JP2012119536A - Coating device, coating method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology which ensures high in-plane uniformity in the thickness of a coating film formed on a substrate by spin coating.SOLUTION: The in-plane film thickness distribution of a wafer W is determined according to a processing recipe including the type of resist liquid and the transition pattern of the number of revolutions of the wafer W. Coating of the wafer W with resist by using the processing recipe not including irradiation by means of an LED 41 is performed previously, and the in-plane film thickness distribution of the wafer W is determined. A recess 8 in the in-plane film thickness distribution of the wafer W is grasped in advance, and the position of the recess 8 in the film thickness distribution is irradiated by means of the LED 41 and that part on the wafer W is heated locally.

Description

  The present invention relates to a technique for forming a coating film on a substrate by rotating the substrate and spreading the coating solution.

  In the photolithography process in the semiconductor device manufacturing process, a resist coating process, an exposure process, a development process, and the like are sequentially performed on the substrate, whereby a predetermined resist pattern is formed on the substrate. Among these, in the resist coating process, for example, a spin coating method is generally used in which the substrate is first rotated, the resist solution is supplied to the center of the rotating substrate, and the resist solution is spread over the entire surface of the substrate by centrifugal force. Has been done.

  In recent years, there is an increasing demand for reducing the amount of resist used for reasons such as cost reduction. However, if the amount of resist used is suppressed, the thickness of the resist film formed on the substrate tends to be non-uniform. Therefore, in each semiconductor manufacturer, transition pattern of substrate rotation speed (so-called rotation speed profile), resist discharge conditions such as resist discharge speed, cool plate temperature before coating processing (substrate temperature before coating processing), resist temperature, etc. We are trying to improve the film thickness uniformity of the resist film by examining the adjustment of the resist and the type of resist. However, since the circuit pattern is becoming finer, higher in-plane uniformity is required for the film thickness, and in addition, further resist savings are required, and the development of a method that satisfies both is desired. Yes.

  Patent Document 1 describes heating of a substrate by light irradiation in a coating process, but this is for the purpose of shortening the drying time of the resist when the resist amount is sufficient, and the problem of the present invention is described. Not.

Japanese Patent Laid-Open No. 2005-322791

  The present invention has been made under such a background, and an object of the present invention is to provide a technique capable of obtaining high in-plane uniformity with respect to the thickness of a coating film formed on a substrate in a spin coating method. is there.

The coating apparatus of the present invention is
In the coating apparatus that spreads the coating liquid supplied from the coating nozzle to the center of the substrate and spreads it on the surface of the substrate by the centrifugal force caused by the rotation of the substrate,
A holding unit for holding the substrate horizontally;
A rotation mechanism for rotating the holding portion around a vertical axis;
A radiation source for locally irradiating the substrate with radiation light having an absorption wavelength region of the substrate material;
A storage unit that stores the processing recipe including the transition pattern of the type of coating liquid and the number of rotations of the substrate and the irradiation information for specifying the irradiation position of the radiation light in the radial direction of the substrate,
The irradiation information corresponding to the selected processing recipe is read, and based on the read irradiation information, the coating liquid is applied to the entire surface of the substrate at the irradiation position specified by the irradiation information, and the coating liquid is dried. A control unit that outputs a control signal so as to irradiate radiation light locally from the radiation source in a time zone including a period in which there is no state, and
The irradiation position corresponds to a position where the film thickness distribution profile in the surface of the substrate becomes concave when the coating film is formed without irradiating radiation light based on the processing recipe.

Other coating apparatuses of the present invention are:
In the coating apparatus that spreads the coating liquid supplied from the coating nozzle to the center of the substrate and spreads it on the surface of the substrate by the centrifugal force caused by the rotation of the substrate,
A holding unit for holding the substrate horizontally;
A rotation mechanism for rotating the holding portion around a vertical axis;
A radiation source for locally irradiating a specific position of the substrate with radiation light having an absorption wavelength region of the material of the substrate from above the substrate,
The specific position is a position where the in-plane film thickness distribution profile becomes concave when the coating film is formed without irradiating radiation.

Other coating methods of the present invention include:
A step of holding the substrate horizontally on the holding portion;
Rotating the holding unit and supplying a coating solution to the center of the substrate, and spreading the coating solution on the surface of the substrate by centrifugal force;
The processing recipe including the transition pattern of the type of coating liquid and the number of rotations of the substrate and the irradiation information for specifying the irradiation position of the radiation light in the radial direction of the substrate are selected from the storage unit stored in association with each other. Reading the irradiation information according to the processing recipe;
Based on the read irradiation information, the substrate is in a time zone including a period in which the coating liquid is applied to the entire surface of the substrate and the coating liquid is not dried at the irradiation position specified by the irradiation information. Irradiating with radiant light having the absorption wavelength range of the material locally,
The irradiation position corresponds to a position where the in-plane film thickness distribution profile becomes concave when the coating film is formed without irradiating radiation light based on the processing recipe.

