JPH1167619A - Substrate-heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat the entire surface of a substrate to be heated approximately uniformly. SOLUTION: A substrate heating device is formed by including an upper plate-shaped member 2, which mounts a semiconductor wafer W on an upper surface and heats the wafer, resistance-heating type heaters 3a-3c, which are divided into three parts, a heating part l, which is formed by laminating a lower plate-shaped member 4 and a heat insulating plate 5 and a control device 21, wherein hole parts 9a-9c are formed at the lower surface of the upper plate- shaped member 2 in contact with the respective heaters 3a-3c, and the supplied electric power to the respective heaters 3a-3C is individually controlled based on the outputs of temperature sensors 10a-10c that are inserted into hole parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate heating apparatus, and more particularly, to a substrate heating apparatus capable of heating substantially uniformly over the entire surface of a substrate to be heated.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for heating a semiconductor wafer, a substrate for liquid crystal, or the like, for example, a semiconductor wafer coated with a photoresist in a photolithography process is heated to bring the photoresist into a chemically stable state. There is a hot plate or the like that is used to make the hot plate. In such a hot plate, according to the temperature set by the control device, the entire resistance heating type heater disposed inside the hot plate generates heat substantially uniformly, and the semiconductor wafer mounted on the upper surface of the hot plate is heated. Those configured to heat are common.

[0003]

By the way, in recent years, in order to satisfy the demand for fine processing in a semiconductor manufacturing process,
Exposure light sources have been shortened in wavelength. On the other hand, shortening the wavelength of the exposure light source leads to a decrease in the exposure intensity, and accordingly, a highly sensitive chemically amplified photoresist corresponding thereto has been attracting attention.

[0004] In this chemically amplified photoresist, an acid generated by exposure is diffused into the photoresist by heat treatment, and the sensitivity is enhanced by utilizing its catalytic action. For this reason, in order to obtain high resolution over the entire surface of the semiconductor wafer, the entire temperature must be kept within 0.1 ° C.
It is necessary to control the temperature to be uniform so as to be below .

However, in the hot plate having the above-described structure, the temperature of the upper surface is not always uniform due to the shape of the hot plate itself and the surrounding environment where the hot plate is installed. A temperature difference is also generated in the plane. For example, in the case of a hot plate formed in a disk shape, heat is more easily radiated in the outer peripheral region than in the central region on the upper surface, and if the entire plate is heated uniformly, the heat is generated between the central region and the outer peripheral region. Causes a temperature difference. Further, in the case where a hot plate is disposed in the process apparatus and the semiconductor wafer is transferred onto the hot plate through the opening of the apparatus, heat radiation of a portion of the upper surface of the hot plate near the opening is dissipated. Since the temperature is further promoted, a temperature difference occurs due to the distance from the opening.

As described above, in a hot plate as a conventional substrate heating apparatus, a total of 1 to 2
In some cases, a temperature difference of about ° C was generated. Therefore, it is difficult to accurately control the post-exposure heat treatment of the chemically amplified photoresist, and there is a problem that high resolution over the entire surface of the semiconductor wafer cannot be obtained.

[0007] The present invention has been made in view of such conventional problems.
It is an object of the present invention to provide a substrate heating apparatus capable of performing precise temperature control so that the entire surface of a substrate to be heated can be heated substantially uniformly.

[0008]

According to the first aspect of the present invention, a plurality of heat sources are provided corresponding to each of a plurality of regions of a substrate to be heated. And a control device capable of individually controlling the heat value of each of the above. Thus, the temperature of each region of the substrate to be heated is individually controlled.

In the invention according to a second aspect, the control device is configured to generate heat of each of the plurality of heat sources based on outputs of a plurality of temperature sensors disposed in correspondence with respective regions of the substrate surface. Are controlled individually, and dynamic control based on the actually measured temperature is performed. In order to detect the temperature of the substrate to be heated, the temperature sensor may be provided on a lower surface of an upper plate member on which the substrate to be heated is mounted on a plurality of surfaces of the substrate to be heated. May be inserted and attached to the holes formed in correspondence with the above-mentioned area.

