JP2001189276A - Wafer heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems, such as a long stabilizing time of temperatures of a heat equalizing plate, and a long cooling time thereof in a mounting step of the heat equalizing plate on the semiconductor processing system when heat capacity of semiconductor processing system is large. SOLUTION: The main face of heat equalizing plate made of ceramics is used for mounting a wafer, while a heating resistor is provided at the other main face or the inside thereof. A power feeding unit, connected electrically to the heating resistor, is provided on the other main face. The circumferential part of the heat equalizing plate is held by a holding member in the wafer heating apparatus. A support member has an inner multilayer structure, and a gas jetting hole for cooling the heat equalizing plate is provided at the multilayer structure. In this case, the opening of the multilayer structure is 5 to 70% of the area of the multilayer structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer heating apparatus mainly used for heating a wafer, for example, for forming a semiconductor thin film on a wafer such as a semiconductor wafer, a liquid crystal substrate, or a circuit substrate. It is suitable for forming a resist film by drying and baking the resist solution applied on the wafer.

[0002]

2. Description of the Related Art For example, in a semiconductor thin film forming process, an etching process, a resist film baking process, etc. in a manufacturing process of a semiconductor manufacturing apparatus, a semiconductor wafer (hereinafter abbreviated as "wafer") is heated to heat a semiconductor wafer. The device is used.

A conventional semiconductor manufacturing apparatus uses a batch-type apparatus for forming a plurality of wafers at a time. However, as the size of a wafer increases from 8 inches to 12 inches, the processing accuracy increases. In order to increase the quality, a technique called a single-wafer processing that processes one sheet at a time has been implemented in recent years. However, in the case of the single-wafer method, the number of processes per one process is reduced, so that the processing time of the wafer is required to be shortened. For this reason, there has been a demand for the wafer support member to shorten the heating time of the wafer, speed up the suction and desorption of the wafer, and simultaneously improve the heating temperature accuracy.

In forming a resist film on a semiconductor wafer, one main surface of a heat equalizing plate 22 made of a metal such as an aluminum alloy or stainless steel as shown in FIG. A plurality of sheathed heaters 25 are brought into contact with the other main surface, and the holding plate 2
The wafer heating device 21 held at 4 was used. Here, the heat equalizing plate 22 is held by a support frame 27, and the temperature of the heat equalizing plate 22 is adjusted by causing the sheath heater 25 to generate heat by electric power supplied from a power supply unit 26.

The mounting surface 23 of the wafer heating device 21
After the wafer W coated with the resist solution is placed thereon, the sheath heater 25 is heated to heat the wafer W on the mounting surface 23 via the soaking plate 22 and dry-bake the resist solution. A resist film is formed on the wafer W.

However, the wafer heating device 21 shown in FIG.
In order to suppress the thermal deformation of the heat equalizing plate 22, the thickness is extremely large as 15 mm or more, so that the heat capacity is large, and the time until the wafer W is heated to a predetermined processing temperature or the processing temperature is close to room temperature. The time to cool down was prolonged and productivity was poor.

Therefore, in the film forming process and the etching process,
A wafer heating device 31 as shown in FIG. 5 is used. That is, a heating resistor 33 is embedded in a plate-shaped ceramic body 32 mainly composed of alumina, silicon nitride, or aluminum nitride, and one main surface of the plate-shaped ceramic body 32 is placed on the mounting surface 34 of the wafer W. And a power supply unit 35 electrically connected to the heating resistor 33 on the other main surface.

As for a wafer heating apparatus for forming a resist film, as shown in FIG.
One main surface of the heat equalizing plate 2 made of a silicon carbide sintered body is a mounting surface 3 for a wafer, and the other main surface is provided with a heating resistor 5 and a heating resistor 5 via an insulating layer 4. A configuration in which a power supply unit 6 electrically connected to the device 5 is provided to constitute a wafer heating device has been proposed (Japanese Patent Application No. 11-184458).

[0009]

However, since the wafer heating device 31 shown in FIG. 5 has a structure in which the cylindrical support portion 36 is provided at the center of the heat equalizing plate 32, the influence of heat removal of the cylindrical support portion 36 is obtained. Therefore, it was difficult to adjust the temperature of the heat equalizing plate 32 with high accuracy. Further, the cylindrical support portion 3
In order to reduce the influence of the heat drawing of No. 6, it is necessary to make the heat equalizing plate 32 thick to some extent, and there has been a problem that it takes time for the heating and cooling cycle.

