means for forming a curtain of ionized inert gas at the entrance of the loader can be used.

[0022]

According to the present invention, the process chamber is filled with the inert gas only by filling the inert gas without evacuating the inside of the process chamber. For this reason, the vacuum pump conventionally required can be eliminated. Further, since it is not necessary to make the inside a vacuum state, the wall thickness (wall thickness) of the process chamber can be reduced. Further, since there is no need to make the inside of the process chamber a vacuum, chambers other than the process chamber can be eliminated.

[0023]

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, a laser annealing apparatus according to one embodiment of the present invention includes a process chamber 10 in which an inert gas atmosphere is provided, and a processing substrate (described later) in the process chamber 10. A laser device 50 for irradiating the substrate with a laser beam, a loader 21 for carrying a processing substrate into the process chamber 10, an unloader 31 for carrying out a processing substrate in the process chamber 10,
Process chamber 10, loader 21, and unloader 3
And a robot 41 for transferring the processing substrate between the two.

As will be described later, the laser annealing apparatus of the present embodiment has a filling means for filling the process chamber 10 with an inert gas without evacuating the inside of the process chamber 10. In the illustrated example, nitrogen (N ₂ ) gas is used as the inert gas, but another inert gas may be used.

Since the inside of the process chamber 10 is not evacuated as described above, the load chamber 20 ', the unload chamber 30' and the transfer chamber 40 'which are conventionally required as shown in FIG. 3 are eliminated. be able to. Because of the open type, the loaders 2 are used instead of the chambers 20 ', 30', and 40 '.
1. HEP above unloader 31 and robot 41
An A-filter (not shown) is provided to prevent dust from being loaded on the processing substrate when transported on the loader 21, the unloader 31, and the robot 41.

Further, since the inside of the process chamber 10 is not evacuated, the dry pumps 12 ', 22', 32 'and 32' as shown in FIG. 3 can be eliminated. An adjustment valve 12 is provided instead of the dry pump 12 '. Further, the robust gate valves 70 ', 80', 90 'which can withstand the pressure difference between the vacuum and the atmosphere can be eliminated. Instead of the gate valve 70 ′, a simple gate valve 70 having a function of simply opening and closing is provided at the entrance of the process chamber 10. The simple gate valve 70 is for opening the entrance of the process chamber 10 only when transferring and carrying out the processing substrate to and from the process chamber 10. That is, the simple gate valve 70 functions as a partition unit that separates the internal atmosphere of the process chamber 10 from the outside air at the entrance and exit of the process chamber 10.

Further, the laser annealing apparatus uses N ₂ ionized nitrogen gas at the entrance and exit of the process chamber 10.
Includes an ionizer 110 forming a ⁺ curtain. The ionizer 110 also functions as a partitioning unit that separates the internal atmosphere of the process chamber 10 from the outside air at the entrance and exit of the process chamber 10. The ionizer 110
Plays a role of removing static electricity generated by N ₂ blow from the processing substrate as described later.

Further, the laser annealing apparatus has an N ₂ blow generator 1 at the outlet and the inlet of the loader 21, respectively.
20 and an ionizer 130. The N ₂ blow generator 120 forms an N ₂ blow (curtain) at the outlet of the loader 21 to blow off dust on the processing substrate. That is, the N ₂ blow generator 120 functions as dust removing means for removing dust attached to the processing substrate before loading the processing substrate into the process chamber 10. Ionizer 13
0 is N ₂ ⁺ ionized N ₂ gas at the entrance of the loader 21
To form a curtain. This ionizer 13
0 before the processing substrate is loaded into the process chamber 10;
It functions as static electricity removing means for removing static electricity from the processing substrate.

Referring to FIG. 2, a process chamber 10 according to the present invention will be described. In FIG. 2, (A) is a transverse sectional view, and (B) is a longitudinal sectional view. As mentioned above,
The inside of the process chamber 10 is not evacuated. Therefore, the wall thickness (thickness) of the process chamber 10
Can be made thinner than the conventional process chamber 10 '(FIG. 4).

The process chamber 10 has N ₂
A supply port 10a for supplying gas and a discharge port 10 for discharging air in the process chamber 10 below the supply port 10a.
b. Supply port 10a is connected to the N ₂ gas generating source for generating a N ₂ gas (not shown). That is, the combination of the N ₂ gas generation source and the supply port 10a is N
₂ functions as an introduction means for introducing gas from the upper part of the process chamber 10, and the outlet 10b is
It functions as a discharge unit that discharges the air inside from the lower part of the process chamber 10. These combinations of the introduction means and the discharge means serve as a filling means for filling the process chamber 10 with the N ₂ gas without evacuating the inside of the process chamber 10.

The regulating valve 12 is provided near the outlet 10b. On the downstream side of the regulating valve 12, oxygen (O
₂ ) An O ₂ concentration meter (not shown) for measuring gas concentration is provided. As is well known, oxygen (O ₂ ) gas is lighter than nitrogen (N ₂ ) gas. Therefore, when the N ₂ gas is supplied into the process chamber 10 from the supply port 10a, the O ₂ gas, which is a component of air originally present in the process chamber 10, gradually moves to the lower portion of the process chamber 10, and finally Most of the O ₂ gas is discharged to the outside of the process chamber 10 through the discharge port 10b. When the oxygen concentration reaches the order of ppm by the O ₂ concentration meter, the regulating valve 12 is closed. Thus, the atmosphere in the process chamber 10 can be filled with the N ₂ gas. The pressure in the process chamber 10 is adjusted by the adjusting valve 12 so as to be slightly higher than the atmospheric pressure. That is, the regulating valve 12 is connected to the process chamber 1.
It works as a means for setting the pressure in 0 to be slightly higher than the atmospheric pressure.

