JP2005159377A - Heat treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus wherein a substrate can be heat-treated by improving the in-plane temperature uniformity of the substrate. <P>SOLUTION: The heat treatment apparatus comprises a heating plate 51' wherein the substrate W is arranged adjacently or mounted and heat-treated; a ceiling plate 63' which is arranged facing the substrate arranging surface of the heating plate 51' and having a temperature control mechanism 80; a surrounding member 62' for surrounding a space between the heating plate 51' and the ceiling plate 63'; a gas supply nozzle 102 which is arranged at one side of the heating plate 51' and for introducing gas into the space; and an exhaust nozzle 107 which is arranged at the other side of the heating plate 51' and for exhausting the gas from the space S'. The gas is supplied from one side of the heating plate 51' to the other side by the gas supply nozzle 102, the gas is exhausted by the exhaust nozzle 107, and an air stream of one direction is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat treatment apparatus that heat-treats a substrate when a resist coating / development treatment is performed on a substrate such as a semiconductor wafer.

  In a photolithography process of a semiconductor device, a resist is applied to a semiconductor wafer (hereinafter simply referred to as a wafer), a resist film formed thereby is exposed according to a predetermined circuit pattern, and the exposure pattern is developed. Thus, a circuit pattern is formed on the resist film.

  In such a photolithography process, various heat treatments such as heat treatment after resist application (pre-baking), heat treatment after exposure (post-exposure baking), heat treatment after development (post-baking), and the like are performed. .

  These heat treatments are usually performed by a heat treatment apparatus configured by disposing a heating plate in a housing. A wafer is brought close to or placed on the surface of the heating plate, and the heating plate is heated by a heater. Thus, the wafer is heated.

  In this type of heat treatment device, a cover that surrounds the outer periphery of the heating plate is disposed, and a top plate is provided on the cover so as to face the wafer placement surface to form a processing space between the heating plate and the top plate. In general, an apparatus that heats a wafer while forming an air flow in the processing space is used. In such a heat treatment apparatus, the wafer is required to be uniformly heated during the heat treatment, and for this purpose, the temperature distribution of the heating plate is to be made as uniform as possible.

  However, a gas supply nozzle is provided on one side of the heating plate, an exhaust nozzle is provided on the other end side, gas is supplied from one side of the heating plate to the other by the gas supply nozzle, and gas is exhausted by the exhaust nozzle. In the case of a heat treatment apparatus that forms a unidirectional airflow, even if the heating plate is heated uniformly, the temperature in the vicinity of the exhaust nozzle of the wafer is actually affected by the airflow. It will be higher than.

  This invention is made | formed in view of this situation, Comprising: It aims at providing the heat processing apparatus which can make the in-plane temperature uniformity of a board | substrate high, and can heat-process a board | substrate.

In order to solve the above problems, according to a first aspect of the present invention, there is provided a heat treatment apparatus for heat-treating a substrate to a predetermined temperature,
A heating plate that heats the substrate close to or on its surface; and
A top plate provided facing the substrate arrangement surface of the heating plate and having a temperature control mechanism;
A surrounding member that surrounds a space between the heating plate and the top plate;
A gas supply nozzle provided on one side of the heating plate for introducing gas into the space;
An exhaust nozzle provided on the other end of the heating plate for exhausting gas from the space;
With
The gas supply nozzle supplies gas from one side of the heating plate to the other, and the exhaust nozzle exhausts the gas to form a one-way airflow. An apparatus is provided.

  The top plate has at least a first region and a second region at a portion facing the heating plate, the first region is provided on the exhaust nozzle side, and the temperature control mechanism The temperature of at least one of the first region and the second region may be controlled. In this case, the temperature control mechanism sets the temperature of the first area of the top plate to the second area according to a set value of the heating temperature of the heating plate or a temperature distribution generated in the substrate by heating of the heating plate. It can also be controlled to be lower.

  Further, the heat absorption rate of the first region can be made larger than the heat absorption rate of the second region. Further, the first area may be a black body, and the second area may be a mirror.

  The first area may be constituted by a first heat pipe, and the second area may be constituted by a second heat pipe. The temperature control mechanism includes a heat dissipation mechanism for releasing heat from the first heat pipe, a heating mechanism for injecting heat into the first heat pipe, the heating mechanism and / or the heat dissipation mechanism. And a controller for controlling. The first heat pipe and the second heat pipe may be provided adjacent to each other, and the space between them may be insulated.

  The heating plate may be rectangular. The gas supply nozzle may have a plurality of gas discharge holes in the width direction of the heating plate. The exhaust nozzle may have a plurality of gas discharge holes in the width direction of the heating plate.

  According to the present invention, since the top plate having the temperature control mechanism is provided, the gas is supplied from one side of the heating plate to the other by the gas supply nozzle, and the gas is exhausted in one direction by the exhaust nozzle. In the heat treatment apparatus configured to form the air current, the substrate can be heat-treated while increasing the uniformity of the in-plane temperature of the substrate.

