JPH11233407A - Temperature control device and temperature control method - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a temperature control device and method capable of improving thermal responsiveness and accurately controlling the temperature of an object to be temperature controlled. According to the present invention, a heat plate (41) and a cooling plate (10) are separated from each other when a heating means (40) is operated by operating a separation pin (30). Further, a heating means is constituted by disposing heaters on both upper and lower surfaces of the heat plate.
The separating means is provided so as to be vertically movable so as to penetrate the base, and moves the heat plate upward with respect to the base when operating the heating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a heating means formed on a heat plate to thereby set a temperature controlled object such as a semiconductor wafer placed on the upper surface of the heat plate in a predetermined high temperature state. While maintaining
The present invention relates to a temperature control apparatus and method for cooling and cooling a base on which the heat plate is mounted, thereby adjusting and maintaining the temperature controlled object at a preset low temperature state via the heat plate.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a semiconductor wafer is prebaked at 110 to 130.degree. C. in order to remove a solvent remaining in a coated resist film, or a resist is easily adhered to a substrate before etching. For this purpose, a heating step such as post-baking for heating the semiconductor wafer to 120 to 150 ° C. is included, and a cooling step such as cooling for cooling the heated semiconductor wafer to a room temperature level of about 20 ° C. is included. In each of these steps, it is important to control the temperature of the semiconductor wafer with good responsiveness and high accuracy in order to improve the throughput.

As this kind of temperature control device, for example,
A hollow cooling plate serving as a base, and a heat plate formed of a metal having excellent thermal conductivity such as aluminum and mounted on the upper surface of the cooling plate, and provided at about 20 ° C. in a hollow portion of the cooling plate. In some cases, a fluid circulating supply system for circulating and supplying the adjusted temperature fluid is connected, and a thin film heater is bonded to the heat plate.

In this temperature control apparatus, a wafer is placed on the upper surface of a heat plate, and the thin film heater is operated in a state where the fluid circulation supply system is stopped, whereby the wafer is heated to a desired temperature by the thin film heater. On the other hand, if the wafer is placed on the upper surface of the heat plate and the fluid circulation supply system is operated from a state where the thin film heater is stopped, the heat plate is cooled to a temperature close to the temperature of the fluid, and the heat of the wafer is further reduced. Is released through the heat plate, and the wafer is cooled to a desired temperature.

According to this temperature control device, the heating step and the cooling step of the wafer can be performed on the same upper surface of the heat plate, so that not only the space can be saved, but also the work efficiency can be reduced. This is advantageous.

[0006]

By the way, in the above-mentioned temperature control device, when the thin film heater is operated, the heat of the thin film heater is released from the cooling plate via the heat plate. Therefore, there is a concern that thermal responsiveness when heating the wafer may be impaired.

Moreover, the above-mentioned heat release causes a temperature difference between the upper surface side portion and the lower surface side portion of the heat plate, and causes the heat plate to be deformed outward. . In such a case, the gap between the thin-film heater of the heat plate and the wafer becomes non-uniform, so that the wafer has a variation in temperature distribution.

Further, in the above temperature control device, the fluid circulation supply system must be stopped while the thin film heater is operating, that is, since the fluid circulation supply system must be intermittently activated, the cooling system must be operated. A time is required until the plate is cooled to a desired temperature, and the thermal responsiveness when cooling the wafer may be impaired.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a temperature control apparatus and a method capable of improving thermal responsiveness and accurately controlling the temperature of an object to be temperature controlled. .

[0010]

Means for Solving the Problems and Functions and Effects
In the invention described in (1), a heat plate that constitutes a heating means for adjusting and maintaining a temperature-controlled object placed on the upper surface at a preset high temperature state mounted on the base, and cooling the base. A cooling means for adjusting and maintaining the temperature-controlled object at a preset low temperature state through the heat plate, wherein the heating means operates the heating means when the heating means is operated. A separating means is provided for separating the plate and the base from each other.

According to the first aspect of the present invention, when the heating means is operated, the heat plate and the base are separated from each other by the separation means, so that the heat of the heating means is released from the base. Does not occur.

