JP2021039959A - Substrate processing method and substrate processing device - Google Patents

Abstract

To provide a technique for preventing a lower layer from being etched to inside a layer located above it in a multilayer film.SOLUTION: In the substrate processing method, an etching process is performed for etching a multilayer film to a peripheral edge of a substrate in which the multilayer film including a first layer and a second layer located above the first layer is formed. The substrate processing method comprises first to fifth steps. In the first step, the substrate is held. In the second step, the rotation of the substrate around a rotation axis running along a vertical direction is started. In the third step, an etchant for etching the multilayer film is ejected from a nozzle and deposited on the substrate at a position which is a given width distant from the peripheral edge of the substrate. In the fourth step, determination is made about whether the first layer or a third layer directly under the multilayer film is exposed or not. If it is determined that the first layer or the third layer is exposed, a depositing position of the etchant is shifted toward the peripheral edge of the substrate.SELECTED DRAWING: Figure 8

Description

The present application relates to a substrate processing method and a substrate processing apparatus.

Conventionally, a substrate processing device for removing a thin film formed on the surface of a substantially disk-shaped substrate at a peripheral portion of the substrate has been proposed (for example, Patent Document 1). In Patent Document 1, a first treatment step of supplying a first treatment liquid containing hydrofluoric acid and nitric acid at a first mixing ratio to a peripheral portion of a rotating substrate to etch a thin film (film to be removed), and a first treatment step. After supplying the first treatment liquid to the substrate, hydrofluoric acid and nitric acid are contained in the peripheral portion of the rotating substrate at a second mixing ratio in which the content ratio of hydrofluoric acid is lower and the content ratio of nitric acid is higher than that of the first treatment liquid. The second treatment step of supplying the second treatment liquid to be removed and etching the film to be removed is executed.

Thereby, when the removal target film made of SiGe, amorphous silicon or polysilicon is removed by wet etching, the undercoat film such as SiO2 existing under the removal target film can be appropriately left.

Japanese Unexamined Patent Publication No. 2004-79908

A multilayer film may be formed on the surface of the substrate, and etching removal of the peripheral portion of the multilayer film may be desired. In this case, if a treatment liquid (etching liquid) capable of etching the multilayer film is adopted, it is possible to remove the multilayer film at the peripheral edge of the substrate even with the technique of Patent Document 1.

However, if the etching solution is continuously supplied to a predetermined liquid landing position on the peripheral edge portion, the upper layer of the multilayer film may be peeled off as described below.

When the etching solution is landed at the landing position, the multilayer film is partially removed at the landing position to form a groove. Since the substrate is rotating, the groove is formed in an annular shape. The groove becomes deeper as the etching progresses, and eventually the surface of the layer (substrate or base layer) directly below the multilayer film is exposed at the bottom of the groove.

After that, the etching solution adheres to the surface of the layer at the bottom of the groove and spreads on the surface. Upon this liquid deposition, the etching liquid also spreads to the inside of the substrate and comes into contact with the side surface of the lowest layer of the multilayer film. As a result, the side surface of the lowermost layer can be etched radially inward (that is, the center side of the substrate) with respect to the upper layer. When the lowermost layer was etched inward of the upper layer in this way, the upper layer was not partially supported by the lowermost layer and could be peeled off.

Therefore, an object of the present application is to provide a technique capable of suppressing etching of the lower layer of the multilayer film to the inside of the upper layer.

The first aspect of the substrate processing method is etching for etching the multilayer film on the peripheral edge of the substrate on which the multilayer film including the first layer and the second layer above the first layer is formed. A substrate processing method for performing the treatment, the first step of holding the substrate, the second step of starting the rotation of the substrate around the rotation axis along the vertical direction, and the etching solution for etching the multilayer film. The third step of ejecting the liquid from the nozzle and landing the liquid on the inner side of the peripheral edge of the substrate by a predetermined width, and whether or not the first layer or the third layer directly under the multilayer film is exposed. The present invention includes a fourth step of determining, and a fifth step of moving the landing position of the etching solution to the peripheral edge side of the substrate when it is determined that the first layer or the third layer is exposed.

The second aspect of the substrate processing method is the substrate processing method according to the first aspect, in which the etching solution is applied to the upper surface of the third layer in the fifth step. The position is moved to the peripheral side of the substrate with the passage of time.

The third aspect of the substrate processing method is the substrate processing method according to the second aspect, in which the liquid landing position is moved to the peripheral edge side of the substrate by a predetermined movement amount every predetermined time in the fifth step. The predetermined time is set shorter as the liquid landing position is closer to the peripheral edge, or the predetermined movement amount is set larger as the liquid landing position is closer to the peripheral edge side.

The fourth aspect of the substrate processing method is the substrate processing method according to any one of the first to third aspects, and in the fourth step, the elapsed time from the start of the third step is a predetermined reference. When it is determined that the time is longer than that, it is determined that the first layer or the third layer is exposed.

The fifth aspect of the substrate processing method is the substrate processing method according to any one of the first to third aspects. In the fourth step, the image sensor receives the reflected light from the substrate and receives the light. It is determined whether or not the first layer or the third layer is exposed based on the reflected light.

The sixth aspect of the substrate processing method is the substrate processing method according to the fifth aspect, which is formed on the substrate by etching at the liquid landing position of the rotating substrate in the fourth step. The first color of the groove and the second color of the region different from the groove are acquired based on the image acquired by the image sensor, and based on the difference between the first color and the second color, It is determined whether or not the first layer or the third layer is exposed.

The seventh aspect of the substrate processing method is the substrate processing method according to the sixth aspect, and the region different from the groove is a region on the rotation axis side of the groove.

The eighth aspect of the substrate processing method is the substrate processing method according to any one of the fifth to seventh aspects, and in the fourth step, by etching the rotating substrate at the liquid landing position. The width of the groove formed on the substrate is determined based on the image acquired by the image sensor, and it is determined whether or not the first layer or the third layer is exposed based on the width of the groove. ..

The ninth aspect of the substrate processing method is the substrate processing method according to any one of the fifth to eighth aspects, and in the third step and the fifth step, the substrate is more than the liquid landing position. An inert gas is supplied to the supply position on the upstream side in the rotation direction to blow off the etching solution from the peripheral edge portion of the substrate, and the image sensor is located upstream of the liquid landing position in the peripheral edge portion of the substrate. The reflected light reflected in the region downstream of the supply position is received.

The tenth aspect of the substrate processing method is the substrate processing method according to any one of the first to ninth aspects, and the etching rate of the second layer by the etching solution is the first aspect of the etching solution. Higher than the etching rate of the layer, the second layer is thicker than the first layer.

The eleventh aspect of the substrate processing method is the substrate processing method according to any one of the first to tenth aspects, wherein the multilayer film is a titanium layer and a titanium nitride layer provided on the titanium layer. And a tungsten layer provided on the titanium nitride layer.

The twelfth aspect of the substrate processing method is the substrate processing method according to any one of the first to eleventh aspects, in which the ejection direction of the nozzle is oblique toward the peripheral edge of the substrate as it goes downward. The direction.

The thirteenth aspect of the substrate processing method is the substrate processing method according to any one of the first to twelfth aspects, wherein the etching solution contains ammonium hydroxide, hydrogen peroxide solution and pure water, and the etching solution contains the above-mentioned. The ratio of the set of ammonium hydroxide and hydrogen peroxide solution to pure water is set in the range of 6: 1 to 11:10.

The fourteenth aspect of the substrate processing method is the substrate processing method according to any one of the first to thirteenth aspects, and in the fifth step, the liquid landing position is set only in one direction toward the peripheral edge of the substrate. Move to.

In the mode of the substrate processing apparatus, an etching process for etching the multilayer film is performed on the peripheral edge of the substrate on which the multilayer film including the first layer and the second layer above the first layer is formed. A substrate processing device that etches a substrate holding portion that holds the substrate, a rotating mechanism that rotates the substrate held by the substrate holding portion around a rotation axis along the vertical direction, and the multilayer film. The etching is performed when the nozzle for discharging the etching solution and landing the solution on the inner side of the peripheral edge of the substrate by a predetermined width and the first layer or the third layer immediately below the multilayer film are exposed. It is provided with a nozzle moving mechanism for moving the liquid landing position to the peripheral edge side of the substrate.

