JP2000260687A - Method and apparatus for heat treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable uniform heat treatment on a substrate by efficiently using electric power. SOLUTION: A prebaking unit 34 is provided with a placing table 56 for placing a wafer W, a laser beam source 57 generating laser beam and a reflecting device 59 for reflecting the laser beam from the laser beam source 57. The reflecting device 59 is provided with a polygon mirror 62 in a polyhedron shape which rotates and pitches by a driving source such as a motor or the like. Radiation points of the laser beam reflected by the polygon mirror onto the wafer W scans the entire surface of the wafer W by rotation and pitching of the polygon mirror 62.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for heating a substrate.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
For example, a lithography process for forming a resist film on a surface of a semiconductor wafer (hereinafter, referred to as “wafer”) or the like is performed. This lithography process includes a resist coating process in which a resist solution is applied to the wafer to process the wafer, an exposure process in which the wafer after the resist coating is exposed, a heating process in which the wafer is heated, and a wafer in which the exposure process is performed. It has various processing steps such as a development processing step for developing, and these processing steps are performed by a coating and developing processing apparatus.

[0003] The coating and developing apparatus is provided with various processing apparatuses for individually performing the above-described processing. In a heat processing apparatus for performing a heating process of a wafer, for example, a disk-shaped mounting device having a built-in heater is used. A table is provided. With this configuration, when electric power is supplied to the heater, the heat of the heater is transmitted to the mounting table, and the heat from the mounting table heats the wafer.

[0004]

However, a large amount of heat is radiated from the periphery of the mounting table, and as a result, the wafer may not be heated uniformly. In view of this point, it has been conventionally proposed to arrange a heater having a large calorific value at the periphery of the mounting table so that the same calorific value is transmitted to the peripheral portion and the central portion of the wafer, respectively. The problem of heat radiation from the periphery of the mounting table remained, and efficient use of power was not possible.

Accordingly, an object of the present invention is to provide a heat treatment method and a heat treatment apparatus capable of uniformly heating a substrate by efficiently using electric power and solving the above-mentioned problems.

[0006]

According to the first aspect of the present invention, there is provided a method of heating a substrate, comprising: reflecting a laser beam from a laser light source by a reflector; A heat treatment method is provided in which a substrate is heated by irradiating light on a substrate and displacing a reflector to change an irradiation position of reflected light on the substrate.

In the heat treatment method according to the first aspect, the substrate is heated by light reflected by the reflector. At this time, the irradiation position of the reflected light is changed by the displacement of the reflector, so that the entire surface of the substrate can be uniformly irradiated with the reflected light. Therefore, uniform heat treatment of the substrate is possible. Further, since the substrate is not heated via the mounting table, there is no problem that heat is radiated from the periphery of the mounting table.

According to a second aspect of the present invention, there is provided a method for heat-treating a substrate, wherein a laser beam from a laser light source is reflected by a reflector having a substantially polygonal prism or a substantially polygonal cylinder, and the reflected light is irradiated onto the substrate. And heating the substrate by changing the irradiation position of the reflected light on the substrate by rotating the reflector at least about the axis of the substantially polygonal prism or the substantially polygonal cylinder and pitching the reflector itself. A heat treatment method is provided.

According to the heat treatment method of the present invention, when the laser light from the laser light source is made incident on a reflector rotating around the axis of the substantially polygonal prism or the substantially polygonal cylinder, the reflected light is reflected on the substrate on the axis. Scan in the direction perpendicular to the length direction. Further, when the laser light from the laser light source is made incident on a reflector that pitches, the reflected light scans on the substrate along the longitudinal direction of the axis.
Therefore, when the reflector is rotated around the axis and pitched, the reflected light from the reflector can be applied to the entire surface of the substrate.

According to a third aspect of the present invention, there is provided an apparatus for heating a substrate supported by a support member, comprising: a laser light source for generating a laser beam for heating the substrate; and a laser beam from the laser light source directed to the substrate. And a reflector for reflecting the laser beam from the laser light source to an arbitrary position on the substrate.

In the heat treatment apparatus according to the third aspect, it is possible to irradiate an arbitrary position on the substrate with the laser beam, so that the heat treatment method according to the first aspect can be suitably implemented. it can. Therefore, the entire surface of the substrate can be irradiated with the reflected light, and uniform heat treatment of the substrate can be performed.