Moreover, the coating method of the present invention comprises:
A step of holding the substrate horizontally on the holding portion;
Rotating the holding unit and supplying a coating solution to the center of the substrate, and spreading the coating solution on the surface of the substrate by centrifugal force;
At a specific position of the substrate, the substrate is irradiated with radiation light having an absorption wavelength region of the substrate material in a time zone including a period in which the coating solution is applied to the entire surface of the substrate and the coating solution is not dried. Irradiating locally from above, and
The specific position is a position where the in-plane film thickness distribution profile becomes concave when the coating film is formed without irradiating radiation.

The storage medium in the present invention is
A storage medium storing a computer program used in a coating apparatus for coating a substrate with a coating liquid,
The computer program is for carrying out the above-described coating method.

  The present invention recognizes in advance the position where the film thickness distribution profile in the surface of the substrate determined according to the processing recipe including the transition pattern of the type of coating liquid and the number of rotations of the substrate, and corresponds to the position. The position of the substrate to be irradiated is irradiated with radiation light locally. Therefore, since the coating liquid at the position is locally heated to increase the film thickness, high in-plane uniformity can be obtained with respect to the film thickness of the coating film.

  In another invention, radiation light is locally irradiated from above the substrate to a concave position in the in-plane film thickness distribution profile. Therefore, high in-plane uniformity can be obtained in the same manner with respect to the thickness of the coating film.

It is sectional drawing which shows the resist coating device which concerns on embodiment of this invention. It is a top view which shows the said coating device. It is a block diagram explaining the top view which shows arrangement | positioning of LED in the said heating part, a control system, and a process recipe. It is a vertical side view explaining the relationship between the processing recipe which concerns on embodiment of this invention, and film thickness distribution. It is a flowchart of the coating process which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the rotation speed of the board | substrate which concerns on embodiment of this invention. It is a film thickness distribution figure explaining the effect | action which concerns on embodiment of this invention. It is a top view which shows the example of LED arrangement | positioning which concerns on other embodiment in this invention. It is a perspective view which shows the moving mechanism of LED which concerns on 2nd Embodiment in this invention. It is a perspective view which shows LED irradiation which concerns on the said 2nd Embodiment. It is a top view which shows the moving mechanism of LED which concerns on 3rd Embodiment in this invention. It is a side view which shows the outline | summary of the moving mechanism of LED which concerns on the said 3rd Embodiment. It is a scatter diagram which shows the influence on the film thickness distribution profile by LED irradiation which concerns on Example 1 in this invention. It is a scatter diagram which shows the influence on the film thickness distribution profile by continuous irradiation of LED which concerns on Example 2 in this invention.

  As a coating apparatus according to the first embodiment of the present invention, a resist coating apparatus will be described with reference to FIGS. 1 and 2 show a longitudinal side surface and a transverse plane of the apparatus, respectively. Reference numeral 1 in FIG. 1 denotes a housing. The housing 1 includes a loading / unloading port 11 for a wafer W that is opened and closed by a shutter 12. Yes. Note that the positions of the loading / unloading port 11 and the shutter 12 in FIG. 1 are changed to the positions in FIG. 2 for easy understanding of the illustrated contents. A fan filter unit (FFU) 13 for forming a downward air flow and a first exhaust port 15 for sucking and exhausting the atmosphere are provided at the top and bottom of the housing 1, respectively. In addition, 14 in FIG. 1 is an intake port.

  A spin chuck 2 serving as a substrate holding unit is provided in the housing 1. The spin chuck 2 is configured to hold the wafer W horizontally by vacuum suction, and can be rotated about a vertical direction by a rotation driving unit 21 which is a rotation mechanism including a rotation motor. A guide ring 31 is provided below the spin chuck 2. The guide ring 31 is inclined so as to be lowered from the horizontal position corresponding to the peripheral edge of the wafer W held by the spin chuck 2 toward the outer peripheral side, and the outer peripheral edge of the guide ring 31 is bent downward. It extends. A cup 3 surrounding the spin chuck 2 and the guide ring 31 is provided around the spin chuck 2.

  In the cup 3, a gap 32 that forms a discharge path is formed between the side peripheral surface and the outer peripheral edge of the guide ring 31. The lower side of the cup 3 forms a curved path together with the outer peripheral edge portion of the guide ring 31 to constitute a gas-liquid separation part. A second exhaust port 33 is formed in the inner region of the bottom of the cup 3. Further, a drain port 34 is formed in the outer region of the bottom of the cup 3.

  Three lifting pins (not shown) are provided in the housing 1 so as to be movable up and down at positions surrounding the spin chuck 2. The transfer of the wafer W between the spin chuck 2 and a transfer arm (not shown) that is provided outside the housing 1 and carries the wafer W in / out via the loading / unloading port 11 is performed via the lift pins. The transfer of the wafer W between the transfer arm and the spin chuck 2 may be performed by moving the spin chuck 2 up and down by a lifting mechanism (not shown).

