JP4549484B2 - Single wafer heat treatment system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single wafer heat treatment apparatus.
[0002]
[Prior art]
In the manufacture of semiconductor devices, various types of heat treatment apparatuses are used for subjecting an object to be processed, such as a semiconductor wafer, to treatments such as oxidation, diffusion CVD, and annealing.
As one of the heat treatment apparatuses, a single wafer type heat treatment apparatus for heat treating wafers one by one is known. This single-wafer type heat treatment apparatus can be used for wafer surface enlargement and semiconductor element miniaturization because it can relatively easily perform in-plane uniform heat treatment and heat treatment that requires rapid heating and cooling. It has become so.
[0003]
In this single wafer heat treatment apparatus, a heating lamp is provided at the top of a processing chamber for accommodating a wafer through a transmission window, and an annular shape supporting the peripheral edge of the wafer in a state where the wafer is floated from the bottom in the processing chamber. Some are provided with a support.
[0004]
[Problems to be solved by the invention]
However, in the single wafer heat treatment apparatus, in order to reduce energy loss, the bottom of the heat treatment chamber facing the heating lamp is a highly reflective metal surface, and the wafer is heated from both the upper and lower surfaces. Form is taken. For this reason, it is possible to raise the temperature of the wafer quickly and efficiently, but on the other hand, the temperature drop rate tends to be slow, which is a factor that adversely affects the results of the heat treatment.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a single wafer heat treatment apparatus capable of increasing the temperature drop rate.
[0006]
[Means for Solving the Problems]
Among the present inventions, the invention of claim 1 provides a heating lamp through a transmission window in the upper part of the processing chamber for accommodating the object to be processed, and the object to be processed is floated from the bottom in the processing chamber. In the single wafer heat treatment apparatus provided with an annular support for supporting the peripheral edge of the body, the bottom of the processing chamber is subjected to uneven processing for increasing the temperature drop rate of the object to be processed. .
[0009]
According to the invention of claim 2 , a heating lamp is provided through a transmission window at the top of a processing chamber that accommodates the object to be processed, and the peripheral portion of the object to be processed is floated from the bottom in the processing chamber. in an annular support single wafer heat treatment apparatus comprising providing a supporting, that Do is subjected to processing which is inclined toward the peripheral portion from the central portion to increase the cooling rate of the workpiece at the bottom of the processing chamber It is characterized by that.
[0010]
According to a third aspect of the present invention, a heating lamp is provided through a transmission window at the top of a processing chamber that accommodates the object to be processed, and the peripheral portion of the object to be processed is floated from its bottom in the processing chamber. In a single wafer heat treatment apparatus provided with an annular support to support, a treatment for increasing the temperature lowering rate of the object to be processed is performed on the bottom of the processing chamber, and the processing makes the temperature lowering rate uniform in the plane. It is characterized by being partly applied.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0014]
In FIG. 1, reference numeral 1 denotes a processing chamber of a single-wafer type heat treatment apparatus that heats an object to be processed, for example, a semiconductor wafer w one by one. The processing chamber 1 is made of a material having heat resistance and corrosion resistance and non-contamination to the wafer w. For example, aluminum is used. A heating lamp 3 is provided above the processing chamber 1 through a transmission window 2.
An upper portion of the processing chamber 1 is opened, and a transmission window 2 made of quartz glass is provided above the processing chamber 1 so as to cover and seal the opening.
[0015]
The heating lamp 3 is composed of, for example, a halogen lamp, and constitutes a heating unit 4 capable of controlling the heating of the wafer w in the processing chamber 1 to a desired temperature, for example, about 500 ° C. to 1000 ° C. The heating unit 4 is detachably provided on the upper portion of the processing chamber 1. The heating lamp 3 may be spherical or tubular. The heating unit 4 is configured by arranging a plurality of heating lamps 3 in a planar shape or a concentric shape so as to uniformly heat the wafer w accommodated in the processing chamber 1 so as to be in-plane. A reflector 5 is provided on the back side of the heating lamp 3.