In order to prevent the influence of the adjacent area on each temperature sensor as much as possible, in the invention according to claim 4, the temperature sensor has a substantially cylindrical shape having a detecting portion at one end in the axial direction. It is assumed that a heat insulating material is provided on the outer surface excluding the detection unit, and is inserted into the hole of the upper plate member from the detection unit side. As the plurality of heat sources, for example, as in the invention according to claim 5, a resistance heating type heater plate attached to the lower surface of an upper plate member on which the substrate to be heated is mounted can be used. As in the invention according to Item 6, the upper plate-shaped member is a disk-shaped member, and the heater plate is a substantially disk-shaped central heater disposed in correspondence with a central region of a lower surface of the upper plate-shaped member. And two substantially C-shaped outer peripheral heaters disposed around the central heater in correspondence with the outer peripheral region of the lower surface of the upper plate-like body. Each temperature can be controlled individually.

[0011] In the invention according to claim 7, the 2
The two outer peripheral heaters are disposed such that an electrode for power supply provided at one end of one outer peripheral heater is located below the other end of the other outer peripheral heater, and is provided at one end of the other outer peripheral heater. The provided electrode is disposed so as to be located below the other end of one of the outer peripheral heaters so that there is no blank portion where the temperature cannot be controlled.

Further, in the invention according to claim 8, a lower plate-like member for pressing the upper surface of the heater plate against the lower surface of the upper plate-like member to make close contact therewith, and an upper surface of the lower plate-like member for the heater plate. A heat insulating plate that is pressed against and fixed to the lower surface is provided so that heat generated from the heater plate is easily transmitted to the upper plate member. On the other hand, in the invention according to claim 9, the heat insulating plate has a surface in contact with the lower plate-shaped member,
A concave portion forming an adiabatic air layer between the lower plate member and the lower plate member prevents heat generated from the heater plate from being released downward.

Further, in the invention according to claim 10, a heat insulating material is provided on the outer peripheral side surface of the upper plate-like member, the heater plate, and the lower plate-like member to prevent the heat from being radiated from the side surface.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view schematically showing an embodiment of a substrate heating apparatus according to the present invention. This substrate heating apparatus is a disk for mounting and heating a semiconductor wafer W as a substrate to be heated on an upper surface. The heating unit 1 includes a heating unit 1 and a control device 21 (including a power supply) for controlling electric power supplied to the heating unit 1.

FIG. 2 is a longitudinal sectional view of the heating unit 1. Referring simultaneously to FIGS. 1 and 2, the heating unit 1 is formed by laminating an upper plate member 2, a resistance heating heater plate 3 as a heat source, a lower plate member 4, and a heat insulating plate 5 from above. The upper surface of the heater plate 3 is pressed against the lower surface of the upper plate-shaped member 2 to be in close contact therewith, and the upper surface of the lower member 4 is fixed by the heat insulating plate 5 so as to be pressed against the lower surface of the heater plate 3. . A plurality of concave portions 5 a are provided concentrically on the surface of the heat insulating plate 5 which is in contact with the lower plate member 4, and a heat insulating air layer 7 is formed between the heat insulating plate 5 and the lower plate member 4. The ratio between the portion where the heat insulating plate 5 is in contact with the lower plate member 4 and the heat insulating air layer 7 is represented by a cross section in the diameter of the heating unit 1
When the ratio is approximately 1: 3, mechanical strength and a good heat insulating effect can be obtained. Further, a heat insulating material 6 is provided on the outer peripheral side surfaces of the upper plate-like member 2, the heater plate 3, and the lower plate-like member 4, so that heat radiation from this portion is also prevented.

The upper plate-like member 2 is preferably formed of aluminum or the like having excellent thermal conductivity. Further, ... Are preferably used as the heat insulating plate 5 and the heat insulating material 6. In the heating unit 1 having such a laminated structure, the heat generated from the heater plate 3 is easily transmitted to the semiconductor wafer W mounted on the upper surface of the upper plate-shaped member 2, and heat radiation in other parts is prevented. Thus, by controlling the power supplied to the heater plate 3, the amount of heat transmitted to the semiconductor wafer W can be easily adjusted.

