JP2017073566A - Liquid-processing device, liquid-processing method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a liquid process on a rotating substrate at a high level of in-plane uniformity while reducing the temperature difference between the center of the substrate and a peripheral edge side thereof in supplying a process liquid to the substrate from a nozzle to perform the process.SOLUTION: In a liquid-processing method, an etchant is discharged while moving a main nozzle 411A of a main nozzle part 30a by a nozzle moving mechanism between a first position that allows the etchant to reach the center of a substrate W and a second position on the side of a peripheral edge of the substrate W with respect to the first position on condition that the substrate W held by a substrate holding part 30 is being rotated. When discharging the etchant toward the substrate W from a sub-nozzle 411B of sub-nozzle part 40b set at a third position on the side of the peripheral edge of the substrate with respect to the first position, the second position is set at a point which makes its distance from the center of the substrate equal to or shorter than the that of the third position.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for performing liquid processing on a substrate by supplying a processing liquid from a nozzle while rotating the substrate held by a substrate holding unit.

  Known as liquid processing for semiconductor substrates are processing for etching by supplying an etching solution, processing for cleaning by supplying a cleaning solution, processing for forming a coating film by supplying a solution containing a plating solution or a precursor of an insulating film, etc. It has been. As one of the methods for performing such liquid processing, the substrate is held and rotated by the substrate holder, the processing liquid is supplied from the nozzle to the center of the substrate, and the processing liquid is fed to the entire surface of the substrate by the centrifugal force of the substrate. There are known methods for extending the above.

  Depending on the type of liquid processing, the processing result depends on the temperature distribution on the surface of the substrate.For example, in the case of etching processing, the etching rate on the surface of the substrate becomes non-uniform in the surface due to the temperature distribution, and the device yield. There is a concern that will contribute to the decline. For this reason, when supplying a process liquid from a nozzle to a board | substrate, the technique which raises the uniformity of the temperature distribution in the surface of a board | substrate is desired.

  In Patent Document 1, in a method of supplying a plating solution to a rotating substrate, a first nozzle and a second nozzle passing through a position closer to the center of the substrate than the first nozzle are used. A method is described in which the temperature of the discharged plating solution is set higher than the temperature of the plating solution discharged from the second nozzle. However, this method is not a sufficient method when a fairly high uniformity is required for the in-plane temperature distribution of the substrate.

JP 2013-10994 A (paragraphs 0010, 0112 and FIG. 17)

  The present invention has been made under such circumstances, and an object of the present invention is to perform processing between a central side and a peripheral side of a substrate when a processing liquid is supplied from a nozzle to a rotating substrate. It is an object of the present invention to provide a technique capable of suppressing the temperature difference between the two and performing a highly uniform process in the plane of the substrate.

A liquid processing apparatus according to a first aspect of the present invention includes a substrate holding unit for holding a substrate horizontally,
A rotation mechanism for rotating the substrate holder around the vertical axis;
A main nozzle for supplying a treatment liquid to the surface of the substrate held by the substrate holding unit;
The main nozzle is reciprocated between a first position where the discharged processing liquid passes through the center of the substrate and a second position on the peripheral side of the substrate with respect to the first position, and between the upper side of the substrate and the standby position. A nozzle moving mechanism for moving with,
A sub nozzle that discharges the processing liquid to a third position on the peripheral side of the substrate from the first position,
The discharge flow rate of the processing liquid of the sub nozzle is set to be larger than the discharge flow rate of the processing liquid of the main nozzle,
The third position is set to a position that is larger than 180 degrees in the rotation direction by an opening angle of 270 degrees or less from the processing liquid ejection position on the substrate at the main nozzle as viewed from the center of the substrate. It is characterized by this.
Further, the liquid processing apparatus according to the second invention includes a substrate holding unit for holding the substrate horizontally,
A rotation mechanism for rotating the substrate holder around the vertical axis;
A main nozzle for supplying a treatment liquid in a continuous flow state to the surface of the substrate held by the substrate holding unit;
The main nozzle is reciprocated between a first position where the discharged processing liquid passes through the center of the substrate and a second position on the peripheral side of the substrate with respect to the first position, and between the upper side of the substrate and the standby position. A nozzle moving mechanism for moving with,
A sub-nozzle that discharges the processing liquid in a continuous flow state to a third position, which is a preset fixed position on the peripheral side of the substrate from the first position,
The discharge flow rate of the processing liquid of the sub nozzle is set to be larger than the discharge flow rate of the processing liquid of the main nozzle,
The second position is characterized in that the distance from the center of the substrate is the same as the third position or a position where the distance from the center of the substrate is shorter than the third position.

The liquid processing apparatus may have the following configuration.
(A) In the first invention, the distance from the center of the substrate at the third position is the same as the distance from the center of the substrate at the second position.
(B) The difference between the maximum value and the minimum value of the substrate temperature from the central part to the peripheral part of the substrate is within 1.5 ° C. Further, assuming that the maximum value of the temperature of the substrate from the center portion to the peripheral portion of the substrate is Max and the minimum value is Min,
[(Max−Min) / {(Max + Min) / 2}] × 100 ≦ 5.0%.
(C) The second position is located closer to the center than a position closer to the center of 45 mm from the periphery of the substrate.

  According to the present invention, the temperature difference between the center side and the peripheral side of the substrate is suppressed, and processing with high uniformity can be performed in the plane of the substrate.

