JP2008034685A - Heat treatment method and heat treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment technique which heats a substrate equally. <P>SOLUTION: A heating plate which heats the substrate placed thereon is divided into three regions composed of a center, a periphery and an intermediate part between them. Temperatures respectively at the center, the periphery and the intermediate part of the heating plate are controlled so as to equalize an amount of heat per a unit area which the substrate receives from the heating plate in a period, between a time (time t=t1) when the mean temperature of the substrate is raised to a first temperature after the substrate is placed on the heating plate and a time (time t=t2) when the mean temperature is lowered to a second temperature after the substrate is separated from the heating plate. In this case, when the temperature is a little higher at the center of the heating plate than at the periphery just after the substrate is placed on the heating plate, the temperature of the heating plate is controlled so as to reverse the high/low relation of the temperature just before the substrate is separated from the heating plate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat treatment method for heating a semiconductor substrate mounted on a heating plate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk (hereinafter simply referred to as “substrate”), and the heat treatment method therefor The present invention relates to a heat treatment apparatus used for the above.

  Products such as semiconductor devices and liquid crystal displays are manufactured by subjecting the substrate to a series of processes such as cleaning, resist coating, exposure, development, etching, formation of an interlayer insulating film, heat treatment, and dicing. Of these, the heat treatment is, for example, a process performed after pattern exposure, after application of an SOG (Spin on glass) material that is a material of an interlayer insulating film, or after application of a photoresist, and is essential for a semiconductor manufacturing process. It is an important processing step.

  When heat-treating a semiconductor wafer or the like, a method of placing and heating a substrate on a heating plate (hot plate) is most commonly performed. In the heat treatment using such a heating plate, for example, the temperature of the central part of the substrate during the heat treatment becomes higher than the temperature of the peripheral part due to differences in the amount of heat generation and heat dissipation between the central part and the peripheral part of the plate. Such a phenomenon that the temperature distribution in the substrate surface becomes non-uniform occurs.

  On the other hand, with the recent progress in design rule accuracy, the temperature accuracy requirement for the heat treatment of the substrate has become increasingly severe. In particular, the heat treatment after the photoresist coating described above directly affects the film thickness and film quality of the resist film to be formed, and the post-exposure heat treatment when using a chemically amplified resist directly affects the line width of the pattern. There is a strong demand for improvement in temperature uniformity within the substrate surface.

  For this reason, Patent Document 1 proposes a technique for heating the substrate uniformly by dividing the heating plate into several zones and individually controlling the temperature of the resistance heating elements arranged in each zone. Yes. For example, when the above non-uniformity occurs, the in-plane temperature distribution of the substrate can be made uniform by increasing the amount of heat generated at the periphery of the plate than at the center.

JP 63-216283 A

  By applying a technique as disclosed in Patent Document 1, it is possible to make the in-plane temperature distribution of the substrate during the heat treatment uniform to some extent, but it is impossible to make it completely uniform. It was. That is, even if the technique disclosed in Patent Document 1 is used, there is inevitably a minute temperature difference of 1 ° C. or less between the highest temperature point and the lowest temperature point of the substrate during the heat treatment. It is impossible to completely eliminate the temperature difference. In view of the required accuracy in recent years, even such a small temperature difference is being regarded as a problem.

  Further, the in-plane temperature distribution varies most greatly immediately after the substrate is placed on the heating plate and immediately after the substrate is separated from the heating plate. No matter how precisely the heating plate is temperature-controlled, it is impossible to control the substrate temperature at these moments. In particular, immediately after the substrate is separated from the heating plate, the substrate temperature is still high. For example, the thermochemical reaction in the resist film on the substrate does not stop, and if the substrate temperature varies at this moment, the properties of the substrate after processing The problem of non-uniformity.

  The present invention has been made in view of the above problems, and an object thereof is to provide a heat treatment method and a heat treatment apparatus capable of uniformly heating a substrate.

  In order to solve the above problems, the invention of claim 1 is a heat treatment method for heating a substrate placed on a heating plate, a placing step for placing the substrate on the heating plate, and a placement on the heating plate. A heating step of heating the substrate, and a separation step of separating the substrate from the heating plate, wherein the heating step raises the temperature to a first temperature by placing the substrate on the heating plate. The substrate is heated so that the amount of heat per unit area received by the substrate from the heating plate is uniform from the time when the substrate is separated to the time when the temperature is lowered to the second temperature.

