JP2000180071A - Heat-treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-treating device for making uniform temperature in the surface of a substrate. SOLUTION: A substrate-heating device is provided with a heating plate 1 for heating a substrate. The heating plate 1 is provided with a substrate- supporting plate 15 for supporting the substrate horizontally, a plurality of Peltier elements 16 for absorbing and radiating heat, and a retention plate for retaining the Peltier elements 16. The plurality of Peltier elements 16 are arranged between the lower surface of the substrate-supporting plate 15 and the upper surface of the retention plate. The Peltier elements 16 are connected in parallel to a power supply circuit 32 via a conductor 34 and a correction circuit 33. The correction circuit 33 consists of an element for adjusting the amount of current of a variable resistor or the like, thus individually correcting current being supplied to the Peltier elements 16 and uniformly setting temperature distribution on the upper surface of the substrate-supporting plate 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a heat treatment apparatus for treating a substrate at a predetermined temperature.

[0002]

2. Description of the Related Art In a process of processing a substrate such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display, and a substrate for an optical disk, for example, a substrate heating apparatus for heating a substrate on which a resist film is formed to a predetermined temperature. A substrate cooling device that cools the heated substrate to a predetermined temperature is used. Hereinafter, the substrate heating device and the substrate cooling device are collectively referred to as a heat treatment device.

FIG. 5 is a schematic view showing the structure of a main part of a conventional substrate heating apparatus. As shown in FIG. 5, the substrate heating device 300 includes a heating plate 1 for heating the substrate W to a predetermined temperature. The heating plate 1 includes a substrate support plate 15 that horizontally supports the substrate W, and a substrate support plate 15.
A plurality of Peltier devices 16 arranged on the lower surface of the Peltier device 16 for absorbing and releasing heat, and a holding plate 17 arranged on the lower surface of the plurality of Peltier devices 16 for holding the Peltier device 16.

Silicon grease or the like is interposed between the upper surface of the Peltier device 16 and the lower surface of the substrate support plate 15 and between the lower surface of the Peltier device 16 and the upper surface of the holding plate 17. As a result, generation of a gap due to variations in the thickness, surface accuracy, and the like of the Peltier element 16 is prevented.

A temperature sensor 14 is provided on a substrate support plate 15.
Is buried. Thereby, the substrate support plate 15
Is detected. A spherical spacer 5 that supports the lower surface of the substrate W is disposed on the upper surface of the substrate support plate 15.

An elevating frame 6 is disposed below the heating plate 1 and extends vertically through the heating plate 1.
The lifting pins 3 are connected to the lifting frame 6. A cylinder 7 is connected to one end of the lifting frame 6,
The substrate W is moved up and down by the three elevating pins 3 according to the expansion and contraction operation of the rod of the cylinder 7.

The substrate heating apparatus 300 includes, for example, a heating process (pre-bake process) before exposure to a resist film on a substrate and a heating process (PEB: Post) after exposure.
Exposure bake) and heat treatment after development (post bake treatment). In each process, the substrate W is sequentially supplied to the substrate heating device 300 by a substrate transfer device provided outside, and a heating process is performed.

FIG. 6 is a plan view of the heating plate 1 of the substrate heating apparatus 300 of FIG. As shown in FIG. 6, a plurality of Peltier elements 16 are arranged at the center and the outer periphery of the lower surface of the substrate support plate 15. Multiple Peltier devices 1
6 is connected in series to a power supply circuit 29 by a conductor 28.

The temperature sensor 14 embedded in the substrate support plate 15 is connected to a controller 30 in which a temperature to be controlled is set in advance. Thereby, the controller 30 controls the power supply circuit 29 so that the temperature detected by the temperature sensor 14 matches the set temperature.
To control the current supplied to the Peltier device 16 from the.

As shown in FIG. 5, when the lifting frame 6 is lowered by retracting the rod of the cylinder 7, the substrate W mounted on the plurality of lifting pins 3 is mounted on the spherical spacer 5. At this time, the temperature of the substrate support plate 15, which has been maintained at the set temperature in advance, rapidly decreases. Thereby, the temperature detected by the temperature sensor 14 decreases.