Therefore, according to the first aspect of the invention, it is possible to improve the thermal responsiveness when heating the object to be temperature-controlled, and to prevent the heat plate from being thermally deformed as much as possible. Accurate temperature control of the temperature-controlled object can be performed.

According to the first aspect of the present invention,
Since the cooling means can be continuously operated even while the heating means is being operated, the thermal responsiveness when cooling the temperature controlled object can be improved. .

According to a second aspect of the present invention, in the first aspect of the present invention, a heater is provided by disposing heaters on both upper and lower surfaces of the heat plate.

According to the second aspect of the present invention, the temperature difference between the upper surface side portion and the lower surface side portion of the heat plate can be made as small as possible irrespective of external factors. It is possible to more accurately control the temperature of the temperature control target.

According to the third aspect of the present invention, the separating means is vertically movably disposed so as to penetrate the base, and when the heating means is operated, the heat plate is moved relative to the base. Is moved upward.

According to the third aspect of the present invention, since the heat plate, which becomes high in temperature, is moved away from the base, which becomes low in temperature, even if the amount of movement is small, the heat plate between them can be thermally moved. Contact can be reliably cut off.

Further, according to the third aspect of the present invention, the movement of the heat plate is above the base, and the separating means is provided within the installation area of the base. It is only necessary to secure a space in which the device can operate, and there is no possibility that the apparatus will be enlarged.

According to the fourth aspect of the present invention, the heating means provided on the heat plate is operated to adjust and maintain the temperature-controlled object placed on the upper surface of the heat plate at a preset high temperature state. On the other hand, in a temperature control method for adjusting and maintaining the temperature-controlled object at a preset low temperature state through the heat plate by cooling a base on which the heat plate is mounted, the heating means is operated. At this time, the heat plate and the base are separated from each other.

According to the fourth aspect of the invention, since the heat plate and the base are separated from each other when the heating means is operated, the heat of the heating means may be released from the base. Does not occur.

Therefore, according to the fourth aspect of the present invention, it is possible to improve the thermal responsiveness when heating the object to be temperature-controlled and to prevent the heat plate from being thermally deformed as much as possible. Accurate temperature control of the temperature-controlled object can be performed.

According to the fourth aspect of the present invention,
Since the cooling can be continuously performed even while the heating unit is operated, the thermal responsiveness when cooling the temperature-controlled object can be improved.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing one embodiment. FIG. 1 and FIG.
1 schematically shows an embodiment of a temperature control device according to the present invention. The temperature control device exemplified here includes (1) wafer cleaning (2) resist coating (3) pre-baking (110 to 130 ° C.) + Cooling (20 ° C.) (4) exposure (5) development (6) rinsing (7) ) Post-baking (120-150 ° C) + cooling (20 ° C) (8) In the semiconductor manufacturing process of forming a resist film through a process called etching, the above-described pre-baking + cooling,
Alternatively, a cycle used in post-baking + cooling, in which a wafer W to be temperature-controlled is first heated to a high temperature (baking) and then cooled to room temperature (cooling), is a wafer unit. Control is repeated every several tens of seconds. That is, the temperature control device has two target temperatures, that is, a target temperature for heating and a target temperature for cooling, and performs control to alternately repeat heating and cooling.

As shown in FIG.
A cooling plate (base) 10 is provided inside the chamber C. The cooling plate 10 is formed by filling a uniform cylindrical member 12 of the same material into a hollow cylindrical shape of a case 11 made of a material having high thermal conductivity such as aluminum, and the upper surface of the case 11 is horizontal. Is fixedly installed in the chamber C.