  Further, the invention of claim 2 is the heat treatment method according to the invention of claim 1, wherein the first temperature is a temperature at which a reaction of the treatment liquid applied to the substrate starts, and the second temperature. Is a temperature at which the reaction of the treatment liquid stops.

  According to a third aspect of the present invention, in the heat treatment method according to the first or second aspect of the present invention, the heating plate is divided into a plurality of regions including at least a first region and a second region, and the heating is performed. The process is such that the temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate is reversed immediately before the substrate is separated from the heating plate. And heating the substrate.

  According to a fourth aspect of the present invention, in the heat treatment method for heating a substrate placed on a heating plate divided into a plurality of regions including at least a first region and a second region, the substrate is placed on the heating plate. A placing step for placing, a heating step for heating the substrate placed on the heating plate, and a separating step for separating the substrate from the heating plate, wherein the heating step comprises: Heating the substrate so that the temperature elevation relationship between the first region and the second region immediately after being placed on the heating plate is reversed immediately before the substrate is separated from the heating plate; It is characterized by.

  Further, the invention of claim 5 is a heat treatment apparatus for heating a substrate placed on a heating plate, and contacting / separating means for moving the substrate up and down relatively with respect to the heating plate; The amount of heat per unit area received by the substrate from the heating plate becomes uniform from the time when it is placed on the heating plate and raised to the first temperature to the time when the temperature is lowered to the second temperature. Temperature control means for controlling the temperature of the heating plate as described above.

  The invention of claim 6 is the heat treatment apparatus according to claim 5, wherein the first temperature is a temperature at which a reaction of the treatment liquid applied to the substrate starts, and the second temperature. Is a temperature at which the reaction of the treatment liquid stops.

  The invention according to claim 7 is the heat treatment apparatus according to claim 5 or 6, wherein the heating plate is divided into a plurality of regions including at least a first region and a second region, and the temperature is set. The control means reverses the temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate immediately before the substrate is separated from the heating plate. As described above, the temperatures of the plurality of regions are individually controlled.

  The invention of claim 8 is a heat treatment apparatus for heating a substrate placed on a heating plate divided into a plurality of regions including at least a first region and a second region. And a contact / separation means for moving up and down relatively, and a temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate is from the heating plate. Temperature control means for individually controlling the temperatures of the plurality of regions so as to be reversed immediately before the substrate is separated.

  According to the first aspect of the present invention, the unit that the substrate receives from the heating plate from the time when the substrate is placed on the heating plate and raised to the first temperature to the time when the substrate is lowered to the second temperature after being separated. Since the substrate is heated so that the amount of heat per area is uniform, the substrate can be uniformly heated as a whole heat treatment step.

  Further, according to the invention of claim 2, since the first temperature is a temperature at which the reaction of the processing liquid applied to the substrate starts, and the second temperature is a temperature at which the reaction of the processing liquid stops, The substrate can be heated uniformly in the temperature range where the reaction of the treatment liquid occurs.

  According to the invention of claim 3, the heating plate is divided into a plurality of regions including at least the first region and the second region, and the first region immediately after the substrate is placed on the heating plate, Since the temperature relationship with the second region is reversed immediately before the substrate is separated from the heating plate, the amount of heat per unit area received by the substrate from the heating plate becomes uniform, and the substrate is heated uniformly throughout the heat treatment process. can do.

  According to the invention of claim 4, the temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate is reversed immediately before the substrate is separated from the heating plate. Therefore, the substrate can be uniformly heated as the entire heat treatment process.

  According to the invention of claim 5, the substrate is placed on the heating plate between the time when the substrate is placed on the heating plate and raised to the first temperature and the time when the substrate is lowered to the second temperature. Since the temperature of the heating plate is controlled so that the amount of heat per unit area received from the substrate becomes uniform, the substrate can be uniformly heated as the entire heat treatment step.

  According to the invention of claim 6, the first temperature is a temperature at which the reaction of the processing liquid applied to the substrate starts, and the second temperature is a temperature at which the reaction of the processing liquid stops, The substrate can be heated uniformly in the temperature range where the reaction of the treatment liquid occurs.