The heater plate 3 has a substantially disk-shaped central heater 3a disposed in correspondence with the central region 2a on the lower surface of the upper plate-shaped member 2, and outer peripheral regions 2b and 2c on the lower surface of the upper plate-shaped member 2. A corresponding C disposed around the central heater 3a
It is composed of two outer heaters 3b and 3c in the shape of a letter. These three heaters are provided with electrodes 8a to 8c for separately receiving power supply from the control device 21. Since the electrodes 8a to 8c do not generate heat, the electrodes 8 provided at one end of the outer peripheral heater 3b are provided in the outer peripheral regions 2b and 2c where heat is easily dissipated as compared with the central region 2a.
b is disposed below the other end of the outer peripheral heater 3c. Similarly, the electrode 8c provided at one end of the outer peripheral heater 3c is positioned below the other end of the outer peripheral heater 3b. The upper plate-like body 2
The entire upper surface can be temperature controlled.

A hole 9a is formed in the lower surface of the upper plate member 2 at a position where each of the three heaters 3a to 3c abuts.
9a to 9c, and temperature sensors 10a to 10c are inserted into the holes 9a to 9c. Each temperature sensor 10a-10
c is a substantially cylindrical shape having a detecting portion 11 at one end in the axial direction, and is inserted into each of the holes 9a to 9c from the detecting portion 11 side. The temperature sensors 10a to 10c are connected to a control device 21. The control device 21 controls the temperature of the upper plate-shaped body 2 based on the outputs of the temperature sensors 10a to 10c so that the entire upper plate 2 has a uniform temperature. The power supplied to each of the three heaters 3a to 3c is adjusted to control the amount of heat generated. In addition, each of the temperature sensors 10a to 10c is covered with a heat insulating material 12 on an outer surface except for a detecting portion so as to prevent a thermal influence from an adjacent region as much as possible.

The above-described substrate heating device is mounted, for example, in a photoresist coating / developing device and used in conjunction with an exposure device. FIG. 3 is a cross-sectional view illustrating a use state of the substrate heating device housed in the coating / developing device. The semiconductor wafer W having the surface coated with the chemically amplified photoresist is exposed to light by an exposure device (not shown), and then is carried into the coating / developing device 31 through an opening 32 and is heated by a heating unit 1 (upper plate) of a substrate heating device. It is placed on the upper surface of the shaped member 2) and heated.

At this time, the central region 2a of the upper plate member 2
The outer regions 2b and 2c are more likely to dissipate heat than the outer regions 2b and 2c, and the temperature tends to decrease. Further, the outer peripheral region 2c located on the opening 32 side of the coating / developing device 31 is more easily radiated by heat than the outer peripheral region 2b located at the back due to the influence of the outside air. Therefore, the control device 21 controls each temperature sensor at predetermined time intervals.
The power supplied to each of the heaters 3a to 3c is adjusted as needed based on the outputs of 10a to 10c, and the center region 2a and the outer peripheral region 2 are adjusted.
The temperature of each of b and 2c is dynamically controlled so as to be kept uniform. 0.01 ° C to keep the temperature difference within 0.1 ° C
Control in units is preferred.

In this way, it is possible to substantially uniformly heat the entire surface of the semiconductor wafer W. On the other hand, depending on the purpose, it is possible to intentionally create a biased temperature distribution by adjusting the power supplied to each of the heaters 3a to 3c. In the example described above, the central region 2a and the outer peripheral region 2
Although the region is divided into three regions b and 2c, more precise control is possible if the structure is further divided into a larger number of regions.

Even in the case where the heaters 3a to 3c vary and the amount of heat generated with respect to the same supplied power is different, the correction can be performed by the control device 21, so that the substrate heating device can be manufactured with good yield and at low cost. be able to.
The heat source is not particularly limited, and a heating lamp or the like can be used in addition to the above-described resistance heating type heater plate.

[0023]

As described above, the first aspect of the present invention is described above.
According to the invention, there is an effect that a desired temperature distribution can be created by individually controlling the temperature of each region of the substrate to be heated. Further, since the variation in the performance of the heat source can be corrected at the time of use, there is also an effect that the substrate heating apparatus can be manufactured with good yield and at low cost.