  In addition, a top plate having a first region and a second region at least at a portion facing the heating plate facing the substrate arrangement surface of the heating plate for heating the substrate is provided. The temperature of at least one of the first region and the second region of the top plate is controlled according to the temperature distribution generated in the substrate by heating the plate. Of the first and second regions of the plate, the temperature corresponding to the portion where the temperature of the substrate is high can be lowered to increase the heat absorption of that region, resulting in excessive heating in the substrate and temperature. Since the heat radiation of the portion that tends to increase can be promoted and the temperature of the portion can be lowered, the in-plane temperature uniformity of the substrate can be improved. In addition, since the degree of temperature decrease can be controlled by the temperature control mechanism, the degree of in-plane temperature uniformity of the substrate is extremely high.

  In addition, the top plate includes a first heat pipe and a second portion, each of which has at least a first region and a second region at a portion facing the heating plate, and each includes the first region and the second region. With the structure having the heat pipes, the temperature can be made uniform in each region by the temperature equalizing action of the heat pipe, and at least one of these regions is heated by the action of easily transporting a large amount of heat. It is possible to quickly reach a predetermined temperature when controlling. Therefore, the in-plane temperature uniformity of the substrate can be further increased.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
1 is a schematic plan view showing a resist coating / development processing system for a semiconductor wafer on which a heat treatment unit according to an embodiment of the present invention is mounted, FIG. 2 is a front view thereof, and FIG. 3 is a rear view thereof.

  The resist coating / development processing system 1 includes a cassette station 10 as a transfer station, a processing station 11 having a plurality of processing units, and an exposure apparatus (not shown) provided adjacent to the processing station 11. An interface unit 12 for delivering a semiconductor wafer (hereinafter simply referred to as a wafer) W is provided.

  The cassette station 10 carries a plurality of, for example, 25 wafers W as an object to be processed into a wafer cassette CR in a state of being loaded on the wafer cassette CR, or carries it out from this system to another system. This is for carrying the wafer W between the wafer cassette CR and the processing station 11.

In this cassette station 10, as shown in FIG. 1, a plurality of (four in the figure) positioning projections 20a are formed on the mounting table 20 on which the cassette C is placed along the X direction in the figure. At the position of the protrusion 20a, the wafer cassette CR can be placed in a row with each wafer inlet / outlet facing the processing station 11 side. In the wafer cassette CR, the wafers W are arranged in the vertical direction (Z direction). The cassette station 10 has a wafer transfer mechanism 21 located between the wafer cassette mounting table 20 and the processing station 11. The wafer transfer mechanism 21 has a wafer transfer arm 21a that can move in the cassette arrangement direction (X direction) and the wafer arrangement direction (Z direction) of the wafer W in the cassette arrangement direction. Any one of the wafer cassettes CR can be selectively accessed. Further, the wafer transfer arm 21a is configured to be rotatable in the θ direction, and is also used for an alignment unit (ALIM) and an extension unit (EXT) belonging to a _third processing unit group G3 on the processing station 11 side described later. It can be accessed.

  The processing station 11 includes a plurality of processing units for performing a series of steps when coating / developing on the wafer W, and these are arranged in multiple stages at predetermined positions. Processed one by one. As shown in FIG. 1, the processing station 11 has a transfer path 22a at the center thereof, in which a main wafer transfer mechanism 22 is provided, and all the processing units are arranged around the transfer path 22a. . The plurality of processing units are divided into a plurality of processing unit groups, and each processing unit group includes a plurality of processing units arranged in multiple stages along the vertical direction.

  As shown in FIG. 3, the main wafer transfer mechanism 22 is equipped with a wafer transfer device 46 that can move up and down in the vertical direction (Z direction) inside a cylindrical support 49. The cylindrical support 49 can be rotated by a rotational driving force of a motor (not shown), and the wafer transfer device 46 can also be rotated integrally with the cylindrical support 49.

  The wafer transfer device 46 includes a plurality of holding members 48 that are movable in the front-rear direction of the transfer base 47, and the transfer of the wafers W between the processing units is realized by these holding members 48.

As shown in FIG. 1, in this embodiment, four processing unit groups G ₁ , G ₂ , G ₃ , G ₄ are actually arranged around the transport path 22a, and the processing unit group G ₅ is adapted to be positioned as required.

Among these, the first and second processing unit groups G ₁ and G ₂ are arranged in parallel on the front side of the system (front side in FIG. 1), and the third processing unit group G ₃ is adjacent to the cassette station 10. The fourth processing unit group G ₄ is disposed adjacent to the interface unit 12. The processing unit group G ₅ of the fifth is adapted to be disposed on the rear portion.

In the first processing unit group G _1, in a cup CP wafers W spin chuck resist coating unit is placed (not shown) for applying a resist on the wafer W (COT) and likewise the cup CP Development processing units (DEV) for developing the resist pattern are stacked in two stages from the bottom. Similarly, the second processing unit group G _2, the resist coating unit (COT) and developing unit (DEV) are two-tiered in order from the bottom as two spinner-type processing units.

In the third processing unit group G _3, as shown in FIG. 3, the oven-type processing units of the wafer W is placed on a mounting table SP performs predetermined processing are multi-tiered. That is, an adhesion unit (AD) that performs so-called hydrophobic treatment for improving the fixability of the resist, an alignment unit (ALIM) that performs alignment, an extension unit (EXT) that carries in and out the wafer W, and cooling processing Cooling units (COL) to be performed, and four heat treatment units (HP) for performing heat treatment on the wafer W before and after the exposure process and after the development process are stacked in eight stages in order from the bottom. A cooling unit (COL) may be provided instead of the alignment unit (ALIM), and the cooling unit (COL) may have an alignment function.