According to the first, tenth, eleventh, thirteenth and fourteenth aspects of the substrate processing method and the aspect of the substrate processing apparatus, the etching solution is applied to the rotating substrate. By etching at this liquid landing position, a substantially circular groove having the liquid landing position as a radial position is formed on the substrate. As the etching at the liquid landing position progresses, the groove becomes deeper and the first layer is exposed at the bottom thereof. As the etching progresses further, the groove becomes deeper and the third layer is exposed at the bottom thereof. According to the fourth step, when the first layer or the third layer is exposed, the liquid landing position moves to the peripheral side of the substrate. That is, the liquid landing position is moved away from the side surface of the first layer (hereinafter referred to as the inner first layer) inside the groove to the outside in the radial direction (peripheral side of the substrate). Therefore, the etching solution is less likely to come into contact with the side surface of the inner first layer. Therefore, it is possible to prevent the side surface of the inner first layer from being unnecessarily etched. As a result, partial peeling of the inner second layer due to the side surface of the inner first layer receding radially inward from the side surface of the inner second layer can be suppressed.

According to the second aspect of the substrate processing method, the liquid landing position can be brought closer to the side surface of the multilayer film radially outer than the groove, so that the etching solution can act on the side surface with higher cleanliness. .. Therefore, it is possible to promote etching of the side surface of the multilayer film on the outer side in the radial direction.

According to the third aspect of the substrate processing method, as time elapses, the time pitch (predetermined time) for moving the nozzle is shortened, or the movement pitch (predetermined movement amount) for moving the nozzle is lengthened. Throughput can be improved.

According to the fourth aspect of the substrate processing method, the timing of moving the nozzle can be easily determined.

According to the fifth aspect of the substrate processing method, since the etching state of the substrate can be confirmed by the image sensor, the liquid landing position can be moved at a more appropriate timing.

According to the sixth aspect of the substrate processing method, the determination is made by using the color difference between the groove formed on the surface of the substrate by etching and the other region. Therefore, it is possible to suppress the influence of the lighting environment and the like on the determination of whether or not the first layer or the third layer is exposed. That is, the judgment can be made with higher accuracy.

According to the seventh aspect of the substrate processing method, a region that is not etched can be adopted. The color of the region is unlikely to change as the etching progresses. Therefore, it is possible to determine with higher accuracy whether or not the first layer or the third layer is exposed.

According to the eighth aspect of the substrate processing method, where the width of the groove becomes wider as the etching progresses, the judgment is made based on the width of the groove, so that the liquid landing position should be moved at an appropriate timing. Can be done.

According to the ninth aspect of the substrate processing method, the image sensor receives the reflected light in the region where the etching solution is blown off. Therefore, it is possible to suppress a decrease in judgment accuracy due to the inclusion of the etching solution in the image.

According to the twelfth aspect of the substrate processing method, it is possible to prevent the etching solution from entering the non-processed region on the central side of the substrate.

It is a figure which shows typically an example of the structure of a substrate processing system. It is a figure which shows typically an example of the structure of the substrate processing apparatus. It is a top view which shows typically an example of the structure of the substrate processing apparatus. It is a perspective view which shows typically an example of the structure of the substrate processing apparatus. It is a figure which shows typically an example of the cross-sectional structure of the peripheral part of a substrate. It is the top view which shows the example of the liquid landing position and the supply position schematicly. It is a side view which shows an example of a liquid landing position and a supply position schematicly. It is a flowchart which shows an example of the operation of a substrate processing apparatus. It is a figure which shows an example of the state of etching schematically. It is a figure which shows an example of the state of etching schematically. It is a figure which shows an example of the state of etching schematically. It is a figure which shows an example of the state of etching schematically. It is a figure which shows an example of the state of etching schematically. It is a graph which shows an example of the time change of the landing position. It is a top view which shows the other example of the structure of the substrate processing apparatus schematicly. It is a figure which shows an example of the image acquired by the image sensor schematically. It is a flowchart which shows a specific example of the judgment process about the exposure of the base layer. It is a flowchart which shows the other specific example of the judgment process about the exposure of the base layer. It is a graph which shows another example of time change of a liquid landing position.

Hereinafter, embodiments will be described with reference to the attached drawings. It should be noted that the drawings are shown schematically, and for convenience of explanation, the configuration is omitted or the configuration is simplified as appropriate. Further, the interrelationship between the sizes and positions of the configurations shown in the drawings is not always accurately described and can be changed as appropriate.

Further, in the description shown below, similar components are illustrated with the same reference numerals, and their names and functions are also the same. Therefore, detailed description of them may be omitted to avoid duplication.

<First Embodiment>
<Outline configuration of board processing system>
FIG. 1 is a diagram schematically showing an example of the configuration of the substrate processing system 100. The substrate processing system 100 is a single-wafer processing substrate processing system that processes substantially circular substrates W such as semiconductor wafers one by one with a processing liquid such as a chemical solution or a rinsing solution. The substrate processing system 100 includes an indexer block 110, a processing block 120 coupled to the indexer block 110, and a control unit 130 that controls the operation of the device provided in the substrate processing system 100 and the opening and closing of valves.

The indexer block 110 includes a carrier holding unit 111, an indexer robot IR, and an IR moving mechanism 112. The carrier holding unit 111 holds a carrier C capable of accommodating a plurality of substrates W. The plurality of carriers C are held by the carrier holding unit 111 in a state of being arranged in the horizontal carrier arrangement direction D. The IR moving mechanism 112 moves the indexer robot IR in the carrier arrangement direction D. The indexer robot IR performs a carry-in operation of carrying the substrate W into the carrier C held by the carrier holding unit 111 and a carry-out operation of carrying out the substrate W from the carrier C. The substrate W is conveyed in a horizontal posture by the indexer robot IR. The horizontal posture referred to here means a state in which the thickness direction of the substrate W is along the vertical direction.

On the other hand, the processing block 120 includes a plurality of (for example, four or more) processing units 121 for processing the substrate W, and a center robot CR. The plurality of processing units 121 are arranged so as to surround the center robot CR in a plan view. The plurality of processing units 121 include a chemical solution supply unit 121a for supplying the chemical solution to the substrate W, a reaction unit 121b for advancing the reaction between the substrate W and the chemical solution, and a rinse unit 121c for washing away the chemical solution supplied to the substrate W. .. The center robot CR performs a carry-in operation of loading the board W into the processing unit 121 and a carry-out operation of carrying out the board W from the processing unit 121. Further, the center robot CR conveys the substrate W between the plurality of processing units 121. The substrate W is conveyed in a horizontal posture by the center robot CR. The center robot CR receives the substrate W from the indexer robot IR and passes the substrate W to the indexer robot IR.

<Configuration of substrate processing device 1>
The configuration of the substrate processing apparatus 1 which is an example of the processing unit 121 will be described with reference to FIGS. 2 to 4. 2 to 4 are diagrams schematically showing an example of the configuration of the substrate processing device 1. 2 and 3 are a schematic side view and a schematic top view of the substrate processing apparatus 1, respectively. FIG. 4 is a schematic perspective view of the substrate processing device 1 viewed from diagonally above.

The substrate processing apparatus 1 is an apparatus that performs bevel etching processing (described later) on the substrate W. The substrate W is, for example, a semiconductor substrate and has a substantially disk shape. The radius of the substrate W is, for example, 150 mm.

FIG. 5 is a cross-sectional view schematically showing an example of the configuration of the peripheral portion of the substrate W. FIG. 5 shows a cross section along the diameter of the substrate W. As illustrated in FIG. 5, a multilayer film 9 is formed on the upper surface of the substrate W. In the example of FIG. 5, the multilayer film 9 includes a lower layer 9a, an intermediate layer 9b, and an upper layer 9c. The lower layer 9a is, for example, a titanium layer. The intermediate layer 9b is, for example, a titanium nitride layer, which is formed on the upper surface of the lower layer 9a. The upper layer 9c is, for example, a tungsten layer, which is formed on the upper surface of the intermediate layer 9b. Further, in the example of FIG. 5, the base layer 91 is formed on the surface of the substrate W, and the multilayer film 9 is formed on the upper surface of the base layer 91. The base layer 91 is, for example, a silicon oxide layer. Focusing on the vertically upper side of the substrate W, the base layer 91, the lower layer 9a, the intermediate layer 9b, and the upper layer 9c are laminated in this order from the upper surface of the substrate W.

The lower layer 9a and the intermediate layer 9b have, for example, the same order of thickness, and the upper layer 9c is thicker than any of the lower layer 9a and the intermediate layer 9b, for example. The upper layer 9c is, for example, 10 times or more thicker than the lower layer 9a and 10 times or more thicker than the intermediate layer 9b.

Such a multilayer film 9 is adopted in a semiconductor device such as a DRAM (Dynamic Random Access Memory) and a NAND (Not AND) type flash memory, for example.

The substrate processing apparatus 1 etches and removes the multilayer film 9 in the processing region R1 (see FIG. 5) on the peripheral edge side of the substrate W (so-called bevel etching treatment). The processing region R1 is an annular portion having a width D1 from the peripheral edge of the substrate W. The width D1 of the processing region R1 is, for example, about 1 mm to 5 mm.