On the other hand, in the case of the wafer heating device 1 shown in FIG. 6, when the heat equalizing plate 2 is fixed to the metal support 7, the heat equalizing plate 2 is deformed or becomes fatigued due to a heat cycle during use. The problem that cracks occur in the soaking plate 2 is the same.
In particular, regarding the heat cycle, the use temperature was as high as 500 ° C. or more, and the influence was large.

Further, for example, in the case of using an insulating ceramic mainly composed of alumina or silicon nitride in the wafer heating device 31 shown in FIG. 5, since the heat conduction is not so good, the temperature variation of the mounting surface 34 is relatively small. There was also a problem of becoming larger.

Therefore, when the wafer W is heated in order to attach a resist film on the wafer W using the wafer heating device 31 in which the plate-shaped ceramic body 32 is made of an insulating ceramic containing alumina or silicon nitride as a main component. , The structure of the resist film that is dried and baked due to temperature unevenness becomes coarse,
There is a problem in that the pattern accuracy becomes poor due to poor photosensitivity of the resist film during the exposure process, and it has been difficult to form fine wiring required in recent years at high density.

In the wafer heating apparatus shown in FIG. 6, when the connecting portion between the power supply portion 6 and the conduction terminal formed on the surface of the heat equalizing plate 2 is joined with a brazing material or the like, the heat equalizing plate 2 and its support 7 are joined together. The thermal stress resulting from the dimensional change due to the temperature difference between them causes a problem in that the brazed portion is broken and a contact failure occurs.

[0014]

Means for Solving the Problems The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, one of the main surfaces made of ceramics is used as a wafer mounting surface, and the other main surface or inside thereof is provided with a heating resistor. A heat equalizing plate having a power supply portion electrically connected to the heat generating resistor on the other main surface, and a wafer heating apparatus having an outer periphery of the heat equalizing plate held on a support. A multilayer structure is provided inside the support, and a gas injection port for cooling the heat equalizing plate is provided in the multilayer structure.
The above problem was solved by providing a wafer heating apparatus having an opening of 0%.

Further, by providing a gas injection port in a layer on the heat equalizing plate side in the plate-like structure portion of the metal support,
For example, it is possible to shorten the time until the temperature when the temperature of the wafer heating device changes is stabilized.

Further, when used as a wafer heating apparatus for forming a resist film, the resist film can be formed without being adversely affected by ammonia gas or the like by using silicon carbide as a main component of the heat equalizing plate. it can.

In an apparatus which may be used at a temperature of 500 to 800 ° C., such as a semiconductor manufacturing apparatus for forming an SOG film or a semiconductor thin film, the main component of the heat equalizing plate is a material having a high thermal conductivity. The use of aluminum nitride makes it possible to provide a wafer heating apparatus having good thermal uniformity.

[0018]

Embodiments of the present invention will be described below.

FIG. 1 is a sectional view showing an example of a wafer heating apparatus according to the present invention, in which one main surface of a heat equalizing plate 2 made of ceramics containing silicon carbide or aluminum nitride as a main component is mounted on a wafer W. In addition to the mounting surface 3, a heating resistor 5 is formed on the other main surface via an insulating layer 4 made of glass or resin.

As the pattern shape of the heating resistor 5, the mounting surface 3 can be uniformly heated, such as a substantially concentric or spiral-shaped one having an arc-shaped electrode portion and a linear electrode portion. Any pattern shape is acceptable. In order to improve heat uniformity, the heating resistor 5 can be divided into a plurality of patterns.

The heat equalizing plate 2 is provided on a metal support 7 so as to cover the opening thereof. Metal support 7
Has a side wall 9 and a multilayer structure 10, and the multilayer structure 1
0 has an opening 14 corresponding to 5 to 70% of its area. In addition, the multi-layer structure portion 10 is further provided with a conduction terminal 11 for conducting with a power supply portion 6 for supplying power to the heating resistor 5 of the heat equalizing plate 2 and the heat equalizing plate 2 as necessary. Thermocouple 13 for measuring the temperature of the gas injection port 12 and the heat equalizing plate 2 for installation.