Fourth processing unit group G ₄ may, oven-type processing units are multi-tiered. That is, there are a cooling unit (COL), an extension / cooling unit (EXTCOL), an extension unit (EXT), a cooling unit (COL), and four heat treatment units (HP), which are wafer loading / unloading units provided with a cooling plate. Are stacked in 8 steps in order.

When the fifth processing unit group G ₅ is provided on the back side of the main wafer transfer mechanism 22, it can move sideways along the guide rail 25 as viewed from the main wafer transfer mechanism 22. Therefore, even in the case where the processing unit group G ₅ of the fifth, the space portion is secured by sliding along the guide rail 25 to this maintenance work from behind the main wafer transfer mechanism 22 easily Can be done.

The interface unit 12 has the same length as the processing station 11 in the depth direction (X direction). As shown in FIGS. 1 and 2, a portable pickup cassette CR and a stationary buffer cassette BR are arranged in two stages on the front part of the interface part 12, and a peripheral exposure device 23 is arranged on the rear part. A wafer transfer mechanism 24 is disposed at the center. The wafer transfer mechanism 24 has a wafer transfer arm 24a. The wafer transfer arm 24a moves in the X direction and the Z direction so that both cassettes CR and BR and the peripheral exposure device 23 can be accessed. ing. Further, the wafer transfer arm 24a is rotatable in θ direction, the fourth processing unit group G ₄ belonging extension unit and (EXT), more wafer delivery of the adjacent exposure device side stand of the process station 11 (Not shown) is also accessible.

In such a resist coating and developing system, first, in the cassette station 10, the wafer transfer arm 21a of the wafer transfer mechanism 21 accesses the wafer cassette CR containing the unprocessed wafers W on the cassette mounting table 20. to retrieve the one wafer W from the cassette CR, transported to the third processing unit group G ₃ of the extension unit (EXT).

The wafer W is transferred from the extension unit (EXT) to the processing station 11 by the wafer transfer device 46 of the main wafer transfer mechanism 22. Then, after being aligned by the third processing unit group G ₃ of the alignment unit (ALIM), it is conveyed to the adhesion process unit (AD), where the resist hydrophobic treatment for enhancing adhesion of (HMDS treatment) facilities Is done. Since this process involves heating, the wafer W is then transferred to the cooling unit (COL) by the wafer transfer device 46 and cooled.

After completion of the adhesion process, the wafer W cooled to a predetermined temperature by the cooling unit (COL) is subsequently transferred to the resist coating unit (COT) by the wafer transfer device 46, where a coating film is formed. After the coating process is completed, the wafer W is pre-baked in one of the processing units (G ₃ , G ₄ ) and then cooled to a predetermined temperature in one of the cooling units (COL). .

The cooled wafer W, the third is the transport to the processing unit group G ₃ of the alignment unit (ALIM), where it is aligned, the interface unit via the fourth processing unit group G ₄ of the extension unit (EXT) 12 is conveyed.

  In the interface unit 12, the peripheral edge of the wafer, for example, 1 mm is exposed by the peripheral exposure device 23 in order to remove excess resist, and then a predetermined pattern is formed by an exposure device (not shown) provided adjacent to the interface unit 12. Accordingly, the resist film on the wafer W is subjected to an exposure process.

Exposed wafer W is returned again to the interface section 12 by the wafer transfer mechanism 24, it is carried to the extension unit (EXT) belonging to the fourth processing unit group G _4. Then, the wafer W is transferred to one of the heat treatment units (HP) by the wafer transfer device 46 and subjected to post-exposure baking, and then cooled to a predetermined temperature by the cooling unit (COL).

Thereafter, the wafer W is transferred to a development processing unit (DEV) where the exposure pattern is developed. After completion of the development processing, the wafer W is transferred to one of the heat processing units (HP), subjected to post-baking processing, and then cooled to a predetermined temperature by the cooling unit (COL). After such a series of processing is completed, and returned to the cassette station 10 through the third processing unit group G ₃ of the extension unit (EXT), is inserted into one of the wafer cassettes CR.

  Next, a heat treatment unit (HP) according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view schematically showing the heat treatment unit according to the first embodiment of the present invention, and FIG. 5 is a perspective view showing the heat treatment unit of FIG. 6 is a cross-sectional view showing first and second heat pipes formed on the top plate of the heat treatment unit of FIG. 4, and FIG. 7 is a block diagram showing a control system of the heat treatment unit of FIG.

  As shown in FIG. 4, the heat treatment unit (HP) of the present embodiment includes a casing 50, and a heating plate 51 having a disk shape is disposed therein. The heating plate 51 is made of, for example, aluminum, and a proximity pin 52 is provided on the surface thereof. Then, the wafer W is placed on the proximity pin 52 in a state of being close to the heating plate 51. A plurality of ring-shaped heating elements 53 are arranged concentrically on the back surface of the heating plate 51. These heating elements 53 generate heat when energized, and heat the heating plate 51 to heat the wafer W. In this case, it is preferable that the energization amount to each ring-shaped heating element 53 can be controlled independently.