With reference to FIG. 2, the substrate processing device 1 includes a rotation holding mechanism 2, a cup unit 3, a gas supply unit 4, a processing liquid supply unit 5, a nozzle moving mechanism 6, and a control unit 130. Each of these units 2 to 6 is electrically connected to the control unit 130 and operates in response to an instruction from the control unit 130. As the control unit 130, for example, the same one as a general computer can be adopted.

The control unit 130 is an electronic circuit and may include, for example, a data processing device and a storage medium. The data processing device may be, for example, an arithmetic processing device such as a CPU (Central Processor Unit). The storage medium may include a non-temporary storage medium (for example, ROM (Read Only Memory) or hard disk) and a temporary storage medium (for example, RAM (Random Access Memory)). The non-temporary storage medium may store, for example, a program that defines the processing executed by the control unit 130. When the processing device executes this program, the control unit 130 can execute the processing specified in the program. Of course, a part or all of the processing executed by the control unit 130 may be executed by the hardware.

<Rotation holding mechanism 2>
The rotation holding mechanism 2 is a mechanism capable of rotating while holding the substrate W in a substantially horizontal posture with one main surface (specifically, the upper surface on which the multilayer film 9 is formed) facing upward. is there. The horizontal posture referred to here means a state in which the thickness direction of the substrate W is along the vertical direction. The rotation holding mechanism 2 rotates the substrate W around the vertical rotation axis a1 passing through the central portion c1 of the main surface thereof. Ideally, the rotation axis a1 passes through the center of the substrate W.

The rotation holding mechanism 2 includes a spin chuck 21 that holds the substrate W. The spin chuck 21 is also called a "holding member" or a "board holding portion". The spin chuck 21 has, for example, a substantially disk shape. The spin chuck 21 is provided so that its upper surface is substantially horizontal and its central axis substantially coincides with the rotation axis a1. In the example of FIG. 2, the diameter of the spin chuck 21 is smaller than the diameter of the substrate W. A substantially cylindrical rotating shaft portion 22 is connected to the lower surface of the spin chuck 21. The rotating shaft portion 22 is a so-called shaft. The rotating shaft portion 22 is arranged in a posture such that its axis is along the vertical direction. The axis of the rotating shaft portion 22 substantially coincides with the rotating axis a1. Further, a rotation drive unit (for example, a motor) 23 is connected to the rotation shaft unit 22. The rotation drive unit 23 rotationally drives the rotation shaft unit 22 around its axis. By this rotation drive, the spin chuck 21 rotates around the rotation axis a1 together with the rotation shaft portion 22. The rotation drive unit 23 and the rotation shaft unit 22 are rotation mechanisms 231 that rotate the spin chuck 21 around the rotation axis a1. A part of the lower side of the rotating shaft portion 22 and the rotating driving portion 23 are housed in a tubular casing 24.

A suction port (not shown) is provided on the upper surface of the spin chuck 21 and communicates with the internal space of the rotating shaft portion 22. The interior space is connected to a pump (not shown) via a pipe (not shown) and an on-off valve. The pump and the on-off valve are electrically connected to the control unit 130. The control unit 130 controls the operation of the pump and the on-off valve. The pump can selectively supply negative pressure and positive pressure according to the control of the control unit 130. When the pump supplies a negative pressure while the substrate W is placed on the upper surface of the spin chuck 21 in a substantially horizontal posture, the spin chuck 21 sucks and holds the substrate W from below. When the pump supplies a positive pressure, the substrate W becomes removable from the upper surface of the spin chuck 21.

In this configuration, when the rotation drive unit 23 rotates the rotation shaft portion 22 while the spin chuck 21 sucks and holds the substrate W, the spin chuck 21 is rotated around the axis along the vertical direction. As a result, the substrate W held by the spin chuck 21 rotates in the rotation direction AR1 about the vertical rotation axis a1 passing through the central portion c1 in the plane thereof.

In the above example, although the spin chuck 21 attracts and holds the substrate W, it is not necessarily limited to this. For example, the spin chuck 21 may include a plurality of (for example, six) chuck pins provided near the peripheral edge of the upper surface thereof at appropriate intervals, and the substrate W may be held by the plurality of chuck pins. .. The spin chuck 21 in this case has, for example, a disk shape slightly larger than the substrate W. The plurality of chuck pins detachably hold the substrate W so that the substrate W is in a substantially horizontal posture at a position slightly higher than the upper surface of the spin chuck 21. Each chuck pin is in a state of being in contact with the peripheral edge of the substrate W to hold the substrate W by a motor or the like electrically connected to the control unit 130, and a state of opening the substrate W away from the peripheral edge of the substrate W. It can be switched selectively.

<Treatment liquid supply unit 5>
The processing liquid supply unit 5 supplies the processing liquid to the processing region R1 of the substrate W held by the spin chuck 21. Specifically, the treatment liquid supply unit 5 applies the treatment liquid so that the treatment liquid is deposited in the treatment region R1 on the upper surface (treatment surface) of the substrate W which is held and rotated by the spin chuck 21. Discharge. In FIGS. 2 and 4, the liquid flow L1 of the discharged treatment liquid is schematically shown. The liquid flow L1 is, for example, a liquid column. The treatment liquid is discharged so as to land on the liquid landing position PL1 in the treatment region R1. The liquid landing position PL1 orbits relatively on the processing region R1 of the substrate W by rotating the substrate W around the rotation axis a1.

The "treatment solution" referred to here includes a "chemical solution" used for the chemical solution treatment and a "rinse solution (also referred to as a" cleaning solution ")" used for the rinsing treatment for rinsing the chemical solution.

In the examples of FIGS. 2 to 4, the processing liquid supply unit 5 includes the nozzle head 50. The nozzle head 50 is attached to the tip of a long arm 63 included in the nozzle moving mechanism 6. The arm 63 extends along the horizontal plane. The nozzle moving mechanism 6 moves the nozzle head 50 between the processing position and the retracted position by moving the arm 63. In addition, in FIGS. 3 and 4, the nozzle moving mechanism 6 is not shown in order to avoid the complexity of the drawings.

2 to 4 show a state in which the substrate W is rotated by the spin chuck 21 in a predetermined rotation direction AR1 around the rotation axis a1 with the nozzle head 50 located at each processing position. .. In the example of FIG. 3, the nozzle head 50 located at the processing position is shown by a solid line, and the nozzle head 50 located at the retracted position is shown by a virtual line. The nozzle heads 48 and 49, which will be described later, are also shown in the same manner.

The nozzle head 50 includes nozzles 51a to 51c and a holding member for holding them. In the illustrated example, the nozzle head 50 also includes the nozzle 51d, but the nozzle 51d will be described in detail later. The holding member is formed by joining, for example, a plate-shaped member extending along a horizontal plane and a protruding member protruding upward from one end of the plate-shaped member, and has an L-shaped cross-sectional shape. There is. The tip of the protruding member is attached to the tip of the arm 63, and the plate-shaped member projects from the tip of the arm 63 to the side opposite to the base end of the arm 63. The nozzles 51a to 51c are arranged side by side in a row along the extending direction of the arm 63 in order from the tip end side of the plate-shaped member. The nozzles 51a to 51c are held by the plate-shaped member in a state of penetrating the plate-shaped member in the vertical direction. The tip portions (lower end portions) of the nozzles 51a to 51c project downward from the lower surface of the plate-shaped member and have a discharge port at the tip end. The base end portion (upper end portion) of the nozzles 51a to 51c projects upward from the upper surface of the plate-shaped member.

A piping system 83 for supplying a treatment liquid to the nozzles 51a to 51c is connected to the nozzles 51a to 51c. Specifically, one ends of the pipes 832a to 832c of the piping system 83 are connected to the upper ends of the nozzles 51a to 51c, respectively. The nozzles 51a to 51c discharge the processing liquids supplied from the piping system 83 from the discharge port at the tip. The processing liquid supply unit 5 discharges the processing liquid from one of the nozzles 51a to 51c, which is determined by the control information set in the control unit 130, according to the control of the control unit 130.

Specifically, the piping system 83 includes an acidic chemical solution supply source 831a, a rinse solution supply source 831b, an SC-1 supply source 831c, a plurality of pipes 832a, 832b, 832c, and a plurality of on-off valves 833a, 833b, 833c. , Consists of a combination.

The acidic chemical solution supply source 831a is a supply source for supplying the acidic chemical solution. The acidic chemical solution is not particularly limited, but is, for example, a chemical solution containing hydrofluoric acid. The acidic chemical solution supply source 831a is connected to the nozzle 51a via a pipe 832a in which an on-off valve 833a is inserted. Therefore, when the on-off valve 833a is opened, the acidic chemical solution supplied from the acidic chemical solution supply source 831a is discharged from the nozzle 51a.