It is a top view which shows the outline | summary of the substrate processing system provided with the processing unit which concerns on embodiment of this invention. It is a vertical side view which shows the outline | summary of the said processing unit. It is an enlarged view of the vicinity region of the wafer held by the holding unit. It is a top view of the processing unit. It is explanatory drawing which shows the change of the in-plane temperature distribution of a wafer by the difference in the discharge position of etching liquid. It is explanatory drawing which shows the flow of the process liquid discharged from a main nozzle and a sub nozzle. It is a top view which shows the relationship between the movement range of a main nozzle, and the arrangement position of a sub nozzle. It is a top view which shows the relationship between the modification of the movement path | route of a main nozzle, and the arrangement position of a sub nozzle. It is explanatory drawing which shows the relationship between the discharge method of etching liquid, and the temperature distribution of a wafer. It is explanatory drawing which shows the relationship between the movement range of a main nozzle, and the temperature distribution of a wafer.

  FIG. 1 is a diagram showing a schematic configuration of a substrate processing system according to the present embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis that are orthogonal to each other are defined, and the positive direction of the Z axis is the vertically upward direction.

  As shown in FIG. 1, the substrate processing system 1 includes a carry-in / out station 2 and a processing station 3. The carry-in / out station 2 and the processing station 3 are provided adjacent to each other.

  The carry-in / out station 2 includes a carrier placement unit 11 and a transport unit 12. A plurality of carriers C that accommodate a plurality of substrates, in this embodiment a semiconductor wafer (hereinafter referred to as a wafer W) in a horizontal state, are placed on the carrier placement unit 11.

  The transport unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 inside. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device 13 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the carrier C and the delivery unit 14 using the wafer holding mechanism. Do.

  The processing station 3 is provided adjacent to the transfer unit 12. The processing station 3 includes a transport unit 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on the transport unit 15.

  The transport unit 15 includes a substrate transport device 17 inside. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. Further, the substrate transfer device 17 can move in the horizontal direction and the vertical direction and can turn around the vertical axis, and transfers the wafer W between the delivery unit 14 and the processing unit 16 using a wafer holding mechanism. I do.

  The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17.

  Further, the substrate processing system 1 includes a control device 4. The control device 4 is a computer, for example, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores a program for controlling various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19.

  Such a program may be recorded on a computer-readable storage medium, and may be installed in the storage unit 19 of the control device 4 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and receives the taken-out wafer W. Place on the transfer section 14. The wafer W placed on the delivery unit 14 is taken out from the delivery unit 14 by the substrate transfer device 17 of the processing station 3 and carried into the processing unit 16.

  The wafer W loaded into the processing unit 16 is processed by the processing unit 16, then unloaded from the processing unit 16 by the substrate transfer device 17, and placed on the delivery unit 14. Then, the processed wafer W placed on the delivery unit 14 is returned to the carrier C of the carrier platform 11 by the substrate transfer device 13.

  As shown in FIG. 2, the processing unit 16 includes a chamber 20, a substrate holding mechanism 30, a processing fluid supply unit 40, and a recovery cup 50.

  The chamber 20 accommodates the substrate holding mechanism 30, the processing fluid supply unit 40, and the recovery cup 50. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20. The FFU 21 forms a down flow in the chamber 20.

  The substrate holding mechanism 30 includes a holding unit 31, a support unit 32, and a driving unit 33. The holding unit 31 holds the wafer W horizontally. The support | pillar part 32 is a member extended in a perpendicular direction, a base end part is rotatably supported by the drive part 33, and supports the holding | maintenance part 31 horizontally in a front-end | tip part. The drive unit 33 rotates the column unit 32 around the vertical axis. The substrate holding mechanism 30 rotates the support unit 32 by rotating the support unit 32 using the drive unit 33, thereby rotating the wafer W held by the support unit 31. .

  The processing fluid supply unit 40 supplies a processing fluid to the wafer W. The processing fluid supply unit 40 is connected to a processing fluid supply source 70.

  The collection cup 50 is disposed so as to surround the holding unit 31, and collects the processing liquid scattered from the wafer W by the rotation of the holding unit 31. A drain port 51 is formed at the bottom of the recovery cup 50, and the processing liquid collected by the recovery cup 50 is discharged from the drain port 51 to the outside of the processing unit 16. Further, an exhaust port 52 for discharging the gas supplied from the FFU 21 to the outside of the processing unit 16 is formed at the bottom of the recovery cup 50.

The processing unit 16 whose schematic configuration has been described above corresponds to the liquid processing apparatus of the present embodiment. When the processing unit 16 supplies the processing liquid to the surface of the wafer W, the processing unit 16 suppresses the difference ΔT between the maximum value and the minimum value of the temperature in the wafer W surface within 1.5 ° C., for example, within 1 ° C. The liquid processing is performed using the types of nozzle portions 40a and 40b (corresponding to the processing fluid supply portion 40 shown in FIG. 2).
Hereinafter, referring to FIGS. 3 to 7, the processing unit 16 is supplied with an organic etching solution to a metal film formed on the surface of the wafer W in a wiring process of a semiconductor device, for example, and unnecessary metal is peeled off. A case where the etching unit is configured as an etching unit for removing foreign substances will be described as an example.

  FIG. 3 is an enlarged view schematically showing a region near the wafer W held by the holding unit 31 of the processing unit 16 shown in FIG. As shown in this figure, the processing unit 16 includes a main nozzle portion 40a for supplying an etching solution to the entire surface of the wafer W, and a temperature distribution formed in the surface of the wafer W by the etching solution supplied from the main nozzle portion 40a. A sub-nozzle portion 40b.

  The main nozzle portion 40a has a structure in which an etching nozzle 411A that supplies an etching solution to the wafer W and a rinse nozzle 412A that supplies a rinsing solution such as DIW (DeIonized Water) are provided on a common nozzle head 41A. ing. As shown in FIGS. 3 and 6, these nozzles 411A and 412A discharge each processing solution (etching solution and rinsing solution) linearly downward (the same applies to the sub nozzle portion 40b).