  The heating plate 51 is supported by a support member 54, and the support member 54 is hollow. The heating plate 51 has three (two only shown) through-holes 55 formed in the center thereof, and three (two only shown) through which the wafer W is raised and lowered are formed in these through-holes 55. Elevating pins 56 are provided so as to be movable up and down. A cylindrical guide member 57 continuous with the through hole 55 is provided between the heating plate 51 and the bottom plate 54 a of the support member 54. These guide members 57 can move the raising / lowering pins 56 without being obstructed by heater wiring or the like under the heating plate 51. These elevating pins 56 are supported by a support plate 58, and are moved up and down by a cylinder 59 provided on the side of the support member 54 via the support plate 58.

  A support ring 61 that surrounds and supports the heating plate 51 and the support member 54 is provided, and a surrounding member 62 that can be raised and lowered is provided on the support ring 61. A top plate 63 is provided on the surrounding member 62. Then, the processing space S of the wafer W is formed between the heating plate 51 and the top plate 63 with the surrounding member 62 lowered to the upper surface of the support ring 61, and the processing space S is surrounded by the surrounding member 62. It becomes a state. At that time, a minute gap 64 is formed between the support ring 61 and the surrounding member 62, and entry of air from the gap 64 into the processing space S is allowed. Further, when the wafer W is carried into and out of the heating plate 51, the surrounding member 62 and the top plate 63 are retracted upward by a cylinder (not shown).

  A central portion of the top plate 63 has an exhaust port 65 to which an exhaust pipe 66 is connected. Air is introduced from a gap 64 between the support ring 61 and the surrounding member 62 on the outer peripheral side of the heating plate 51, and exhausted. The processing space S is exhausted by an exhaust mechanism (not shown) through the port 65 and the exhaust pipe 66. Therefore, an air flow from the outer peripheral side of the heating plate 51 toward the center of the top plate 63 is formed in the processing space S. This airflow control is performed by an electromagnetic valve 67 provided in the exhaust pipe 66.

  As shown in FIGS. 4 and 5, the surface of the top plate 63 that faces the heating plate 51 has an annular first region 71 that is provided so as to surround the exhaust port 65 and an annular shape that is provided outside the first region 71. Second region 72. The top plate 63 includes a first heat pipe 73 having the first region 71 as a lower surface, a second heat pipe 74 having the second region 72 as a lower surface, and first and second heat pipes 73. And a heat insulating member 75 provided between 74 and 74. The heat insulating member 75 has a function of preventing thermal interference between the first heat pipe 71 and the second heat pipe 72. Instead of providing the heat insulating member 75, the first and second heat pipes 71 and 72 may be provided apart from each other so that a space is generated between them.

  As shown in FIG. 6, the first heat pipe 73 and the second heat pipe 74 have containers 77 and 78 as outer shell members made of a metal material such as copper or a copper alloy, respectively. A working liquid L is sealed in the space in 78. Such first and second heat pipes 73 and 74 use the evaporation phenomenon and the condensation phenomenon of the working fluid filled therein to easily transport a large amount of heat, and the temperature therein. When there is high or low, it has the effect of transporting heat quickly and making the temperature uniform. Specifically, as shown in FIG. 6, when the lower part of the first and second heat pipes 73 and 74 is heated by the heating plate 51, the working liquid L evaporates and becomes a steam flow to form a low temperature part. It moves at high speed to the upper part, and the temperature is made uniform in the vertical direction. At this time, it cools and condenses by contacting the upper walls of the low-temperature containers 77 and 78 at the upper part, and the condensed liquid returns to its original position by gravity. Further, even when the temperature is high or low in the circumferential direction and the radial direction, the temperature is made uniform by the movement of the steam flow. The internal spaces of the first and second heat pipes 73 and 74 have a substantially constant cross-sectional thickness in the circumferential direction of the surrounding member 62. The hydraulic fluid L is selected from those that do not adversely affect the materials of the containers 77 and 78. For example, water, ammonia, methanol, acetone, chlorofluorocarbon, etc. can be used.

  The first heat pipe 73 is provided with a temperature control mechanism 80 for controlling the temperature and consequently controlling the temperature of the first region 71. The temperature control mechanism 80 has a rod-shaped metal heat transfer member 81 for transferring heat to the first region, and a heat dissipating member provided at the tip of the heat transfer member 81 and having a fin 82a having a variable heat dissipating area. A heat radiation mechanism 84 including an actuator 83 for changing the heat radiation area of the member 82 and the fin 82a, an induction coil 85 wound around a part of the heat transfer member 81, and a high frequency power supply 86 for supplying high frequency power to the induction coil 85 And a controller 88 that controls the actuator 83 of the heat dissipation mechanism 84 and the high-frequency power source 86 of the heating mechanism 87. As will be described later, the temperature control mechanism 80 controls the first region 71 to be lower than the second region 72 by a predetermined temperature.