The rinse liquid supply source 831b is a supply source for supplying the rinse liquid. The rinsing solution includes, for example, pure water (DIW: DE-IONIZED WATER), hot water, ozone water, magnetic water, reduced water (hydrogen water), various organic solvents (ionized water, IPA (isopropyl alcohol)) and functional water (CO). ₂ Includes at least one of)). The rinse liquid supply source 831b is connected to the nozzle 51b via a pipe 832b in which an on-off valve 833b is inserted. Therefore, when the on-off valve 833b is opened, the rinse liquid supplied from the rinse liquid supply source 831b is discharged from the nozzle 51b.

The SC-1 supply source 831c is a supply source for supplying SC-1. SC-1 is a chemical solution containing ammonium hydroxide, hydrogen peroxide solution, and pure water. The ratio of a set of ammonium hydroxide and hydrogen peroxide solution to pure water (the set: pure water) is set in the range of 6: 1 to 11:10. For example, the ratio of ammonium hydroxide, hydrogen peroxide solution, and pure water is set in the range of 1: 5: 1 to 1:10:10. The SC-1 supply source 831c is connected to the nozzle 51c via a pipe 832c in which an on-off valve 833c is inserted. Therefore, when the on-off valve 833c is opened, the SC-1 supplied from the SC-1 supply source 831c is discharged from the nozzle 51c. Since SC-1 can etch the multilayer film 9, SC-1 is also referred to as an etching solution below. The etching rate of the upper layer 9c by SC-1 is higher than the etching rate of the intermediate layer 9b and the lower layer 9a.

In the example of FIG. 3, the nozzles 51a to 51c are arranged in this order from the downstream side to the upstream side of the rotation direction AR1 of the substrate W. That is, the nozzle 51a is arranged on the most downstream side.

The treatment liquid supply unit 5 selectively supplies an acidic chemical solution, a rinse solution, and SC-1. When the treatment liquid (acidic chemical liquid, rinse liquid and SC-1) is supplied to the corresponding nozzles of the nozzles 51a to 51c, the liquid is landed at a position in the treatment region R1 on the peripheral edge of the upper surface of the rotating substrate W. As such, the nozzle discharges the processing liquid. Each of the on-off valves 833a to 833c is opened and closed under the control of the control unit 130. That is, the discharge mode of the processing liquid from the nozzle head 50 (specifically, the type of the processing liquid to be discharged, the discharge start timing, the discharge end timing, the discharge flow rate, etc.) is controlled by the control unit 130. The processing liquid that has landed on the substrate W receives centrifugal force due to the rotation of the substrate W and scatters outward from the peripheral edge of the substrate W.

FIG. 5 schematically shows an example of the nozzle 51c. In the example of FIG. 5, the nozzle 51c discharges the treatment liquid (etching liquid) along the discharge direction described below. That is, the nozzle 51c discharges the processing liquid in an oblique direction (discharge direction) that approaches the peripheral edge of the substrate W as it goes downward from the discharge port. That is, the nozzle 51c discharges the processing liquid in an oblique direction that is inclined outward in the radial direction toward the lower side. The angle formed by this discharge direction with respect to the horizontal plane is, for example, about 45 degrees. The discharge direction of the nozzle 51c is defined by, for example, the extending direction of the internal flow path formed in the nozzle 51c. Specifically, the internal flow path of the nozzle 51c extends in the diagonal direction on the discharge side thereof and reaches the discharge port. As a result, the nozzle 51c can discharge the processing liquid from the discharge port in the diagonal direction.

When the treatment liquid is discharged in the diagonal direction in this way, the treatment liquid that has landed on the liquid landing position PL1 on the upper surface of the substrate W faces the peripheral edge of the substrate W in the radial direction, that is, toward the peripheral edge side of the substrate W. Easy to flow. Therefore, it is possible to prevent the treatment liquid from entering the non-treatment region (“device region”) R2 inside in the radial direction. The non-processed region R2 is an region other than the processed region R1 on the upper surface of the substrate W. The same applies to the other nozzles 51a and 51b.

When the nozzle 51c discharges the etching solution while the substrate W is rotating, the multilayer film 9 in the processing region R1 of the substrate W is etched and removed. In the present embodiment, the nozzle moving mechanism 6 described later spatially moves the nozzle 51c according to the progress of etching to move the etching solution landing position PL1 to the peripheral edge side of the substrate W. As a result, the multilayer film 9 is appropriately removed. This point will be described in detail later.

<Cup part 3>
The cup portion 3 receives the processing liquid or the like scattered from the substrate W rotating together with the spin chuck 21. In addition, in FIG. 3 and FIG. 4, the illustration of the cup portion 3 is omitted in order to avoid the complexity of the drawings.

The cup portion 3 includes a splash guard 31. The splash guard 31 is a tubular member having an open upper end, and is provided so as to surround the rotation holding mechanism 2. In this embodiment, the splash guard 31 is, for example, 3 of a bottom member 311, an inner member (also referred to as an "inner guard" or simply "guard") 312, and an outer member (also referred to as an "outer guard") 313. It is composed of individual members. The outer member 313 may not be provided, or conversely, a guard may be further provided on the outside of the outer member 313 so as to surround the rotation holding mechanism 2.

The bottom member 311 is a cylindrical member having an open upper end, and has an annular bottom portion, a cylindrical inner side wall portion extending upward from the inner edge portion of the bottom portion, and a cylinder extending upward from the outer edge portion of the bottom portion. Includes a shaped outer wall. At least the vicinity of the tip of the inner side wall portion is accommodated in the inner space of the collar-shaped member 241 provided in the casing 24 of the rotation holding mechanism 2.

A drainage groove (not shown) communicating with the space between the inner side wall portion and the outer wall portion is formed on the bottom portion. This drainage groove is connected to the drainage line of the factory. Further, an exhaust liquid mechanism is connected to the drainage groove for forcibly exhausting the inside of the groove so that the space between the inner side wall portion and the outer wall portion is in a negative pressure state. The space between the inner side wall portion and the outer wall portion is a space for collecting and draining the treatment liquid used for processing the substrate W, and the treatment liquid collected in this space is discharged from the drainage groove. It is drained.

The inner member 312 is a tubular member having an open upper end, and the upper portion (“upper end side portion”, “upper end portion”) of the inner member 312 extends inward and upward. That is, the upper portion extends diagonally upward toward the rotation axis a1. At the lower part of the inner member 312, a tubular inner peripheral wall portion extending downward along the upper inner peripheral surface and a tubular outer peripheral wall portion extending downward along the upper outer peripheral surface are formed. In a state where the bottom member 311 and the inner member 312 are close to each other, the outer wall portion of the bottom member 311 is accommodated between the inner peripheral wall portion and the outer peripheral wall portion of the inner member 312. The treatment liquid or the like received by the upper portion of the inner member 312 is discharged via the bottom member 311.

The outer member 313 is a tubular member with an open upper end, and is provided on the outside of the inner member 312. The upper portion (“upper end side portion”, “upper end portion”) of the outer member 313 extends inward and upward. That is, the upper portion extends diagonally upward toward the rotation axis a1. The lower portion extends downward along the outer peripheral wall portion of the inner member 312. The treatment liquid or the like received by the upper part of the outer member 313 is discharged from the gap between the outer peripheral wall portion of the inner member 312 and the lower part of the outer member 313.

The splash guard 31 is provided with a guard drive mechanism (“elevation drive unit”) 32 for moving the splash guard 31 up and down. The guard drive mechanism 32 is composed of, for example, a stepping motor. In this embodiment, the guard drive mechanism 32 independently raises and lowers the three members 311, 312, and 313 included in the splash guard 31.

Each of the inner member 312 and the outer member 313 is driven by the guard drive mechanism 32 and moves between the upper position and the lower position of each. Here, the upper position of each member 312, 313 is a position where the upper end edge portion of the member 312, 313 is arranged sideways and above the substrate W held by the spin chuck 21. On the other hand, the lower position of each member 312, 313 is a position where the upper end edge portion of the member 312, 313 is arranged below the upper surface of the spin chuck 21. The upper position (lower position) of the outer member 313 is located slightly above the upper position (lower position) of the inner member 312. The inner member 312 and the outer member 313 move up and down at the same time or sequentially so as not to collide with each other. The bottom member 311 is moved by a guard drive mechanism 32 between a position where the inner side wall portion thereof is accommodated in the inner space of the flange-shaped member 241 provided on the casing 24 and a position below the bottom member 311. However, the guard drive mechanism 32 is electrically connected to the control unit 130 and operates under the control of the control unit 130. That is, the position of the splash guard 31 (specifically, the positions of the bottom member 311, the inner member 312, and the outer member 313) is controlled by the control unit 130.