[0016]
In the processing chamber 1, the wafer w is floated from the bottom (also referred to as a bottom plate portion) 6 in the processing chamber 1 in order to rotatably support the wafer w so as to be uniformly heat-treated in the plane. An annular support 7 is provided to support the peripheral portion of the ring. In addition to the function of supporting the peripheral portion of the wafer w, the support 7 has a mechanism for preventing slip (crystal misalignment) due to a rapid temperature change at the peripheral portion of the wafer w, and the bottom portion 6 and the rotating mechanism 20 are heated. A function of shielding so as not to receive radiant heat from the lamp 3 directly is provided.
[0017]
The support 7 is formed to be wide because the processing chamber 1 is large enough to accommodate not only a normal size wafer having a diameter of, for example, 200 mm, but also a large wafer having a diameter of, for example, 300 mm. In order to prevent deformation and cracking due to internal stress due to the temperature difference between the inner peripheral side and the outer peripheral side of the support 7, the support 7 is composed of the inner peripheral support 7 A and the outer periphery as shown in FIG. It is formed so as to be split into two concentrically with the side support 7B. Further, the inner support 7A is formed to be thinner than the outer support 7B in order to reduce the heat capacity as much as the wafer w in order to minimize the temperature difference from the wafer w at the time of raising and lowering the temperature. Has been.
[0018]
The inner support 7A is preferably made of the same material as the wafer w, for example, silicon (Si), and the outer support 7B is made of a strong material, for example, silicon carbide (SiC), to support the load of the wafer w and the inner support 7A. It is preferable to become. The inner support 7A and the outer support 7B may both be made of silicon carbide, or both may be made of silicon. Alternatively, the inner support 7A may be made of silicon carbide, and the outer support 7B may be made of silicon.
[0019]
On the inner peripheral portion of the inner peripheral support 7A, a bowl-shaped support portion 8 that supports a peripheral portion of a wafer having a diameter d1, for example, d1 = 200 mm is formed. In order to position the peripheral edge of the wafer w and to reinforce the inner peripheral support 7A itself, it is preferable that the inner peripheral support 7A is formed with a protrusion 9 that is continuous in the circumferential direction. As shown in FIG. 3 or 4, the outer peripheral side support 7 </ b> B has an outer periphery (diameter) d <b> 2, for example, d <b> 2, which is the same as the outer peripheral part of the inner peripheral support 7 </ b> A or the inner peripheral support 7 </ b> A. A bowl-shaped support portion 10 is formed so as to be capable of positioning and supporting the peripheral portion of the wafer wx of 300 mm.
[0020]
An annular support 11 is provided on the lower surface of the bottom 6 of the processing chamber 1, and an annular groove 12 that is open to the processing chamber 1 is formed in the support 11 and the bottom 6. An annular inner rotating body 13 is rotatably provided in the groove 12 via a bearing 14, and the outer support 7 </ b> B is fixed to the upper portion of the inner rotating body 13 by screws. In order to rotationally drive the inner rotator 13 from the outside in a non-contact manner, an outer rotator 16 having a gear 15 that is driven to rotate by a drive pinion of an electric motor (not shown) on the outer periphery of the support 11 is a bearing. The inner rotating body 13 and the outer rotating body 16 are provided with magnets 18 and 19 for transmitting a rotational force so as to face each other across the groove wall of the support column 11. . As a result, a rotation mechanism 20 that rotates the wafer w in a non-contact state with the bottom 6 via the support 7 is configured.
[0021]
An inlet / outlet 21 is formed at one side of the processing chamber 1 for loading / unloading the wafer w into / from the processing chamber 1 by a transfer arm mechanism (not shown), and a gate valve 22 for opening / closing the inlet / outlet 21 is provided. It has been. A viewing window 23 made of quartz glass is provided on the other side of the processing chamber 1. Further, as shown in FIG. 2, a shower head-like gas introduction section 24 for introducing a processing gas or an inert gas such as nitrogen (N ₂ ) gas is provided on the other side of the processing chamber 1. An exhaust part 25 for exhausting the inside of the processing chamber 1 is provided on the side part. A gas supply source is connected to the gas introduction unit 24, and an exhaust system including a decompression control mechanism capable of decompressing the inside of the processing chamber 1 to a desired pressure is connected to the exhaust unit 25.