  According to the invention of claim 7, the heating plate is divided into a plurality of regions including at least the first region and the second region, and the first region immediately after the substrate is placed on the heating plate, Since the temperature relationship with the second region is reversed immediately before the substrate is separated from the heating plate, the amount of heat per unit area received by the substrate from the heating plate becomes uniform, and the substrate is heated uniformly throughout the heat treatment process. can do.

  According to the invention of claim 8, the temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate is reversed immediately before the substrate is separated from the heating plate. As described above, since the temperatures of the plurality of regions are individually controlled, the substrate can be uniformly heated as the entire heat treatment process.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side sectional view showing a schematic configuration of a heat treatment apparatus according to the present invention. In this heat treatment apparatus, a substrate W is placed on a heating plate (hot plate) 1 and heated to a predetermined temperature. The substrate W is brought into contact with and separated from the heating plate 1 by the elevating mechanism 5.

The heating plate 1 is configured by sandwiching a heating element 20 between an upper plate 10 and a lower plate 30. The upper plate 10 is a metal (for example, aluminum alloy) plate having a disk shape. The upper plate 10 is for placing the substrate W to be heat-treated, and its upper surface is preferably as flat as possible. The upper plate 10 is not limited to metal, but may be made of ceramics (for example, aluminum nitride (AlN)). Further, the upper surface of the upper plate 10 is made of a low heat transfer member such as alumina (Al ₂ O ₃ ), and a plurality of (three or more) spheres whose upper ends protrude by a minute amount from the surface of the upper plate 10. (So-called proximity balls) may be provided.

  The lower plate 30 is a disk-like member having a plane size and a plane shape comparable to those of the upper plate 10. The lower plate 30 is for pressing the heating element 20 against the upper plate 10 by sandwiching the heating element 20 with the upper plate 10 and screwing (not shown). As the material of the lower plate 30, an appropriate material made of metal or ceramics can be used.

  FIG. 2 is a plan view of the heating element 20. As the heating element 20, for example, a mica heater in which both sides of a metal foil as a heating resistor are sandwiched between mica plates may be employed. The heating element 20 is divided into three regions, a central portion 20a, an intermediate portion 20b, and a peripheral portion 20c. As shown in FIG. 2, the central portion 20a is a circular region, and the intermediate portion 20b and the peripheral portion 20c are annular regions. The central portion 20a, the intermediate portion 20b, and the peripheral portion 20c are concentrically arranged. When the substrate W is placed on the heating plate 1, the central portion 20a faces the vicinity of the center of the substrate W, and the peripheral portion The part 20c faces the peripheral edge of the substrate W, and the intermediate part 20b faces the intermediate area.

  The central portion 20 a, the intermediate portion 20 b, and the peripheral portion 20 c of the heating element 20 are independently connected to the power supply unit 25 and are individually supplied with power from the power supply unit 25. The temperatures of the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c are individually detected by temperature sensors 31a, 31b, and 31c embedded in the lower plate 30. More specifically, electrical signals generated in the temperature sensors 31a, 31b, and 31c according to the temperatures of the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c of the heating element 20 are detected by the temperature measuring unit 35, and the temperature measuring The unit 35 detects the temperatures of the three zones individually by performing a predetermined calculation process. As the temperature sensors 31a, 31b, 31c, various known temperature measuring elements such as thermocouples and resistance temperature detectors can be used.

  The temperatures of the central part 20a, the intermediate part 20b and the peripheral part 20c detected by the temperature measuring part 35 are transmitted to the temperature control part 40. The temperature control unit 40 is a control unit including a CPU, a memory, and the like. The temperature control unit 40 controls the power supply unit 25 based on the temperature measurement result transmitted from the temperature measurement unit 35 to control the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c. The amount of power supplied to each is adjusted individually. With such a configuration, in the heating plate 1, it is possible to arbitrarily adjust the temperature relationship between the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c.

  The elevating mechanism 5 includes a plurality of (three in this embodiment) lift pins 51, a support plate 52, and an actuator 55. The three lift pins 51 are made of quartz, and are fixedly erected on the support plate 52. The support plate 52 is moved up and down by an actuator 55. As the actuator 55, various known linear drive mechanisms such as a pulse motor and an air cylinder can be employed.