The multilayer structure 10 preferably has two or more layers. If this is a single layer, it takes a long time to achieve uniform heat, which is not preferable. Note that the uppermost layer of the multilayer structure 10 is desirably installed at a distance of 5 to 15 mm from the heat equalizing plate 2. Thereby, the heat equalizing plate 2 and the multilayer structure 10
Mutual radiant heat facilitates soaking and has a heat insulating effect with other layers, so that the time required for soaking becomes short. Further, at the time of cooling, the gas that has received the heat of the surface of the soaking plate 2 from the gas injection port 12 is sequentially discharged to the outside of the layer, and a new cooling gas can cool the surface of the soaking plate, so that the cooling time can be reduced. .

Further, operations such as placing the wafer W on the mounting surface 3 and lifting the wafer W from the mounting surface 3 are performed by the lift pins 8 installed in the support 7 so as to be able to move up and down. The wafer W is held in a state of being lifted from the mounting surface by the wafer support pins 17 so as to prevent a temperature variation due to a one-side contact or the like.

Then, in order to heat the wafer W by the wafer heating apparatus 1, the transfer surface (not shown)
Is supported by the lift pins 8, and then the lift pins 8 are lowered to place the wafer W on the mounting surface 3.
Put on top.

Next, the power supply 6 is energized to cause the heating resistor 5 to generate heat, and the wafer W on the mounting surface 3 is heated via the insulating layer 4 and the soaking plate 2. According to this, since the support 7 has the multilayer structure 10, the multilayer structure 10 adjacent to the heat equalizing plate 2 can be used as a heat radiation plate of the heat equalizing plate 2, so that the heat equalizing plate 2 can be effectively used. It can be soaked in a short time. Further, since the heat equalizing plate 2 is formed of a silicon carbide-based sintered body or an aluminum nitride-based sintered body, deformation is small even when heat is applied, and the plate thickness can be reduced. The heat-up time before cooling and the cooling time from the predetermined processing temperature to cooling to around room temperature can be shortened, and the productivity can be increased, and the heat conductivity is 50 W / m · K or more. From
Even with a small thickness, the Joule heat of the heating resistor 5 can be quickly transmitted, and the temperature variation of the mounting surface 3 can be extremely reduced.

Further, as the structure of the heat equalizing plate, as shown in FIG. 2, a structure having a built-in heating resistor 5 may be used.

The thickness of the heat equalizing plate 2 is preferably 2 to 7 mm. When the thickness of the heat equalizing plate 2 is less than 2 mm, the strength of the heat equalizing plate 2 is weakened, so that it cannot withstand the thermal stress at the time of heating by the heat generation of the heating resistor 5 and at the time of cooling by blowing the gas from the air injection port 12, Cracks occur in the soaking plate 2.
On the other hand, if the thickness of the heat equalizing plate 2 exceeds 7 mm, the heat capacity of the heat equalizing plate 2 increases, so that the time until the temperature during heating and cooling stabilizes becomes long, which is not preferable.

As described above, when the heat capacity of the heat equalizing plate 2 is reduced, the temperature distribution of the heat equalizing plate 2 is deteriorated due to the heat drawn from the support 7. Therefore, the support 7 has a structure in which the heat equalizing plate 2 is held at the outer peripheral portion.

When cooling the soaking plate 2, gas is injected from the gas injection ports 12 to the surface of the soaking plate 2 to improve the cooling efficiency. Although it is preferable to provide as many gas injection ports 12 as possible in order to uniformly cool the whole, 4 to 15
It is good to make about. As the type of gas, it is advantageous to use a gas having a large constant-pressure heat capacity for cooling, but from the viewpoint of safety, it is preferable to use air or carbon dioxide gas. The gas flow rate is 1 to 100 × 1
It is preferably 0 ^-3 m ³ / min.

In order to discharge the supplied gas to the outside, the multilayer structure 10 of the support 7 has an opening 14 having a size of 5 to 70% of its area. If the area of the opening 14 is less than 5%, the gas discharged from the gas injection port 12 and the gas to be discharged are mixed in the volume of the support 7, and the cooling efficiency is reduced. When the area of the opening 14 exceeds 70%, the conductive terminal 1
1 and the space for holding the gas injection port 12 are insufficient, and the strength is insufficient, the pressing force of the conductive terminal 11 against the electrode pad 6 is not stable, and the durability at the time of intermittent use is deteriorated.

Each layer of the multilayer structure 10 is reinforced by columns (not shown) provided between the layers as needed.

