JPWO2017061199A1 - Liquid processing apparatus, liquid processing method, and storage medium - Google Patents

Abstract

In supplying a processing liquid to the peripheral edge of a substrate along the periphery of the substrate, the width of a ring-shaped region to which the processing liquid is supplied is prevented from fluctuating from a set value.
A substrate holding unit, a processing liquid discharge nozzle for locally discharging a processing liquid to a peripheral edge of the substrate, and a substrate holding unit for supplying the processing liquid along the circumference of the substrate. A rotation mechanism that rotates the held substrate; a height position detection unit that detects the height position of the peripheral edge of the substrate held by the substrate holding unit along the circumference of the substrate; and The processing liquid discharge nozzle is moved relative to the substrate based on the detected height position of the peripheral edge of the substrate so that the discharge position is away from a predetermined distance from the edge of the substrate. And a moving mechanism. As a result, even if the peripheral heights of the portions of the substrate are different, fluctuations in the width of the ring-shaped region can be prevented.
[Selection] Figure 1

Description

  The present invention relates to a liquid processing apparatus, a liquid processing method, and a storage medium that supply a processing liquid to a peripheral portion of a substrate.

  In a photolithography process for forming a resist pattern on a semiconductor wafer (hereinafter referred to as a wafer) that is a substrate, various processing liquids are supplied to the wafer and liquid processing is performed. As one of the liquid processes, there is a case where a process of supplying a processing liquid in a ring shape along the circumference of the wafer is performed. As a specific example, a processing liquid is applied to a wafer having a coating film formed on the surface. There is an edge bead removal (EBR) process in which a solvent for the coating film is supplied to remove unnecessary coating films in a ring shape. In this EBR process, the solvent is locally discharged from the solvent discharge nozzle onto the peripheral edge of the wafer placed on the spin chuck and rotated.

In the EBR process, the accuracy of the position at which the solvent is discharged on the wafer is increased so that the width (cut width) of the ring-shaped region from which the coating film is removed becomes a set value, and the cut width at each part of the wafer It is required to increase the uniformity of the. By the way, a process for manufacturing a memory having a multilayer wiring structure called 3D NAND is expected to become popular in the future. In this process, a plurality of films having a relatively large film thickness are stacked on the surface of the wafer. Therefore, a relatively large warp occurs when a relatively large stress is applied from each film to a wafer that has been processed in the process. There is a fear. If the wafer is warped in such a manner when the spin chuck is mounted, the position at which the solvent is discharged on the wafer deviates from a preset position, and thus the cut width may deviate from the set value. . Further, as described in the embodiment of the invention as a saddle-shaped warp, there are cases where the peripheral portions of the wafer are warped so as to have different heights, and when such warpage occurs, The cut width varies in each part.

In Patent Document 1, the size of the wafer is detected by a sensor that optically detects the position in the horizontal direction of the edge of the wafer provided on the transfer arm of the wafer, and the EBR processing is performed based on the detection result. A technique for determining the position of a solvent discharge nozzle is shown. Further, Patent Document 2 shows that a CCD camera is used to image the solvent discharged from the solvent discharge nozzle to the peripheral edge of the wafer and scatter, and the solvent discharge nozzle is attached to the holder based on the imaging result. Has been. However, Patent Documents 1 and 2 do not describe a method of setting the cut width as a set value on the entire circumference of the wafer when the wafer is warped as described above.

JP 2012-222238 A JP 2008-183559 A

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a ring-shaped region to which the processing liquid is supplied when the processing liquid is supplied to the peripheral portion of the substrate along the periphery of the substrate. It is to provide a technique capable of preventing the width of the fluctuation from the set value.

The liquid processing apparatus of the present invention includes a substrate holding unit that holds a substrate,
A processing liquid discharge nozzle for locally discharging the processing liquid to the peripheral edge of the substrate;
A rotation mechanism for rotating the substrate held by the substrate holding unit to supply the processing liquid along the circumference of the substrate;
A height position detector for detecting the height position of the peripheral edge of the substrate held by the substrate holder along the circumference of the substrate;
Based on the detected height position of the peripheral edge of the substrate, the processing liquid discharge nozzle is moved with respect to the substrate such that the processing liquid discharge position leaves a predetermined distance from the edge of the substrate. A relatively moving mechanism;
It is provided with.

The liquid processing method of the present invention includes a step of holding a substrate in a substrate holding portion,
A treatment liquid discharge step of locally discharging the treatment liquid from the treatment liquid discharge nozzle to the peripheral edge of the substrate;
Rotating the substrate held by the substrate holder by a rotation mechanism to supply the processing liquid along the circumference of the substrate;
Detecting the height position of the peripheral portion of the substrate held by the substrate holding unit by the height position detecting unit along the circumference of the substrate;
Based on the detected height position of the peripheral edge of the substrate, the processing liquid discharge nozzle is moved by the moving mechanism so that the processing liquid discharge position leaves a predetermined distance from the edge of the substrate. Moving relative to
It is provided with.