  A heating unit 4 including a large number of radiation sources 41 is provided at a position corresponding to the lower side of the wafer W held by the spin chuck 2. In this embodiment, as shown in FIG. 3, a large number of LEDs (light emitting diodes) 41 that are concentric circles are arranged so as to surround the spin chuck 2. The LED 41 emits infrared light that is an absorption wavelength band of silicon that is a material of the wafer W (substrate material). For this reason, the wafer W can be locally heated by locally irradiating infrared rays in the radial direction of the wafer W toward the back surface of the wafer W held by the spin chuck 2. In this example, the corresponding LEDs 41 on each concentric circle form a row in the radial direction of the wafer W, and are arranged radially as a whole.

  These LED 41 can be turned on / off for each group of LEDs 41 concentrically divided by a lighting controller 55 to be described later if the LED group positioned for each concentric circle is called an LED group. Radiation intensity, that is, emission intensity can be controlled by adjusting the value. In the present application, the region of the wafer W to be heated, more specifically, the irradiation region of the LED 41, will be referred to as regions P1, P2,. Since these regions P1 to Pn correspond to the groups of LEDs 41 arranged in the respective concentric circles, the groups of LEDs 41 corresponding to the regions P1 to Pn on the wafer W side are also respectively referred to as P1 to Pn in order to simplify the description. The sign of is used. A cooling jacket 42 is provided below the LED 41 so that the temperature of the LED 41 itself does not rise excessively even if the LED 41 is frequently turned on. The temperature adjustment water that flows through the cooling jacket 42 uses, for example, temperature adjustment water for adjusting the motor flange temperature of the rotation drive unit 21.

  In addition, the resist coating apparatus includes a resist solution nozzle 6 that is a coating solution nozzle for supplying a resist solution to the center portion of the wafer W surface and a solvent nozzle 7 for supplying a solvent such as thinner to the center portion of the wafer W surface. I have. The thinner is supplied to perform a prewetting process that improves the wetting and spreading of the resist solution on the wafer W. The resist solution nozzle 6 is connected to a resist solution supply source 62 via a resist solution supply pipe 61 and a supply device group including a valve and a flow rate adjusting unit (not shown). The solvent nozzle 7 is connected to a solvent supply source 72 via a supply device group including a solvent supply pipe 71 and a valve and a flow rate adjusting unit (not shown).

  The resist solution nozzle 6 is connected to a moving mechanism 64 via an arm 63 extending in the horizontal direction as shown in FIG. The arm 63 extends from a standby position 65 provided on the outer side of one end side (left side in FIG. 2) of the cup 3 toward the other end side along a guide rail 60 provided along the lateral direction by the moving mechanism 64. It is configured so that it can move and move vertically. The solvent nozzle 7 is connected to a moving mechanism 74 through an arm 73 that extends in the horizontal direction in the same manner as the resist solution nozzle 6. The arm 73 can be moved from the standby position 75 provided on the outer side of the other end side (right side in FIG. 2) of the cup 3 along the guide rail 60 toward the one end side along the guide rail 60 and can move in the vertical direction. It is configured as follows.

  In addition, the resist coating apparatus includes a control unit 5 including a computer for controlling a series of operations of the apparatus described later. As shown in FIG. 3, the control unit 5 includes a program 51, a CPU 53, a recipe storage unit 54, an input unit 56, and a bus 50 connecting them. The program 51 includes a group of steps for controlling operations of the rotation drive unit 21, the supply device group, the LED 41, and the like. The recipe storage unit 54 that is a storage unit stores a processing recipe for the coating process.

  This processing recipe is data in which information for setting parameters necessary for performing the coating process is written, and there is a processing recipe for each coating process. FIG. 3 schematically shows a state in which n recipes 1 to n are stored in a recipe storage unit 54 that is a storage unit. Parameters include resist type, rotation speed transition pattern (profile), resist discharge amount, resist discharge timing, exhaust amount in the cup, solvent discharge amount for prewetting, solvent discharge timing, etc. In this example, the lighting area of the LED 41 is also described.

The transition pattern of the rotational speed indicates the relationship between each time and the rotational speed of the substrate, that is, the temporal transition of the rotational speed of the substrate, based on the reference time, for example, the time when the wafer W is held on the spin chuck 2. Data (for example, see FIG. 6 described later).
The lighting region of the LED 41 is an irradiation region by the LED 41 among the regions P1 to Pn on the wafer W side assigned to each group of the LED 41 corresponding to each concentric circle as described above, that is, in the group of the LED 41, the lighting is performed. This is an area (group) to be turned on. For example, the process recipe 1 is set to P3 to P6, the process recipe 2 is set to P4 to P7, and the process recipe n is set to Pk to P (k + 3). The setting of the lighting area of the LED 41 is determined as follows. A resist solution is applied to the wafer W in advance using a processing recipe that does not include the irradiation of the LED 41, and then the wafer W is loaded into a heating device and subjected to heat treatment. The film thickness distribution profile (hereinafter simply referred to as film thickness distribution) is obtained. And the area | region corresponding to the site | part (part where a film thickness becomes small) which becomes concave in this film thickness distribution is selected from area | regions P1-Pn.