The opening 14 is connected to the multilayer structure 10.
The purpose of this is to prevent the gas discharged therefrom from leaking to the wafer mounting surface 2 side. As shown in FIG. 1, the support 7 is installed in the wafer heating device 1 so that the gas injection port 12 and the wafer mounting surface 3 are separated. It is possible to provide an opening 14 in the side wall 9 and form a cover that does not allow gas to permeate, so that the gas does not leak to the mounting surface 3 side. However, the device becomes large and the shape becomes complicated. Is not preferred.

The power supply to the heating resistor 5 is performed by pressing the conductive terminal 11 provided on the support 7 against the power supply section 6 formed on the surface of the heat equalizing plate 2 with a spring to secure the connection and supply the power. I do. This is a heat equalizing plate 2 having a thickness of 2 to 7 mm.
This is because if a metal terminal portion is embedded and formed, the heat capacity of the terminal portion deteriorates the heat uniformity. Therefore, as in the present invention, the conductive terminals 11 are pressed by a spring to secure the electrical connection, thereby alleviating the thermal stress caused by the temperature difference between the heat equalizing plate 2 and the support 7 thereof, and achieving high reliability. Can maintain electrical continuity. Furthermore, an elastic conductor may be inserted as an intermediate layer in order to prevent the contacts from becoming point contacts. Simply inserting a foil sheet is also effective. The diameter of the conduction terminal 11 on the side of the power supply unit 6 is
It is preferably 1.5 to 4 mm.

Here, an example of a sectional view of the conductive terminal 11 is shown in FIG. The terminal portion 41 of the conduction terminal 11 is provided so as to press the power supply portion 6 by a spring 43 built in the outer cover 45. A contact 44 to which a lead wire for supplying power from a power supply is connected is formed at a rear end of the terminal 41. The energizing terminal 11 is fixed to the multilayer structure 10 by a screw 41. The terminal 41
As the material of the material, a material such as brass or stainless steel can be used depending on the operating temperature. Further, as the mantle 45 and the screw 41, an electrically insulating PEEK material (polyethoxyethoxyketone resin) or a ceramic material can be used. Further, as the spring 43, a material such as stainless steel or Inconel can be used. Further, the structure of the terminal portion is not limited to that shown in FIG. 3, and various shapes having a combination of the terminal portion 41 and the spring 43 may be used.

The temperature of the soaking plate 2 is measured by a thermocouple 13 whose tip is embedded in the soaking plate 2. As the thermocouple 13, from the viewpoint of its responsiveness and workability of holding,
It is preferable to use a sheath-type thermocouple 13 having an outer diameter of 1.0 mm or less. Further, the middle of the thermocouple 13 is held by the plate-like structure portion 10 of the support portion 7 so that no force is applied to the tip portion embedded in the heat equalizing plate 2. The distal end of the thermocouple 13 has a hole formed in the heat equalizing plate 2 and is pressed and fixed to the inner wall surface of a cylindrical metal body provided therein with a spring material to improve the reliability of temperature measurement. Preferred for.

Further, when used as a wafer heating apparatus 1 for forming a resist film, if the main component of the heat equalizing plate 2 is silicon carbide, it does not react with moisture in the atmosphere and generate gas. Even if it is used for attaching a resist film on the wafer W, fine wiring can be formed at high density without adversely affecting the structure of the resist film. At this time, it is necessary to prevent the sintering aid from containing a nitride that may react with water to form ammonia or an amine.

The silicon carbide sintered body forming the heat equalizing plate 2 is obtained by adding boron (B) and carbon (C) as sintering aids to silicon carbide as a main component, or using alumina ( Al ₂ O ₃ ) A metal oxide such as yttria (Y ₂ O ₃ ) is added, mixed well, processed into a flat plate, and
It is obtained by firing at 0 to 2100 ° C. Silicon carbide may be any of those mainly composed of α-type and those mainly composed of β-type.

In addition, the aluminum nitride sintered body forming the heat equalizing plate 2 requires a rare earth element oxide such as Y ₂ O ₃ or Yb ₂ O ₃ as a sintering aid with respect to aluminum nitride as a main component. According to the above, an alkaline earth metal oxide such as CaO is added, mixed well, processed into a plate shape,
It is obtained by firing at 0 to 2100 ° C.

Further, the main surface of the heat equalizing plate 2 on the side opposite to the mounting surface 3 has a flatness of 20 μm or less and a surface roughness of the center line from the viewpoint of enhancing the adhesion to the insulating layer 4 made of glass or resin. It is preferable to polish to an average roughness (Ra) of 0.1 μm to 0.5 μm.