The storage medium of the present invention is a storage medium storing a computer program used in the liquid processing apparatus,
A storage medium characterized in that the program includes steps for executing the liquid processing method of the present invention.

  According to the present invention, the height position detection unit that detects the height position of the peripheral portion of the substrate held by the substrate holding unit along the periphery of the substrate, and the detected height of the peripheral portion of the substrate And a moving mechanism for moving the processing liquid discharge nozzle relative to the substrate based on the position. Therefore, since the discharge position of the processing liquid at the peripheral edge of the substrate can be controlled with high accuracy, the width of the ring-shaped region to which the processing liquid is supplied can be controlled with high accuracy.

It is a vertical side view of the resist coating apparatus which concerns on embodiment of this invention. It is a top view of the said resist coating apparatus. It is a schematic perspective view of a wafer. It is a top view of a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a schematic perspective view of a wafer. It is a side view of the EBR nozzle provided in the said resist coating apparatus. It is a top view of a wafer. It is a graph which shows distribution of the height of the peripheral part of a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a schematic perspective view of a wafer. It is a schematic perspective view of a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a schematic perspective view of a wafer. It is a graph which shows distribution of the height of the peripheral part of a wafer. It is a graph which shows the area | region where a resist film is removed in a wafer. It is a side view of the EBR nozzle provided in the said resist coating apparatus. It is a top view of a wafer. It is a graph which shows the relationship between the discharge position of a thinner, and the error of the height of the peripheral part of a wafer. It is a graph which shows the relationship between the correction value of a discharge position, and the error of the height of the peripheral part of a wafer. It is a graph which shows the relationship between the correction value of an ejection position, and the position of the horizontal direction of the peripheral edge of a wafer. It is explanatory drawing which shows operation | movement of a resist coating apparatus. It is explanatory drawing which shows operation | movement of a resist coating apparatus. It is explanatory drawing which shows operation | movement of a resist coating apparatus. It is a graph which shows the position of the horizontal direction of the peripheral edge of a wafer. It is a graph which shows distribution of the error of the cut width resulting from the said position of the horizontal direction. It is a graph which shows distribution of the difference | error of the height of the peripheral part of a wafer. It is a graph which shows distribution of the error of the cut width resulting from the error of the height of the said peripheral part. It is a graph which shows distribution of the error of the height of the said peripheral part, and the error of the cut width resulting from the horizontal position of the peripheral edge of a wafer. 6 is a graph showing correction values for thinner discharge positions on the entire circumference of wafer B. FIG. It is explanatory drawing which shows the other structural example of the moving mechanism which moves an EBR nozzle. It is explanatory drawing which shows the other structural example of the said moving mechanism. It is explanatory drawing which shows the other structural example of the said moving mechanism.

  A resist coating apparatus 1 which is an embodiment of the liquid processing apparatus of the present invention will be described with reference to a longitudinal side view of FIG. 1 and a plan view of FIG. The resist coating apparatus 1 performs a process of forming a resist film by applying a resist to the wafer B, which is a substrate, and an EBR process of removing an unnecessary resist film on the peripheral edge of the wafer B after the resist film is formed. It is configured to be able to. The wafer B is circular, and a notch N is formed as a notch representing the direction of the wafer B at the peripheral edge. In this example, the diameter of the wafer B is 300 mm.

In the figure, reference numeral 11 denotes a spin chuck that forms a mounting portion for the wafer B, and sucks the center of the back surface of the wafer B in order to hold the wafer B horizontally. In FIG. 1, reference numeral 12 denotes a rotating mechanism that rotates the wafer B held by the spin chuck 11 clockwise along the vertical axis in plan view. In FIG. 1, reference numeral 11 </ b> A denotes a shaft that connects the spin chuck 11 serving as a substrate holder and the rotation mechanism 12, and reference numeral 13 denotes a cup that surrounds the wafer B held by the spin chuck 11. In the figure, reference numeral 14 denotes an exhaust pipe that exhausts the inside of the cup 13. Reference numeral 15 denotes a drainage pipe, which removes liquid spilled from the wafer B into the cup 13. In the figure, reference numeral 16 denotes an elevating pin, which is moved up and down by an elevating mechanism 17 to transfer the wafer B between a wafer B transfer mechanism (not shown) and the spin chuck 11.

In the figure, reference numeral 21 denotes a resist discharge nozzle, which is connected to a resist supply mechanism 23 that discharges the resist vertically downward and supplies the resist to the nozzle 21 through a flow path 22. In the figure, reference numeral 24 denotes a thinner discharge nozzle, which discharges a thinner, which is a resist solvent, vertically downward. The thinner discharge nozzle 24 is a nozzle used for pre-processing performed before applying a resist to the wafer B, and is connected to a thinner supply mechanism 26 that supplies thinner to the nozzle 24 via a flow path 25.