  Here, before describing the reason for locally irradiating the wafer W by the LED 41, the reason why a concave portion occurs in the film thickness distribution will be described. The reason for this is speculation, but is considered as follows. In the case of the spin coating method, since the centrifugal force acting on the resist solution in the central portion of the wafer W is small, the film thickness is considered to be large, but at the peripheral portion of the wafer W, the centrifugal force acting on the resist solution is large. . However, on the other hand, it is considered that the resist solution is highly concentrated in the process in which the resist solution diffuses from the central portion to the peripheral portion. It is considered that one of the causes that the film thickness is increased at the peripheral portion is that the influence of the higher concentration of the resist solution is larger than the influence of the centrifugal force.

  Therefore, when the LED 41 is irradiated, the wafer temperature in the irradiated region is locally increased. As a result, the volatilization of the solvent contained in the resist solution in the irradiated region is promoted, and the concentration of the resist solution in the irradiated region is changed to other regions. It becomes higher than the concentration of a certain resist solution. Since the high-concentration resist solution has a high viscosity, even if the wafer W rotates at a relatively high speed, it becomes difficult to move in the peripheral direction, so that the film thickness in the irradiated region increases. On the other hand, the resist solution is shaken off at the periphery of the wafer W while the movement of the resist solution moving from the radial direction is reduced. As a result, it is considered that the film thickness in the periphery of the wafer W decreases as the film thickness in the irradiation region increases.

  For this reason, a region for heating the concave portion is obtained from the regions P1 to Pn divided in the radial direction of the wafer W, and the region is set as the lighting region of the LED 41 corresponding to the processing recipe. ing. The larger the number of LEDs 41 in the radial direction of the wafer W, the higher the resolution of the irradiation region, so that the concave portion can be locally heated with high accuracy. From the above, the lighting region (for example, P3 to P6) of the LED 41 corresponds to the irradiation information for specifying the irradiation position of the radiation light in the radial direction of the wafer W.

  An example of the relationship between the processing recipe and the lighting area of the LED 41 will be described. The resist solution 200 supplied to the central portion of the wafer W is less likely to diffuse in the peripheral direction of the wafer W because the centrifugal force in addition to its viscosity is smaller than that on the peripheral side. In addition, the resist solution 200 that has reached the vicinity of the periphery has a greater centrifugal force that acts closer to the periphery, and therefore the resist solution 200 tends to gather near the periphery. Therefore, when looking at the film thickness distribution profile in the radial direction of the wafer W, the film thickness of the central portion and the peripheral portion of the wafer W is large, and there is a tendency that the concave portion 8 is formed therebetween. As shown in FIG. 4, when the viscosity of the resist solution 200 is high, the concave portion 8 tends to be closer to the central portion side of the wafer W. Conversely, when the viscosity of the resist solution 200 is low, the concave portion 8 of the film thickness distribution profile tends to be closer to the peripheral side of the wafer W. For this reason, the lighting region of the LED 41 is closer to the center of the wafer W as the viscosity of the resist solution 200 is higher. The relationship between the viscosity of the resist solution 200, which is one of the processing recipe items, and the lighting region of the LED 41 has been described above. Other items in the processing recipe, such as the number of rotations of the wafer W and the discharge of the resist solution 200, are described. Regarding the time, the lower the rotation speed of the wafer W or the shorter the discharge time of the resist solution 200, the closer the lighting area of the LED 41 is to the center of the wafer W.

  In this example, an area in which the LED 41 is turned on is set in the processing recipe. However, when the wafer W is locally heated by the LED 41, heat is also conducted to the neighboring area. For example, for the areas P3 to P6, the intensity of the LED 41 is set to the maximum, and for P2 and P7 adjacent to the areas P3 to P6, the intensity of the LED 41 is made smaller than the maximum, and as a result the area to be heated as much as possible It may be devised to heat only. As described above, the number of the LEDs 41 shown in FIG. 3 and the number of the regions P3 to P6 are for convenience, so in practice, the LED 41 is slightly increased in the region where the intensity of the LED 41 is maximized or in the vicinity of the region. The number of regions in which the intensity of light is reduced is determined depending on the number of LEDs 41 arranged, the shape of the film thickness distribution, and the like.