In this case, a temperature sensor capable of detecting infrared rays emitted from the substrate as an in-plane temperature of the substrate, and reflected light from the reflector based on the temperature detected by the temperature sensor. Control means for controlling the irradiation position of the light.

According to the fourth aspect of the present invention, the irradiation position of the reflected light is controlled based on the temperature on the substrate detected by the infrared ray emitted from the substrate. When the temperature is low, the reflector can be displaced by the control means so that the specific portion is irradiated with the reflected light, whereby the temperature on the substrate can be corrected. Therefore, a more uniform heat treatment of the substrate can be performed.

According to a fifth aspect of the present invention, a temperature sensor capable of detecting infrared rays emitted from the substrate as an in-plane temperature of the substrate, and an output of the laser light source is adjusted based on the temperature detected by the temperature sensor. Light amount control means for controlling an irradiation amount of reflected light from the reflector.

In the heat treatment apparatus according to the present invention, the output of the laser light source is adjusted based on the temperature detected by the temperature sensor. Can control the light amount control means to increase the irradiation amount of the reflected light to the specific portion.

According to a sixth aspect of the present invention, there is provided an apparatus for heating a substrate supported by a support member, comprising: a laser light source for generating a laser beam for heating the substrate; and a laser beam from the laser light source directed to the substrate. A reflector for reflecting light, wherein the reflector is rotatable about an axis of a polygonal cylinder or a polygonal cylinder having a polygonal peripheral surface, and is pitchable with respect to a substrate. A processing device is provided.

In the heat treatment apparatus according to the sixth aspect, by rotating the reflector around the axis of the substantially polygonal prism or the substantially polygonal cylinder, the reflected light can be scanned in a direction perpendicular to the length of the axis. . Further, by pitching the reflector, the reflected light can be scanned along the longitudinal direction of the axis.
Therefore, as in the case of the second aspect, the light reflected from the reflector can be applied to the entire surface of the substrate.

In this case, a temperature sensor capable of detecting infrared rays emitted from the substrate as an in-plane temperature of the substrate, and a light reflected from the reflector based on the temperature detected by the temperature sensor. To adjust the irradiation position of
It is preferable to provide at least control means for controlling rotation or pitching of the reflector.

According to the heat treatment apparatus of the present invention, the rotation or pitching of the reflector is controlled based on the temperature detected by the temperature sensor to adjust the irradiation position of the reflected light. If the temperature of the specific part is low,
The reflector can be displaced so that the specific portion is irradiated with the reflected light. As a result, the temperature on the substrate can be appropriately corrected, and the heat treatment of the substrate can be performed more uniformly.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coating and developing apparatus having a prebaking unit according to an embodiment of the present invention will be described below. 1 to 3 show the appearance of the coating and developing apparatus, FIG. 1 is a plan view, FIG. 2 is a front view, and FIG. 3 is a rear view.

As shown in FIG.
For example, a cassette station 2 for loading and unloading 25 wafers W from the outside to the coating and developing apparatus 1 in cassette units and loading and unloading wafers W to and from the cassette C, The wafer W is transferred between a processing station 3 in which various processing units for performing a predetermined processing in a single-wafer manner are arranged in multiple stages and an exposure apparatus (not shown) provided adjacent to the processing station 3. And an interface unit 5 for the same.

In the cassette station 2, the cassettes C can be mounted at a predetermined position on the cassette mounting table 6 in a row in the X direction (vertical direction in FIG. 1) with the entrance of the wafer W facing the processing station 3. . The wafer W accommodated in the cassette arrangement direction (X direction) and the cassette C
The wafer carrier 8 movable in the wafer arrangement direction (Z direction; vertical direction) is movable along the carrier path 9 so that the cassette C can be selectively accessed.

The wafer carrier 8 is also configured to be rotatable in the θ direction (rotational direction about the Z axis), and as will be described later, an alignment belonging to a _third processing unit group G ₃ on the processing station 3 side. The unit 32 and the extension unit 33 are configured to be accessible.

In the processing station 3, a main transfer device 13 having three sets of tweezers 10, 11, and 12 for holding a wafer W is disposed at a central portion.
Various processing units are arranged in multiple stages around 3 to constitute a processing apparatus group. In the coating and developing treatment apparatus 1, four processing unit groups _{G 1, G 2, G 3} , G 4 are possible arrangement. The first and second processing unit groups G ₁ and G ₂ are disposed on the front side of the coating and developing processing unit 1, and the third processing unit group G ₃ is disposed adjacent to the cassette station 2. the fourth processing unit group G ₄ is arranged adjacent to the interface section 5. In addition, if necessary,
Processing unit group G ₅ can also be arranged on the rear side.