Next, the operation of the laser annealing apparatus will be described with reference to FIGS.

First, the atmosphere in the process chamber 10 is changed from air to N ₂ gas. Therefore, N ₂ gas is introduced from the supply port 10a from above the process chamber 10. Then, the outlet 1 from the lower part of the process chamber 10
Air is discharged from the inside from 0b. At this time, the regulating valve 12
Thus, the opening of the control valve 12 is adjusted so that the amount of N ₂ gas introduced and the amount of air exhausted are such that the pressure in the process chamber 10 becomes slightly higher than the atmospheric pressure. When the oxygen concentration measured by the O ₂ concentration meter falls below a predetermined concentration, the regulating valve 12 is closed. Thereby, the process chamber 10
The inside is filled with N ₂ gas, and there is almost no O ₂ gas in the process chamber 10.

In this state, a processing substrate (hereinafter, simply referred to as a substrate) 17 is inserted into the loader 21. At this time, since the substrate 17 passes under the ionizer 130,
The static electricity on the substrate 17 is removed by N ₂ ⁺ . The substrate 17 is aligned in the loader 21 using the substrate outline so that the substrate 17 comes to a fixed position.

Next, the simple gate valve 70 is opened, the substrate 17 is transferred from the loader 21 to the process chamber 10 by the robot 41, and the simple gate valve 70 is closed.
When the substrate 17 is unloaded from the loader 21, the substrate 17 by N ₂ blow generator 120 N ₂ blowing (curtains)
Pass under At this time, dust on the substrate 17 is blown off. When the substrate 17 is carried into the process chamber 10, the ionizer 110 removes static electricity generated by the N ₂ blow by the N ₂ ⁺ again. Anyway, dust on the substrate 17 is removed in this way.

Next, the substrate 17 is set in the process chamber 10.
Is annealed by irradiating the laser light emitted from the laser device 50.

When this annealing is completed, the simple gate valve 70 is opened, the substrate 17 is transferred from the process chamber 10 to the unloader 31 by the robot 41, and the simple gate valve 70 is closed. Using the board outline on the unloader 31, alignment is performed so that the board 17 comes to a fixed position. Then, the substrate 17 is unloaded from the unloader 31.

With such a configuration, the laser annealing apparatus according to the present embodiment has the following effects.
The need for a vacuum pump is eliminated. The thickness of the process chamber 10 can be reduced. The loader 21, the unloader 31, and the robot 41 do not need to be covered with the chamber. Eliminates bellows for vacuum and atmosphere shielding. Maintenance of each device becomes easy. Since no time is required for evacuation and filling with N ₂ gas, productivity can be improved accordingly. Therefore, an inexpensive laser annealing device can be provided.

The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, the ionizer 100 is provided at the entrance of the process chamber 10, but an N ₂ blow generator may be provided instead.
The inert gas is not limited to nitrogen gas. The dust removing means and the static electricity removing means are not limited to those in the above-described embodiment.

[0041]

As described above, according to the present invention, since the process chamber is filled with the inert gas without evacuating the inside of the process chamber, the vacuum pump attached to all the chambers is eliminated. can do. Further, since there is no need to make a vacuum state, the thickness of the process chamber can be reduced. Chambers other than the process chamber can be eliminated. Since there is no need to make a vacuum state, or to once make a vacuum state to make the atmosphere of N ₂ gas, productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a laser annealing device according to an embodiment of the present invention.

FIG. 2 is a view showing a process chamber used in the laser annealing apparatus shown in FIG. 1, wherein FIG.
(B) is a longitudinal section.

FIG. 3 is a schematic plan view showing a conventional laser annealing apparatus.

4 is a cross-sectional view showing a process chamber used in the laser annealing device shown in FIG.

[Explanation of symbols]

10 process chamber 10a supply port 10b outlet port 12 control valve 17 substrate 21 loader 31 unloader 41 robot 50 laser device 60 an optical system 70 simple gate valve 110 ionizer 120 N ₂ blowing (curtains) generator 130 ionizer

Claims (3)

(57) [Claims] 1. A process chamber having an inert gas atmosphere therein, a laser device for irradiating a processing substrate with laser light in the processing chamber, and a loader for carrying the processing substrate into the processing chamber. A laser annealing apparatus comprising: an unloader for unloading the processing substrate in the process chamber; and a robot for transferring the processing substrate between the process chamber, the loader, and the unloader. Filling means for filling the process chamber with the inert gas without evacuating the chamber
And inert gas or ions at the entrance and exit of the process chamber
Partitioning means for forming a curtain of inertized gas
A laser annealing device comprising: 2. The method according to claim 1, wherein the processing substrate is placed in the process chamber.
Before carrying in, remove dust attached to the processing substrate.
2. The laser annealing apparatus according to claim 1, further comprising dust removing means . 3. The process substrate is placed in the process chamber.
Before loading, remove static electricity from the processing substrate
The laser annealing apparatus according to claim 2 , further comprising a removing unit .