  The program 51 and the processing recipe are stored in a storage medium such as a flexible disk (FD), a memory card, a compact disk (CD), a magnetic optical desk (MO), or a hard disk and installed in the control unit 5. The control unit 5 controls the operation of the apparatus according to the program 51 based on the processing recipe installed in the recipe storage unit 54.

  Next, the effect | action in the above-mentioned embodiment is demonstrated, referring FIGS. FIG. 5 is a schematic diagram for explaining the operational flow of the present embodiment, FIG. 6 is a graph showing a temporal transition pattern of the rotational speed of the wafer W at that time, and FIG. 7 is a wafer at the LED 41 in the present embodiment. It is the schematic based on the experimental result for demonstrating the film thickness uniformity by the heating of W. Before the operation described below is executed, for example, a processing recipe is selected from the input unit 56 by an operator, and the program reads the contents of the processing recipe and sequentially executes the steps corresponding to the contents. . First, the shutter 12 at the loading / unloading port 11 provided in the housing 1 is opened, and the wafer W is loaded into the housing 1 by a transfer arm (not shown), and is sucked and held by the spin chuck 2 via a lifting pin (not shown). The Next, after the solvent nozzle 7 located at the standby position 75 is moved to a substantially central portion above the wafer W by the moving mechanism 74, the thinner 100 is supplied to the wafer W from the solvent nozzle 7 (FIG. 5A and FIG. 6 solvent supply step S1).

  Thereafter, the wafer W is rotated by the spin chuck 2 at a rotational speed V1 of, for example, 500 rpm, the thinner 100 on the wafer W is diffused over the entire surface of the wafer W, and the entire surface of the wafer W is wetted by the thinner 100 ( FIG. 5B and FIG. 6 solvent diffusion step S2). During this time, the solvent nozzle 7 is retracted from the wafer W to the original standby position 75, and the resist solution nozzle 6 at the standby position 65 is moved to a substantially upper center portion of the wafer W by the moving mechanism 64. Then, the discharge of the resist solution 200 from the resist solution nozzle 6 onto the wafer W is started, and the resist solution 200 is supplied to the central portion of the wafer W (FIG. 5C). At this time, the rotation speed of the wafer W is increased from V1 to a high speed V2, for example, 2000 to 4000 rpm. The acceleration in the rotation of the wafer W is gradually accelerated so that the rotation speed continuously and smoothly fluctuates from the rotation speed V1. In other words, the rotational acceleration of the wafer W gradually increases from zero, for example.

  Then, when the rotational speed of the wafer W approaches V2, the rotational acceleration is gradually decreased, and the rotational speed of the wafer W is smoothly converged to V2. In this way, the rotation speed of the wafer W is changed from V1 to V2 so as to change in an S shape on the graph of FIG. The resist solution 200 is discharged while the rotational speed changes in an S-shape, and the resist solution 200 supplied to the central portion of the wafer W is diffused over the entire surface of the wafer W by centrifugal force (FIG. 6 in resist solution coating step S3).

  After the discharge (supply) of the resist solution 200 is completed, the rotation speed is reduced from V2 to a low speed of, for example, 300 rpm V3, and the resist solution 200 diffused on the wafer W is roughly leveled and flattened (FIG. 5 ( d) and the flattening step S4) in FIG. It should be noted that the timing when the rotation speed starts to decrease from V2 to V3 and the timing of stopping the discharge of the resist solution 200 may be simultaneous. This flattening step S4 is performed for about 1 second, for example. At the end of the flattening step S4, the film thickness distribution profile of the resist solution 200 on the wafer W is roughly flattened, but as shown in the upper diagrams of FIGS. In this state, the concave portion 8 can be seen on the surface. Next, the wafer W is accelerated to a medium rotational speed V4, for example, about 1500 rpm, and the resist solution 200 on the wafer W is dried (drying step S5 in FIG. 6).

  This drying step S5 is performed for about 20 seconds, for example, and simultaneously with the start of this drying step S5, the radiant heating of the wafer W by the heating unit 4 is started. That is, the program 51 of the control unit 5 reads the lighting area of the LED 41 written in the already selected processing recipe and outputs it to the lighting controller 55. The lighting controller 55 turns on the group of LEDs 41 for the designated lighting area, for example, P4 to P7 in FIG. Thereby, infrared rays are irradiated from the LED 41 in the lighting region toward the wafer W, and the irradiated region in the wafer W is locally heated to a predetermined temperature, for example, 30 ° C. to 40 ° C. (FIG. 5E). As a result, as described above, the resist solution 200 stays in this region against the centrifugal force in the irradiation region, and the resist that moves from the central portion of the wafer W at the peripheral portion of the wafer W correspondingly. The amount of liquid 200 decreases. In this way, the film thickness increases in the irradiated region and conversely decreases in the peripheral portion of the wafer W, so that the thickness of the resist film finally obtained after the drying step S5 becomes uniform (FIG. Figure 7 below). In this way, a resist film having a high in-plane film thickness uniformity is formed on the surface of the wafer W. After the drying of the wafer W is completed, the rotation of the wafer W is stopped, and the wafer W is unloaded from the spin chuck 2 via a lift pin and a transfer arm (not shown) to the outside of the housing 1 to complete a series of resist coating processes.