On the other hand, when a silicon carbide sintered body is used as the heat equalizing plate 2, the insulating layer 4 for maintaining insulation between the heat equalizing plate 2 having semi-conductivity and the heat generating resistor 5 is made of glass or glass. It is possible to use resin, and when using glass, if the thickness is less than 100 μm, the withstand voltage is less than 1.5 kV and the insulating property cannot be maintained, and if the thickness exceeds 350 μm,
Since the difference in thermal expansion between the silicon carbide-based sintered body and the aluminum nitride-based sintered body forming the heat equalizing plate 2 becomes too large, cracks occur, and the insulating layer 4 does not function. Therefore, when glass is used as the insulating layer 4, the thickness of the insulating layer 4 is preferably in the range of 100 μm to 350 μm, and more preferably in the range of 200 μm to 350 μm.

When the soaking plate 2 is formed of a ceramic sintered body containing aluminum nitride as a main component, in order to improve the adhesion of the heating resistor 5 to the soaking plate 2,
An insulating layer 4 made of glass is formed. However, when sufficient glass is added to the heat generating resistor 5 and a sufficient adhesion strength can be obtained by this, it can be omitted.

The glass forming the insulating layer 4 may be crystalline or amorphous, and has a heat resistance of 200 ° C. or higher and a thermal expansion coefficient in a temperature range of 0 ° C. to 200 ° C. It is preferable to appropriately select and use a ceramic having a coefficient of thermal expansion in the range of -5 to + 5 × 10 ⁻⁷ / ° C. with respect to the thermal expansion coefficient of the ceramic constituting the plate 2. In other words, when a glass having a coefficient of thermal expansion outside the above range is used, the difference in thermal expansion between the ceramic forming the soaking plate 2 and the ceramic becomes too large.
This is because defects such as cracks and peeling easily occur during cooling after baking of the glass.

Next, when a resin is used for the insulating layer 4, if the thickness is less than 30 μm, the withstand voltage falls below 1.5 kV, the insulating property cannot be maintained, and the heating resistor 5 is trimmed by, for example, laser processing. In this case, the insulating layer 4 is damaged and does not function as the insulating layer 4. Conversely, when the thickness exceeds 150 μm, the amount of evaporation of the solvent and water generated during baking of the resin increases, and a foam-like peeling portion called blister is formed between the heat equalizing plate 2 and the presence of this peeling portion. Since the heat transfer becomes worse, the soaking of the mounting surface 3 is hindered. Therefore, when a resin is used as the insulating layer 4, the thickness of the insulating layer 4 is preferably in the range of 30 μm to 150 μm, and more preferably in the range of 60 μm to 150 μm.

In the case where the insulating layer 4 is formed of a resin, polyimide resin, polyimide amide resin, or the like may be used in consideration of heat resistance of 200 ° C. or more and adhesion to the heating resistor 5.
It is preferable to use a polyamide resin or the like.

In order to apply the insulating layer 4 made of glass or resin on the heat equalizing plate 2, a suitable amount of the glass paste or the resin paste is dropped on the center of the heat equalizing plate 2 and spin coating is performed. Stretch and apply uniformly, or apply evenly by screen printing, dipping, spray coating, etc., then at a temperature of 600 ° C. for glass paste and 3 for resin paste.
What is necessary is just to bake at the temperature of 00 degreeC or more. Also, the insulating layer 4
When glass is used as the material, a heat equalizing plate 2 made of a silicon carbide-based sintered body or an aluminum nitride-based sintered body is previously 1200
By heating to a temperature of about ° C. and oxidizing the surface on which the insulating layer 4 is to be adhered, the adhesion with the insulating layer 4 made of glass can be increased.

Further, as the heating resistor 5 to be deposited on the insulating layer 4, a simple metal such as gold (Au), silver (Ag), copper (Cu), palladium (Pd) is formed by a vapor deposition method or a plating method. Directly, or the above-mentioned metal simple substance, rhenium oxide (Re ₂ O ₃ ), lanthanum manganate (LaMn)
A conductive metal oxide such as O ₃ ) or a paste obtained by dispersing the above metal material in a resin paste or a glass paste is prepared, printed in a predetermined pattern shape by a screen printing method or the like, and then baked. May be combined with a matrix made of resin or glass. When glass is used as the matrix, either crystallized glass or amorphous glass may be used, but it is preferable to use crystallized glass in order to suppress a change in resistance due to thermal cycling.