[0025] In the first processing unit group G ₁ as shown in FIG. 2, two spinner-type processing units, for example the wafer W
A resist coating unit 15 for applying a resist solution to the wafer W and a developing unit 16 for supplying a developer to the wafer W for processing are arranged in two stages from the bottom. In the second processing unit group G _2, the resist coating unit 17 having a resist coating unit 15 basically the same configuration, the developing unit 18 having a developing unit 16 is basically the same configuration They are stacked in two stages from the bottom.

As shown in FIG. 3, the third processing unit group G _3, a cooling unit 30 carries out the oven-type processing units, for example, a cooling process for performing predetermined processing put on the mounting table the wafer W, the resist and the wafer An adhesion unit 31 for improving the fixability with W, an alignment unit 32 for positioning the wafer W, an extension unit 33 for holding the wafer W on standby, prebaking units 34 and 35 for performing a heating process before the exposure process, and a developing process Post-baking units 36 and 3 for performing a subsequent heat treatment
7 and the like are stacked in eight stages in order from the bottom.

[0027] In the fourth processing unit group G _4, post carried out, for example, cooling unit 40, an extension and cooling unit 41 to cool the wafer W mounted thereon, an extension unit 42, cooling unit 43, the heat treatment after the exposure processing Exposure baking units 44 and 45, post baking unit 4
6, 47, etc. are stacked in eight stages in order from the bottom.

The interface section 5 is provided with a peripheral exposure device 51 for exposing the peripheral portion of the wafer W and a wafer carrier 52. The wafer carrier 52 is formed such that movement in the X direction (vertical direction in FIG. 1) and Z direction (vertical direction) and rotation in the θ direction (rotational direction around the Z axis) are each free. The exposure unit (not shown), the extension cooling unit 41, the extension unit 42, and the peripheral exposure unit 51 can be accessed.

The coating and developing apparatus 1 is configured as described above. Next, the pre-baking unit 34 according to the embodiment of the present invention will be described.

As shown in FIG. 4, the pre-baking unit 34 includes a mounting table 56 as a support member on which a wafer W can be mounted in a casing 55, and a light source such as GaAlAs.
And a laser light source 57 having an output of about several W
It has a slit 58 as light amount control means capable of controlling the amount of laser light emitted from the laser light source, and a reflecting device 59 for reflecting the laser light emitted from the laser light source 57.

The mounting table 56 is formed in a disk shape. The mounting table 56 is provided with three support pins (not shown) that can protrude from the front surface and can horizontally support the back surface of the wafer W. Have been. With this configuration, the wafer W supported by these support pins (not shown) moves up and down in the casing 55 and can be mounted on the mounting table 56.

As shown in FIGS. 5 and 6, the reflection device 59 is housed in an appropriate case 60, and a base 61 is provided inside the reflection device 59. At the center of the base 61, a polygon mirror 62 as a reflector having, for example, an octagonal prism shape is rotatably provided. On the surface of the polygon mirror 62, eight mirrors 63 are provided. The polygon mirror 62 has a rotation shaft 65 that is rotated by driving a motor 64 mounted on the axis of the polygon mirror 62. Further, an opening 61a is formed in the base 61, and the polygon mirror 62 is rotated by driving a motor 64 in the opening 61a.

The base 61 is rotatably supported by a pitching shaft 70 extending in a direction perpendicular to the rotation shaft 65, and the pitching shaft 70 is driven by a driving force of a motor 69 by a pitching means 71 for driving the case. It rotates within a predetermined angle at a high speed in an opening 60a provided on the bottom surface of 60. Thereby, the base 61 is pitched.

The pre-baking unit 34 according to the present embodiment is configured as described above. Next, the operation and effect of the pre-baking unit 34 will be described.

The wafer W whose alignment has been completed by the alignment unit 32 of the cassette station 2 is sequentially transferred to the adhesion unit 31 and the cooling unit 30 and subjected to a predetermined process. Conveyed. Then, the wafer W on which the resist coating process has been completed is transferred to the pre-baking unit 34 and is supported by three support pins (not shown) protruding from the surface of the mounting table 56. Thereafter, the wafer W is lowered while being supported by the support pins (not shown), and is mounted on the mounting table 56.