  As shown in FIG. 2, three through holes 21 through which the lift pins 51 are inserted are formed in the heating element 20 every 120 ° along the circumference of the gap between the central portion 20 a and the intermediate portion 20 b. . The upper plate 10 and the lower plate 30 are also provided with through holes in the vertical direction so that the lift pins 51 can be inserted at positions corresponding to the three through holes 21. When the actuator 55 moves the support plate 52 up and down, the three lift pins 51 erected on the support plate 52 move up and down along the through holes all at once.

  The three lift pins 51 are moved up and down by an actuator 55 between a processing position indicated by a solid line in FIG. 1 and a delivery position indicated by a two-dot chain line. As shown in FIG. 1, when the lift pin 51 is lowered to the processing position, the upper end of the lift pin 51 is embedded in the through hole of the upper plate 10. On the other hand, when the lift pin 51 rises to the delivery position, the upper end of the lift pin 51 protrudes from the upper surface of the upper plate 10.

  Next, a heat treatment operation in the heat treatment apparatus having the above configuration will be described. Here, a case where a heat treatment is performed using the above heat treatment apparatus after pattern exposure is performed on a semiconductor wafer coated with a chemically amplified resist will be described as an example. When a chemically amplified resist is used, an acid is generated by a photochemical reaction only in the exposed portion of the resist film formed on the substrate W. Then, when the exposed substrate W is heated by the heat treatment apparatus of the present embodiment, a reaction such as crosslinking / polymerization of the resin of the resist proceeds using the product generated by the photochemical reaction during the exposure as an acid catalyst, and the solubility in the developer However, only the exposed part changes locally. Such a heat treatment is called “Post Exposure Bake”, and is extremely important in today's photolithography process. In this post-exposure heat treatment, if the in-plane temperature distribution of the substrate W becomes non-uniform, the line width of the pattern becomes non-uniform.

  First, after the substrate W after exposure is carried into the apparatus by a substrate transport robot (not shown), the three lift pins 51 are raised to the delivery position (the two-dot chain line position in FIG. 1) to receive the substrate W. The heating plate 1 is heated by energizing the heating element 20 in advance. Accordingly, the three lift pins 51 are lowered to the processing position (solid line position in FIG. 1) and the substrate W is placed on the upper surface of the upper plate 10, and at the same time, the heating process of the substrate W is started. Then, after the heat treatment for a predetermined time, the three lift pins 51 rise again to the delivery position, and the substrate W is separated from the upper plate 10. After that, the substrate W that has been cooled slightly after waiting at the delivery position is unloaded from the lift pins 51.

  FIG. 3 is a diagram illustrating a temperature change of the substrate W during the heat treatment. The figure shows the transition of the in-plane average temperature of the substrate W. When the lift pin 51 is lowered to the processing position at time t = 0 seconds and the substrate W is placed on the upper plate 10, the substrate W is immediately heated to increase its temperature, and eventually reaches 125 ° C. This 125 ° C. is a general heating temperature for post-exposure heat treatment when a chemically amplified resist is used. Then, at time t = 120 seconds, the lift pins 51 rise to the delivery position, push the substrate W up and away from the upper plate 10, and the temperature of the substrate W starts to fall.

  The substrate W is heated by the heating plate 1 to cause a chemical reaction of the resist after exposure to progress. It is known that this chemical reaction occurs in a temperature range of about 75 ° C. or higher. On the other hand, the variation in the in-plane temperature distribution of the substrate W is large because the substrate W is placed on the heating plate 1 and the temperature rise period until the substrate temperature reaches the set temperature (125 ° C. in this case) and the substrate W. Is a temperature drop period after being separated from the heating plate 1, and the latter variation is particularly large. Since the chemical reaction of the resist on the substrate W occurs at 75 ° C. or higher, the variation in the in-plane temperature distribution during the temperature rising period and the temperature falling period may also affect the processing result (here, the line width).