The cooling plate 10 has only one discharge pipe 13 at the center of the bottom wall, and a plurality of inflow pipes 14 at a portion of the bottom wall located around the discharge pipe 13.
have. These discharge pipe 13 and inflow pipe 14
Each of them communicates with each other via the above-mentioned uniform member 12 inside the case 11, and the discharge pipe 13 is connected to the return port 21 a of the heat storage tank (cooling means) 21 through the discharge passage (cooling means) 20. After the plurality of inflow pipes 14 merge with each other, they are connected to the discharge port 21b of the heat storage tank 21 through a common supply passage (cooling means) 23 having a supply pump (cooling means) 22. The heat storage tank 21 has therein a temperature fluid L, specifically, a liquid such as a fluorocarbon liquid (= Fluorinert: registered trademark), ethylene glycol, oil, water, nitrogen, air, or the like.
By storing a gas appropriately selected from gases such as helium in accordance with a target temperature to be controlled, and circulating this temperature fluid L between the chiller tank 24 and the temperature fluid L at a temperature near 20 ° C. Adjustment and maintenance. Reference numeral 25 in the drawing denotes an opening / closing valve interposed in the supply passage 23.

The cooling plate 10 has a plurality (at least three) of spaced-apart pin insertion holes 15 which are equally spaced from each other on the same circumference located at the outer peripheral edge thereof. Plural (at least three) which are located on the inner peripheral side of the pin insertion hole 15 and are evenly spaced from each other on the same circumference having a smaller diameter than the wafer W to be processed.
The susceptor pin insertion hole 16 is formed. The separation pin insertion hole 15 and the susceptor pin insertion hole 16 extend in the vertical direction so as to penetrate the cooling plate 10, respectively, and allow the separation pins (separation means) 30 to pass through the inside of the separation pin insertion hole 15. Meanwhile, the susceptor pins 31 are inserted into the susceptor pin insertion holes 16 respectively.

The separation pins 30 have a small diameter with their respective tips being pointed, and each have a length sufficiently larger than the height of the cooling plate 10 to connect the respective base ends. The actuator is connected to an actuator such as a cylinder actuator (not shown) via a horizontal outer connecting plate 32, and can be moved in the vertical direction in synchronization with each other by the operation of the actuator.

The susceptor pin 31 has a small diameter with a pointed tip like the spacing pin 30 and each has a length sufficiently larger than the height of the cooling plate 10. It is connected to an actuator such as a cylinder actuator (not shown) via a horizontal inner connecting plate 33 for connecting the parts, and by the operation of the actuator, it is possible to move up and down in synchronization with each other.

On the other hand, the temperature control device has a heating means 40 on the upper surface of the cooling plate 10. Heating means 40
Like the cooling plate 10 described above, a circular thin plate made of a material having high thermal conductivity such as aluminum, specifically, a plate thickness of about 2 mm when the height of the cooling plate 10 is 30 to 40 mm. Heat plate 41 formed
And thin-film heaters 42 and 43 adhered and held on both the front and back surfaces of the heat plate 41. The cooling plate 10 has through holes 44 at positions corresponding to the susceptor pin insertion holes 16, respectively. The through holes 44 are mounted on the upper surface of the cooling plate 10 in such a manner that the through holes 44 respectively match the susceptor pin insertion holes 16 and cover the separation pin insertion holes 15.

Although not shown in the drawing, the thin film heaters 42 and 43 are formed by appropriately forming a resistance wire inside a resin having heat stress resistance such as a polyimide resin. It is laid in a shape having an equal heat generation density, has a thin film disk shape having a diameter larger than the wafer W to be processed, and is bonded to the heat plate 41 by bonding means such as a welding sheet. . In addition, a shim 45 for securing a gap of about 0.1 mm between the thin film heater 42 and the wafer W is disposed at an appropriate position on the upper surface of the heat plate 41.

Hereinafter, in the temperature control device configured as described above, the operation when the temperature of the wafer W is alternately controlled at 150 ° C. and 20 ° C. at intervals of several tens of seconds, that is, the temperature of the wafer W is reduced by 150 ° C. A description will be given of an operation in a case where baking performed at a temperature of ° C. and cooling for subsequently cooling the temperature of the wafer W to 20 ° C. are alternately performed.

First, in the temperature control device, when in a start-up standby state, the distal ends of the above-described separation pins 30 are respectively disposed inside the separation pin insertion holes 15, and the heating means 4.
0 is mounted on the upper surface of the cooling plate 10, and the respective tips of the susceptor pins 31 are arranged inside the susceptor pin insertion holes 16.