  In the above-described embodiment, as described above, the transition pattern of the viscosity of the resist solution and the rotation speed of the wafer W corresponds to the position of the recess 8 in the film thickness distribution in the plane of the wafer W. The coating process is carried out with a focus on the fact that the film thickness increases if the resist is heated while it is fluid. That is, a resist coating process is performed on the wafer W in advance using a processing recipe that does not include the irradiation of the LED 41, the film thickness distribution in the surface of the wafer W is obtained, and the LED 41 is irradiated to the position of the recess 8 in the film thickness distribution. The part is heated locally. Therefore, since the thickness of the resist film at the portion corresponding to the concave portion 8 tends to increase, high in-plane uniformity can be obtained with respect to the thickness of the resist film.

  In the above-described embodiment, the information on the lighting area of the LED 41 that is irradiation information is written in association with the processing recipe in a storage area different from the storage area that stores the processing recipe. When selected, the irradiation information may be read from the storage area.

  Moreover, in the above-mentioned embodiment, although irradiation by LED41 is started simultaneously with the start of drying process S5, the timing of irradiation of LED41 in this invention is not limited to this. The irradiation of the LED 41 may be started, for example, before the resist solution is discharged, when the resist solution is diffused on the wafer W, or during the planarization step S4. Moreover, the timing of completion | finish of irradiation of LED41 may be during drying process S5, and may be after completion | finish of drying process S5. That is, the timing at which the LED 41 irradiates the wafer W may be a time zone including a period in which the resist solution is applied to the entire surface of the wafer W and the resist solution is not dried.

Further, another example of the arrangement position of the LEDs 41 constituting the heating unit 4 is shown in FIG.
In FIG. 8A, the LEDs 41 are arranged in one line in the radial direction of the wafer W at one location.
In FIG. 8B, two rows of LEDs 41 arranged in the radial direction of the wafer W are arranged with a 180 ° shift in the circumferential direction of the wafer W.
In FIG. 8C, four rows of LEDs 41 arranged in the radial direction of the wafer W are arranged so as to be shifted from each other by 90 ° in the circumferential direction of the wafer W.
In FIG. 8D, the rows of the LEDs 41 are arranged at a plurality of locations in the circumferential direction of the wafer W, for example, at four locations as shown in FIG. 8C. The rows of LEDs 41 are set so that the concentric zones where the LEDs 41 are placed and the concentric zones where the LEDs 41 in the other row are placed overlap in the radial direction of the wafer W.

  In the above-described embodiment, the formation of the resist film is described. However, the present invention is not limited to this. For example, the wafer W may be heated by applying a chemical solution in which a precursor of the SiO 2 film is dissolved to the wafer W. This includes the case where a SiO2 film is formed thereon.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 9 shows a moving mechanism 9 that moves the resist solution nozzle 6, and this moving mechanism 9 is movable along a guide rail 60 extending in the X direction, and is movable up and down with respect to the column 94. And a horizontally extending arm 91. A resist solution nozzle 6 is attached to the tip of the arm 91. In this embodiment, the LED 41 is attached downward to the arm 91 at a position spaced apart from the resist solution nozzle 6 in the X direction. Accordingly, when the support column 94 moves along the guide rail 60, the irradiation area of the LED 41 moves along the diameter of the wafer W.
In the previous embodiment, the lighting area is set as the irradiation information according to the processing recipe, but in this embodiment, the irradiation information is written in the processing recipe as the stop position of the support column 94, that is, the arm 91 in the X direction. .

FIG. 10 is a diagram showing a state in which the wafer W is locally irradiated by the LED 41, and the irradiation timing is the same as that of the previous embodiment. In FIG. 10, for convenience, an example in which one LED 41 is provided on the arm 91 is described. However, a plurality of LEDs 41 are arranged in the X direction, and the LEDs 41 are arranged according to the width dimension of the recess 8 in the film thickness distribution described above. An appropriate number of LEDs 41 may be lit from the group. Alternatively, the LED 41 may be moved by reciprocating once or twice or more in the region corresponding to the recess 8 with the LED 41 turned on.
Further, the LED 41 may be attached to an arm provided with the solvent nozzle 7 instead of being attached to the arm for the resist solution nozzle 6, and a separate moving mechanism such as shown in FIG. You may provide in the same movement mechanism.

  According to such an embodiment, in addition to the effect of the previous embodiment, there is an advantage that the region of the adsorption portion of the wafer W by the spin chuck 2 can be heated. Further, in this embodiment, since the LEDs 41 are movable with respect to the radial direction of the wafer W, the number of LEDs 41 to be used can be suppressed.