In the figure, reference numeral 31 denotes a thinner discharge nozzle used for performing the above-described EBR processing, and is referred to as an EBR nozzle in order to distinguish it from the above-described thinner discharge nozzle 24. The EBR nozzle 31 is a processing liquid discharge nozzle that locally discharges a thinner, which is a resist solvent, to the peripheral portion of the rotating wafer B and removes the resist film in a ring shape over the entire circumference of the wafer B. The EBR nozzle 31 discharges thinner, which is a processing liquid, obliquely downward from the center side to the peripheral side of the wafer B, so that the thinner is supplied to the wafer B at the thinner discharge position and outside the discharge position. The The thinner discharge position is the projection area of the discharge port of the EBR nozzle 31 onto the wafer B in the thinner discharge direction.

The thinner discharge position and discharge direction will be described in more detail. In FIG. 2, the discharge position of this thinner is shown as a point C1. A point C2 in FIG. 2 is an intersection of an extension line D1 of a thinner locus extending from the point C1 in the thinner discharge direction and the peripheral edge of the wafer B. The tangent line D2 of the wafer B at this point C2 and the extension line D1 of the above-mentioned thinner trajectory intersect.

Since the thinner is discharged in such a position and direction, and the EBR nozzle 31 is movable in the horizontal direction during the thinner discharge, the width of the ring-shaped region from which the resist film is removed (hereinafter, cut) Width may be described). Further, in order to suppress liquid splashing of the discharged thinner, the EBR nozzle 31 discharges thinner from the upstream side in the rotation direction of the wafer B toward the downstream side. The EBR nozzle 31 is connected to the above-described thinner supply mechanism 26 via the flow path 32, and thinner is supplied to the thinner discharge nozzle 24 and the EBR nozzle 31 independently from each other from the thinner supply mechanism 26.

In the figure, reference numeral 41 denotes an arm, and the resist discharge nozzle 21 and the thinner discharge nozzle 24 are supported on one end side of the arm 41. The other end side of the arm 41 is connected to the moving mechanism 42 shown in FIG. The arm 41 can be moved up and down and moved in the horizontal direction by the moving mechanism 42, and the movement of the arm 41 causes the nozzles 21 and 24 to move between the central portion of the wafer B and the standby area of the nozzle outside the cup 13. Can move. In the figure, reference numeral 43 denotes a guide for moving the moving mechanism 42 in the horizontal direction as described above.

  In the figure, 45 is an arm, and the EBR nozzle 31 is supported on one end side of the arm 45. The other end side of the arm 45 is connected to the moving mechanism 46. The arm 45 can be moved up and down and moved in the horizontal direction by the moving mechanism 46, and the movement of the arm 45 allows the EBR nozzle 31 to move between the wafer B and the standby area of the nozzle outside the cup 13. it can. In FIG. 2, the moving direction of the EBR nozzle 31 is shown as the Y direction, and the horizontal direction orthogonal to the Y direction is shown as the X direction. In the figure, 47 is a guide for moving the moving mechanism 46 in the horizontal direction as described above.

Below the peripheral edge of the wafer B held by the spin chuck 11, a height position detection sensor 18 that is a height position detection unit and a horizontal position detection sensor 19 that is a surface direction position detection unit are provided. These sensors 18 and 19 are provided close to each other, for example, as shown in FIG. 2, but for convenience of illustration, in FIG. 1, they are shown at positions separated from each other on the left and right of the spin chuck 11. The height position detection sensor 18 is constituted by, for example, a reflection type laser displacement meter, and a light projecting unit that projects laser light upward and a reflected light of the laser light reflected by the peripheral edge of the back surface of the wafer B. A light receiving portion for receiving light. The light receiving unit of the height position detection sensor 18 transmits a detection signal corresponding to the amount of received light to the control unit 2 described later. The controller 2 can detect the height of the peripheral edge of the wafer B where the laser beam is projected based on the amount of received light.

The horizontal position detection sensor 19 emits light upward in a radial direction of the wafer B from a position inside the peripheral edge of the wafer B in plan view to a position outside the peripheral edge. And a light receiving unit that receives light from the light projecting unit reflected by the peripheral portion of the back surface of the wafer B. The light receiving unit of the horizontal position detection sensor 19 transmits a detection signal corresponding to the amount of received light to the control unit 2 described later. Based on the amount of received light, the control unit 2 can detect the position of the peripheral edge of the wafer B in the length direction of the strip-shaped light. That is, the position of the peripheral edge of the wafer B in the surface direction of the wafer B, that is, the XY plane can be detected.

  Next, the control unit 2 will be described. The control unit 2 is composed of a computer, for example, and has a program storage unit (not shown). As will be described later, the program storage unit stores a program in which instructions (step groups) are set so that a resist coating process and an EBR process can be performed. And the operation of each part of the resist coating apparatus 1 is controlled by outputting a control signal from the control part 2 to each part of the resist coating apparatus 1 by the program. Specifically, the lifting / lowering pin 16 is lifted / lowered by the lifting / lowering mechanism 17, the nozzles 21 and 24 are moved by the moving mechanism 42, the EBR nozzle 31 is moved by the moving mechanism 46, the spin chuck 11 is rotated by the rotating mechanism 12, and the sensors 18 and 19. Each operation such as light irradiation is controlled. This program is stored in the program storage unit while being stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card.