  These heat treatment units (HP) are controlled by a unit controller 90 as shown in FIG. Specifically, a plurality of temperature sensors 70 such as thermocouples for measuring the temperature of the heating plate 51 are provided at appropriate locations in the heating plate 51, and detection signals from the temperature sensors 70 are transmitted to the unit controller 90. The control signal is transmitted from the unit controller 90 to the temperature controller 91 based on the detection information, and the output adjustment signal is transmitted from the temperature controller 91 to the heating element power source 92 based on the control signal. Further, the unit controller 90 sends a control signal to the cylinder 59 during the heat treatment to control the raising and lowering of the raising and lowering pins 56 and also controls the opening degree of the electromagnetic valve 67 provided in the exhaust pipe 66 to reduce the exhaust amount. Control. Further, the controller 88 is instructed to control the first heat pipe 73 based on an appropriate reference value, for example, a detection signal or set value of the temperature sensor 70. The unit controller 90 outputs a control signal based on a command from a system controller (not shown) of the coating / developing system.

  In the heat treatment unit (HP) configured as described above, the heat treatment of the wafer W is performed as follows.

  First, the wafer W is carried into the casing 50 of the heat treatment unit (HP) by the wafer transfer device 46, transferred to the lift pins 56, and the lift pins 56 are lowered to heat the wafer W to a predetermined temperature. It is placed on a proximity pin 52 provided on the surface of the heating plate 51 in a state.

  Next, the surrounding member 62 and the top plate 63 are lowered to form the processing space S, and exhausted through the exhaust port 65 and the exhaust pipe 66 by an exhaust mechanism (not shown), so that air flows in from the gap 64 and the heating plate Heat treatment is performed on the wafer W in a state where an airflow from the outer peripheral side of the head 51 toward the center of the top plate 63 is formed.

  In this case, such an air flow flows from the peripheral edge of the wafer W toward the center of the wafer, and after the gas heated by passing over the high-temperature wafer gathers in the center of the wafer W, the processing space. In the case of the conventional heat treatment apparatus, even if the heating plate 51 is uniformly heated by the heating element 53, the center of the wafer W is actually affected by such an air flow. The temperature of the part becomes higher than the temperature of the peripheral part.

  For this reason, in the present embodiment, in the top plate 63, the temperature control mechanism 80 is set so that the temperature of the first region 71 corresponding to the central portion of the wafer W is lower than the second region 72 around it. Control by. The temperature of the wafer W is influenced not only by the heating plate 51 but also by the top plate 63 facing the heating plate. The greater the heat absorption of the top plate 63 and the smaller the heat radiation of the top plate 63, the higher the temperature of the wafer W. Therefore, when the temperature distribution occurs in the wafer W surface such that the temperature of the central portion of the wafer W increases as described above, the first plate corresponding to the central portion of the wafer W of the top plate 63 is used. If the temperature of the region 71 is lower than the temperature of the second region 72, the heat absorption of the first region 71 can be increased. The temperature of the portion can be lowered, and the in-plane temperature uniformity of the wafer W can be increased. In addition, since the temperature control mechanism 80 can control the degree of temperature decrease, the in-plane temperature uniformity of the wafer W becomes extremely high.

Hereinafter, the principle of making the temperature of the wafer W uniform in this way will be briefly described.
When the heating plate 51 and the top plate 63 are provided so as to face each other as described above, the thermal radiation energy released from the wafer W heated by the heating plate 51 reaches the top plate 63 and a part of the energy is emitted. The remaining part is reflected and returned to the wafer W, and a part of the wafer W is similarly absorbed and the remaining part is reflected. Therefore, the total energy per unit area emitted from the wafer W and Q _1, Q ₁ is equal to the sum of the irradiance E ₁ and reflected energy of the wafer W. The reflected energy at this time is obtained by multiplying the total energy Q ₂ per unit area emitted from the top plate 63 by the reflectance r ₁ of the wafer W. That is, the relationship expressed by the following formula (1) is established.
Q ₁ = E ₁ + r ₁ Q ₂ (1)

Similarly, for the top plate 63, the total energy Q ₂ per unit area emitted from the top plate 63 is equal to the sum of the irradiance E ₂ of the top plate 63 and the reflected energy, and this reflected energy is the above Q _1. Is multiplied by the reflectance r ₂ of the top plate, and the relationship expressed by the following equation (2) is established.
Q ₂ = E ₂ + r ₂ Q ₁ (2)

Here, assuming that the emissivity of the wafer W is ε ₁ and the emissivity of the top plate 63 is ε ₂ , the following equations (3) and (4) are satisfied, and these are represented by (1) and (2), respectively. Substituting into, the relationship of equations (5) and (6) is derived.
r ₁ = 1−ε ₁ (3)
r ₂ = 1−ε ₂ (4)
Q ₁ = E ₁ + (1−ε ₁ ) Q ₂ (5)
Q ₂ = E ₂ + (1−ε ₂ ) Q ₁ (6)

Since the wafer W is heated, the temperature T ₁ of the wafer W is higher than the temperature T ₂ of the top plate 63, it becomes possible to correspondingly heat is supplied by radiation from the wafer W to the top plate 63, The amount of heat Q per unit area at that time can be expressed by the following equation (7).
Q = Q ₁ −Q ₂ (7)

  Here, as the amount of heat Q, that is, the amount of heat released from the wafer, increases, the temperature of the wafer W can be lowered. Therefore, conventionally, it is only necessary to increase the amount of heat Q released at the central portion of the wafer W that tends to increase in temperature. For that purpose, it is only necessary to increase the heat absorption of the region corresponding to that portion of the top plate 63, that is, the first region 71. In the present embodiment, the first region 71 is used to increase the heat absorption. The temperature of the region 71 was made lower than the temperature of the second region 72.