<Gas supply unit 4>
The gas supply unit 4 is a gas discharge mechanism that discharges an inert gas so as to hit the peripheral edge of the upper surface of the substrate W that is held and rotated by the spin chuck 21 (both the "gas discharge mechanism for the peripheral edge" and "gas discharge". Includes 441 and 445 (also referred to as "parts"). The "inert gas" is a gas having poor reactivity with the material of the substrate W and the thin film formed on the surface thereof. The inert gas includes, for example, _{at least one of nitrogen (N 2} ) gas, argon gas and helium gas. The gas discharge mechanism 441 discharges the inert gas to form, for example, a gas columnar gas flow G1 in the vicinity of the peripheral edge of the upper surface of the substrate W. The gas discharge mechanism 445 discharges the inert gas at a position in the circumferential direction different from that of the gas discharge mechanism 441, and forms, for example, a gas columnar gas flow G5 near the peripheral edge of the upper surface of the substrate W. These gas streams G1 and G5 can blow the etching solution on the processing region R1 of the substrate W radially outward, as will be described in detail later.

The gas supply unit 4 is a gas discharge mechanism that discharges an inert gas to the vicinity of the center of the upper surface of the substrate W that is held and rotated by the spin chuck 21 (also referred to as a "central gas discharge mechanism", "another Also referred to as a "gas discharge section") 443. In the example of FIG. 2, the gas flow G3 formed by the inert gas discharged from the gas discharge mechanism 443 is schematically shown. The gas supply unit 4 forms gas flows G1, G3, and G5 of the inert gas toward the upper surface of the substrate W from the gas discharge mechanisms 441, 443, and 445, so that the treatment liquid is formed in the non-treatment region R2 on the upper surface of the substrate W. Suppresses the flow to (see FIG. 5).

The gas discharge mechanism 445 includes a nozzle 51d. The nozzle 51d is attached to the nozzle head 50 of the processing liquid supply unit 5 (see FIGS. 2 to 4). The nozzle 51d is attached to the plate-shaped member of the nozzle head 50 in the same manner as the nozzles 51a to 51c. In the example of FIG. 3, the nozzles 51d are arranged in a line with the nozzles 51a to 51c, and are arranged on the upstream side of the rotation direction AR1 from any of the nozzles 51a to 51c.

The gas discharge mechanism 441 includes a nozzle head 48. The gas discharge mechanism 443 includes a nozzle head 49. The nozzle heads 48 and 49 are attached to the tips of the long arms 61 and 62 provided in the nozzle moving mechanism 6 described later, respectively. The arms 61 and 62 extend along the horizontal plane. The nozzle moving mechanism 6 moves the nozzle heads 48 and 49 between the respective processing positions and the retracted positions by moving the arms 61 and 62.

The nozzle head 48 includes a nozzle (“gas discharge nozzle for processing surface”) 41 and a holding member for holding the nozzle (“gas discharge nozzle for processing surface”) 41. The holding member is formed by joining, for example, a plate-shaped member extending along a horizontal plane and a protruding member protruding upward from one end of the plate-shaped member, and has an L-shaped cross-sectional shape. There is. The tip of the protruding member is attached to the tip of the arm 61, and the plate-shaped member projects from the tip of the arm 61 to the side opposite to the base end of the arm 61. The nozzle 41 is held by the plate-shaped member in a state of penetrating the plate-shaped member in the vertical direction. The tip end portion (lower end portion) of the nozzle 41 projects downward from the lower surface of the plate-shaped member, and the upper end portion projects upward from the upper surface. One end of the pipe 471 is connected to the upper end of the nozzle 41. The other end of the pipe 471 is connected to the gas supply source 451. A flow rate controller 481 and an on-off valve 461 are provided in order from the gas supply source 451 side in the middle of the path of the pipe 471.

Here, when the nozzle moving mechanism 6 moves the nozzle head 48 to the processing position, the discharge port of the nozzle 41 faces the peripheral edge of the upper surface of the substrate W.

When the nozzle head 48 is located at the processing position, the nozzle 41 is supplied with an inert gas (nitrogen (N ₂ ) gas in the illustrated example) from the gas supply source 451. The nozzle 41 discharges the supplied inert gas from above so as to hit the supply position P1 on the peripheral edge of the upper surface of the substrate W. Since the substrate W rotates around the rotation axis a1, the supply position P1 also orbits relatively on the peripheral edge of the substrate W, similarly to the liquid landing position PL1.

6 and 7 show an example of the positional relationship between the liquid flow L1 of the processing liquid discharged by the substrate processing apparatus 1 and the positions where the gas flows G1 and G5 of the inert gas hit the peripheral edge of the substrate W, respectively. It is a top surface schematic view and a side surface schematic view of a substrate W.

After the discharged inert gas reaches the supply position P1, the nozzle 41 discharges the inert gas from the discharge port in a predetermined direction so as to flow from the supply position P1 toward the peripheral edge of the substrate W.

The liquid flow L1 of the treatment liquid discharged from the nozzle head 50 of the treatment liquid supply unit 5 is landed at the liquid landing position PL1 on the peripheral edge of the upper surface of the substrate W. The radial width of the substrate W of the liquid flow L1 is, for example, 0.5 mm to 2.5 mm. The nozzle head 50 can selectively discharge the treatment liquid from each of the plurality of nozzles 51a to 51c. The landing positions PL1 of the processing liquids discharged from the nozzles 51a to 51c are different from each other. The supply position P1 to which the gas flow G1 hits is located on the upstream side of the rotation direction AR1 of the substrate W with respect to the liquid landing position PL1 corresponding to any of the nozzles 51a to 51c. The position on the upstream side of the liquid landing position PL1 here means a position within a half circumference on the opposite side of the rotation direction AR1 from the liquid landing position PL1.

That is, the gas discharge mechanism 441 supplies the gas discharge mechanism 441 on the upstream side of the rotation direction AR1 of the substrate W with respect to the liquid landing position PL1 on which the treatment liquid discharged from the treatment liquid supply unit 5 is landed on the peripheral edge of the upper surface of the substrate W. The inert gas is discharged from above toward the position P1. The gas flow G1 formed by the inert gas discharged by the gas discharge mechanism 441 hits the upper surface of the substrate W at the supply position P1. The gas discharge mechanism 441 discharges the inert gas in a predetermined discharge direction so that the gas flow G1 is directed from the supply position P1 toward the peripheral edge of the substrate W.

By the way, the processing liquid landed at the liquid landing position PL1 moves in the rotation direction AR1 by the rotation of the substrate W. When the processing liquid on the substrate W reaches the supply position P1, most of it is blown to the outside of the substrate W by the gas flow G1. That is, most of the old processing liquid before one rotation is blown to the outside of the substrate W by the gas flow G1. According to this, the amount of the old processing liquid that reaches the liquid landing position PL1 can be reduced. In other words, the amount of the old treatment liquid mixed in the new treatment liquid landed at the liquid landing position PL1 can be reduced.

One end of the pipe 475 is connected to the upper end of the nozzle 51d. The other end of the pipe 475 is connected to the gas supply source 455 (see also FIG. 2). A flow rate controller 485 and an on-off valve 465 are provided in order from the gas supply source 455 side in the middle of the path of the pipe 475. The lower end of the nozzle 51d is open. The opening is the discharge port of the nozzle 51d.

When the nozzle moving mechanism 6 moves the nozzle head 50 to the processing position, the discharge port of the nozzle 51d faces the peripheral edge of the upper surface of the substrate W. When the nozzle head 50 is located at the processing position, the nozzle 51d is supplied with an inert gas (nitrogen (N ₂ ) gas in the illustrated example) from the gas supply source 455. The nozzle 51d discharges the supplied inert gas from above so as to hit the supply position P5 on the peripheral edge of the upper surface of the substrate W to form the gas flow G5. The supply position P5 is located between the supply position P1 and the liquid landing position PL1 in the circumferential direction with respect to the rotation axis a1. That is, the supply position P5 is located on the downstream side of the rotation direction AR1 from the supply position P1 and on the upstream side of the rotation direction AR1 from the liquid landing position PL1. Similar to the supply position P1 and the liquid landing position PL1, the supply position P5 also orbits relatively on the peripheral edge of the substrate W as the substrate W rotates.

After the gas flow G5 reaches the supply position P5, the nozzle 51d discharges the inert gas from the discharge port in the specified discharge direction so as to flow from the supply position P5 toward the peripheral edge of the substrate W. By this gas flow G5, most of the processing liquid at the supply position P5 is blown to the outside of the substrate W. That is, the processing liquid that remains on the peripheral edge of the substrate W even after being blown off at the supply position P1 by the gas flow G1 is blown off by the gas flow G5 at the supply position P5.