The controller 30 increases the current supplied from the power supply circuit 29 to the Peltier element 16 in response to the output of the temperature sensor 14. As a result, the amount of heat transfer from the holding plate 17 to the substrate support plate 15 increases, and the substrate W is heated by the substrate support plate 15 being heated.

As described above, the controller 30 controls the current supplied from the power supply circuit 29 to the Peltier element 16 so that the temperature obtained from the temperature sensor 14 matches the set temperature. The heat treatment is performed by holding the substrate W at the set temperature for a predetermined time.

[0013]

The above substrate heating apparatus 3
In 00, since a plurality of Peltier elements 16 are connected in series, the same current flows through each Peltier element 16. However, since the heat transfer capability of each Peltier device 16 varies, the amount of heat transfer from the holding plate 17 to the substrate support plate 15 varies.

As described above, by interposing silicon grease or the like between the upper surface of the Peltier device 16 and the lower surface of the substrate support plate 15 and between the lower surface of the Peltier device 16 and the upper surface of the holding plate 17, The occurrence of gaps due to variations in the thickness, surface accuracy, and the like of the Peltier element 16 is prevented. However, since the thickness of the silicon grease or the like varies due to the variation in the thickness, the surface accuracy, or the like of the Peltier element 16, the heat transfer efficiency varies.

For the above reasons, the amount of heat transmitted to the substrate support plate 15 becomes uneven, and the temperature distribution on the upper surface of the substrate support plate 15 becomes uneven. As a result, the in-plane temperature of the substrate W becomes non-uniform.

If the in-plane temperature of the substrate W becomes non-uniform when the temperature of the substrate W rises, there arises a problem that the line width of the pattern formed on the resist film on the substrate W during the developing process becomes non-uniform.

An object of the present invention is to provide a heat treatment apparatus capable of making the in-plane temperature of a substrate uniform.

[0018]

Means for Solving the Problems and Effects of the Invention A heat treatment apparatus according to a first aspect of the present invention is a heat treatment apparatus for treating a substrate at a predetermined temperature, and includes a substrate support for supporting the substrate, and a substrate support. A plurality of Peltier elements for raising or lowering the temperature of the substrate, a current supply means for supplying current to each of the plurality of Peltier elements, and a value of a current supplied to the plurality of Peltier elements by the current supply means. It comprises a plurality of correction means and a control means for controlling the operation of the current supply means.

In the heat treatment apparatus according to the first invention,
Current is supplied to the plurality of Peltier elements by the current supply means under the control of the control means, and the temperature of the substrate supported by the substrate support is raised or lowered by the plurality of Peltier elements. The current supplied to the plurality of Peltier elements for raising or lowering the temperature of the substrate can be respectively corrected by a plurality of correction means. This makes it possible to individually adjust the heat transfer amounts in the plurality of Peltier elements.
Therefore, the heat transfer capability, thickness,
Even if the surface accuracy or the like varies, the temperature distribution on the upper surface of the substrate support can be made uniform, and the in-plane temperature of the substrate can be made uniform.

A heat treatment apparatus according to a second aspect of the present invention is the heat treatment apparatus according to the first aspect, further comprising a temperature detection means for detecting a temperature of the substrate support, and a control means for detecting the temperature of the substrate support. The operation of the current supply means is controlled based on the temperature.

In this case, the operation of supplying current to the plurality of Peltier elements by the current supply means is performed based on the temperature of the substrate support. Thus, the temperature of the substrate support can be accurately set to a desired temperature by feedback control.

A heat treatment apparatus according to a third aspect of the present invention is the heat treatment apparatus according to the first or second aspect, further comprising heating means for heating the substrate support.

In this case, the temperature of the substrate support is quickly raised. Thereby, the time required for the heat treatment of the substrate is reduced.

A heat treatment apparatus according to a fourth aspect of the present invention is the heat treatment apparatus according to the third aspect, wherein the control means operates the heating means until the temperature detected by the temperature detection means reaches a predetermined temperature. It is.

In this case, the heating means operates until the substrate support reaches a predetermined temperature, and stops after the temperature reaches the predetermined temperature. Thereby, the substrate support can reach a predetermined temperature in a short time by the heating means and the Peltier element. After reaching the predetermined temperature, the temperature of the substrate support is controlled to the set temperature by the operation of the Peltier element. Thus, the temperature of the substrate can be quickly raised and the in-plane temperature of the substrate can be made uniform.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a substrate heating apparatus will be described as an example of a heat treatment according to the present invention.