However, when silver or copper is used for the heating resistor 5, migration may occur. In such a case, the insulating layer 4 covers the heating resistor 5.
A protective film made of the same material as described above may be coated with a thickness of about 30 μm.

In FIG. 1, the power supply 6 is connected to the heating resistor 5.
In (2), the conduction terminal 11 is pressed by a spring (not shown) to ensure conduction. The power supply portion 6 may be formed by applying and curing a conductive adhesive on the terminal portion of the heating resistor.

The heating resistor 5 has been connected to the heat equalizing plate 2 so far.
Although the wafer heating apparatus 1 of the type formed on the surface of the above has been described, the heating resistor 5 may be built in the heat equalizing plate 2. To explain using FIG. 2 as an example, for example, in the case of using a heat equalizing plate 2 whose main component is aluminum nitride, first, as a material of the heating resistor 5, W or W
C is used. The heat equalizing plate 2 is formed into a disc shape after sufficiently mixing raw materials containing aluminum nitride as a main component and appropriately containing a sintering aid, and a paste made of W or WC is formed on the surface thereof in a pattern shape of the heating resistor 5. It can be obtained by printing, stacking another aluminum nitride molded body on top of the printed body, and then sintering it at a temperature of 1900 to 2100 ° C. in nitrogen gas. Further, conduction from the heating resistor 5 may be achieved by forming a through hole 19 in an aluminum nitride base material, embedding a paste made of W or WC, and firing the paste to draw out an electrode to the surface. When the heating temperature of the wafer W is high, the power supply unit 6 applies a paste containing a noble metal such as Au or Ag as a main component on the through hole 19 and bake it at 900 to 1000 ° C. Oxidation of the resistor 5 can be prevented.

[0050]

EXAMPLES Example 1 A plurality of disc-shaped soaking plates 2 having a thickness of 4 mm and an outer diameter of 230 mm were manufactured by grinding a silicon carbide sintered body having a thermal conductivity of 80 W / m · K. In order to apply an insulating layer to one main surface of each heat equalizing plate 2, a glass paste prepared by kneading ethyl cellulose as a binder and terpineol as an organic solvent with glass powder is laid by a screen printing method. The organic solvent was dried by heating to 150 ° C., and then degreased at 550 ° C. for 30 minutes.
By baking at a temperature of 00 to 900 ° C., an insulating layer 4 made of glass and having a thickness of 200 μm was formed. Next, in order to apply the heating resistor 5 on the insulating layer 4, a glass paste to which Au powder and Pd powder are added as a conductive material is printed in a predetermined pattern shape by a screen printing method, and then heated to 150 ° C. After drying the organic solvent and further performing a degreasing treatment at 550 ° C. for 30 minutes,
By baking at a temperature of 900 ° C., a thickness of 5
A heating resistor 5 having a thickness of 0 μm was formed. The heating resistor 5 has a five-pattern configuration in which a central portion and an outer peripheral portion are divided into four in the circumferential direction. Thereafter, the power supply unit 6 was fixed to the heating resistor 5 with a conductive adhesive, whereby the heat equalizing plate 2 was manufactured.

For the support 7, two multilayer structures 10 each made of SUS304 having a thickness of 2.5 mm and having an opening 14 formed in 30% of the main surface are prepared.
Gas injection ports 12, thermocouples 13, and 10 conducting terminals 1
1 was formed at a predetermined position, and was fixed to the side wall 9 also made of SUS304 by screws to prepare a support 7.

Thereafter, the heat equalizing plate 2 was placed on the support 7 and the outer peripheral portion thereof was screwed to complete the wafer heating device 1.

The gas injection port 12 is not formed at the same time, and 3%, 5%, 10%, 25%
%, 50%, 70%, and 75% of the wafer heating apparatus 1 in which the openings 14 were formed.

Then, the power supply unit 6 of each wafer heating apparatus 1 is energized to adjust the temperature variation on the surface of the wafer W when the temperature is maintained at 250 ° C. to ± 0.5 ° C. The time required for the temperature to drop to and stabilize to ° C and the temperature variation on the surface of the wafer W to reach ± 0.5 ° C was evaluated.
The temperature variation on the wafer W surface is centered on the wafer surface,
A total of 9 thermocouples were installed at 90 degree intervals at radii of 1 / 3A and 2 / 3A with respect to the wafer radius A, and the temperature was measured. Also, 2
Adjust the temperature variation of the wafer surface at 50 ° C. to be ± 0.5 ° C.
The temperature variation on the wafer surface after 500 cycles of the 0 minute cycle was examined.