  As shown in FIG. 4, the nozzle head 41 </ b> A of the main nozzle portion 40 a is provided at the tip of a nozzle arm 42 </ b> A extending along the wafer W held by the holding portion 31, and is on the upper surface (surface to be processed) of the wafer W. Arranged on the upper side. The base end portion of the nozzle arm 42A is supported by a slider 43 that can run on the guide rail 44. By moving the slider 43 on the guide rail 44, an area from the center side to the peripheral side of the wafer W can be obtained. Thus, the main nozzle portion 40a can be freely moved in the lateral direction along the radial direction of the wafer W. The main nozzle portion 40a can also move to a standby position where the wafer W is retracted from the upper side to the side. The guide rail 44, the slider 43, the nozzle arm 42A, and the nozzle head 41A correspond to the nozzle moving mechanism of the etching nozzle 411A provided in the main nozzle portion 40a. As shown in FIG. 8 described later, the guide rail 44 may be configured to be movable in the vertical direction in order to move the slider 43 in a curved shape.

  On the other hand, the sub-nozzle portion 40b also has a structure in which an etching nozzle 411B that supplies an etching solution to the wafer W and a rinsing nozzle 412B that supplies a rinsing solution are provided in a common nozzle head 41B. This is the same as the main nozzle portion 40a.

  The nozzle head 41 </ b> B of the sub-nozzle part 40 b is provided at the tip of a nozzle arm 42 </ b> B extending along the wafer W held by the holding part 31 and is arranged on the upper side of the wafer W. As shown in FIG. 4, the base end of the nozzle arm 42 </ b> B is supported by a rotating shaft 45 that is rotatable by a drive unit 46, and a predetermined processing position on the peripheral side of the wafer W (shown by a solid line in FIG. 4). And a standby position (shown by a broken line in the figure) retracted from the upper side of the wafer W to the side. The drive unit 46, the nozzle arm 42B, and the nozzle head 41B correspond to a nozzle moving mechanism that is separate from the main nozzle unit 40a side of the etching nozzle 411B provided in the sub nozzle unit 40b.

  The etching nozzles 411A and 411B of the main nozzle portion 40a and the sub nozzle portion 40b are supplied with an etching solution supply source 701 (corresponding to the processing solution fluid supply source 70 in FIG. 2) via the nozzle heads 41A and B and the nozzle arms 42A and 42B. It is connected to the. The etchant supply source 701 is provided with a reservoir (not shown) that stores the etchant and a temperature controller (not shown) such as a heater that adjusts the temperature of the etchant in the reservoir, and the temperature is 20 to 70 ° C. In this range, for example, an etching solution adjusted to 50 ° C. can be supplied to the etching nozzles 411A and 411B. At the outlet of the etching solution supply source 701, flow rate adjusting units 71a and 71b for adjusting the flow rate of the etching solution fed to the etching nozzles 411A and 411B are provided.

Further, the rinse nozzle 412 of the main nozzle section 40a and the sub nozzle section 40b also has a rinse liquid supply source 702 (corresponding to the processing liquid fluid supply source 70 in FIG. 2) provided with a storage section (not shown) for storing the rinse liquid. )It is connected to the. From the rinse liquid supply source 702, the rinse liquid whose flow rate is adjusted by the flow rate adjusting units 71c and 71d can be supplied.
Control of the flow rate of the etching liquid and the rinsing liquid, the temperature adjustment of the etching liquid, and the movement operation of the main nozzle portion 40a and the sub nozzle portion 40b are controlled by the control device 4 described above.

The main nozzle portion 40a and the sub nozzle portion 40b having the above-described configuration discharge the etching solution from the etching nozzles 411A and 411B at different positions with respect to the wafer W, so that the wafer W during the etching process is discharged. The in-plane temperature distribution can be adjusted uniformly. Hereinafter, a method for setting the discharge position of the etching solution from each of the etching nozzles 411A and 411B in order to make the in-plane temperature distribution of the wafer W uniform will be described with reference to FIG.
Further, for convenience of explanation, in the following explanation, the discharge of the etching liquid from the etching nozzles 411A and B of the main nozzle section 40a and the sub nozzle section 40b is referred to as “discharge of the etching liquid from the main nozzle section 40a and the sub nozzle section 40b”. Also called.

FIG. 5 schematically shows how the in-plane temperature distribution of the wafer W changes when the discharge position of the etching solution is changed. The horizontal axis in FIG. 5 indicates the radial position of the surface of the wafer W from the center (C) to the peripheral edge (E), and the vertical axis indicates the temperature of the wafer W at each position.
In FIG. 5, a curve (indicated by a thin solid line) with the number (1) is a predetermined temperature (for example, FIG. 5) from one etching nozzle 411A to the central region of the wafer W including the center C. 4 shows the in-plane temperature of the wafer W when the etching liquid adjusted to 50 ° C. in the example of the etching liquid supply source 701 is discharged.

  As shown in the in-plane temperature distribution of (1), when the etching solution is discharged only to the central region of the wafer W, the temperature of the etching solution decreases as the surface of the rotating wafer W expands. The temperature of W gradually decreases from the center side toward the peripheral side. If this temperature change is large, the result of the etching process becomes non-uniform in the plane.

  In order to improve the in-plane temperature distribution of (1) in which the temperature on the peripheral side of the wafer W becomes low in this way, the temperature was adjusted by moving the etching nozzle 411A in the peripheral direction from the center of the wafer W. There is a method of directly supplying an etching solution to a region on the peripheral side of the central region. On the other hand, if the etching nozzle 411A is left moved from the center of the wafer W, the etching solution does not reach the central area of the wafer W, and the etching process in that area cannot be performed.

  Therefore, in order to make the in-plane temperature distribution of the wafer W uniform while performing the etching process in the central region of the wafer W, the discharged etching solution passes through the center of the wafer W (hereinafter referred to as “first position”). ”) And a position closer to the periphery of the wafer W than the central position (hereinafter referred to as“ second position ”), the etching solution may be discharged while the etching nozzle 411A is repeatedly reciprocated.