[0022]
A plurality of, for example, three lifter pins 26 for lifting and lowering the wafer w in order to transfer the wafer w between the transfer arm mechanism and the support 7 are provided in the bottom portion 6 of the processing chamber 1. An actuator (not shown) for moving these up and down is provided at the lower end of the actuator. A radiation thermometer 27 for detecting the temperature of the wafer w is provided at the bottom of the processing chamber 1.
[0023]
The bottom 6 in the processing chamber 1 is subjected to processing for increasing the temperature drop rate of the wafer w. By the way, the heat flux Q from the wafer w to the bottom 6 is
Q = εAFσ (Tw ⁴ −Tp ⁴ )
It can be expressed by the following formula. Here, ε is the emissivity of the bottom surface, A is the surface area of the bottom surface, and F is the shape factor of the bottom surface, where F = 1. σ is the Stefan Boltzmann constant, Tw is the wafer temperature, and Tp is the bottom temperature.
[0024]
From the above equation, in order to increase the temperature decrease rate of the wafer w, the emissivity ε is increased, the surface area A is increased, or (Tw ⁴ −Tp ⁴ ) is increased, that is, the temperature Tp of the bottom 6 is decreased. do it.
[0025]
Therefore, in the present embodiment, as shown in FIG. 5, the surface (upper surface) of the bottom portion 6 is subjected to a surface treatment for increasing the emissivity (a surface treatment having a high emissivity), for example, an alumite treatment. This alumite treatment 28 oxidizes the surface of the bottom 6 made of aluminum (Al) to form a black aluminum oxide film. In addition, what is necessary is just to oxidize the surface of a bottom part, when the material of the bottom part 6 is stainless steel (SUS). Further, in the present embodiment, as shown in FIG. 1, a cooling water passage 29 for controlling the temperature through the cooling water is formed in the bottom portion 6 in order to reduce (lower) the temperature of the bottom portion 6.
[0026]
Next, the operation of the single wafer heat treatment apparatus having the above configuration will be described. First, the gate valve 22 at the entrance / exit 21 of the processing chamber 1 is opened, the wafer w is loaded into the processing chamber 1 by the transfer arm mechanism, and the lifter pin 26 is pushed up to transfer the wafer w from the transfer arm mechanism to the lifter pin 26. Next, the lifter pins 26 are lowered so that the peripheral portion of the wafer w is supported by the support 7 and the gate valve 22 is closed.
[0027]
Next, the inside of the processing chamber 1 is sucked and exhausted from the exhaust unit 25 by the exhaust system and controlled to a predetermined degree of vacuum. Is turned on to heat and heat the wafer w, and a predetermined heat treatment such as a CVD process is started while the wafer w is rotated by the rotating mechanism 20 via the support 7.
[0028]
When the heating lamp 3 is turned on, radiant heat (heat rays) is radiated from the heating lamp 3, and this radiant heat passes through the transmission window 2 and is directly irradiated onto the surface of the wafer w, so that the wafer w rapidly rises to a predetermined temperature. Be warmed. At this time, the temperature of the wafer w is detected by the radiation thermometer 27, the output of the heating lamp 3 is controlled based on the detected temperature, and the temperature of the wafer w is controlled to a predetermined heat treatment temperature.
[0029]
When the predetermined heat treatment time is reached, the supply of the processing gas is stopped, the heating lamp 3 is turned off, and the heat treatment is finished. As the heating lamp 3 is turned off, the temperature in the processing chamber 1 and the wafer w are lowered. At this time, by introducing an inert gas such as nitrogen gas into the processing chamber 1 and replacing the processing chamber with the inert gas, the temperature drop is promoted. However, since the temperature of the wafer w itself is rising as well as the quartz glass of the transmission window 2 of the processing chamber 1, there is a limit to increasing the temperature lowering rate of the wafer w.