A third embodiment of the present invention will be described with reference to FIGS. In addition, the description here is abbreviate | omitted about the part of a structure and an effect | action similar to 1st Embodiment. As shown in FIG. 11, the resist coating apparatus in this embodiment is provided with an arm 91 that is a part of a moving mechanism 9 that extends from the center of the wafer W in a direction orthogonal to the guide rail 60. As shown in FIG. 12, a large number of LEDs 41 are arranged in a row in the radial direction of the wafer W so as to face the surface of the wafer W from the center to the peripheral edge of the wafer 91. It has been. The arm 91 can move horizontally along the guide rail 60 via the support column 94. The LED 41 is connected to the lighting controller 55, and on / off control is performed for each lighting region via the lighting controller 55. As in the first embodiment, the LED 41 to be lit according to the processing recipe is determined. Selected.
When irradiating with the LED 41, the arm 91 moves to the center position of the wafer W after the resist solution nozzle 6 starts moving toward the standby position 65. Then, infrared irradiation is performed from the LED 41 to the irradiation region on the wafer W based on the irradiation information.

  Also in such an embodiment, the same effect as the previous embodiment can be obtained. In this embodiment, a large number of LEDs 41 are arranged in a row in the radial direction of the wafer W so as to face the surface of the wafer W under the arm 63 of the resist solution nozzle 6 or the arm 73 of the solvent nozzle 7. It may be done. In the present invention, the wafer W may be heated from above and below in combination with the first embodiment and the second or third embodiment.

Then, the Example performed in order to confirm the effect of irradiation by LED41 in this invention is described.
[Example 1]
In FIG. 13, when a resist solution is applied to a wafer W having a diameter of 300 mm, irradiation is performed by the LED 41 as in the first embodiment described above, and the current value applied to the LED 41 at that time, that is, the irradiation intensity of the LED 41 is determined. The result of having measured the change of the film thickness distribution profile as a parameter is shown. The experimental conditions at this time are that the temperature of the LED 41 itself before irradiation is 25 ° C. (room temperature), the irradiation time is 5 seconds, and the LED irradiation position is 65 mm to 90 mm in the radial direction from the center of the wafer W. Moreover, although the current value of LED41 which is a parameter in this experiment was set to 0 mA, 50 mA, 75 mA, 100 mA, 150 mA and 200 mA, it was measured in FIG. Only 200 mA is shown.
As shown in FIG. 13, the larger the current value of the LED 41, the greater the film thickness of the resist film at the irradiation position. From this, it was confirmed that the film thickness of the resist film could be controlled by irradiation with the LED 41, and that the increase amount of the film thickness at the irradiation position could be adjusted by adjusting the irradiation intensity of the LED 41.

[Example 2]
In the present embodiment, as in the first embodiment described above, the resist coating process with irradiation by the LEDs 41 is continuously performed on 10 wafers W, and the stability of the coating process during that time (reproducibility of the film thickness distribution profile) is performed. Confirmed. In particular, when the wafer W is continuously processed, the LED 41 emits light more frequently, and therefore the LED temperature is expected to rise and thereby affect the film thickness distribution profile. Therefore, the LED temperature immediately after the end of the coating process is also measured. did. The experimental conditions of this example are: the temperature of the LED 41 itself before irradiation is 25 ° C. (room temperature), the irradiation time is 5 seconds, the applied current value to the LED 41 is 100 mA, and the LED irradiation position is the diameter from the center of the wafer W. The distance in the direction is 65 mm to 90 mm. FIG. 14 shows the film thickness difference in the film thickness distribution profile when LED irradiation is performed with respect to the film thickness distribution profile when LED irradiation is not performed for all 10 wafers W at that time. .
In FIG. 14, the film thickness difference for all 10 wafers is plotted for each measurement position in the radial direction of the wafer W. The film thickness difference between the wafers W at each measurement position is plotted in the radial direction of the wafer W. It is within about 1 nm at any position in. This value is equivalent to the maximum film thickness difference in the film thickness distribution profile (a plot where the LED current value is 0 mA in FIG. 13) in one wafer W that is not irradiated with LED, and the film thickness at the irradiation position by LED irradiation. Is smaller than the maximum increase amount. Further, the temperature of the LED 41 had risen to 40 ° C. at the time when the final 10th wafer W was coated. Therefore, the possibility that the film thickness distribution profile changes during continuous processing of the wafer W in the coating process is low, and when the LED temperature is at least 40 ° C. or less, the film thickness increase amount due to the temperature rise of the LED 41 is low. There is little change.