The outline of the EBR process of the resist coating apparatus 1 will be described. Light is applied to the rotating wafer B from the height position detection sensor 18 and the horizontal position detection sensor 19, and the height of the peripheral edge on the entire circumference of the wafer B The position of the peripheral edge in the horizontal direction is detected. Then, while the thinner is being discharged onto the rotating wafer B, the EBR nozzle 31 is moved left and right based on the detection result to correct the thinner discharge position, and the resist film is removed in a ring shape.

  As described above, the EBR nozzle 31 is moved to the left and right during the thinner discharge because the thinner B discharge position on the wafer B may deviate from the set position when the position of the EBR nozzle 31 is fixed. This is because the cut width is made uniform over the entire circumference of the wafer B. In order to explain the reason why the EBR nozzle 31 is moved in more detail, each of the factors causing the thinner discharge position to shift and the EBR given by each factor when the thinner is discharged while the position of the EBR nozzle 31 is fixed. The effect on processing will be described. In this description, the set value of the cut width is 1.5 mm.

(Factor 1: Wafer B transfer error)
In order to make the cut width uniform over the entire circumference of the wafer B, the wafer B is placed on the spin chuck so that the center P of the wafer B placed on the spin chuck 11 is positioned on the rotation axis P1 of the spin chuck 11. 11 is mounted. However, for example, due to the limit of the operation accuracy of the transfer mechanism of the wafer B, the center P is shifted from the rotation axis P1 as shown in the perspective view of FIG. 3 and the plan view of FIG. May be placed. 4 shows an XY orthogonal coordinate system in which the origin overlaps the center P and the Y axis passes through the notch N in order to show the positional relationship between the center P and the rotation axis P1. Moreover, L1 in each figure has shown the locus | trajectory of the discharge position of the thinner from the EBR nozzle 31 in the rotating wafer B. Therefore, this locus L1 is the inner peripheral edge of the ring-shaped region from which the resist film is removed.

Since the center of the locus L1 of the thinner discharge position located on the rotation axis P1 is eccentric with respect to the center P of the wafer B, the thinner discharge position when viewed from the center P toward the periphery of the wafer B. The distance to the locus L1 (referred to as the EBR radius) varies depending on the position of the wafer B viewed in the circumferential direction. Also, in FIG. 4, the intersections of the extension line of the line passing through the center P and the rotation axis P1 and the locus L1 are shown as P2 and P3. In the locus L1, the point P2 is closest to the peripheral edge of the wafer B, and the point P3 is farthest from the peripheral edge of the wafer B.

The graph of FIG. 5 shows the relationship between the cut width when the wafer B is placed as shown in FIG. 4 and the position in the circumferential direction of the wafer B viewed from the center P. The width (unit: mm) and the position in the circumferential direction are set on the horizontal axis. Hereinafter, the cut width may be expressed as Wcut. Further, supplementing the horizontal axis of the graph, each position is shown in the range of 0 ° to 360 ° counterclockwise with the position of the notch N being 0 ° (= 360 °). As shown in the graph, the value on the vertical axis is displaced in a sine waveform with respect to the displacement on the horizontal axis. That is, the wafer P is placed on the spin chuck 11 with the center P and the rotation axis P1 shifted from each other, so that the cut width Wcut is not uniform in the circumferential direction of the wafer B.

(Factor 2: Inclination of wafer B with respect to rotation axis P1)
For example, the mounting surface of the wafer B on the spin chuck 11 is inclined with respect to the rotation axis P1 due to the limit of the molding accuracy of the spin chuck 11, and thereby the wafer B mounted on the spin chuck 11 as shown in FIG. May be inclined with respect to the rotation axis P1. In this case, a variation in height with respect to the spin chuck 11 occurs in each part of the wafer B in the circumferential direction. In FIG. 6, L <b> 2 is a horizontal plane that passes through the center of the surface of the spin chuck 11. Also, points Q1 to Q4 are shown on the locus L1 of the thinner discharge position. Here, for convenience of explanation, it is assumed that the thickness of the wafer B is 0 mm. The points Q1 and Q3 are located on the horizontal plane L2, the point Q2 is the lowest in the locus L1, and the point Q4 is the highest in the locus L1. FIG. 7 shows the positional relationship between the heights of the points Q1 to Q4 with respect to the EBR nozzle 31 as viewed from the side, and reference numeral 31A in the figure denotes a discharged thinner.

As described above, since the EBR nozzle 31 discharges the thinner obliquely from the inner side to the peripheral end side of the wafer B, each part corresponds to the variation in height between the EBR nozzle 31 of the wafer B and each part. The cutting width of fluctuates. FIG. 8 shows the positional relationship between the EBR nozzle 31 and the points Q1 to Q4 as viewed from above the wafer B. As shown in FIG. 8, the point Q4 is located closer to the center of the wafer B than the points Q1 and Q3, and the point Q2 is located closer to the peripheral edge of the wafer B than the points Q1 and Q3. The cut width is different between the point Q2 and the point Q4.