The nozzle head 49 of the gas discharge mechanism 443 includes a cylindrical member 93 attached to the lower surface of the tip end portion of the arm 62, a disk-shaped blocking plate 90 attached to the lower surface of the cylindrical member 93, and a cylindrical nozzle 43. Includes. The axis of the cylindrical member 93 and the axis of the blocking plate 90 are substantially the same, and are along the vertical directions, respectively. The lower surface of the blocking plate 90 is along the horizontal plane. The nozzle 43 penetrates the cylindrical member 93 and the blocking plate 90 in the vertical direction so that the axis thereof substantially coincides with the axis of the blocking plate 90 and the cylindrical member 93. The upper end of the nozzle 43 also penetrates the tip of the arm 62 and opens to the upper surface of the arm 62. One end of the pipe 473 is connected to the upper end of the nozzle 43. The other end of the pipe 473 is connected to the gas supply source 453. A flow rate controller 483 and an on-off valve 463 are provided in order from the gas supply source 453 side in the middle of the path of the pipe 473. The lower end of the nozzle 43 is open to the lower surface of the blocking plate 90. The opening is the discharge port of the nozzle 43.

When the nozzle moving mechanism 6 moves the nozzle head 49 to the processing position, the discharge port of the nozzle 43 faces the vicinity of the center of the upper surface of the substrate W. In this state, the nozzle 43 is supplied with an inert gas (nitrogen (N ₂ ) gas in the illustrated example) from the gas supply source 453 via the pipe 473. The nozzle 43 discharges the supplied inert gas toward the center of the upper surface of the substrate W to form the gas flow G3. The gas flow G3 radiates from above the central portion of the substrate W toward the peripheral edge of the substrate W. That is, the gas discharge mechanism 443 discharges the inert gas from above the central portion of the upper surface of the substrate W to generate a gas flow G3 that spreads from above the central portion toward the peripheral edge of the substrate W. Since the gas flow G3 can apply a wind pressure outward in the radial direction to the processing liquid flowing through the processing region R1 of the substrate W, it is possible to prevent the treatment liquid from entering the non-treatment region R2.

The flow rate controllers 481, 483, and 485 can, for example, adjust the flow rate of the gas according to the opening and closing amount of the valve and the flow meter that detects the flow rate of the gas flowing through the pipes 471, 473, and 475 provided with each. It is configured with a variable valve. The control unit 130 can change the flow rate controllers 481, 483, and 485 via a valve control mechanism (not shown) so that the flow rate detected by the flow meter becomes the target flow rate for each of the flow rate controllers 481, 483, and 485. Controls the amount of opening and closing of the valve. The control unit 130 freely controls the flow rate of each gas passing through the flow rate controllers 481, 483, and 485 within a predetermined range by setting a target flow rate within a predetermined range according to preset setting information. can do. Further, the control unit 130 controls the on-off valves 461, 463, 465 to the open state or the closed state via the valve control mechanism. Therefore, the discharge mode of the inert gas from the nozzles 41, 43, 51d (specifically, the discharge start timing, the discharge end timing, the discharge flow rate, etc.) is controlled by the control unit 130.

<Nozzle movement mechanism 6>
The nozzle moving mechanism 6 is a mechanism for moving the nozzle heads 48 to 50 between the respective processing positions and the retracted positions.

The nozzle moving mechanism 6 includes horizontally extending arms 61 to 63, nozzle bases 64 to 66, and drive units 67 to 69. The nozzle heads 48 to 50 are attached to the tip portions of the arms 61 to 63, respectively.

The base end portions of the arms 61 to 63 are connected to the upper end portions of the nozzle bases 64 to 66, respectively. The nozzle bases 64 to 66 are arranged so as to be dispersed around the casing 24 in a posture such that their axes are along the vertical direction. The nozzle bases 64 to 66 extend vertically along the axis thereof. The nozzle bases 64 to 66 are rotatable around their respective axes. The nozzle bases 64 to 66 are provided with drive units 67 to 69 that rotate around their respective axes. The drive units 67 to 69 include, for example, a motor such as a stepping motor.

The drive units 67 to 69 rotate the upper end portions of the nozzle bases 64 to 66 via the rotation shafts of the nozzle bases 64 to 66, respectively. Along with the rotation of each upper end portion, the nozzle heads 48 to 50 also rotate around the axis of the nozzle bases 64 to 66. As a result, the drive units 67 to 69 move the nozzle heads 48 to 50 horizontally between the respective processing positions and the retracted positions.

When the nozzle head 48 moves to the processing position, the discharge port of the nozzle 41 faces a part of the peripheral edge of the substrate W held by the spin chuck 21.

When the nozzle head 49 moves to the processing position, the nozzle 43 is located above the central portion c1 of the substrate W, and the axis of the nozzle 43 substantially coincides with the rotation axis a1 of the spin chuck 21. The discharge port (lower opening) of the nozzle 43 faces the central portion c1 of the substrate W. Further, the lower surface of the blocking plate 90 faces substantially parallel to the upper surface of the substrate W. The blocking plate 90 is in close contact with the upper surface of the substrate W in a non-contact state.

When the nozzle head 50 moves to the processing position, the nozzles 51a to 51d move to the respective processing positions. More precisely, for example, when the nozzles 51a to 51d are arranged in a row along the extending direction of the arm 63, the distance between the nozzles 51a to 51d and the peripheral edge of the circular substrate W is determined. Usually slightly different from each other. Even when the width of the processing region R1 is narrow, the drive unit 69 is set to the nozzle that discharges the processing liquid from the nozzles 51a to 51c so that the processing liquid selectively discharged from the nozzles 51a to 51c hits the processing region R1. Accordingly, the processing position of the nozzle head 50 is adjusted under the control of the control unit 130.

The loading / unloading of the substrate W into the substrate processing device 1 is performed by the center robot CR with the nozzle heads 48 to 50 and the like stopped at the retracted position. The substrate W carried into the substrate processing apparatus 1 is detachably held by the spin chuck 21. That is, the retracted positions of the nozzle heads 48 to 50 are positions where they do not interfere with the transport path of the substrate W and they do not interfere with each other. Each retracted position is, for example, a position outside and above the splash guard 31.

The drive units 67 to 69 are electrically connected to the control unit 130 and operate under the control of the control unit 130. The control unit 130 moves the nozzle heads 48 and 50 to the processing position so that the gas flows G1, G5 and the liquid flow L1 hit the supply positions P1, P5 and the liquid landing position PL1 in the peripheral edge of the upper surface of the substrate W, respectively. Is performed by the nozzle moving mechanism 6 according to the preset setting information. The supply positions P1, P5 and the liquid landing position PL1 are adjusted by changing the setting information. Further, the control unit 130 causes the nozzle movement mechanism 6 to move the nozzle head 49 to the processing position according to the setting information so that the gas flow G3 hits the vicinity of the center of the substrate W. That is, the positions of the nozzle heads 48 to 50 are controlled by the control unit 130. That is, the positions of the nozzles 41, 43, 51a to 51d are controlled by the control unit 130.

The processing liquid discharged to the liquid landing position PL1 on the peripheral edge of the upper surface of the substrate W moves in the circumferential direction of the substrate W in a state of forming a liquid film and adhering to the processing region R1. Centrifugal force due to the rotation of the substrate W acts on the liquid film of the treatment liquid in the process of the movement, and a part of the treatment liquid scatters outward from the peripheral edge of the substrate W. Therefore, the amount of the liquid film of the treatment liquid decreases as the distance from the liquid landing position PL1 along the rotation direction AR1. The degree of this decrease varies depending on the rotation speed of the substrate W, the film quality of the multilayer film 9, the amount and viscosity of the discharged treatment liquid, and the like. When the processing liquid on the peripheral edge of the upper surface of the substrate W reaches the supply position P1 as it rotates, most of it is blown out of the peripheral edge of the substrate W by the gas flow G1. Subsequently, when the processing liquid still remaining due to the gas flow G1 reaches the supply position P5, the gas flow G5 blows the treatment liquid to the outside of the peripheral edge of the substrate W.

If the width D1 of the processing region R1, that is, the width of the region to be etched is 2 mm, the liquid flow L1 of the treatment liquid is discharged so as to land in a range of 1.5 mm in width from the peripheral edge of the substrate W. Is preferable. In this case, in order to efficiently remove the residual treated liquid from the substrate W while suppressing the liquid splashing reaching the non-treated region R2, the center of the cross section of the gas flow G1 of the inert gas is from the peripheral edge of the substrate W. For example, it is preferable to discharge the gas flow G1 so as to hit the range of 4 mm to 8 mm. The width of the liquid film of the residual treatment liquid on the peripheral edge of the substrate W is usually wider than the width of the liquid flow L1 of the treatment liquid landing on the liquid landing position PL1. Therefore, as described above, it is more preferable that the width of the gas flow G1 of the inert gas is wider than the width of the liquid flow L1 of the treatment liquid landing on the peripheral edge of the substrate W. Specifically, the width of the gas flow G1 of the inert gas is preferably set to, for example, 3 to 5 times the width of the liquid flow L1. As a result, the residual treatment liquid on the peripheral edge of the substrate W can be efficiently discharged to the outside of the substrate W by the gas flow G1.