When the wafer W coated with the resist is loaded into the chamber C while being mounted on the robot hand R from the above-described standby state, as shown in FIG.
The susceptor pin 31 moves upward in synchronization with the robot hand R.
Is received between the tips of these susceptor pins 31.

During this time, in the temperature control device, the separation pin 30 moves upward in synchronization with the temperature control device, and the heating means 40 moves the cooling plate 1
0, more specifically, about 20 mm apart from the upper surface of the thin film heater 4.
The heating means 40 is maintained at a temperature close to 150 ° C. by operating the heat storage tanks 2 and 43, and the supply pump 22 is operated and the temperature fluid L stored in the heat storage tank 21 is circulated and supplied to cool the heating means 40. Plate 10
Is maintained at a temperature near 20 ° C.

Here, in the above-mentioned state, although the heating means 40 in the high temperature state and the cooling plate 10 in the low temperature state are arranged to face each other, most of the heat radiation from the heating means 40 is upward. Since most of the heat radiation from the cooling plate 10 proceeds downward, the thermal contact is also cut off, and there is no possibility that both will thermally affect each other.

Further, in the heating means 40, the thin film heaters 42, 4 adhered to the front and back surfaces of the heat plate 41 are provided.
3 operates, there is no possibility that a temperature difference occurs between the front side portion and the back side portion, and the heat plate 41 does not deform out of the plane.

Therefore, after the robot hand R has evacuated, as shown in FIG. 3A, the susceptor pin 31 is synchronously moved down while the separating pin 30 is moved upward, and the wafer is moved via the shim 45. If W is placed on the upper surface of the heating means 40, the wafer W can be heated at a high speed and accurately to 150 ° C. with a uniform gap secured between the wafer W and the upper surface of the heating means 40. .

The wafer W is moved to 15 by the above operation.
When the baking performed by heating to 0 ° C. is completed,
Cooling for cooling the temperature of the wafer W to 20 ° C. is performed.

That is, when the baking is completed, the operations of the thin film heaters 42 and 43 are immediately stopped. Thereafter, the separation pin 30 is moved down synchronously, and the heating means 40 is mounted on the upper surface of the cooling plate 10. Is done.

At this time, the heating means 40 is connected to the cooling plate 10
In the initial stage when the upper surface of the heat plate 41 is reached, as shown in FIG. 3 (b), the back side of the heat plate 41 is at a lower temperature than the front side, so that the heat plate 41 faces upward. It will be deformed outward.

However, in the state shown in FIG. 3B, the outer peripheral portion of the heat plate 41 which comes into contact with the cooling plate 10 and is in a lower temperature state is separated from the wafer W while being separated from the cooling plate 10. The central portion of the heat plate 41 where the temperature is higher than the outer peripheral portion is close to the wafer W, and the variation in the temperature distribution with respect to the wafer W is offset by the relationship between these distances, and There is no possibility of the influence of the variation in the temperature distribution.

As the cooling by the cooling plate 10 progresses, the temperature difference between the front side portion and the back side portion of the heat plate 41 is eliminated, and the heat plate 41 becomes flat as shown in FIG. The heat of the wafer W is uniformly radiated through the heat plate 41 and the cooling plate 10, and the wafer W is cooled to 20 ° C. at high speed and accurately.

When the cooling of the wafer W is completed as described above, the susceptor pins 31 move upward in synchronization with each other, so that the wafer W is separated from the heating means 40. Thereafter, the processing is terminated by the operation of the robot hand R. The new wafer W is replaced with the new wafer W,
The same heating and cooling are repeatedly performed on the new wafer W.

As described above, according to the temperature control device,
When the thin film heaters 42 and 43 are operated, the separation pin 3
0, the heat plate 41 and the cooling plate 10 are spaced apart from each other, and the thermal contact between them can be cut off.
And the heat plate 41 can be prevented from being deformed toward the out-of-plane direction, and the wafer W can be heated quickly and accurately.