[0030]
Therefore, in the present embodiment, the bottom portion 6 facing the wafer w is subjected to a surface treatment for increasing the emissivity, for example, alumite treatment 28, as a treatment for lowering the temperature of the wafer w, and the temperature of the bottom portion 6 is increased. Since the cooling water passage 29 for reducing (lowering) is formed, it is possible to absorb the radiant heat from the wafer w and increase the temperature drop rate of the wafer w.
[0031]
In addition, the support body 7 is formed so as to be divided into an inner periphery side support body 7A and an outer periphery side support body 7B, and the inner periphery side support body 7A is formed thinner than the outer periphery side support body 7B. The temperature difference due to the difference in heat capacity between the wafer w and the support 7 can be reduced, the temperature drop rate of the wafer w can be increased, and the support caused by the temperature difference between the inner peripheral side and the outer peripheral side can be achieved. The crack of the body 7 can be prevented.
[0032]
In this case, the outer peripheral support 7B is formed so as to be able to support the inner peripheral support 7A or the wafer w having the same outer diameter as the inner peripheral support 7A. Heat treatment of wafers w and wx having different diameters is possible. That is, if the inner peripheral side support 7A is attached to the outer peripheral side support 7B, the inner peripheral side support 7A can support the wafer w having a diameter d1, for example, d1 = 200 mm, from the outer peripheral side support 7B. If the peripheral support 7A is removed, a wafer wx having a diameter d2, for example, d2 = 300 mm can be supported by the outer support 7B, and two types of wafers having different diameters can be obtained with one single wafer heat treatment apparatus. Heat treatment of w and wx becomes possible.
[0033]
6 to 8 schematically show another embodiment of the present invention. In the embodiment of FIG. 6, a process for increasing the surface area of the bottom 6 of the processing chamber 1, for example, an uneven process 30 is performed as a process for increasing the temperature lowering rate of the wafer w. It is preferable that this uneven | corrugated process 30 is performed to concentric form. According to the embodiment of FIG. 6, since the surface of the bottom portion 6 of the processing chamber 1 is provided with the unevenness processing 30, the heat flux from the wafer w to the bottom portion 6 increases as the surface area of the bottom portion 6 increases. At the same time, reflection from the bottom 6 to the wafer w is reduced, and the temperature drop rate of the wafer w can be increased.
[0034]
In the embodiment of FIG. 7, as a process for increasing the temperature drop rate of the wafer w, a process for increasing the surface area of the bottom 6 of the processing chamber 1, for example, a conical inclined process that is inclined downward from the central part toward the peripheral part. 31 is given. According to the embodiment of FIG. 7, since the surface of the bottom portion 6 of the processing chamber 1 is inclined, the heat flux from the wafer w to the bottom portion 6 increases as the surface area of the bottom portion 6 increases. At the same time, reflection from the bottom 6 to the wafer w is reduced, and the temperature drop rate of the wafer w can be increased.
[0035]
In the embodiment of FIG. 8, the peripheral portion of the wafer w is more likely to dissipate heat than the central portion, and the temperature decreasing rate is fast. Therefore, in order to make the temperature decreasing rate in-plane uniform, not only the entire surface of the bottom 6 but only the central portion. In part, a process for increasing the temperature drop rate of the wafer w, for example, an alumite process 28 which is a surface process for increasing the emissivity is performed. In place of this alumite treatment, unevenness processing or inclination processing for increasing the surface area may be performed. According to the embodiment of FIG. 8, a process for increasing the temperature decrease rate of the wafer w, for example, an alumite process 28, is performed not only on the surface of the bottom portion 6 of the process chamber 1 but only on a portion where the temperature decrease rate is low. Therefore, the temperature of the wafer w can be lowered uniformly in the surface. 6 to 8, it is preferable that a cooling water passage is formed in the bottom 6 of the processing chamber 1.
[0036]
Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments, and various design changes and the like can be made without departing from the scope of the present invention. is there. For example, in the said embodiment, although the example in which the support body is divided | segmented into two is shown, the support body may be divided | segmented into multiple, for example, three. In addition to silicon (Si) and silicon carbide (SiC), the support may be made of aluminum nitride (AlN), for example. As the object to be processed, for example, a glass substrate or an LCD substrate can be applied in addition to the semiconductor wafer.