<Operation of board processing device>
FIG. 8 is a flowchart showing an example of the operation of the substrate processing device 1. Initially, the nozzle heads 48 to 50 are stopped at their respective retracted positions. First, the center robot CR carries the substrate W into the substrate processing device 1, and the spin chuck 21 holds the substrate W (step S1). Next, the rotation mechanism 231 starts rotating the spin chuck 21 around the rotation axis a1 (step S2). As a result, the substrate W also starts to rotate around the rotation axis a1.

Next, the gas supply unit 4 starts discharging the gas streams G1, G3, and G5 (step S3). Specifically, first, the nozzle moving mechanism 6 moves the nozzle heads 48 to 50 to the respective processing positions. Then, the control unit 130 opens the on-off valves 461, 463, and 465 to discharge the inert gas from the nozzles 41, 43, and 51d, respectively. As a result, gas streams G1, G3, and G5 are formed.

Next, the processing liquid supply unit 5 starts discharging the etching liquid (step S4). That is, the processing liquid supply unit 5 discharges the etching liquid from the nozzle 51c and causes the etching liquid to land on the liquid landing position PL1 on the substrate W. The liquid landing position PL1 (that is, the initial position) is a position inside the substrate W by a predetermined width, for example, about 1.5 mm. Specifically, the control unit 130 opens the on-off valve 833c to discharge the etching solution from the nozzle 51c. The treatment liquid supply unit 5 may also discharge the treatment liquid from other nozzles 51a and 51b, if necessary. These treatment liquids may be supplied sequentially or in parallel at the same time. The term "same period" as used herein means that at least a part of the ejection period of at least two nozzles of the nozzles 51a to 51c overlap each other on the time axis. Here, for the sake of simplicity, it is assumed that the treatment liquid is not discharged from the nozzles 51a and 51b.

The etching solution deposited on the liquid landing position PL1 moves in the circumferential direction as the substrate W rotates, and also flows outward in the radial direction due to centrifugal force, and a part of the etching liquid scatters outward from the peripheral edge of the substrate W. To do. The etching solution remaining on the processing region R1 of the substrate W reaches the supply position P1 by the rotation of the substrate W. The etching solution is blown outside the substrate W by the gas flow G1 at the supply position P1, and the etching solution remaining at the supply position P1 is also blown outside the substrate W by the gas flow G5 at the supply position P5. According to this, it is possible to prevent the old etching solution from being mixed with the newly supplied etching solution at the liquid landing position PL1.

When the etching solution continues to be supplied toward the liquid landing position PL1, the multilayer film 9 of the substrate W is mainly etched at the liquid landing position PL1. 9 to 13 are diagrams schematically showing an example of the state of etching on the substrate W. As shown in FIG. 9, the groove 92 is formed in the region where the liquid landing position PL1 is the radial position by etching the multilayer film 9 at the liquid landing position PL1. That is, of the upper surface of the upper layer 9c, the region radially outside the liquid landing position PL1 is not uniformly etched, but the region including the liquid landing position PL1 is mainly etched. The groove 92 is initially formed by removing the upper layer 9c of the multilayer film 9 by etching. Since the substrate W rotates around the rotation axis a1, the groove 92 is formed in a substantially circular shape centered on the rotation axis a1 in a plan view.

As the etching progresses, the width of the groove 92 increases and the depth of the groove 92 increases. As the etching progresses, the intermediate layer 9b is exposed at the bottom of the groove 92. Further progress of etching exposes the lower layer 9a at the bottom of the groove 92, and further progress of etching exposes the base layer 91 at the bottom of the groove 92 (see FIG. 10). In the example of FIG. 10, the thickness of the upper layer 9c is reduced on the outer side in the radial direction (right side of the paper surface) from the groove 92. This is because the etching solution receives centrifugal force and flows outward in the radial direction on the upper surface of the upper layer 9c, and at that time, the etching solution etches the upper surface of the upper layer 9c.

When the base layer 91 is exposed, the multilayer film 9 is divided into two multilayer films 9A and 9B by the groove 92. The multilayer film 9A is located radially inside the groove 92 (that is, the rotation axis a1 side: the left side of the paper surface), and the multilayer film 9B is located radially outside the groove 92 (that is, the peripheral side of the substrate W). There is. In the following, the lower layer 9a, the intermediate layer 9b and the upper layer 9c belonging to the multilayer film 9A are also referred to as the lower layer 9aA, the intermediate layer 9bA and the upper layer 9cA, respectively, and the lower layer 9a, the intermediate layer 9b and the upper layer 9c belonging to the multilayer film 9B are referred to as the lower layer 9aB and the upper layer 9c, respectively. It is also called an intermediate layer 9bB and an upper layer 9cB.

When the base layer 91 is exposed, the etching solution is applied to the upper surface of the base layer 91. Since the etching solution can hardly etch the base layer 91, the height position of the liquid landing position PL1 does not decrease so much thereafter. Since the etching solution spreads on the upper surface of the base layer 91 at the time of landing, a part of the etching solution flows inward in the radial direction on the upper surface of the base layer 91.

Here, etching on the inner side surface in the radial direction among the side surfaces forming the groove 92 will be described. The radial inner side surface of the groove 92 is composed of a side surface 9a1 of the lower layer 9aA, a side surface 9b1 of the intermediate layer 9bA, and a side surface 9c1 of the upper layer 9cA.

Since a part of the etching solution flows inward in the radial direction on the upper surface of the base layer 91, it can come into contact with the inner side surface in the radial direction of the groove 92. Therefore, the side surfaces 9a1, 9b1, and 9c1 can also be etched. However, in this etching, the etching on the side surface 9a1 of the lower layer 9aA proceeds at least more than the side surface 9c1 of the upper layer 9cA. This is considered for the following reasons.

First, since the intermediate layer 9bA and the upper layer 9cA are formed at a position higher than the lower layer 9aA, the etching solution spreading on the upper surface of the base layer 91 contacts at least the side surface 9a1 of the lower layer 9aA rather than the side surface 9c1 of the upper layer 9cA. It's easy to do. As a result, the side surface 9a1 of the lower layer 9aA is etched and recedes more radially inward, whereas the side surface 9c1 of the upper layer 9cA does not recede so much in the radial direction. Further, from this viewpoint, the side surface 9b1 of the intermediate layer 9bA does not recede inward in the radial direction as compared with the side surface 9a1 of the lower layer 9aA. On the other hand, for the same reason, the side surface 9b1 of the intermediate layer 9bA is more likely to recede radially inward than the side surface 9c1 of the upper layer 9cA.

Secondly, since the thickness of the upper layer 9cA is 10 times or more that of the lower layer 9aA, it is also considered that the etching on the side surface 9a1 of the lower layer 9aA proceeds more than the side surface 9c1 of the upper layer 9cA. Further, since the thickness of the upper layer 9cA is 10 times or more that of the intermediate layer 9bA, it is also considered that the etching on the side surface 9b1 of the intermediate layer 9bA proceeds from the side surface 9c1 of the upper layer 9cA.

Then, when the etching of the side surface 9a1 of the lower layer 9aA proceeds more than the side surface 9c1 of the upper layer 9cA, the radially outer portion of the upper layer 9cA is not supported by the lower layer 9aA. That is, the upper layer 9cA projects outward in the radial direction. Since the bonding force of the multilayer film 9 on the bonding surface between different materials is relatively weak, the protruding portion can be peeled off. It is not desirable for such peeling to occur.

Therefore, when the base layer 91 is exposed, the substrate processing apparatus 1 spatially moves the nozzle 51c to move the etching solution landing position PL1 to the radial outer side (that is, the peripheral edge of the substrate W). Hereinafter, a specific description will be given.

With reference to FIG. 8 again, after the start of ejection of the etching solution (step S4), the control unit 130 determines whether or not the base layer 91 is exposed at the bottom of the groove 92, for example, at predetermined intervals (step S5). .. The control unit 130 may make this determination based on, for example, the elapsed time from the start of ejection of the etching solution (step S4). The correspondence between the progress of etching and the elapsed time can be determined in advance by, for example, simulation or experiment. Therefore, the control unit 130 determines whether or not the elapsed time from the start of discharging the etching solution is equal to or longer than the reference time. This reference time is the time from the start of ejection of the etching solution to the exposure of the base layer 91 at the bottom of the groove 92, and is set in advance, for example.