When the laser light from the laser light source 57 is directed toward the polygon mirror 62 as shown in FIG. 7 with the polygon mirror 62 rotated and pitched by driving the motors 64 and 69, the polygon mirror 62 is rotated. The reflected light reflected by the light source irradiates and heats the wafer W on the mounting table 56. During the heating process, when the polygon mirror 62 is rotated by the motor 64 around the rotation axis 65 from the state of FIG. 8 to the state of FIG. 9, for example, the angle of the mirror 63 with respect to the laser light source 57 changes. The reflection angle of the reflected light also changes. As a result, as the polygon mirror 62 rotates, the reflected light scans on the wafer W in a direction perpendicular to the length direction of the polygon mirror 62 as shown by a reciprocating arrow in FIG.

When the base 61 itself is pitched by the pitching means 71, the polygon mirror 6
Numeral 2 tilts upward with respect to the horizontal wafer W as shown in FIG. 11 or downward as shown in FIG. As a result, the reflection angle of the reflected light changes, and the reflected light
As shown by the reciprocating arrow 3, the wafer W is scanned along the length direction of the polygon mirror 62.

Accordingly, as shown in FIG. 14, the light reflected by the polygon mirror 62 can be irradiated on the entire surface of the wafer W, and the wafer W can be uniformly heated.

Further, since the heat treatment is performed by directly irradiating the wafer W with the reflected light, there is no heat radiation from the mounting table 56, and the power can be used more efficiently than in the conventional case. Moreover, the mounting table 56 does not need to be provided with an appropriate heating means such as a heater as in the related art.

Further, as shown by the broken line in FIG. 4, a temperature sensor 75 for detecting the infrared light emitted from the wafer W and reflected by the polygon mirror 62 to detect the in-plane temperature of the wafer W is provided. The amount of laser light emitted from the laser light source 57 is controlled by the slit 58. Therefore, according to the in-plane temperature of the specific portion on the wafer W detected by the temperature sensor 75,
The irradiation amount of the infrared ray reflected by the polygon mirror 62 can be suitably adjusted to irradiate the specific portion. Further, based on the detected temperature, the polygon mirror 62
If it is configured to control the rotation and pitching of the motor, more preferable effects can be obtained.

That is, as shown in FIG. 15, when the temperature of a specific portion on the wafer W detected by the temperature sensor 75 is lower than a predetermined temperature, the address on the wafer W at that time is recognized. If a control device 76 for controlling the rotation of the motor 64 for rotating the polygon mirror 62 and the motor 69 for pitching is provided so that the laser beam is applied to the address portion, the feedback control is performed thereafter. By heating the temperature of the specific portion to a predetermined temperature, the distribution of the in-plane temperature of the wafer W can be corrected, and a heating process according to the in-plane temperature of the wafer W can be performed. Therefore, a more uniform heat treatment can be performed. As described above, by utilizing the rotation and pitching of the polygon mirror 62, infrared rays from the wafer W are reflected by the polygon mirror 62 and detected by the temperature sensor 75, so that the temperature of the entire surface of the wafer W is always detected. This eliminates the need for a sensor to be used.

In the above embodiment, an example was described in which the polygon mirror 62 was an octagonal prism. However, the polygon mirror 62 may be a polygonal prism such as a dodecagonal prism or a 24 prism. It is also possible to form a polygonal cylinder.

Also, an example has been described in which the wafer W is mounted on the mounting table 56 and heat treatment is performed. However, the present invention is not limited to such an example. The wafer W may be supported by an appropriate support member such as a support pin or the like, and may be heated.

Further, the heat treatment apparatus applicable to the present invention is not limited to the pre-baking unit 34 as in the above-described embodiment.
5, Post baking units 36, 37, 46, 4
7, post-exposure baking unit 44,
Other heat treatment devices such as 45 may be used. The substrate that can be used in the present invention is not limited to the wafer W, and may be, for example, an LCD substrate or a CD substrate.

[0045]

According to the first and second aspects, the substrate can be uniformly heated by irradiating the entire surface of the substrate with the reflected light uniformly.

According to the third to seventh aspects, it is possible to provide a heat treatment apparatus capable of suitably executing the heat treatment method according to the first and second aspects.

In particular, according to the fourth and seventh aspects, the irradiation position of the reflected light on the substrate is changed on the basis of the temperature detected by the temperature sensor, so that the substrate can be more uniformly heated.