  Moreover, since the top plate 63 includes the first heat pipe 73 and the second heat pipe 74 including the first region 71 and the second region 72, respectively, the temperature equalizing action of the heat pipe causes each region to The temperature can be made uniform, and the temperature of the first heat pipe 73 can be quickly controlled to a predetermined temperature by the temperature control mechanism 80 by the action of easily transporting a large amount of heat. Therefore, also from this point, the in-plane temperature uniformity of the wafer W can be made extremely high.

  As described above, since heat absorption in the first region 71 may be increased, in addition to lowering the temperature of the first region 71, heat absorption itself in the first region 71 is changed to the second region 72. It is also effective to make it higher. For this purpose, it is possible to change the color between the first region 71 and the second region 72, but the most effective one is to make the first region 71 a black body with an emissivity of 1. The second region 72 is a mirror having a reflectance of 1. In order to make the first region 71 a black body, it is preferable to provide a black ceramic 95 on the lower surface of the container 77 as shown in FIG. In order to use the second region 72 as a mirror, a gold night 96 may be attached to the lower surface of the container 78.

  After the heat treatment of the wafer W is performed as described above, the surrounding member 62 and the top plate 63 are moved upward, and the wafer W is lifted by the lift pins 56. In this state, the wafer transfer device 46 is inserted below the wafer W, and the wafer transfer device 46 receives the wafer W. The wafer W is unloaded from the heat treatment unit (HP) and transferred to the next process unit.

  In the above example, air is introduced from the outside of the wafer W to form an air flow in the processing space S. However, a gas such as an inert gas may be introduced into the processing space S as shown in FIG. Good. That is, instead of the support ring 61, a support ring 61 ′ having a gas flow hole 97 is provided, and a gas supply pipe 98 is connected to the gas flow hole 97 to introduce gas into the processing space S. The surrounding member 62 and the support ring 61 ′ may be sealed with the seal ring 99. The gas flow holes 97 may be formed in a circumferential shape, or a plurality of gas flow holes 97 may be provided along the circumference of a cylindrical support ring 61 ′.

  Next, with reference to FIG. 10 and FIG. 11, the heat processing unit which concerns on the 2nd Embodiment of this invention is demonstrated. FIG. 10 is a cross-sectional view schematically showing a heat treatment unit according to the second embodiment of the present invention, and FIG. 11 is a horizontal cross-sectional view schematically showing the interior and air flow. 10 and 11, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, a rectangular heating plate 51 ′ is disposed on the lower side of the casing 50. Proximity pins 52 ′ are provided on the surface of the heating plate 51 ′, and the wafer W is placed on the proximity pins 52 ′ in the state of being close to the surface of the heating plate 51 ′. . A plurality of linear heating elements 53 ′ are arranged substantially in parallel on the back surface of the heating plate 51 ′. These heating elements 53 'generate heat when energized, and heat the heating plate 51' to raise the temperature of the wafer W.

  The heating plate 51 'is supported by a support member 54', and the support member 54 'is hollow. A support ring 61 ′ is provided around the support member 54 ′ to surround and support the support member 54 ′, and an up and down encircling member 62 ′ is provided on the support ring 61 ′. A top plate 63 'is provided on the surrounding member 62'. Then, with the surrounding member 62 'lowered to the upper surface of the support ring 61', a processing space S 'sealed from the outside by the seal ring 101 is formed between the heating plate 51' and the top plate 63 '. The processing space S ′ is surrounded by the surrounding member 62 ′.

  One side of the heating plate 51 ′ has a width of approximately one side of the heating plate 51 ′ and a plurality of gas discharge holes 103, and supplies a gas such as an inert gas or air into the processing space S ′. A gas supply nozzle 102 is provided, and the gas supply nozzle 102 is connected to a plurality of gas flow holes 104 provided in the support ring 61 ′. A gas supply pipe 105 for supplying a gas such as an inert gas or air is connected.

  On the other hand, on the other side of the heating plate 51 ', there is an exhaust nozzle for discharging the gas in the processing space S' having a width of substantially one side of the heating plate 51 'and having a plurality of gas discharge holes 107. 106 is provided, and the exhaust nozzle 106 is connected to a plurality of gas flow holes 108 provided in the support ring 61 ′. Further, an exhaust pipe 109 is connected to the gas flow holes 108. .

  Then, the gas supplied from the gas supply nozzle 102 to the processing space S ′ is exhausted from the exhaust nozzle 106, and moves from one end side to the other end side of the heating plate 51 ′ as shown in FIG. 10 in the processing space S ′. A unidirectional airflow is formed.

  The surface of the top plate 63 'facing the heating plate 51' has a first area 71 'having a rectangular shape on the exhaust nozzle 106 side and a second area 72' having a remaining rectangular shape. . The top plate 63 'includes a first heat pipe 73' having a first area 71 'as a lower surface, a second heat pipe 74' having a second area 72 'as a lower surface, and a first and a first heat pipe 73'. And a heat insulating member 75 'provided between the two heat pipes 73' and 74 '. Instead of providing the heat insulating member 75 ′, the first and second heat pipes 71 ′ and 72 ′ may be provided apart from each other so that a space is generated between them.