Further, even while the thin film heaters 42 and 43 are operating, the cooling plate 10 can be cooled by continuously operating the supply pump 22 without causing energy loss. Therefore, the wafer W can be cooled quickly and accurately.

Further, according to the temperature control device, since the heating step and the cooling step of the wafer W can be performed on the same upper surface of the heat plate 41, not only the space can be saved, but also the work can be performed. This is extremely advantageous in terms of efficiency.

In the above-described embodiment, an example in which the temperature of the wafer is controlled in the semiconductor manufacturing process is described. However, the present invention can be applied to the case where the temperature of another object to be controlled is controlled. It is.

Further, in the above-described embodiment, since the heating means is such that the thin film heaters are adhered to both the front and back surfaces of the heat plate, deformation of the heat plate in the out-of-plane direction is more reliably prevented. However, the present invention is not limited to this. For example, the heating unit may be configured by incorporating a heater in the heat plate, or a plate-shaped heater may be applied as the heating unit, and the plate-shaped heater may be used as the heat plate. Further, as in the case of cooling, the heating means may be formed by forming the heat plate in a hollow shape and supplying a high-temperature fluid to the hollow portion.

Further, in the above-described embodiment, when the heat plate and the cooling plate are spaced apart from each other, the heat plate is moved with respect to the fixed cooling plate. May be moved, or both may be moved at the same time. In addition, as the separating means, a separating pin that moves in a vertical direction in a manner penetrating the cooling plate is applied,
Moreover, since the heat plate is moved to a region above the cooling plate, it is sufficient to secure a space for installing the cooling plate, and it is possible to reduce the size of the apparatus. It is not limited to. For example, a fixed arm may be provided on the heat plate, and the heat plate and the cooling plate may be separated from each other by operating the fixed arm. In this case, the direction of movement of the heat plate does not necessarily need to be in the upper region of the cooling plate, but may be moved to the side region or lower region of the cooling plate. In addition,
When the fixing arm is provided on the heat plate, it is needless to say that a heat insulating material is preferably interposed between the heat plate and the heat plate.

Further, in the above-described embodiment, the cooling means for supplying the temperature fluid into the closed hollow portion of the cooling plate is exemplified. However, a chamber which is open to the atmosphere is formed in the cooling plate, and the chamber is provided in the chamber. The same effect can be expected even if the cooling means is formed by injecting a temperature fluid or by directly arranging the heat transfer element of the cooling plate.

[Brief description of the drawings]

FIG. 1 is a diagram conceptually showing an embodiment of a temperature control device according to the present invention.

FIG. 2 is an exploded perspective view of a main part of the temperature control device shown in FIG.

FIG. 3 is a view sequentially showing the operation of the temperature control device shown in FIG. 1;

[Explanation of symbols]

Reference Signs List 10 cooling plate, 20 discharge passage, 21 heat storage tank, 22 supply pump, 23 supply passage, 30 separation pin, 40 heating means, 41 heat plate, 42, 4
3 ... thin film heater, L: temperature fluid, W: wafer.

Claims (4)

[Claims] 1. A heat plate mounted on a base and constituting a heating means for adjusting and maintaining a temperature controlled object mounted on an upper surface to a preset high temperature state, and cooling the base. A cooling means for adjusting and maintaining the temperature-controlled object at a preset low temperature state via the heat plate, wherein the heat plate is used when the heating means is operated. A temperature control device provided with a separation means for separating the base and the base from each other. 2. The temperature control device according to claim 1, wherein said heating means is constituted by disposing heaters on both upper and lower surfaces of said heat plate. 3. The apparatus according to claim 1, wherein the separating means is vertically movable so as to penetrate the base, and moves the heat plate upward with respect to the base when operating the heating means. The temperature control device according to claim 1, wherein 4. A heating means configured on the heat plate is operated to adjust and maintain the temperature-controlled object placed on the upper surface of the heat plate at a preset high temperature state, and to operate the heat plate. By cooling the base to be mounted, in the temperature control method of adjusting and maintaining the temperature-controlled object to a preset low-temperature state through the heat plate, the heat plate and the heat plate when operating the heating means A temperature control method, wherein the base is separated from the base.