  For example, assume that the distance between the first position on the center side of the wafer W and the second position on the peripheral side is gradually increased from a zero state, and the in-plane temperature distribution is measured under each condition. In this case, as the distance between the first position and the second position increases, the temperature on the center side of the wafer W decreases, while the temperature difference between the center side and the peripheral side decreases, and the in-plane temperature distribution. The slope of becomes gentle.

  However, even if the distance between the first position and the second position is further increased, the reduction width of the temperature difference between the central side and the peripheral side gradually decreases, and eventually, the temperature at the central portion is excessively lowered and the temperature difference is increased. May grow. FIG. 5 shows the in-plane temperature distribution in this state by a curve (thin broken line) numbered (2).

  As shown in FIG. 5, the etching position of the etching liquid from the etching nozzle 411A is moved between the first position on the center side and the second position on the peripheral side, and these positions are set appropriately, so that The uniformity of the in-plane temperature distribution of the wafer W can be improved as compared with the case where the etching solution is supplied only to the side. On the other hand, when a more uniform in-plane temperature distribution is required, not only reciprocating the etching nozzle 411A between the first position and the second position but also another method is required.

  Therefore, in the processing unit 16 of the present embodiment, in addition to the main nozzle portion 40a including the etching nozzle 411A (main nozzle) that reciprocates between the first position and the second position, the wafer is more than the first position. A sub-nozzle portion 40b including an etching nozzle 411B (sub-nozzle) that directly discharges an etching solution is provided at a preset position (third position) on the peripheral side of W to adjust the in-plane temperature distribution of the wafer W. Yes.

  The in-plane temperature distribution (shown by a thick broken line) numbered (3) in FIG. 5 is located at a predetermined position (third position) on the peripheral side of the wafer W relative to the first position. The example at the time of discharging an etching liquid from only is shown. If the etching liquid is directly supplied to the position on the peripheral side of the wafer W, the temperature at the position where the etching liquid reaches the wafer W becomes the highest, and the temperature on the center side and the peripheral side is lower than the reaching position. The in-plane temperature distribution is formed so as to spread in an annular shape along the circumferential direction of the wafer W.

  Therefore, if the sub-nozzle part 40b is provided so as to discharge the etching liquid toward the region where the temperature difference from the center side becomes large in the in-plane temperature distribution of (2), the surfaces of (2) and (3) The inner temperature distribution is synthesized to form an in-plane temperature distribution (shown by a thick broken line) numbered (4) in which the difference between the maximum value and the minimum value of the wafer W is made smaller and uniform. can do.

Here, the position at which the etching solution is discharged from the sub-nozzle portion 40b is, for example, a difference ΔT between the maximum value and the minimum value of the temperature of the wafer W is set to a preset target temperature difference, for example, a value within 1.0 ° C. It is set to a position where it can.
Further, paying attention to the in-plane uniformity of the temperature of the wafer W, when the maximum value of the temperature of the wafer W from the central part to the peripheral part of the wafer W is Max and the minimum value is Min, the temperature is uniform in the plane. You may set to the position which satisfy | fills the following formula which is the parameter | index showing sex.
[(Max-Min) / {(Max + Min) / 2}] × 100 ≦ 2.0%

The etching position at which the above-mentioned target temperature difference and target in-plane uniformity can be realized is, for example, an experiment in which the temperature of the wafer W is actually measured by discharging the etching liquid from the main nozzle portion 40a and the sub nozzle portion 40b. In this case, the position where the target value is achieved may be searched by gradually moving the discharge position of the sub nozzle 40b from the first position toward the peripheral edge. Moreover, the discharge position of the etching liquid from the sub nozzle part 40b that can realize the target value may be obtained by simulation using fluid analysis software or the like.
Even in the case where the strict search for the etching solution discharge position is not performed in this manner, the region is located toward the peripheral side of the center position between the center (C) and the peripheral edge (E) of the wafer W. When the etching solution is discharged, at least the difference ΔT between the maximum value and the minimum value of the temperature in the wafer W plane can be reduced as compared with the case where the discharge to this region is not performed.

  Here, in each process related to the in-plane temperature distribution of (1) and (4) in FIG. 5, the temperatures of the processing liquids supplied in these processes match so that the amount of heat supplied to the wafer W is uniform. ing. Further, the discharge flow rate F1 of the etching liquid discharged toward the central region of the wafer W in the processing according to (1) and the total value F2 of the discharge flow rates of the etching liquid from the main nozzle portion 40a and the sub nozzle portion 40b are: It is assumed that they match each other (F1 = F2). Therefore, the in-plane temperature distribution of the wafer W when the etching liquid having the same discharge flow rate F1 as that in the process according to (1) is discharged from the main nozzle portion 40a is generally higher than the in-plane temperature distribution of (2). Move to the side.

  Next, the relationship of the discharge flow rate of the etching liquid between the main nozzle part 40a and the sub nozzle part 40b is demonstrated. For example, the sub nozzle portion 40b is arranged at a predetermined discharge position so that the total value f1 + f2 = F2 of the discharge flow rate f1 from the main nozzle portion 40a and the discharge flow rate f2 from the sub nozzle portion 40b is constant. Consider the case where the discharge flow rate of the main nozzle portion 40b is gradually increased from the state of f2 = 0.