FIG. 1 is a sectional view of a substrate heating apparatus according to a first embodiment of the present invention, and FIG. 2 is a plan view of a heating plate of the substrate heating apparatus of FIG.

The substrate heating apparatus 100 of this embodiment is used for, for example, a pre-bake process, a PEB process, and a post-bake process for a resist film on a substrate. In each process, the substrate W is sequentially supplied to the substrate heating device 100 by a substrate transport device provided outside, and the heat treatment is performed.

As shown in FIG. 1, the substrate heating apparatus 100 includes a heating plate 1 for heating a substrate W inside a housing 10. On the upper surface of the heating plate 1, three spherical spacers 5 supporting the lower surface of the substrate W are arranged in a regular triangular shape. Further, the heating plate 1 is formed with three through holes 4 for passing three lifting pins 3 for moving the substrate W up and down (see FIG. 2).

The heating plate 1 includes a substrate support plate 15 for horizontally supporting the substrate W, a plurality of Peltier elements 16 for absorbing and releasing heat, and a holding plate 17 for holding the Peltier elements 16. Peltier elements 16
Is disposed between the lower surface of the substrate support plate 15 and the upper surface of the holding plate 17. When attaching the Peltier device 16 between the substrate support plate 15 and the holding plate 17, by applying silicon grease or the like to the Peltier device 16, the occurrence of gaps due to variations in the thickness, surface accuracy, etc. of the Peltier device 16 is prevented. Is done. Thereby, the heat transfer efficiency between the Peltier device 16 and the substrate support plate 15 and between the Peltier device 16 and the holding plate 17 are improved.

The Peltier element 16 absorbs heat on one side and dissipates heat on the other side when a current is supplied. Thereby, heat can be transferred from one side to the other side. The direction of heat transfer can be switched by switching the direction of the current supplied to the Peltier element 16. When increasing the temperature of the substrate support plate 15, heat is transferred from the holding plate 17 to the substrate support plate 15, and when decreasing the temperature of the substrate support plate 15, the heat is transferred from the substrate support plate 15 to the holding plate 17. Transfer heat to

An upper cover 2 that covers the upper surface of the heating plate 1 is mounted on the heating plate 1 in the housing 10. Further, below the heating plate 1, a lifting frame 6 connected to the three lifting pins 3 is arranged. A cylinder 7 is connected to one end of the lifting frame 6 outside the housing 10. Then, the elevating frame 6 and the elevating pins 3 are moved up and down by the expansion and contraction of the rod of the cylinder 7. When the lifting frame 6 and the lifting pins 3 are raised, the substrate W waits above the heating plate 1, and when lowered, the substrate W is placed on the spherical spacer 5 on the heating plate 1.

A substrate supply / discharge port 11 is formed on the front surface of the housing 10. A shutter 9 is arranged inside the substrate supply / discharge port 11. The lower end of the shutter 9 is connected to the lifting frame 6 by an interlocking member 8. As a result, when the rod of the cylinder 7 expands and contracts, the elevating frame 6 rises to raise the substrate W to the standby position, and the shutter 9 descends to open the substrate supply / discharge port 11. Also, cylinder 7
When the rod is retracted, the lifting frame 6 is lowered to place the substrate W on the spherical spacer 5 and to release the shutter 9.
Rises to close the substrate supply / discharge port 11.

As shown in FIG. 2, the substrate support plate 15
A plurality of Peltier elements 16
Is arranged. A plurality of correction circuits 33 are provided corresponding to the plurality of Peltier elements 16. Each Peltier element 16 is connected to a corresponding correction circuit 33 by a lead 34, and the plurality of correction circuits 33 are connected to a common power supply circuit 32. Thus, the plurality of Peltier elements 16 are connected in parallel to the power supply circuit 32 via the correction circuit 33. The correction circuit 33 is made up of an element such as a variable resistor that can control the amount of current.

The substrate support plate 15 has a temperature sensor 14
Is embedded, and the temperature sensor 14
It is connected to the. A temperature to be a control target is set in the controller 30 in advance. The controller 30 controls the current supplied from the power supply circuit 32 to the plurality of Peltier elements 16 so that the temperature detected by the temperature sensor 14 matches the set temperature. Thereby, the temperature of the substrate support plate 15 is controlled so as to reach the set temperature.