  In addition, even during the period from when the temperature of the substrate W reaches the set temperature to when it is separated, there is a minute temperature difference in the plane of the substrate W, and this tendency continues during the heat treatment period. There are many. For example, when the temperature of the substrate W reaches the set temperature, if the central portion of the substrate W is slightly higher than the peripheral portion, the temperature relationship continues until the substrate W is separated from the heating plate 1. . Then, even if the temperature difference is extremely small, the cumulative amount of heat received by the high temperature portion of the substrate W becomes correspondingly larger than that of the low temperature portion, which affects the processing result.

  For this reason, in the heat treatment apparatus according to the present invention, when the substrate W is placed on the heating plate 1 and the average temperature is raised to 75 ° C. (time t = t1), the temperature is lowered to 75 ° C. after the separation (time t = t1). The substrate W is heated so that the amount of heat per unit area received by the substrate W from the heating plate 1 becomes uniform until time t = t2). Specifically, the temperature control unit 40 causes the heating element 20 so that the amount of heat received from the heating plate 1 is uniform between the central portion, the peripheral portion, and the intermediate portion of the substrate W from time t = t1 to time t = t2. The temperatures of the central part 20a, the intermediate part 20b and the peripheral part 20c are controlled.

  FIG. 4 is a diagram showing a temperature change of each part of the substrate W during the heat treatment. In the same figure, each temperature transition of the center part of the board | substrate W, a peripheral part, and its intermediate part is shown. The temperature control unit 40 is configured so that the center and peripheral edges of the substrate W are between the time when the average temperature of the substrate W is raised to 75 ° C. (time t = t1) and the time when the temperature is lowered to 75 ° C. (time t = t2). Part and its intermediate part so that the amount of heat received from the heating plate 1 is uniform, that is, the integrated value in the range of time t = t1 to t2 of the temperature T of the central part, the peripheral part and the intermediate part shown in FIG. The temperatures of the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c of the heating element 20 are controlled so as to be equal.

  The temperatures of the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c of the heating element 20 are determined directly by the amount of power supplied from the power supply unit 25. The temperature control unit 40 includes the central portion 20a and the intermediate portion 20b. The power supply unit 25 is instructed to supply power to each of the peripheral portions 20c and the power supply pattern (time change pattern of the power supply amount). As such a power supply pattern, the in-plane temperature distribution change of the sample substrate placed on the heating plate 1 while finely adjusting the temperatures of the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c of the heating element 20 is used. Measure (preferably measure the temperature at as many measurement points as possible), and determine in advance a pattern in which the amount of heat received by the central portion, the peripheral portion and the intermediate portion of the substrate W is uniform, and store it in the memory of the temperature control unit 40 Store it. When performing the heat treatment of the substrate W to be processed, the temperature control unit 40 controls the power supply unit 25 according to the power supply pattern and adjusts the power supply amount to each of the central portion 20a, the intermediate portion 20b, and the peripheral portion 20c. Temperature control. Note that the power supply pattern may be determined by simulation instead of (or in combination with) the actual temperature measurement.

  When such temperature control is performed, when the temperature of the substrate W reaches a set temperature as shown in FIG. 4, for example, if the central portion of the substrate W is slightly higher than the peripheral portion, the substrate W Immediately before being separated from the heating plate 1, heat treatment is performed so that the temperature relationship is reversed, that is, the peripheral portion of the substrate W is slightly higher in temperature than the central portion. More specifically, in the case of FIG. 4, since the central portion 20a of the heating element 20 is slightly hotter than the peripheral portion 20c at the time immediately after the substrate W is placed on the heating plate 1, the substrate W However, the relationship between the temperature levels is reversed immediately before the substrate W is separated from the heating plate 1 (the peripheral portion 20c is the central portion 20a). The temperature control unit 40 controls the power supply unit 25 so that the temperature is slightly higher than that. Note that the temperature of the intermediate portion 20b is between the central portion 20a and the peripheral portion 20c immediately after the substrate W is placed on the heating plate 1, and the peripheral portion 20c even after the above temperature relationship is reversed. And the temperature between the central portion 20a.

  As described above, when the substrate W is placed on the heating plate 1 and the average temperature is raised to 75 ° C. (time t = t1), the temperature is lowered to 75 ° C. after being separated (time t = t2). ), The substrate W is heated so that the amount of heat per unit area received by the substrate W from the heating plate 1 is uniform, so that the chemical reaction of the resist after exposure proceeds at a temperature range of about 75 ° C. or higher. Then, the amount of heat per unit area received by the substrate W becomes equal, and the substrate W can be uniformly heated as a whole in the heat treatment process. As a result, the line width of the processed substrate W can be made uniform. .