As the evaluation criteria, those in which the gas injection port 12 was not formed but the cooling time could be reduced by half to 45 minutes or less with respect to the cooling time of 90 minutes were OK. In addition, samples having a temperature variation within 1 ° C. after the cycle test were regarded as OK.

The results are as shown in Table 1.

[0057]

[Table 1]

As can be seen from Table 1, first, the gas injection port 1
No. 2 not formed Sample No. 1 required 90 minutes to stabilize from 250 ° C. to 150 ° C. On the other hand, in the case of No. In Nos. 2 to 12, the cooling time could be reduced to 60% or less. However, in the case of No. 3 in which the opening ratio of the opening 14 of the multilayer structure 10 is 3%. In No. 2, the cooling time was 55 minutes due to insufficient cooling. On the other hand, the opening ratio of the opening 14 of the plate-like structure 10 was set to 5% or more. In Nos. 3 to 12, the cooling time could be shortened within 30 minutes.

On the other hand, with respect to the evaluation of the temperature variation after the cycle test, the evaluation was made in the case of No. 3 in which the opening ratio of the opening 14 of the plate-like structure 10 was 75%. No. 10 is not preferable because deformation or rubbing occurs due to stress due to a temperature difference between the conductive terminal 11 holding portion and the heat equalizing plate 2, thereby lowering the reliability of the contact of the conductive terminal 11 and increasing the temperature distribution.

On the other hand, the opening 14 of the multilayer structure 10
When the opening ratio is set to 5 to 70%, it is possible to quickly achieve the soaking during cooling of the soaking plate 2 and to prevent an increase in temperature variation after the durability test.

[0061]

As described above, according to the present invention, one of the main surfaces of the heat equalizing plate made of ceramics is used as a wafer mounting surface, and the other main surface or inside has a heating resistor. In a wafer heating apparatus having a power supply portion electrically connected to a heating resistor on the other main surface and holding an outer periphery of the heat equalizing plate on a support, a multilayer structure portion is provided inside the support. And a gas injection port for cooling the heat equalizing plate is provided in the multilayer structure, and an opening having an area of 5 to 70% of the area of the multilayer structure is formed in the multilayer structure. The time required for the temperature to stabilize can be reduced.

Thus, in the manufacturing process of the semiconductor device, for example, a uniform resist film can be formed on the wafer surface, a uniform semiconductor thin film can be formed, and a uniform etching process can be performed. Was.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a wafer heating apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view of a conduction terminal of the wafer heating apparatus according to the present invention.

FIG. 4 is a sectional view showing a conventional wafer heating apparatus.

FIG. 5 is a sectional view showing a conventional wafer heating apparatus.

FIG. 6 is a sectional view showing a conventional wafer heating apparatus.

[Explanation of symbols]

 1: Wafer heating device 2: Heat equalizing plate 3: Placement surface 4: Insulating layer 5: Heating resistor 6: Power supply 7: Support 8: Lift pin 9: Side wall 10: Plate-like structure 12: Gas injection port W: Semiconductor wafer

Claims (4)

[Claims] A power supply electrically connected to one of the main surface of a heat equalizing plate made of ceramics, the main surface being a mounting surface of a wafer, the other main surface or an internal heating resistor and being electrically connected to the heating resistor. Part on the other main surface, a wafer heating apparatus comprising an outer periphery of the heat equalizing plate held by a support,
Having a multilayer structure inside the support, a gas injection port for cooling the heat equalizing plate is further installed in the multilayer structure,
A wafer heating apparatus, wherein an opening of 5 to 70% of the area of the multilayer structure is formed. 2. The wafer heating apparatus according to claim 1, wherein a gas injection port is provided in a layer on the heat equalizing plate side in the multilayer structure of the metal support. 3. The wafer heating apparatus according to claim 1, wherein a conduction terminal is pressed and brought into contact with a power supply portion of the heat equalizing plate. 4. The method according to claim 1, wherein said ceramics is mainly composed of silicon carbide or aluminum nitride.
A wafer heating apparatus as described in the above.