  When the etching solution is not discharged from the sub nozzle part 40b, the function of adjusting the in-plane temperature distribution does not work. Next, when the discharge flow rate from the sub nozzle portion 40b is increased, the effect of adjusting the in-plane temperature distribution by the sub nozzle portion 40b is combined with the action of decreasing the discharge flow rate from the main nozzle portion 40a. growing. Furthermore, if the discharge flow rate of the sub nozzle part 40b is increased and the discharge flow rate becomes larger than the discharge flow rate of the main nozzle part 40a (f2> f1), the influence of the processing liquid from the sub nozzle part 40b on the in-plane temperature distribution. Becomes relatively large, and the temperature of the wafer W on the peripheral side is significantly increased. As a result, as shown in (4) of FIG. 5, an in-plane temperature distribution in which the difference ΔT between the maximum value and the minimum value of the temperature of the wafer W is small can be realized. Therefore, in the present embodiment, the relationship between the discharge flow rates of the etching liquid from the main nozzle portion 40a and the sub nozzle portion 40b is such that the discharge flow rate of the sub nozzle portion 40b is larger than the discharge flow rate of the main nozzle portion 40a. The discharge flow rate capable of realizing the target temperature difference and target in-plane uniformity is selected.

As described above, etching is performed using the main nozzle portion 40a that reciprocates between the first position and the second position, and the sub nozzle portion 40b that is disposed at a preset position (third position). By discharging the liquid, the etching process can be performed in a state where the in-plane temperature distribution is made more uniform, which contributes to the improvement of the in-plane uniformity of the etching process.
On the other hand, when the etching solution is discharged onto the wafer W using the plurality of etching nozzles 411A and 411B, the flow of the etching solution collides with the surface of the wafer W, splash occurs, and the scattered mist is formed on the wafer W. It can be a source of pollution.

  For example, in FIG. 6, the flow of the etching solution discharged from the main nozzle portion 40 a to the surface of the wafer W is indicated by a dashed arrow, and the flow of the etching solution discharged from the sub nozzle portion 40 b to the surface of the wafer W is indicated by a solid line. It is indicated by an arrow. In the main nozzle part 40a that reciprocates between the first position on the center side of the wafer W and the second position on the peripheral side, the flow of the etching solution supplied when the main nozzle part 40a moves to the peripheral side is: The thickness of the etching solution is increased as compared with the case where it is supplied on the center side. Further, the centrifugal force applied to the etching solution is larger on the peripheral side than on the central side. Therefore, a position where the flow of the thickened etchant is applied with a large centrifugal force and the flow of the etchant supplied from the sub-nozzle portion 40b (indicated by reference numerals S1 and S2 in FIG. 6). ), A large splash is likely to occur.

  Therefore, in the processing unit 16 of this example, the sub nozzle part 40b is arranged at a position as far as possible on the downstream side in the rotation direction of the wafer W with respect to the flow of the etching solution supplied from the main nozzle part 40a moved to the peripheral side. As described above, the arrangement of the nozzle portions 40a and 40b viewed in the circumferential direction of the wafer W is set. That is, the discharge position of the etching liquid on the wafer W in the sub nozzle part 40b is larger than 180 degrees in the rotation direction from the discharge position of the etching liquid on the wafer W in the main nozzle part 40a when viewed from the center of the wafer W. It is set at a position separated by an opening angle of 270 degrees or less. In the present embodiment, the distance from the substrate center at the position of the sub nozzle portion 40b (third position) is the same as the distance from the substrate center at the second position.

  FIG. 7 shows the settable range 6 of the discharge position of the sub nozzle part 40b. Since the flow of the etching solution supplied from the reciprocating main nozzle portion 40a may have a larger energy, the opening angle is preferably in the range of 185 degrees or more and 270 degrees or less. When the opening angle is larger than 270 degrees, the sub nozzle part 40b is close to the main nozzle part 40a moved to the outer edge side, and there is a possibility that the splash at the position of S2 becomes large.

  The occurrence of splash is also affected by the setting position of the second position in the main nozzle portion 40a that reciprocates. That is, it has been experimentally confirmed that the splash becomes larger as the set position of the second position is moved toward the peripheral edge of the wafer W (see (Experiment 2) described later). On the other hand, the closer the second position is to the center of the wafer W, the closer the in-plane temperature distribution of (2) is to the in-plane temperature distribution of (1), and the highest temperature-the lowest temperature in the in-plane temperature distribution of (4). The temperature difference ΔT between the two becomes large.

  Therefore, in order to suppress the occurrence of splash, the second position of the main nozzle portion 40a may be moved to the center side within a range that satisfies the above-described target temperature difference and target in-plane uniformity. As shown in an experimental result (Experiment 2) described later, from the viewpoint of reducing splash, the second position is set to be positioned closer to the center than a position closer to the center of 45 mm from the periphery of the wafer W. Is preferred. The distance from the center of the substrate at the position of the sub-nozzle portion 40b (third position) is not limited to the same distance as the second position, and is adjusted as appropriate, such as being positioned closer to the periphery to reduce the influence of splash. You may do it.

  The operation of the processing unit 16 having the configuration described above will be described. The wafers W transferred to the processing units 16 by the substrate transfer device 17 are transferred into the chamber 20 via a loading / unloading port (not shown). The substrate holding mechanism 30 (substrate holding unit) transfers the wafer W to be processed from the wafer holding mechanism of the substrate transfer device 17 onto the holding surface 311 of the holding unit 31 via a lifting pin (not shown) and the like. Retreat from within 20.

  When the wafer W is placed on the holding unit 31, the holding unit 31 is rotated by the driving unit 33 (rotating mechanism), the main nozzle unit 40a is advanced from the standby position to the first position, and the sub nozzle unit 40b is set on standby. Move from the position to a preset discharge position.

  Then, when the rotation speed of the wafer W reaches a predetermined set speed, the discharge of the etching liquid is started from the main nozzle portion 40a and the sub nozzle portion 40b, and the main nozzle portion 40a is reciprocated. The moving speed of the main nozzle part 40a is set so that it can move, for example, several times to several tens of times per minute between the first position and the second position.