[0037]
【The invention's effect】
In short, according to the present invention, the following effects can be obtained.
[0040]
( 1 ) According to the invention of claim 1 , a heating lamp is provided through the transmission window in the upper part of the processing chamber for storing the target object, and the target object is floated from the bottom in the processing chamber. in an annular support single wafer heat treatment apparatus comprising providing a for supporting the periphery of the body, because such is subjected to patterned indentation to increase the cooling rate of the workpiece at the bottom of the processing chamber, the bottom By increasing the surface area, the heat flux from the object to be processed to the bottom is increased, and reflection from the bottom to the object to be processed is reduced, so that the temperature decrease rate of the object to be processed can be increased.
[0041]
( 2 ) According to the invention of claim 2 , a heating lamp is provided through the transmission window in the upper part of the processing chamber for accommodating the object to be processed, and the object to be processed is floated from the bottom in the processing chamber. In a single wafer heat treatment apparatus provided with an annular support for supporting a peripheral edge of a body, a process of inclining from a central part toward a peripheral part at the bottom of the processing chamber to increase the temperature drop rate of the object to be processed because such is subjected to, by the surface area of the bottom increases with the heat flux to the bottom of the object to be processed increases, the reflection of the object to be processed is reduced from the bottom, to increase the cooling rate of the object be able to.
[0042]
( 3 ) According to the invention of claim 3 , a heating lamp is provided in the upper part of the processing chamber for accommodating the object to be processed through the transmission window, and the object to be processed is floated from the bottom in the processing chamber. In a single wafer heat treatment apparatus provided with an annular support for supporting the peripheral edge of the body, a treatment for increasing the temperature drop rate of the object to be processed is applied to the bottom of the processing chamber, and the temperature reduction rate Therefore, it is possible to lower the temperature of the object to be processed uniformly in the surface.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a single wafer heat treatment apparatus showing an embodiment of the present invention.
FIG. 2 is a transverse sectional view of the heat treatment apparatus.
FIG. 3 is a cross-sectional view showing the structure of a support.
FIG. 4 is a cross-sectional view showing a state in which a wafer is supported on an outer peripheral support.
FIG. 5 is a cross-sectional view schematically showing a structure in which the bottom is surface-treated.
FIG. 6 is a cross-sectional view schematically showing a structure in which a bottom portion is processed to be uneven.
FIG. 7 is a cross-sectional view schematically showing a structure in which a bottom portion is inclined.
FIG. 8 is a cross-sectional view schematically showing a structure in which the bottom is partially surface-treated.
[Explanation of symbols]
w Semiconductor wafer (object to be processed)
DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Transmission window 3 Heating lamp 6 Bottom part 7 Support body 7A Inner peripheral side support body 7B Outer peripheral side support body 28 Anodizing (surface treatment)
30 Concavity and convexity 31 Inclination

Claims (3)

A heating lamp is provided through a transmission window at the top of the processing chamber that accommodates the object to be processed, and an annular support that supports the peripheral edge of the object to be processed is floated from the bottom in the processing chamber. In the single-wafer heat treatment apparatus provided, the single-wafer heat treatment apparatus is characterized in that the bottom of the processing chamber is subjected to uneven processing for increasing the temperature drop rate of the object to be processed. A heating lamp is provided through a transmission window at the top of the processing chamber that accommodates the object to be processed, and an annular support that supports the peripheral edge of the object to be processed is floated from the bottom in the processing chamber. In the single-wafer type heat treatment apparatus provided, the single-wafer type is characterized in that the bottom of the processing chamber is subjected to a process that is inclined from the central portion toward the peripheral portion in order to increase the temperature drop rate of the object to be processed. Heat treatment equipment. A heating lamp is provided through a transmission window at the top of the processing chamber that accommodates the object to be processed, and an annular support that supports the peripheral edge of the object to be processed is floated from the bottom in the processing chamber. In the single wafer heat treatment apparatus provided, the bottom of the processing chamber is subjected to a process for increasing the temperature decrease rate of the object to be processed, and the process is partially performed to make the temperature decrease rate uniform in the surface. and single wafer heat treatment apparatus, characterized in that are.

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