In this embodiment, the substrate support plate 15 corresponds to the substrate support, the Peltier element 16 corresponds to the Peltier element, the power supply circuit 32 corresponds to the current supply means, and the correction circuit 33 corresponds to the correction means. , The controller 30 corresponds to control means, and the temperature sensor 14 corresponds to temperature detection means.

Next, the operation of determining the correction amount of the correction circuit and the operation of the substrate heating device will be described with reference to FIGS.

(1) Operation of Determining Correction Amount of Correction Circuit 33 To determine the correction amount of each correction circuit 33, a temperature measurement substrate on which a large number of temperature sensors are embedded is used. A substrate for temperature measurement (not shown) is placed on the elevating pin 3 and the rod of the cylinder 7 is retracted to place the substrate for temperature measurement on the spherical spacer 5. Then, a current is supplied from the power supply circuit 32 to the plurality of Peltier elements 16. As a result, heat transfer occurs in each Peltier element 16 and the substrate holding plate 1
By raising the temperature of 5, the temperature measurement substrate is heated.

Next, each correction amount of the correction circuit 33 is adjusted so that the temperatures obtained from the plurality of temperature sensors on the temperature measurement substrate become uniform and the target temperature. Specifically, the resistance value of each correction circuit 33 is adjusted. Thereby, the correction amount of each of the correction circuits 33 is determined. At this time, the temperature obtained from the temperature sensor 14 of the substrate support plate 15 becomes the set temperature set in the controller 30 when performing the substrate heating process.

(2) Operation of Substrate Heating Apparatus The substrate support plate 15 is controlled at a temperature set in advance by the controller 30. In this state, the substrate W held by the arm of the substrate transfer device (not shown) is carried in from the substrate supply / discharge port 11 and placed on the elevating pins 3. The rod of the cylinder 7 is retracted, and the elevating frame 6 is lowered to place the substrate W on the spherical spacer 5. At this time, the shutter 9 moves up to close the substrate supply / discharge port 11.

When the substrate W is carried into the substrate heating apparatus 100, the temperature of the substrate W is rapidly lowered because the temperature of the substrate W is as low as about room temperature. Therefore, the controller 30 controls the power supply circuit 32 so that the temperature detected by the temperature sensor 14 matches the set temperature. Thereby, the current supplied from the power supply circuit 32 to the plurality of Peltier elements 16 increases. As a result, heat transfer increases in the plurality of Peltier elements 16, and the temperature of the substrate supporting plate 15 is increased.

When the temperature detected by the temperature sensor 14 matches the set temperature, the substrate W is held in this state for a predetermined time.

When the above-described heating process is completed, the elevating frame 6 moves up and moves upward while supporting the lower surface of the substrate W by the elevating pins 3. Then, the shutter 9 moves down. The arm of the substrate transfer device enters the inside of the substrate heating device 100, and the substrate W is transferred from the lifting pins 3 to the arm.
The arm holding the substrate W retreats from the substrate heating device 100 and transports the substrate W to the next step.

In the substrate heating apparatus of this embodiment, the amount of heat transfer in each Peltier element 16 can be individually adjusted by individually correcting the current supplied to each Peltier element 16 by the correction circuit 33. Becomes Thereby, even if the heat transfer capability, thickness, surface accuracy, and the like of the plurality of Peltier elements 16 vary, the temperature distribution on the upper surface of the substrate support plate 15 can be set uniformly. Therefore, the in-plane temperature of the substrate W placed on the spherical spacer 5 can be made uniform.

FIG. 3 is a sectional view of a substrate heat treatment apparatus according to a second embodiment of the present invention, and FIG. 4 is a plan view of a heating plate of the substrate heating apparatus of FIG. Substrate heating device 30 of the present embodiment
Numeral 0 indicates that the heater 18 is added to the heating plate 1 of the substrate heating apparatus 200 of FIG. 1 so that the temperature can be rapidly raised.

As shown in FIG. 3, a plurality of Peltier devices 1
6 and the substrate support plate 15, the intermediate plate 1
9 and the heater 18 are sandwiched. As a result, the temperature of the substrate support plate 15 is rapidly raised by the plurality of Peltier elements 16 and the heater 18.