W Wafers P1 to Pn Each group of LEDs and irradiation area 1 of the group 1 Case 2 Spin chuck 3 Cup 4 Heating part 41 LED
42 Cooling Jacket 5 Control Unit 54 Recipe Storage Unit 6 Resist Liquid Nozzle 7 Solvent Nozzle 8 Recessed Part 9 in Film Thickness Distribution Profile LED Movement Mechanism in Second and Third Embodiments

Claims (14)

In the coating apparatus that spreads the coating liquid supplied from the coating nozzle to the center of the substrate and spreads it on the surface of the substrate by the centrifugal force caused by the rotation of the substrate,
A holding unit for holding the substrate horizontally;
A rotation mechanism for rotating the holding portion around a vertical axis;
A radiation source for locally irradiating the substrate with radiation light having an absorption wavelength region of the substrate material;
A storage unit that stores the processing recipe including the transition pattern of the type of coating liquid and the number of rotations of the substrate and the irradiation information for specifying the irradiation position of the radiation light in the radial direction of the substrate,
The irradiation information corresponding to the selected processing recipe is read, and based on the read irradiation information, the coating liquid is applied to the entire surface of the substrate at the irradiation position specified by the irradiation information, and the coating liquid is dried. A control unit that outputs a control signal so as to irradiate radiation light locally from the radiation source in a time zone including a period in which there is no state, and
The said irradiation position respond | corresponds to the position where the film thickness distribution profile in the surface of a board | substrate becomes concave shape, when a coating film is formed without irradiating radiation light based on a process recipe . A large number of the radiation sources are arranged in the radial direction of the substrate,
The coating apparatus according to claim 1, wherein the irradiation information is information for specifying a plurality of radiation sources that are a part of a large number of radiation sources. In the coating apparatus that spreads the coating liquid supplied from the coating nozzle to the center of the substrate and spreads it on the surface of the substrate by the centrifugal force caused by the rotation of the substrate,
A holding unit for holding the substrate horizontally;
A rotation mechanism for rotating the holding portion around a vertical axis;
A radiation source for locally irradiating a specific position of the substrate with radiation light having an absorption wavelength region of the material of the substrate from above the substrate,
The coating apparatus according to claim 1, wherein the specific position is a position where the in-plane film thickness distribution profile becomes concave when the coating film is formed without irradiating radiation.   A control signal for locally irradiating the substrate with radiation light from the radiation source in a time period including a period in which the coating liquid is applied to the entire surface of the substrate and the coating liquid is not dried. The coating apparatus according to claim 3, further comprising a control unit that outputs   5. The coating apparatus according to claim 3, wherein the radiation source is provided on a moving member that is movable in a radial direction of the substrate.   5. The coating according to claim 1, wherein the control unit outputs a control signal so as to irradiate the substrate with radiation light from a radiation source after the coating liquid spreads over the entire substrate. apparatus.   The coating apparatus according to claim 1, wherein the radiation source is a light emitting diode. A step of holding the substrate horizontally on the holding portion;
Rotating the holding unit and supplying a coating solution to the center of the substrate, and spreading the coating solution on the surface of the substrate by centrifugal force;
The processing recipe including the transition pattern of the type of coating liquid and the number of rotations of the substrate and the irradiation information for specifying the irradiation position of the radiation light in the radial direction of the substrate are selected from the storage unit stored in association with each other. Reading the irradiation information according to the processing recipe;
Based on the read irradiation information, the substrate is in a time zone including a period in which the coating liquid is applied to the entire surface of the substrate and the coating liquid is not dried at the irradiation position specified by the irradiation information. Irradiating with radiant light having the absorption wavelength range of the material locally,
The said irradiation position respond | corresponds to the position where the film thickness distribution profile in the surface of a board | substrate becomes concave shape, when a coating film is formed without irradiating radiation light based on a process recipe. Radiation of radiant light is performed using a radiation source arranged in a large number in the radial direction of the substrate,
9. The coating method according to claim 8, wherein the irradiation information is information for specifying a plurality of radiation sources that are a part of a large number of radiation sources. A step of holding the substrate horizontally on the holding portion;
Rotating the holding unit and supplying a coating solution to the center of the substrate, and spreading the coating solution on the surface of the substrate by centrifugal force;
At a specific position of the substrate, the substrate is irradiated with radiation light having an absorption wavelength region of the substrate material in a time zone including a period in which the coating solution is applied to the entire surface of the substrate and the coating solution is not dried. Irradiating locally from above, and
The coating method according to claim 1, wherein the specific position is a position where the in-plane film thickness distribution profile becomes concave when the coating film is formed without irradiating radiation.   The coating method according to claim 10, wherein the irradiation of the radiation light is performed by a radiation source provided to be movable in a radial direction of the substrate.   12. The coating method according to claim 8, wherein the irradiation of the substrate with the radiant light starts after the coating liquid spreads over the entire substrate.   The coating method according to any one of claims 8 to 12, wherein the radiation source for irradiating the radiation light is a light emitting diode. A storage medium storing a computer program used in a coating apparatus for coating a substrate with a coating liquid,
A storage medium characterized in that the computer program is for carrying out the coating method according to any one of claims 8 to 13.

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