  The ideal heat treatment is that there is no temperature difference between the highest temperature point and the lowest temperature point of the substrate W during the heat treatment, that is, the in-plane temperature distribution is completely uniform. In order to realize this heat treatment, various attempts have been made as disclosed in Patent Document 1, for example. Although it was possible to approach the ideal heat treatment to some extent, it is possible to eliminate the minute unavoidable temperature difference of 1 ° C. or less existing between the highest temperature point and the lowest temperature point of the substrate W during the heat treatment. It was impossible. Even if the minute temperature difference at the set temperature can be eliminated, it is almost impossible to control the substrate temperature immediately after the substrate W is placed on the heating plate 1 and immediately after being separated from the heating plate 1. The influence of variations in the in-plane temperature distribution during the period cannot be excluded.

  The heat treatment apparatus according to the present invention changes the in-plane temperature distribution according to the time zone during the heat treatment on the premise that the temperature adjustment of the heating element 20 that eliminates the minute temperature difference is not realistic. Technically, the substrate W is heated uniformly in consideration of the entire period of the heat treatment by making the amount of heat per unit area received by the substrate W equal (by switching the high temperature region and the low temperature region). It has significance.

  In addition, the heat treatment apparatus of this embodiment has a time point (time) when the substrate W is placed on the heating plate 1 and the average temperature is raised to 75 ° C. (time t = t1) and then the temperature is lowered to 75 ° C. after being separated. Since the in-plane temperature distribution until t = t2) is adjusted, the variation in the in-plane temperature distribution immediately after the substrate W is placed on the heating plate 1 and immediately after being separated from the heating plate 1 is also taken into consideration. The temperature control of the heating element 20 is performed, and the substrate W can be uniformly heated as a whole in the heat treatment process.

  While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above embodiment, the substrate W is heated to the heating plate 1 between the time when the average temperature of the substrate W is raised to 75 ° C. (time t = t1) and the time when the temperature is lowered to 75 ° C. (time t = t2). However, the temperature control start and end temperatures are not limited to 75 ° C. The type of process liquid applied to the substrate W and the process purpose It is a value that can be set as appropriate according to. The temperature at the beginning of temperature control (substrate average temperature at time t = t1) and the temperature at the end (substrate average temperature at time t = t2) may be different values.

  Further, in the above embodiment, the central portion 20a of the heating element 20 is slightly higher in temperature than the peripheral portion 20c in the initial stage, and then the temperature level relationship is reversed. Alternatively, the temperature of the peripheral portion 20c of the heating element 20 may be higher than that of the central portion 20a in the initial stage, and the temperature of the central portion 20a may be higher than that of the peripheral portion 20c in the latter stage.

  Further, the process performed by the heat treatment apparatus according to the present invention is not limited to the post-exposure heat treatment, and various heat treatments executed in a manufacturing process of a semiconductor wafer or the like can be targeted. For example, a post-application baking process (Post Applied Bake) may be performed in which the substrate W coated with a photoresist is heated and a resist film is baked on the substrate. If this post-coating heat treatment is performed in the heat treatment apparatus according to the present invention, the substrate W can be uniformly heated as a whole heat treatment step, and as a result, the film thickness and film quality of the resist film formed on the substrate W can be improved. In-plane uniformity can be improved. The set temperature for the post-application heat treatment is naturally different from the set temperature for the post-exposure heat treatment in the above embodiment, and the initial temperature of the temperature control is the temperature at which the baking of the photoresist starts, and the final temperature. May be a temperature at which baking of the photoresist stops. That is, the initial temperature (first temperature) of the temperature control is a temperature at which the reaction of the processing liquid applied to the substrate W starts, and the final temperature control (second temperature) is the reaction of the processing liquid. It is sufficient to set the temperature to stop.