FIG. 9 is a graph showing the relationship between the orientation of the spin chuck 11 and the height of each position in the locus L1 of the thinner discharge position. The horizontal axis of the graph indicates the direction of the spin chuck 11 as a chuck angle in a range of 0 ° to 360 °, and the direction toward the notch N of the wafer B is 0 °, and every 90 ° counterclockwise in plan view. , 90 °, 180 °, and 270 °. Since it is set in this way, it can be said that the chuck angle represents the position of the wafer B in the circumferential direction. The vertical axis of the graph indicates the height error of each point of the locus L1 with respect to the horizontal plane L2 by ΔH (unit: mm), and is + when the point of the locus L1 is higher than L2, and − when it is lower. As shown in this graph, with respect to the displacement of the direction of the spin chuck 11, the height error ΔH is displaced so as to draw a sine waveform. The graph of FIG. 10 represents the relationship between the chuck angle and the cut width Wcut, the vertical axis of the graph shows the cut width Wcut (unit: mm), and the horizontal axis of the graph is the same as the graph of FIG. The chuck angle is shown. Since the height between the wafer B and the EBR nozzle 31 and the cut width Wcut correspond to each other as shown by the following equations, the waveform in the graph of FIG. 10 is also a sine waveform. Thus, even when the wafer B is tilted with respect to the rotation axis P 1, the cut width Wcut is not uniform in the circumferential direction of the wafer B.

(Factor 3: When wafer B warps in a mountain shape or a saddle shape)
The wafer B placed on the spin chuck 11 may be warped in a saddle shape as shown in FIG. 11 or warped in a mountain shape as shown in FIG. The warp shape warps so that the center portion of the wafer B is lower than the peripheral portion, and the warp shape warps so that the peripheral portion of the wafer B is higher than the center portion. It is warping. Further, as to the case of warping the chevron, the wafer B before being placed on the spin chuck 11 is already warped, and before being placed on the spin chuck 11, it is not so warped. When the wafer B is placed on the spin chuck 11, it may be warped as it is bent by its own weight. 11 and 12, the diameter of the warped wafer B is indicated by a dotted line.

For the wafer B warped in the saddle shape of FIG. 11, the graph of FIG. 13 shows the relationship between the chuck angle and the error ΔH of the height of the thinner discharge position in the same manner as the graph of FIG. Similar to the graph of FIG. 10, the relationship between the chuck angle and the cut width Wcut is shown. As shown in the graphs of FIGS. 13 and 14, the wafer B warped in a bowl shape has a smaller distance between the EBR nozzle 31 and the thinner discharge position on the entire circumference than the flat wafer B, and the cut width Wcut. Becomes larger than the set value. Further, for the wafer B warped in the mountain shape of FIG. 12, the relationship between the chuck angle and the error ΔH of the height of the thinner discharge position is shown in the graph of FIG. 15 as in the graph of FIG. As in the graph of FIG. 10, the relationship between the chuck angle and the cut width Wcut is shown. As shown in the graphs of FIGS. 15 and 16, in the wafer B warped in a mountain shape, the distance between the EBR nozzle 31 and the discharge position of the thinner is larger than the flat wafer B, and the cut width Wcut. Becomes smaller than the set value.

(Factor 4: When wafer B warps in a bowl shape)
The wafer B placed on the spin chuck 11 may be warped in a bowl shape due to the shape of the spin chuck 11 or the stress of the film described in the background art section. The warp shape is such that the diameters of the wafer B intersecting each other are the first diameter and the second diameter, so that both ends of the first diameter descend relatively large with respect to the center P of the wafer B. Warping is that there is no difference from the center P at both ends of the second diameter or the difference is relatively small. FIG. 17 shows the wafer B warped like that, and points on the locus L1 of the thinner discharge position are R1, R2, R3, and R4. Points R1 and R3 are points on the first diameter, and points R2 and R4 are points on the second diameter. Accordingly, the heights of the points R1 and R3 are lower than the heights of the points R2 and R4.

For the wafer B of FIG. 17, the graph of FIG. 18 shows the relationship between the chuck angle and the height error ΔH of the thinner discharge position in the same manner as the graph of FIG. 9, and the graph of FIG. Similarly, the relationship between the chuck angle and the cut width Wcut is shown. Since there are two relatively high positions and two relatively low positions in the surface of the wafer B, in the graphs of FIGS. 18 and 19, a sine wave is present in the range of the chuck angle of 0 ° to 360 °. The waveform has two cycles. In FIG. 17, the region surrounded by the thinner discharge position locus L1 is an ellipse. Thus, even when the wafer B is warped, the cut width Wcut is not uniform in the circumferential direction of the wafer B.
Even when one or a plurality of factors that cause the cut width Wcut described above to deviate from the set value occurs, the resist coating apparatus 1 performs the processing as described in the above outline so that the entire wafer B is processed. The cut width Wcut is controlled to be a set value around the circumference.