According to the second and third aspects of the present invention, there is an effect that a desired temperature distribution can be automatically controlled based on the output of the temperature sensor. Further, according to the invention of claim 4, there is an effect that a desired temperature distribution can be obtained with higher accuracy by eliminating thermal influence from other regions. Further, according to the fifth aspect of the invention, there is an effect that the control can be performed with high accuracy by using the resistance heating type heater plate in which the amount of generated heat can be easily controlled.

Further, according to the invention of claim 6, there is an effect that the temperature distribution can be efficiently controlled by treating the portions having significantly different tendency of heat radiation as different regions. Further, in the invention according to claim 7, there is an effect that the entire temperature distribution can be controlled by eliminating a portion that cannot be directly heated.

According to the eighth aspect of the invention, the result of the control by the control device is accurately reflected on the temperature of the substrate to be heated placed on the upper surface of the upper plate member. There is. According to the ninth and tenth aspects of the present invention, by suppressing excessive release of heat, the lead time of the substrate heating device can be reduced, and the substrate to be heated can be efficiently heated. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a use state of the substrate heating apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating part 2 Upper plate member 2a Central region 2b, 2c External region 3 Heater plate 3a Central heater 3b, 3c Outer peripheral heater 4 Lower plate member 5 Heat insulating plate 5a Depression 6 Heat insulating material 7 Heat insulating air layer 8a-8c Electrode 9a ~ 9c Hole 10a ~ 10c Temperature sensor 11 Detector 12 Insulation material 21 Control device 31 Coating / developing device

Claims (10)

[Claims] 1. A heating apparatus comprising: a plurality of heat sources disposed in correspondence with a plurality of regions of a substrate to be heated; and a control device capable of individually controlling a heat value of each of the plurality of heat sources. A substrate heating apparatus, characterized in that: 2. The apparatus according to claim 1, wherein the control device individually controls the heat value of each of the plurality of heat sources based on outputs of a plurality of temperature sensors disposed in correspondence with each area of the substrate. The substrate heating apparatus according to claim 1, wherein: 3. The temperature sensor is inserted into holes formed in a lower surface of an upper plate member on which the substrate to be heated is mounted on the upper surface so as to correspond to a plurality of regions on the surface of the substrate to be heated. The substrate heating device according to claim 2, wherein the substrate heating device is attached. 4. The temperature sensor has a substantially cylindrical shape having a detecting portion at one end in the axial direction, a heat insulating material is provided on an outer surface except for the detecting portion, and the upper plate-shaped member is provided from the side of the detecting portion. 4. The substrate heating device according to claim 3, wherein the substrate heating device is inserted into a hole of the member. 5. The heating plate according to claim 1, wherein said plurality of heat sources are resistance heating heater plates mounted on a lower surface of an upper plate member on which said substrate to be heated is mounted. The substrate heating device according to any one of the above. 6. The heater according to claim 6, wherein the upper plate has a disk shape, and the heater plate has a substantially disk-shaped central heater disposed in correspondence with a central region of a lower surface of the upper plate. The substrate heating according to claim 5, comprising: two substantially C-shaped outer peripheral heaters disposed around the central heater corresponding to the outer peripheral region of the lower surface of the plate-like body. apparatus. 7. The two outer heaters are arranged such that an electrode for power supply provided at one end of one outer heater is positioned below the other end of the other outer heater. 7. The substrate heating apparatus according to claim 6, wherein the electrode provided at one end of the outer peripheral heater is disposed below the other end of the one outer peripheral heater. 8. A lower plate member which presses the upper surface of the heater plate against the lower surface of the upper plate member to make close contact therewith, and a heat insulating member which presses the upper surface of the lower plate member against the lower surface of the heater plate to fix it. The substrate heating device according to any one of claims 5 to 7, further comprising: a plate. 9. The substrate according to claim 8, wherein the heat insulating plate has a concave portion on the surface in contact with the lower plate member, the concave portion forming a heat insulating air layer between the heat insulating plate and the lower plate member. Heating equipment. 10. The substrate heating apparatus according to claim 8, wherein a heat insulating material is provided on outer peripheral side surfaces of the upper plate-shaped member, the heater plate, and the lower plate-shaped member. .