  Moreover, in the said embodiment, although the heat generating body 20 was divided into 3 area | regions of the center part 20a, the intermediate part 20b, and the peripheral part 20c, it is not limited to this, It divides | segments into at least 2 area | region or more. Anything to do. The larger the number of regions into which the heating element 20 is divided, the easier it is to make the amount of heat per unit area received by the substrate W from the heating plate 1, but the control by the temperature control unit 40 becomes more complicated.

  Further, in the above embodiment, the substrate W is brought into contact with and separated from the heating plate 1 by raising and lowering the three lift pins 51, but the substrate W is brought into contact with the heating plate 1 by raising and lowering the heating plate 1. Alternatively, an external transfer robot that holds the substrate W may be moved up and down to bring the substrate W into and out of contact with the heating plate 1.

  The substrate to be heated by the heat treatment apparatus according to the present invention is not limited to a semiconductor wafer, and may be a liquid crystal glass substrate.

It is a sectional side view which shows schematic structure of the heat processing apparatus which concerns on this invention. It is a top view of a heat generating body. It is a figure which shows the temperature change of the board | substrate during heat processing. It is a figure which shows the temperature change of each part of the board | substrate during heat processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating plate 5 Elevating mechanism 10 Upper plate 20 Heating element 20a Center part 20b Middle part 20c Peripheral part 25 Power supply unit 30 Lower plate 35 Temperature measuring part 40 Temperature control part 51 Lift pin 55 Actuator W board

Claims (8)

A heat treatment method for heating a substrate placed on a heating plate,
A placing step of placing the substrate on the heating plate;
A heating step of heating the substrate placed on the heating plate;
A separation step of separating the substrate from the heating plate;
With
The heating step is a unit that the substrate receives from the heating plate from the time when the substrate is placed on the heating plate and raised to the first temperature to the time when the substrate is lowered to the second temperature after being separated. A heat treatment method, wherein the substrate is heated so that the amount of heat per area is uniform. The heat treatment method according to claim 1,
The first temperature is a temperature at which a reaction of the treatment liquid applied to the substrate starts,
The heat treatment method, wherein the second temperature is a temperature at which the reaction of the treatment liquid stops. In the heat processing method of Claim 1 or Claim 2,
The heating plate is divided into a plurality of regions including at least a first region and a second region;
The heating step is reversed immediately before the substrate is separated from the heating plate because the temperature elevation relationship between the first region and the second region immediately after the substrate is placed on the heating plate. A method of heat treatment characterized by heating the substrate. A heat treatment method for heating a substrate placed on a heating plate divided into a plurality of regions including at least a first region and a second region,
A placing step of placing a substrate on the heating plate;
A heating step of heating the substrate placed on the heating plate;
A separation step of separating the substrate from the heating plate;
With
The heating step is reversed immediately before the substrate is separated from the heating plate because the temperature elevation relationship between the first region and the second region immediately after the substrate is placed on the heating plate. A method of heat treatment characterized by heating the substrate. A heat treatment apparatus for heating a substrate placed on a heating plate,
Contact / separation means for moving the substrate up and down relatively with respect to the heating plate;
The amount of heat per unit area received by the substrate from the heating plate from the time when the substrate is placed on the heating plate and raised to the first temperature to the time when the substrate is lowered to the second temperature. Temperature control means for controlling the temperature of the heating plate so as to be uniform,
A heat treatment apparatus comprising: The heat treatment apparatus according to claim 5, wherein
The first temperature is a temperature at which a reaction of the treatment liquid applied to the substrate starts,
The heat treatment apparatus, wherein the second temperature is a temperature at which the reaction of the treatment liquid stops. In the heat treatment apparatus according to claim 5 or 6,
The heating plate is divided into a plurality of regions including at least a first region and a second region;
The temperature control means may be configured so that the temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate is immediately before the substrate is separated from the heating plate. A heat treatment apparatus that individually controls the temperatures of the plurality of regions so as to be reversed. A heat treatment apparatus for heating a substrate placed on a heating plate divided into a plurality of regions including at least a first region and a second region,
Contact / separation means for moving the substrate up and down relatively with respect to the heating plate;
The plurality of temperature reversals so that the temperature level relationship between the first region and the second region immediately after the substrate is placed on the heating plate is reversed immediately before the substrate is separated from the heating plate. Temperature control means for individually controlling the temperature of the area of
A heat treatment apparatus comprising:

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