  As a result, as shown in FIG. 6, the etching liquid discharged from the nozzle portions 40a and 40b spreads on the surface of the rotating wafer W, and the etching process of the wafer W is performed. At this time, the etching solution is supplied using the main nozzle portion 40a that reciprocates between the center side and the peripheral side of the wafer W and the sub nozzle portion 40b for adjusting the in-plane temperature distribution, whereby (4) in FIG. Etching is performed while forming a uniform in-plane temperature distribution shown in FIG. Further, as shown in FIGS. 6 and 7, the opening angle between the discharge positions of the main nozzle portion 40a and the sub nozzle portion 40b is set to a range greater than 180 degrees and 270 degrees or less, and a range in which the main nozzle section 40a reciprocates. By setting the second position that defines the distance to the center side rather than the position 45 mm closer to the center side from the periphery of the wafer W, occurrence of splash can be suppressed and contamination of the wafer W can be suppressed.

  When the wafer W is etched for a predetermined time in this way, the discharge of the etching liquid from the main nozzle portion 40a and the sub nozzle portion 40b is stopped, and the rinse liquid is discharged from the rinse nozzles 412A and B of the nozzle portions 40a and 40b. . Here, when the in-plane temperature distribution of the wafer W at the time of rinsing with a rinsing liquid, such as hot rinsing, affects the result of the etching process, the first position and the second position are the same as when the etching liquid is supplied. The rinsing liquid is supplied using both the main nozzle part 40a reciprocally moving between and the sub nozzle part 40b for adjusting the in-plane temperature distribution. At this time, the same examination as the example described with reference to FIG. 5 is performed, and the first position and the second position of the main nozzle portion 40a and the discharge position of the sub nozzle portion 40b are set to positions different from those at the time of discharging the etching liquid. You may keep it.

Further, when the in-plane temperature distribution of the wafer W during the rinse cleaning has little influence on the result of the etching process, for example, the main nozzle portion 40a is stopped above the central portion of the wafer W, and only the main nozzle portion 40a is concerned. Alternatively, the rinse liquid may be supplied from the sub nozzle portion 40b so that the in-plane temperature distribution is not adjusted.
After rinsing cleaning is performed in this manner and the swing-off drying is performed, the rotation of the holding unit 31 is stopped. Then, the wafer W is transferred to the wafer holding mechanism that has entered the chamber 20 by a procedure opposite to that at the time of loading, and the wafer W is unloaded from the processing unit 16.

  The processing unit according to the present embodiment has the following effects. The etching solution is moved while the etching nozzle 411A (main nozzle) of the main nozzle portion 40a is moved between a position where the etching solution passes through the center of the wafer W and a position closer to the peripheral side than this position with respect to the rotating substrate. In addition, the etching liquid is discharged from the etching nozzle 411B (sub nozzle) of the sub nozzle portion 40b at a higher discharge flow rate than that of the main nozzle portion 40a in order to suppress the temperature drop on the peripheral side of the wafer W. . For this reason, the temperature difference between the center side and the peripheral side of the wafer W is suppressed, and processing with high uniformity can be performed within the surface of the wafer W.

  Here, the movement path of the main nozzle portion 40a that reciprocates between the first position on the center side of the wafer W and the second position on the outer peripheral side is limited to a case where the movement path is linear in the radial direction of the wafer W. Not. For example, as shown in FIG. 8, the main nozzle 40a is drawn so as to draw a curved trajectory that jumps out from the first position on the center side in the rotation direction of the wafer W and then returns to the second position on the peripheral side of the first position. May be moved. In this case, the opening angle between the discharge position of the main nozzle portion 40a and the discharge position of the sub nozzle portion 40b is a circle concentric with the wafer W passing through the position where the sub nozzle portion 40b is disposed as shown in FIG. The opening angle may be set to be larger than 180 degrees and 270 degrees or less with reference to a time point when the main nozzle portion 40a moves on 61.

Further, the position (third position) of the sub nozzle 411B provided for adjusting the in-plane temperature distribution of the wafer W is not limited to the fixed position as in the sub nozzle portion 40b. For example, during the discharge of the etching solution, the sub nozzle 411B is moved from the central side to the peripheral side, or from the peripheral side to the central side in the peripheral region from the first position, or between these regions. You may reciprocate.
In addition, the position (third position) at which the sub nozzle 411B is arranged is not limited to the upper side of the wafer W. For example, the sub nozzle 411B is arranged on the side of the wafer W held by the holding unit 31. The processing liquid may be discharged obliquely downward toward the direction in which the wafer W is arranged, and the processing liquid may be supplied to a preset position on the wafer W.

  Further, the type of processing liquid that can adjust the in-plane temperature distribution of the wafer W using the main nozzle 411A and the sub nozzle 411B of the present embodiment is not limited to the etching liquid. Even if the resist solution supplied to the wafer W by the coating and developing device, the thinner for spreading the resist solution on the surface of the wafer W, the raw material solution for the antireflection film or the developer supplied to the developed resist film Good. Also for supplying various processing liquids such as acidic or alkaline chemicals supplied by a cleaning apparatus for cleaning the wafer W, plating liquids supplied by a plating apparatus for forming a metal film on the wafer W, etc. The present invention is applicable. In these cases, the various processing liquids may be supplied at a temperature lower than that of the wafer W as well as when the processing liquid is supplied at a temperature higher than the temperature of the wafer W. In this case as well, the sub nozzle 411B. The in-plane temperature distribution of the wafer W can be adjusted.

  And the kind of board | substrate which can be processed using the processing unit (liquid processing apparatus) of this Embodiment is not limited to a semiconductor wafer. For example, the present invention can also be applied to a processing unit that performs liquid processing of a glass substrate for a flat panel display.