As shown in FIG. 4, the heater 18 is connected to a power supply circuit 35, and the power supply circuit 35 is controlled by a controller 36. The controller 36
Controls the power supply circuit 32 similarly to the controller 30 of FIG.

The above is the difference between the substrate heating apparatus 200 of this embodiment and the substrate heating apparatus 100 of FIG.

In this embodiment, the substrate support plate 15 corresponds to the substrate support, the Peltier element 16 corresponds to the Peltier element, the power supply circuit 32 corresponds to the current supply means, and the correction circuit 33 corresponds to the correction means. , The controller 36 corresponds to control means, the temperature sensor 14 corresponds to temperature detection means,
The heater 18 corresponds to a heating unit.

Next, the operation of the substrate heating apparatus will be described. The operation of determining the correction amount of the correction circuit 33 is the same as in the case of the substrate heating apparatus 100 of FIG. 1, and it is assumed that the correction has already been performed.

Before the loading of the substrate W, the substrate support plate 15 is controlled to the temperature set by the controller 36.
When the substrate W is loaded, the temperature of the substrate W is as low as about room temperature.
The temperature of the substrate support plate 15 drops rapidly. Therefore, the power supply circuits 32 and 35 are controlled by the controller 36 so that the temperature of the substrate supporting plate 15 increases.
Thereby, the temperature of the substrate support plate 15 rapidly rises.

When the temperature of the substrate supporting plate 15 reaches a predetermined temperature, the operation of the heater 18 is stopped by the controller 36. Thereafter, the substrate supporting plate 15 is controlled by the plurality of Peltier elements 16 so as to match the set temperature. As a result, the substrate W reaches the target temperature, and the in-plane temperature becomes uniform. In this state, the substrate W is held for a predetermined time.

By operating the heater 18 and the plurality of Peltier elements 16 as described above, the temperature of the substrate W can be rapidly increased.

In the first and second embodiments,
Although the case where the present invention is applied to the substrate heating device has been described, the present invention can also be applied to the substrate cooling device.

[Brief description of the drawings]

FIG. 1 is a sectional view of a substrate heating apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of a heating plate of the substrate heating device of FIG.

FIG. 3 is a plan view of a substrate heating device according to a second embodiment of the present invention.

FIG. 4 is a plan view of a heating plate of the substrate heating device of FIG.

FIG. 5 is a schematic sectional view showing a configuration of a conventional substrate heating apparatus.

FIG. 6 is a plan view of a heating plate of the substrate heating device of FIG.

[Explanation of symbols]

 14 Temperature Sensor 15 Substrate Support Plate 16 Peltier Element 18 Heater 30 Controller 32 Power Supply Circuit 33 Correction Circuit 36 Controller

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Masami Otani 4-chome Tenjin Kitamachi 1-chome, Horikawa-dori-Terauchi, Kamigyo-ku, Kyoto F-term (reference) in Dainippon Screen Mfg. Co., Ltd. 4K063 AA05 BA12 CA03 FA03 FA25 FA29 5F046 KA04 KA07 5H323 AA40 BB06 CA06 CB03 CB12 CB42 CB44 DA01 EE05 FF02 FF10 HH02 KK05

Claims (4)

[Claims] 1. A heat treatment apparatus for processing a substrate at a predetermined temperature, comprising: a substrate support for supporting the substrate; a plurality of Peltier elements provided on the substrate support for raising or lowering the temperature of the substrate; A current supply unit that supplies a current to each of the plurality of Peltier elements; a plurality of correction units that respectively correct values of currents supplied to the plurality of Peltier elements by the current supply unit; and an operation of the current supply unit is controlled. A heat treatment apparatus, comprising: 2. The temperature control device according to claim 1, further comprising a temperature detection unit configured to detect a temperature of the substrate support, wherein the control unit controls an operation of the current supply unit based on the temperature detected by the temperature detection unit. The heat treatment apparatus according to claim 1, wherein the heat treatment is performed. 3. The heat treatment apparatus according to claim 1, further comprising heating means for heating the substrate support. 4. The heat treatment apparatus according to claim 3, wherein said control means operates said heating means until the temperature detected by said temperature detection means reaches a predetermined temperature.