In particular, according to the fifth aspect, the irradiation amount of the reflected light from the reflector can be controlled by the light amount control means based on the temperature detected by the temperature sensor, so that the substrate can be more uniformly heated.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a coating and developing apparatus including a prebaking unit according to an embodiment of the present invention.

FIG. 2 is a front view of the coating and developing apparatus of FIG. 1;

FIG. 3 is a rear view of the coating and developing apparatus of FIG. 1;

FIG. 4 is a schematic explanatory diagram of a prebaking unit according to the embodiment of the present invention.

FIG. 5 is a schematic perspective view of a reflection device provided in the pre-baking unit of FIG. 4;

FIG. 6 is a cross-sectional view of the reflection device of FIG.

FIG. 7 is an explanatory diagram showing a configuration of a main part of the prebaking unit of FIG. 4;

FIG. 8 is an explanatory diagram showing an irradiation position of reflected light when a polygon mirror of the reflection device of FIG. 5 rotates around a rotation axis.

FIG. 9 is an explanatory diagram showing an irradiation position of reflected light when the polygon mirror is further rotated around a rotation axis from the state of FIG. 8;

FIG. 10 is an explanatory diagram showing an irradiation locus of reflected light on a wafer when the polygon mirror of FIG. 8 is rotated around a rotation axis.

11 is an explanatory diagram showing an irradiation position of reflected light when a base of the reflection device in FIG. 5 is pitched.

FIG. 12 is an explanatory diagram showing irradiation positions of reflected light when the base is further pitched from the state of FIG. 11;

13 is an explanatory diagram showing an irradiation locus of reflected light on a wafer when the base of FIG. 11 is pitched.

FIG. 14 is an explanatory diagram showing an irradiation locus of reflected light on a wafer due to rotation and pitching of a polygon mirror.

FIG. 15 is an explanatory diagram showing a schematic configuration of a pre-baking unit of FIG. 4 including a temperature sensor and a control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coating / developing apparatus 34, 35 Prebaking unit 57 Laser light source 59 Reflector 62 Polygon mirror 64, 69 Motor 65 Rotation axis 70 Pitching axis 71 Pitching means 75 Temperature sensor 76 Control device W Wafer

Claims (7)

[Claims] 1. A method of heating a substrate, comprising: reflecting a laser beam from a laser light source by a reflector, irradiating the substrate with the reflected light, and displacing the reflector to form a substrate. Heating the substrate by changing the irradiation position of reflected light in the substrate. 2. A method of heat-treating a substrate, comprising: reflecting a laser beam from a laser light source by a reflector having a substantially polygonal prism or a substantially polygonal cylinder; irradiating the reflected light onto the substrate; Heating the substrate by rotating at least about the axis of a substantially polygonal prism or a substantially polygonal cylinder and pitching the reflector itself to change the irradiation position of the reflected light on the substrate. . 3. An apparatus for heating a substrate supported by a support member, comprising: a laser light source for generating laser light for heating the substrate; and a reflector for reflecting laser light from the laser light source toward the substrate. Wherein the reflector is capable of reflecting laser light from a laser light source to an arbitrary position on a substrate. 4. A temperature sensor capable of detecting infrared light emitted from a substrate as an in-plane temperature of the substrate, and control means for controlling an irradiation position of reflected light from the reflector based on the temperature detected by the temperature sensor. The heat treatment apparatus according to claim 3, further comprising: 5. A temperature sensor capable of detecting infrared light emitted from a substrate as an in-plane temperature of the substrate, and an output of a laser light source is adjusted based on the temperature detected by the temperature sensor, and the reflected light from the reflector is adjusted. 4. The heat treatment apparatus according to claim 3, further comprising a light amount control means for controlling an irradiation amount of the light. 6. An apparatus for heating a substrate supported by a support member, comprising: a laser light source for generating laser light for heating the substrate; and a reflector for reflecting laser light from the laser light source toward the substrate. Wherein the reflector is rotatable about the axis of a polygonal column or polygonal cylinder whose peripheral surface is polygonal, and is pitchable with respect to the substrate. 7. A temperature sensor capable of detecting an infrared ray emitted from a substrate as an in-plane temperature of the substrate, and an irradiation position of reflected light from a reflector is adjusted based on the temperature detected by the temperature sensor. 7. The heat treatment apparatus according to claim 6, further comprising control means for controlling at least rotation or pitching of the reflector.