(Experiment 1)
While changing the discharge method, DIW, which is a simulation processing liquid, was supplied to the surface of the rotating wafer W, and the in-plane temperature distribution on the surface of the wafer W was measured.
A. Experimental conditions
(Example 1) A wafer W having a diameter of 300 mm was rotated at a rotation speed of 150 rpm, and a processing liquid whose temperature was adjusted to 50 ° C. was supplied from the main nozzle part 40a and the sub nozzle part 40b shown in FIGS. The total discharge flow rate of the processing liquid was F2 = 1.5 L / min (discharge flow rate f1 from the main nozzle portion 40a = 0.6 L / min, discharge flow rate f2 from the sub nozzle portion 40b = 0.9 L / min). . The movement range of the main nozzle portion 40a is 30 mm from the center of the wafer W to the outer edge side position (first position) to 120 mm of the outer edge side position (second position). The position was on the outer edge side. Even if the first position is set to 30 mm, the processing liquid can reach the center of the substrate as long as the discharge flow rate is as described above. In addition, it is preferable from the viewpoint of in-plane uniformity because the processing liquid having the same flow rate as the other positions can be supplied to the central position rather than setting the first position to 0 mm (center position). The moving speed of the main nozzle part 40a was 150 mm / second, and the treatment liquid was discharged for 2 minutes. For the sake of simplicity, in the following description, the fact that the first position and the second position are “positions on the Xmm outer edge side from the center of the wafer W” will be simply referred to as “Xmm”.
(Comparative Example 1-1) Under the same conditions as in Example 1, except that the processing liquid was discharged at a discharge flow rate of 1.5 L / min using only the etching nozzle 411A fixedly arranged above the center of the wafer W. The experiment was conducted.
(Comparative Example 1-2) Except that the processing liquid was discharged at a discharge flow rate of 1.5 L / min using only the main nozzle part 40a reciprocating between the first position and the second position, (Example 1) The experiment was performed under the same conditions.

B. Experimental result
The results of (Example 1, Comparative Examples 1-1, 1-2) are shown in FIG. The horizontal axis in FIG. 9 indicates the position in the radial direction from the center (C) of the wafer W, and the vertical axis indicates the temperature of the wafer W at each measurement position. The results of (Example 1) were shown as square plots, and each plot was connected with a thick line (corresponding to the in-plane temperature distribution (4) in FIG. 5). The result of (Comparative Example 1-1) is shown by a rhombus plot, and each plot is connected by a thin line (corresponding to the in-plane temperature distribution (1) in FIG. 5). Moreover, the result of (Comparative Example 1-2) was shown by a cross-marked plot, and each plot was connected by a thin broken line (corresponding to the in-plane temperature distribution (2) in FIG. 5).

  According to the result of (Example 1), the difference ΔT between the maximum value (Max = 54.5 ° C.) and the minimum value (Min = 53.8 ° C.) in the wafer W surface is 0.7 ° C. It was. The in-plane uniformity of the temperature distribution was 1.3%. In contrast, in (Comparative Example 1-1) in which the treatment liquid was supplied only from the central part, the temperature on the central side increased significantly compared to (Example 1), and the temperature difference ΔT was 2.2 ° C. The maximum in-plane uniformity was 4.0%. On the other hand, in the case where the processing liquid is discharged only by the main nozzle portion 40a that reciprocates (Comparative Example 1-1), the temperature on the peripheral side of the wafer W is lower than that in Example 1, and the temperature difference ΔT is 1. Increased to 2 ° C, and in-plane uniformity became 2.2%.

  From these experimental results, it can be seen that a more uniform in-plane temperature distribution can be realized by combining the main nozzle portion 40a that reciprocates and the sub-nozzle portion 40b for adjusting the in-plane temperature distribution to discharge the processing liquid.

(Experiment 2)
Experiments similar to (Example 1) were performed by changing the second position of the main nozzle portion 40a in various ways, and the occurrence of splash was examined.
A. Experimental conditions
(Example 2-1) The treatment liquid was discharged under the same conditions as in Example 1 except that the second position of the main nozzle portion 40a was set to 60 mm. The opening angle of the sub nozzle part 40b with respect to the main nozzle part 40a is 210 degrees. The surface of the wafer W at this time was photographed with a speed camera, and the occurrence of splash was observed.
(Example 2-2) The occurrence of splash was observed under the same conditions as in Example 2-1 except that the second position of the main nozzle portion 40a was set to 75 mm. Further, the in-plane temperature distribution of the wafer W was measured under the same conditions as in Example 2-1, except that the first position of the main nozzle portion 40a was 15 mm and the second position was 75 mm.
(Example 2-3) The occurrence of splash was observed under the same conditions as in Example 2-1 except that the second position of the main nozzle portion 40a was set to 90 mm. The in-plane temperature distribution of the wafer W was measured under the same conditions as in Example 2-1 except that the first position of the main nozzle portion 40a was 15 mm and the second position was 90 mm.
(Example 2-4) The occurrence of splash was observed under the same conditions as in Example 2-1 except that the second position of the main nozzle portion 40a was set to 105 mm.
(Example 2-5) The occurrence of splash was observed under the same conditions as in (Example 2-1). Further, the in-plane temperature distribution of the wafer W was measured under the same conditions as in Example 2-1 except that the first position of the main nozzle portion 40a was 15 mm.

B. Experimental result
(Table 1) shows the evaluation of the occurrence of splash in Examples 2-1 to 2-5. Moreover, the in-plane temperature distribution of the wafer W in (Examples 2-2, 2-3, 2-5) is shown in FIG. The horizontal and vertical axes in FIG. 10 are the same as those in FIG. The results of (Example 2-2) are indicated by rhombus plots, the results of (Example 2-3) are indicated by square plots, and the results of (Example 2-5) are indicated by triangular plots.
(Table 1)

  According to the splash observation results shown in Table 1, the second position of the main nozzle portion 40a is smaller than 90 mm, that is, 60 mm or more away from the periphery of the wafer W (Example 2-1). In 2-3), no splash was observed. A small amount of splash was confirmed at (Example 2-4) where the second position was 105 mm (closer to the center side of 45 mm from the periphery of the wafer W). In the case of (Example 2-5) in which the second position is 120 mm (closer to the center side of 30 mm from the periphery of the wafer W), a relatively large splash occurred.