  The first heat pipe 73 ′ and the second heat pipe 74 ′ are basically made of a metal material in the same manner as the first heat pipe 73 and the second heat pipe 74 of the first embodiment except for the shapes. A container as an outer shell member, and a working liquid L sealed in the space in the container, and an action of easily transporting a large amount of heat by utilizing evaporation and condensation phenomena of the working liquid, In addition, when the temperature is high or low, the heat is quickly transported and the temperature is made uniform. Specifically, when the lower part is heated by the heating plate 51 ′, the working liquid L evaporates and becomes a vapor stream, moves at a high speed to the upper part which is a low temperature part, and the temperature is made uniform in the vertical direction. At this time, the upper part contacts the upper wall of the low-temperature container and cools and condenses, and the condensed liquid returns to the original position by gravity. Even when the temperature is high or low in the horizontal direction, the temperature is made uniform by the movement of the steam flow. The internal spaces of the first and second heat pipes 73 'and 74' have a substantially constant cross-sectional thickness in the horizontal direction.

  Similar to the first heat pipe 73 of the first embodiment, the first heat pipe 73 ′ controls the temperature and consequently controls the temperature of the first region 71 ′. Is provided. The temperature control mechanism 80 controls the first region 71 ′ to be a predetermined temperature lower than the second region 72 ′.

  When performing the heat treatment by the heat treatment unit (HP) configured as described above, first, similarly to the case of the first embodiment, the wafer W is carried into the casing 50 by the wafer transfer device 46, and It is placed on the proximity pin 52 '.

  Next, the surrounding member 62 ′ and the top plate 63 ′ are lowered to form a processing space S ′, and the processing space is formed from the plurality of gas discharge holes 103 of the gas supply nozzle 102 through the gas supply pipe 105 and the gas flow hole 104. The gas is supplied into S ′ and exhausted from the gas exhaust hole 107 of the exhaust nozzle 106 through the gas flow hole 108 and the exhaust pipe 109, whereby the other end from the one end side of the heating plate 51 ′ to the processing space S ′. Creates a one-way airflow toward the side.

  In a state where such a one-way airflow is formed, the wafer W on the heating plate 51 ′ is heated by supplying power to the heating element 53 ′. In this way, since a one-way air flow is formed on the upper surface of the heating plate 51 ′, unlike the top plate 63 of the first embodiment, the central portion of the top plate 63 ′ is not provided with an exhaust port and stays there. The dust does not fall on the upper surface of the wafer. Further, since there is no need to provide an exhaust structure on the top plate 63 ', the vertical dimension of the device itself can be reduced.

  When a unidirectional airflow is formed in this way, the gas heated by passing over the high-temperature wafer is discharged from the exhaust nozzle 106, so that the heating plate 51 'is uniformly heated by the heating element 53'. Even if the top plate is a simple metal plate as in the prior art, the temperature in the vicinity of the exhaust nozzle 106 of the wafer W tends to be higher than the temperature in the other portions due to the influence of such an air flow. is there.

  For this reason, in the present embodiment, the top plate 63 ′ is used as the first region 71 ′ in the vicinity of the exhaust nozzle 106 and the other second region 72 ′ as described above, and the temperature of the first region 71 ′ is set to the first region 71 ′. The temperature control mechanism 80 controls the temperature to be lower than the second region 72 ′ by a predetermined temperature. Therefore, as in the first embodiment, the temperature of the first region 71 ′ of the top plate 63 ′ is made lower than the temperature of the second region 72 ′, thereby increasing the heat absorption of the first region 71 ′. As a result, the heat release in the vicinity of the exhaust nozzle 106 of the wafer W can be increased to lower the temperature of that portion, and the in-plane temperature uniformity of the wafer W can be increased. In addition, since the temperature control mechanism 80 can control the degree of temperature decrease, the in-plane temperature uniformity of the wafer W becomes extremely high.

  Further, since the top plate 63 'has the first heat pipe 73' and the second heat pipe 74 'each including the first region 71' and the second region 72 ', the temperature equalizing action of the heat pipe is achieved. As a result, the temperature can be made uniform in each region, and when the first heat pipe 73 'is temperature-controlled by the temperature control mechanism 80 by the action of easily transporting a large amount of heat, the temperature is quickly brought to a predetermined temperature. be able to. Therefore, also from this point, the in-plane temperature uniformity of the wafer W can be made extremely high.

  Also in the present embodiment, as in the first embodiment, in addition to lowering the temperature of the first region 71 ′, the heat absorption itself of the first region 71 ′ is made higher than that of the second region 72 ′. Therefore, the color can be changed between the first region 71 'and the second region 72'. Most effectively, the first region 71 'is a black body and the second region 71' The region 72 'is a mirror.