Incidentally, the relationship between the height of the peripheral edge of the wafer B detected by the height position detection sensor 18 and the correction value of the discharge position of the thinner is a side view of the EBR nozzle 31 and a plan view of the wafer B. FIG. 21 will be described respectively. When the angle of the EBR nozzle 31 with respect to the horizontal plane is θz and the set value of the height between the wafer B and the tip of the EBR nozzle 31 is H ₀ , the flying distance of the thinner 31A (the thinner 31A on the wafer B from the tip of the EBR nozzle 31). The distance L to the discharge position is expressed by the following formula 1. ΔH in Equation 1 is an error in the height of the thinner discharge position indicated by the vertical axis of the graph of FIG. 9 and the like, and is therefore an error with respect to the set value H ₀ . For the flying distance L, the length (described as a cut width component) in the moving direction (Y direction) of the EBR nozzle 31 is W. Further, if the angle formed by the thinner discharge direction of the EBR nozzle 31 and the X direction (horizontal direction orthogonal to the Y direction) is θx, the following Expression 2 is established.
L = (H ₀ −ΔH) / tan θz Equation 1
W = L × sin θx Equation 2

The cut width component W when the height between the surface of the wafer B and the tip of the EBR nozzle 31 is the set value H ₀ is W ₀ , and the error of the cut width component W due to the height error ΔH is ΔW And That is, this ΔW is an error in the thinner discharge position in the Y direction caused by ΔH. When the thinner discharge position moves from the set position to the inner side of the wafer B, the error ΔW is +, and the peripheral edge of the wafer B It is assumed that the error ΔW is − when moving to the side. When Equation 2 is transformed using W ₀ and W, Equation 3 below is established. Further, assuming that the correction value of the thinner ejection position in the Y direction is ΔWcor, since W−W0 = ΔWcor, Expression 4 is satisfied. It is assumed that ΔWcor is + when the thinner discharge position is moved inward of the wafer B with respect to the set position, and ΔWcor is − when the thinner discharge position is moved toward the peripheral end of the wafer B.
W = L × sin θx = (H ₀ −ΔH) × (sin θx / tan θz) = H ₀ × (sin θx / tan θz) −ΔH × (sin θx / tan θz) = W ₀ −ΔW Equation 3
ΔWcor = −ΔW Equation 4

The height position detection sensor 18 described above detects a value corresponding to the height error ΔH. Since H ₀ , θz, θx, and W _{0 in} each equation are known, a thinner discharge position error ΔW and a thinner discharge position correction value ΔWcor in the Y direction are calculated from the detected height error ΔH. be able to. FIG. 22 is a graph showing an example of the correspondence relationship between ΔH and ΔW obtained from the above equations, and the horizontal axis and the vertical axis indicate ΔH and ΔW, respectively. The unit of each axis of the graph is mm. For example, the correspondence shown in FIG. 22 is stored in the memory of the control unit 2 and is used to calculate the correction value ΔWcor as described later. Since ΔWcor = −ΔW as described above, the correspondence between the correction value ΔWcor and ΔH of the position of the EBR nozzle 31 corresponds to the graph of FIG. 22 and is represented by the graph of FIG. The horizontal axis of the graph of FIG. 23 is ΔH (unit: mm), and the vertical axis is ΔWcor (unit: mm).

The relationship between the detection result by the horizontal position detection sensor 19 and the thinner discharge position error ΔW in the Y direction and the thinner discharge position correction value ΔWcor will also be described. The graph of FIG. 24 shows the correspondence between the horizontal position of the peripheral edge of the wafer B detected by the horizontal position detection sensor 19 and the thinner discharge position correction value ΔWcor. Supplementing the horizontal axis of the graph, the detected peripheral end position of the wafer B is expressed as a distance R (unit: mm) to the rotation axis P1 of the spin chuck 11. The vertical axis represents ΔWcor (unit: mm). Since the diameter of the wafer B is 300 mm, the set value of the distance R is 150 mm. When an error with respect to this set value is ΔR, ΔR = ΔW. Since ΔW = −ΔWcor as shown in Equation 4 above, ΔR = −ΔWcor, and this relationship is shown in the graph.

Next, the resist coating process and the EBR process will be described with reference to FIGS. 25 to 27 showing the operation of each part of the resist coating apparatus 1. The wafer B is transferred onto the spin chuck 11 by the transfer mechanism and placed on the spin chuck 11. The thinner is discharged from the thinner discharge nozzle 24 onto the central portion of the wafer B, the wafer B starts to rotate (time t1), and the thinner is applied to the entire surface of the wafer B by centrifugal force. Improves wettability. Thereafter, the resist is discharged from the resist discharge nozzle 21 onto the center of the wafer B, and the resist is applied to the entire surface of the wafer B by centrifugal force, whereby the resist film 30 is formed.

Light irradiation is started from the horizontal position detection sensor 19 and the height position detection sensor 18 to the rotating wafer B at an arbitrary timing after the above-described time t1 (FIG. 25). Stops. Based on the detection signal output from the horizontal position detection sensor 19, the position of the notch N and the distance R from the rotation axis P1 to the peripheral end of the entire circumference of the wafer B are detected. The graph of FIG. 28 shows the detection result of the distance R, and the horizontal axis of the graph is set with the chuck angle described in FIG. 9, and the vertical axis is the distance R.