  On the other hand, according to the measurement result of the in-plane temperature distribution of the wafer W shown in FIG. 10, the second example is compared with (Example 2-5) in which the experiment was performed under substantially the same conditions as (Example 1). When the position was moved toward the center side of the wafer W (Examples 2-2 and 2-3), the temperature on the center side of the wafer W slightly increased. However, in any of Examples 2-2, 2-3, and 2-5, the value of the temperature difference ΔT is adjusted within 1 ° C., and a good in-plane temperature distribution is formed.

  According to the experimental results shown in Table 1 and FIG. 10, even if the second position is moved inward from 120 mm, the maximum temperature difference ΔT in the wafer W surface can be adjusted within 1 ° C. It can be seen that the condition exists. Further, when it is desired to suppress the occurrence of splash while keeping the in-plane temperature distribution of the wafer W uniform, for example, the second position of the main nozzle portion 40a is set to be more than 105 mm within a range where the in-plane temperature distribution satisfies the target value. It can be seen that a small position, that is, a position closer to the center side by 45 mm or more from the periphery of the wafer W may be set.

W Wafer 40a Main nozzle part 40b Sub nozzle part 41A, 41B
Nozzle heads 411A, 411B
Etching nozzles 412A, 412B
Rinse nozzles 42A, 42B
Nozzle arm 43 Slider 44 Guide rail 45 Rotating shaft 46 Drive unit 701 Etching solution supply source 702 Rinse solution supply sources 71a to 71d
Flow rate adjuster

The liquid processing apparatus according to the present invention includes a substrate holding unit for holding the substrate horizontally,
A rotation mechanism for rotating the substrate holder around the vertical axis;
A main nozzle for supplying a treatment liquid in a continuous flow state to the surface of the substrate held by the substrate holding unit;
The main nozzle is reciprocated between a first position where the discharged processing liquid reaches the center of the substrate and a second position on the peripheral side of the substrate with respect to the first position, and between the upper position of the substrate and the standby position. A nozzle moving mechanism for moving between,
A sub-nozzle that discharges the processing liquid in a continuous flow state to a third position, which is a preset fixed position on the peripheral side of the substrate from the first position ,
Before Stories second position, the distance from the center of the substrate or equal to the third position, the distance from the center of the substrate than the third position, characterized in that you have been set to be shorter position.

The liquid processing apparatus may have the following configuration.
(A) The first position is set closer to the second position than the center of the substrate.
(B) The nozzle moving mechanism moves the main nozzle twice or more per minute between the first position and the second position.
( C ) The difference between the maximum value and the minimum value of the substrate temperature from the center to the periphery of the substrate is within 1.5 ° C. Further, assuming that the maximum value of the temperature of the substrate from the center portion to the peripheral portion of the substrate is Max and the minimum value is Min,
[(Max−Min) / {(Max + Min) / 2}] × 100 ≦ 5.0%.
( D ) The second position is located closer to the center than a position closer to the center 45 mm from the periphery of the substrate.

Claims (8)

A substrate holder for holding the substrate horizontally;
A rotation mechanism for rotating the substrate holder around the vertical axis;
A main nozzle for supplying a treatment liquid in a continuous flow state to the surface of the substrate held by the substrate holding unit;
The main nozzle is reciprocated between a first position where the discharged processing liquid reaches the center of the substrate and a second position on the peripheral side of the substrate with respect to the first position, and between the upper position of the substrate and the standby position. A nozzle moving mechanism for moving between,
A sub-nozzle that discharges the processing liquid in a continuous flow state to a third position, which is a preset fixed position on the peripheral side of the substrate from the first position ,
Before Stories second position, liquid which is characterized that you distance from the center of the substrate is the third position and whether the same distance from the center of the substrate than the third position is set to be shorter position Processing equipment.   The liquid processing apparatus according to claim 1, wherein the first position is set closer to the second position than the center of the substrate. The liquid processing apparatus according to claim 1, wherein the nozzle moving mechanism moves the main nozzle portion at least twice per minute between the first position and the second position.   4. The difference between the maximum value and the minimum value of the substrate temperature from the center to the peripheral edge of the substrate is within 1.5 ° C. 4. Liquid processing equipment. When the maximum value of the temperature of the substrate from the central part to the peripheral part of the substrate is Max and the minimum value is Min,
The liquid processing apparatus according to claim 1, wherein [(Max−Min) / {(Max + Min) / 2}] × 100 ≦ 5.0%.   6. The liquid processing apparatus according to claim 1, wherein the second position is located closer to a center side than a position closer to a center side of 45 mm from a peripheral edge of the substrate. Holding the substrate horizontally on the substrate holder;
While discharging the processing liquid from the main nozzle to the surface of the substrate in a continuous flow state while rotating the substrate holding portion around the vertical axis, the main nozzle is moved to a first position where the processing liquid reaches the center of the substrate. Reciprocating between the first position and the second position on the peripheral side of the substrate;
When the ejection of the treatment liquid by the main nozzle is being performed, the third position is a predetermined fixed position of peripheral edge of the substrate than the first position from the sub nozzle, the continuous flow of the treatment liquid And adjusting the in-plane temperature distribution of the substrate by the processing liquid supplied from the main nozzle.
The liquid processing method is characterized in that the second position is set such that the distance from the center of the substrate is the same as the third position, or the distance from the center of the substrate is shorter than the third position. . A storage medium storing a computer program used in a liquid processing apparatus for supplying a processing liquid to a substrate and performing liquid processing, wherein the program includes steps for executing the liquid processing method according to claim 7. A storage medium characterized by being rare.

Images