  After the heat treatment of the wafer W is completed in this way, the surrounding member 62 ′ and the top plate 63 ′ are moved upward, the wafer W is lifted by the lift pins 56, and the wafer transfer device 46 is moved below the wafer W in this state. Inserted and the wafer transfer device 46 receives the wafer W, unloads the wafer from the heat treatment unit (HP), and transfers it to the next process unit.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible within the range of the thought of this invention. For example, in the above-described embodiment, the opposing surfaces of the heating plate of the top plate are the first region and the second region, but it is needless to say that three or more regions may be used. Moreover, although the temperature of the 1st area | region of a top plate was controlled, the temperature of a 2nd area | region may be controlled and you may make it control both temperature. Furthermore, although the top plate is composed of a heat pipe, it is not limited to this. The structure of the heat treatment apparatus is not limited to the heat treatment unit exemplified in the above embodiment, and various forms are possible. Furthermore, although the heat treatment of the resist coating / development processing system has been described, the present invention can be applied to other heat treatments. Furthermore, in the above-described embodiment, the case where the wafer is mounted on the proximity pin and heated indirectly is shown. However, the wafer may be directly mounted on the heating plate and heated. Furthermore, although the case where a semiconductor wafer is used as the substrate has been described in the above embodiment, the present invention can also be applied to a case where heat treatment is performed on a substrate other than the semiconductor wafer, for example, a glass substrate for a liquid crystal display device (LCD). It is.

The top view which shows the whole structure of the resist application | coating / development processing system of the semiconductor wafer provided with the heat processing unit which is one Embodiment of the heat processing apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The front view which shows the whole structure of the resist application | coating and image development processing system of the semiconductor wafer provided with the heat processing unit which is one Embodiment of the heat processing apparatus of this invention. The rear view which shows the whole structure of the resist application | coating / development processing system of the semiconductor wafer provided with the heat processing unit which is one Embodiment of the heat processing apparatus of this invention. Sectional drawing which shows typically the heat processing unit which concerns on the 1st Embodiment of this invention. FIG. 5 is a perspective view showing the top plate and the surrounding member of the heat treatment unit in FIG. Sectional drawing which shows the 1st and 2nd heat pipe formed in the top plate of the heat processing unit of FIG. The block diagram which shows the control system of the heat processing unit of FIG. Sectional drawing which shows the principal part of the modification of the heat processing unit which concerns on the 1st Embodiment of this invention. Sectional drawing which shows typically the other modification of the heat processing unit which concerns on the 1st Embodiment of this invention. Sectional drawing which shows typically the heat processing unit which concerns on the 2nd Embodiment of this invention. The horizontal sectional view which shows typically the inside of the heat processing unit of FIG. 10, and airflow.

Explanation of symbols

51, 51 ′; heating plate 52, 52 ′; proximity pin 56; elevating pin 53, 53 ′; heating element 62, 62 ′; enclosing member 63, 63 ′; top plate 71, 71 ′; 72 '; second region 73, 73'; first heat pipe 74, 74 '; second heat pipe 75, 75'; heat insulating member 80; temperature control mechanism S, S '; Wafer

Claims (11)

A heat treatment apparatus for heat-treating a substrate to a predetermined temperature,
A heating plate that heats the substrate close to or on its surface; and
A top plate provided facing the substrate arrangement surface of the heating plate and having a temperature control mechanism;
A surrounding member that surrounds a space between the heating plate and the top plate;
A gas supply nozzle provided on one side of the heating plate for introducing gas into the space;
An exhaust nozzle provided on the other end of the heating plate for exhausting gas from the space;
With
The gas supply nozzle supplies gas from one side of the heating plate to the other, and the exhaust nozzle exhausts the gas to form a one-way airflow. apparatus.   The top plate has at least a first region and a second region at a portion facing the heating plate, the first region is provided on the exhaust nozzle side, and the temperature control mechanism The heat treatment apparatus according to claim 1, wherein the temperature of at least one of the first region and the second region is controlled.   The temperature control mechanism lowers the temperature of the first region of the top plate from that of the second region according to a set value of the heating temperature of the heating plate or a temperature distribution generated in the substrate by heating of the heating plate. The heat treatment apparatus according to claim 2, wherein the heat treatment apparatus is controlled to perform.   The heat treatment apparatus according to claim 3, wherein the heat absorption rate of the first region is larger than the heat absorption rate of the second region.   The heat treatment apparatus according to claim 3 or 4, wherein the first region is a black body, and the second region is a mirror.   The said 1st area | region is comprised by the 1st heat pipe, The said 2nd area | region is comprised by the 2nd heat pipe, The any one of Claims 2-5 characterized by the above-mentioned. The heat treatment apparatus as described.   The temperature control mechanism controls a heat dissipation mechanism for releasing heat from the first heat pipe, a heating mechanism for injecting heat into the first heat pipe, and the heating mechanism and / or the heat dissipation mechanism. The heat processing apparatus according to claim 6, further comprising:   The heat treatment apparatus according to claim 6 or 7, wherein the first heat pipe and the second heat pipe are provided adjacent to each other, and are insulated from each other.   The heat treatment apparatus according to claim 1, wherein the heating plate has a rectangular shape.   The heat treatment apparatus according to claim 1, wherein the gas supply nozzle has a plurality of gas discharge holes in a width direction of the heating plate.   The heat treatment apparatus according to any one of claims 1 to 9, wherein the exhaust nozzle has a plurality of gas discharge holes in a width direction of the heating plate.

Images