As described with reference to FIG. 24, since the error ΔR with respect to the set value of the distance R = the error ΔW of the cut width, based on the error ΔR in the entire circumference of the wafer B as shown in the graph of FIG. The cut width Wcut (referred to as Wcut1) and the cut width error ΔW (referred to as ΔWcut1) can be acquired without the cut width, that is, the height error ΔH. In the graph of FIG. 29, the horizontal axis and the vertical axis indicate the chuck angle and the cut width Wcut1 (unit: mm), respectively.

Further, the graph of FIG. 30 shows the detection result by the height position detection sensor 18, and the horizontal axis and the vertical axis of the graph indicate the chuck angle and the height error ΔH, respectively. According to this detection result and the correspondence relationship between the height error ΔH and the cut width error ΔW described in FIG. 22, the cut width based on the error ΔH in the entire circumference of the wafer B as shown in the graph of FIG. In other words, the cut width Wcut (referred to as Wcut2) and the cut width error ΔW (referred to as ΔWcut2) that have no error ΔR are acquired. The horizontal axis and vertical axis of the graph of FIG. 31 are the chuck angle and the cut width Wcut2 (unit: mm), respectively.

  Then, ΔWcut1 and ΔWcut2 at the same position of the chuck angle are summed to obtain a cut width error ΔWcut based on ΔR and ΔH. The graph of FIG. 32 represents the cut width error ΔWcut on the entire circumference of the wafer B. More specifically, the vertical axis represents the cut width Wcut which is the sum of the acquired cut width error ΔWcut and the set value of the cut width, and the horizontal axis represents the chuck angle. When the cut width error ΔWcut for the entire circumference of the wafer B is obtained in this way, the correction value ΔWcor for the thinner discharge position for the entire circumference of the wafer B shown in the graph of FIG. The The vertical axis and horizontal axis of the graph indicate the correction value ΔWcor (unit: mm) and the chuck angle, respectively.

Thereafter, the position of the EBR nozzle 31 is corrected from the set position based on the acquired correction value ΔWcor, the thinner is discharged from the EBR nozzle 31 at a position where the cut width Wcut becomes the set value, and outside the discharge position. The resist film 30 is removed (FIG. 26). The rotation of the wafer B and the discharge of the thinner are continued, and the EBR nozzle 31 is moved based on the correction value ΔWcor so that the cut width Wcut becomes the set value, and the resist film 30 is removed along the circumferential direction of the wafer B. (FIG. 27). When the thinner is supplied to the entire circumference of the wafer B and the resist film is removed in a ring shape, the discharge of the thinner from the EBR nozzle 31 is stopped, and then the rotation of the wafer B is stopped. B is unloaded from the resist coating apparatus 1.

According to the resist coating apparatus 1, the height position detection sensor 18 that detects the height position of the peripheral portion of the wafer B held by the spin chuck 11 along the circumference of the wafer B is provided. The position of the EBR nozzle 31 that is discharging the thinner is adjusted by the moving mechanism 46 based on the detection result using 18. Therefore, the cut width Wcut can be controlled with high accuracy over the entire circumference of the wafer B. Further, the resist coating apparatus 1 is provided with a horizontal position detection sensor 19 for detecting the position of the peripheral edge of the wafer B in the horizontal direction, and the position of the EBR nozzle 31 is controlled based on the detection result by the sensor 18. Therefore, the cut width Wcut can be controlled with higher accuracy.

Although the apparatus for supplying the thinner for removing the resist film to the wafer B as the processing liquid has been shown, the present invention is not limited to such an apparatus. For example, a liquid that discharges a chemical solution for forming a coating film such as a resist to the rotating wafer B as a processing liquid from a nozzle configured to be able to locally supply the processing liquid to the peripheral edge of the wafer B as in the EBR nozzle 31. It can be applied to a processing apparatus. In that case, the width of the coating film formed in a ring shape can be controlled with high accuracy over the entire circumference of the wafer B.

In the resist coating apparatus 1, in order to control the discharge position of the thinner on the wafer B, instead of moving the EBR nozzle 31 relative to the rotation mechanism 12 and the spin chuck 11, the rotation mechanism 12 and the spin chuck 11 are moved in the horizontal direction. A moving mechanism for moving the thinner may be provided to control the discharge position of the thinner. Further, in the above processing, the period during which light is applied to the wafer B by the sensors 18 and 19 and the period during which the thinner is discharged do not overlap, but the processing may be performed so that these periods overlap. Specifically, with respect to the peripheral portion of the wafer B, assuming that the downstream side in the rotational direction is the first peripheral region and the upstream side in the rotational direction is the second peripheral region, first, light from the sensors 18 and 19 enters the first peripheral region. As described above, the height position of the first peripheral region and the position in the horizontal direction are detected as described above. As the wafer B rotates, the region irradiated with light moves to the second peripheral region, and the thinner is discharged from the EBR nozzle 31 to the first peripheral region that has moved to a position where the thinner can be discharged. Then, the resist film is removed. That is, the thinner is supplied to the region irradiated with the light before the wafer B rotates once after the light is irradiated from the sensors 18 and 19. By performing processing in this way, throughput can be improved.

Further, in the above example, the thinner discharge position is controlled by the movement of the EBR nozzle 31 in the Y direction. However, as shown in FIG. 34, the moving mechanism 46 is configured to move the EBR nozzle 31 in the X direction. The thinner discharge position may be controlled by the movement in the X direction. In the example shown in FIG. 35, the base end of the arm 45 is connected to the rotation mechanism 51 so that the EBR nozzle 31 can rotate around the rotation axis of the rotation mechanism 51. By this rotation, the direction of the EBR nozzle 31, that is, the discharge direction of the thinner is changed, and the discharge position of the thinner is controlled. Further, as shown in FIG. 36, the discharge position of the thinner may be controlled by moving the EBR nozzle 31 in the vertical direction by the moving mechanism 46. In the example of FIG. 36, the EBR nozzle 31 is raised and lowered with respect to the wafer B. However, a raising and lowering mechanism for raising and lowering the rotating mechanism 12 and the spin chuck 11 may be provided to raise and lower the wafer B with respect to the EBR nozzle 31.

For the wafer B on which a coating film is formed in an external apparatus, the apparatus 1 can perform EBR processing of the coating film. That is, the device 1 may be configured as a dedicated device that performs only EBR processing. Further, the discharge of thinner from the EBR nozzle 31 and the movement of the EBR nozzle 31 are not limited to being performed in parallel, and the discharge and movement may be alternately repeated. In that case, the rotation of the wafer B is stopped during the discharge of the thinner. That is, the wafer B is intermittently rotated. By the way, the embodiments described above can be combined with each other. Specifically, for example, in order to control the discharge position of the thinner, both the height of the EBR nozzle 31 and the position in the Y direction may be adjusted.

B Wafer 1 Resist coating device 11 Spin chuck 12 Rotation mechanism 18 Height position detection sensor 19 Horizontal position detection sensor 2 Control unit 31 EBR nozzle 46 Movement mechanism

Claims (9)

A substrate holder for holding the substrate;
A processing liquid discharge nozzle for locally discharging the processing liquid to the peripheral edge of the substrate;
A rotation mechanism for rotating the substrate held by the substrate holding unit to supply the processing liquid along the circumference of the substrate;
A height position detector for detecting the height position of the peripheral edge of the substrate held by the substrate holder along the circumference of the substrate;
Based on the detected height position of the peripheral edge of the substrate, the processing liquid discharge nozzle is moved with respect to the substrate such that the processing liquid discharge position leaves a predetermined distance from the edge of the substrate. A relatively moving mechanism;
A liquid processing apparatus comprising: A surface direction position detection unit that detects the position in the surface direction of the end portion of the substrate held by the substrate holding unit along the circumference of the substrate,
The liquid processing apparatus according to claim 1, wherein the moving mechanism moves the processing liquid discharge nozzle relative to the substrate based on the detected position in the surface direction of the end portion of the substrate. The substrate is circular;
The processing liquid discharge nozzle is provided in a plan view so that an extension line of the processing liquid discharged to the substrate intersects with a tangent line at an intersection of the extension line with an end portion of the substrate. The liquid processing apparatus according to claim 1. The liquid processing apparatus according to claim 1, wherein the moving mechanism moves the processing liquid discharge nozzle in a horizontal direction with respect to the substrate. The liquid processing apparatus according to claim 1, wherein the moving mechanism is configured to change a height of the processing liquid discharge nozzle with respect to the substrate. The liquid processing apparatus according to claim 1, wherein the moving mechanism moves the processing liquid discharge nozzle so that a discharge direction of the processing liquid is changed. A step of holding the substrate in the substrate holding portion;
A treatment liquid discharge step of locally discharging the treatment liquid from the treatment liquid discharge nozzle to the peripheral edge of the substrate;
Rotating the substrate held by the substrate holder by a rotation mechanism to supply the processing liquid along the circumference of the substrate;
Detecting the height position of the peripheral portion of the substrate held by the substrate holding unit by the height position detecting unit along the circumference of the substrate;
Based on the detected height position of the peripheral edge of the substrate, the processing liquid discharge nozzle is moved by the moving mechanism so that the processing liquid discharge position leaves a predetermined distance from the edge of the substrate. Moving relative to
A liquid treatment method comprising: A step of detecting the position in the surface direction of the end portion of the substrate held by the substrate holding unit by the surface direction position detection unit along the circumference of the substrate;
The moving step includes
The liquid processing according to claim 7, further comprising a step of moving the processing liquid supply unit relative to the substrate based on the detected position in the surface direction of the end portion of the substrate by the moving mechanism. Method. A storage medium storing a computer program used in a liquid processing apparatus,
A storage medium characterized in that the program includes steps for executing the liquid processing method according to claim 7.

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