When the elapsed time is less than the reference time, the base layer 91 is not yet exposed at the bottom of the groove 92, so the control unit 130 executes step S5 again. When the elapsed time is equal to or longer than the reference time, the base layer 91 is exposed at the bottom of the groove 92, so that the nozzle moving mechanism 6 spatially moves the nozzle 51c (here, the nozzle head 50) to deposit the etching solution. The liquid position PL1 is moved outward in the radial direction by a predetermined movement amount (see also step S6 and FIG. 11). Specifically, the nozzle moving mechanism 6 moves the nozzle 51c outward by a predetermined movement amount in the radial direction. In the example of FIG. 11, the position of the nozzle 51c before movement is indicated by a virtual line. The predetermined movement amount is set in advance to, for example, about several hundred μm.

As a result, the landing position PL1 of the etching solution is moved away from the side surface 9a1 of the lower layer 9aA in the radial direction. Therefore, even if the etching solution spreads on the upper surface of the base layer 91 at the time of landing, the etching solution does not easily reach the side surface 9a1 of the lower layer 9aA. In other words, the amount of etching solution that comes into contact with the side surface 9a1 can be reduced. As a result, etching on the side surface 9a1 of the lower layer 9aA can be suppressed. Therefore, the peeling of the above-mentioned upper layer 9cA can be suppressed.

Next, etching on the radial outer side surface of the side surface forming the groove 92 will be described. The radial outer side surface of the groove 92 is composed of a side surface 9a2 of the lower layer 9aB, a side surface 9b2 of the intermediate layer 9bB, and a side surface 9c2 of the upper layer 9cB.

The etching solution spreads radially outward on the upper surface of the base layer 91 at the time of landing, and further flows outward in the radial direction due to the centrifugal force due to the rotation of the substrate W. Therefore, the etching solution naturally acts on the radial outer side surface of the groove 92. Specifically, when the etching solution flows radially outward on the upper surface of the base layer 91, it first collides with the side surface 9a2 of the lower layer 9aB. Then, the etching solution flows upward along the side surface 9a2 of the lower layer 9aB, the side surface 9b2 of the intermediate layer 9bB, and the side surface 9c2 of the upper layer 9cB by centrifugal force, and flows outward in the radial direction on the upper surface of the upper layer 9cB.

As a result, the side surface 9a2 of the lower layer 9aB, the side surface 9b2 of the intermediate layer 9bB, and the side surface 9c2 (further, the upper surface) of the upper layer 9cB are etched. Therefore, if the etching solution continues to be supplied to the liquid landing position PL1, the etching on the multilayer film 9B proceeds and the side surfaces 9a2, 9b2, and 9c2 gradually recede outward in the radial direction. Here, the etching rate for the upper layer 9c of the etching solution is higher than the etching rate for the intermediate layer 9b and the lower layer 9a. However, the etching on the side surface 9a2 of the lower layer 9aB proceeds at least more than the side surface 9c2 of the upper layer 9cB. This is considered for the following reasons.

First, the etching solution flows radially outward on the upper surface of the base layer 91 and collides with the side surface 9a2 of the lower layer 9aB, whereas the etching solution does not collide with the side surface 9c2 of the upper layer 9cB and collides with the side surface 9c2. It is considered that it flows along the. As a result, the etching solution acts more strongly on the side surface 9a2 of the lower layer 9aB than on the side surface 9c2 of the upper layer 9cB.

Secondly, it is considered that the etching solution first etches the side surface 9a2 of the lower layer 9aB and then etches the side surface 9c2 of the upper layer 9cB. That is, the etching solution acts on the lower layer 9aB with a high degree of cleanliness, whereas the etching solution acts on the upper layer 9cB with a low degree of cleanliness. From this viewpoint as well, it is considered that etching proceeds on the side surface 9a2 of the lower layer 9aB rather than the side surface 9c2 of the upper layer 9cB.

Thirdly, since the thickness of the upper layer 9cB is 10 times or more that of the lower layer 9aB, it is also considered that the etching on the side surface 9c2 of the lower layer 9aB proceeds more than the side surface 9a2 of the upper layer 9cB.

Further, for the same reason as described above, etching on the side surface 9b2 of the intermediate layer 9bB can also proceed from the side surface 9c1 of the upper layer 9cA.

As described above, the etching of the multilayer film 9B proceeds while the side surface 9a2 of the lower layer 9aB of the multilayer film 9B recedes radially outward from at least the side surface 9c2 of the upper layer 9cB.

In the first embodiment, after the base layer 91 is exposed, the substrate processing apparatus 1 sets the liquid landing position PL1 further radially outward according to the progress of etching (that is, with the passage of time). Move. For example, the nozzle moving mechanism 6 moves the nozzle 51c at predetermined time intervals to move the liquid landing position PL1 radially outward by a predetermined movement amount (see also FIG. 12). The predetermined time is preset to, for example, about several hundred μm, and the predetermined movement amount is preset to, for example, about several hundred μm. However, the predetermined time and the predetermined movement amount are set so that the liquid landing position PL1 is located on the upper surface of the base layer 91. In other words, the nozzle moving mechanism 6 moves the nozzle 51c within the range in which the etching solution is landed on the upper surface of the base layer 91 (that is, the liquid landing position PL1 is not located on the upper surface of the multilayer film 9B).

FIG. 14 is a graph schematically showing an example of the time change of the liquid landing position PL1. In the example of FIG. 14, the vertical axis represents the liquid landing position PL1 in the radial direction, and the horizontal axis represents time. In FIG. 14, the vertical axis indicates the position on the outer side in the radial direction toward the upper position. In the example of FIG. 14, the nozzle moving mechanism 6 moves the liquid landing position PL1 in only one direction outward in the radial direction, and moves the liquid landing position PL1 radially outward by a substantially constant amount at substantially regular time intervals. There is.

As a result, the liquid landing position PL1 can be further separated from the side surface 9a1 of the lower layer 9aA on the inner side in the radial direction. Therefore, etching on the side surface 9a1 of the lower layer 9aA can be further suppressed.

Further, the distance between the liquid landing position PL1 and the radial outer side surface of the groove 92 (that is, the side surfaces 9a2, 9b2, 9c2) can be shortened. As a result, the etching solution acts on the side surfaces 9a2, 9b2, and 9c2 immediately after landing on the liquid landing position PL1. Therefore, the etching solution can act on the side surfaces 9a2, 9b2, and 9c2 with higher cleanliness.

As the etching progresses, as illustrated in FIG. 12, the etching on the side surface 9a2 of the lower layer 9aB further progresses. Then, when the lower layer 9aB is removed, the upper layer 9cB and the intermediate layer 9bB supported by the lower layer 9aB fall from the peripheral edge of the substrate W as a lump (see FIG. 13). Thereby, the multilayer film 9 in the processing region R1 can be removed. When not only the lower layer 9aB but also the intermediate layer 9bB is removed by etching, only the upper layer 9cB falls from the peripheral edge of the substrate W as a lump.

When the multilayer film 9 in the processing region R1 is removed, the processing liquid supply unit 5 stops discharging the etching liquid (step S7). Next, the rotation mechanism 231 stops the rotation of the spin chuck 21 (step S8). As a result, the rotation of the substrate W is also stopped. Next, the gas supply unit 4 stops the discharge of the inert gas (step S9).

As described above, the substrate processing apparatus 1 can remove the multilayer film 9 in the processing region R1. Moreover, the control unit 130 of the substrate processing device 1 determines whether or not the base layer 91 is exposed at the bottom of the groove 92, and when the base layer 91 is exposed, the nozzle moving mechanism 6 causes the nozzle 51c (nozzle head 50). ) Is spatially moved to move the liquid landing position PL1 radially outward. As a result, the liquid landing position PL1 can be kept away from the side surface 9a1 of the lower layer 9aA on the inner side in the radial direction. Therefore, etching on the side surface 9a1 of the lower layer 9aA can be suppressed. Therefore, peeling of the upper layer 9cA can be suppressed.

Further, in the above example, the nozzle moving mechanism 6 gradually moves the liquid landing position PL1 radially outward with the passage of time after the base layer 91 is exposed. As a result, the liquid landing position PL1 can be further separated from the side surface 9a1 of the lower layer 9aA. Therefore, etching on the side surface 9a1 of the lower layer 9aA can be further suppressed.

Further, in the above example, in the nozzle moving mechanism 6, the etching solution is applied to the upper surface of the underlying layer 91 after the underlying layer 91 is exposed, in other words, the etching solution is applied to the upper surface of the multilayer film 9. The liquid landing position PL1 is gradually moved outward in the radial direction so as not to prevent it. According to this, the liquid landing position PL1 can be brought closer to the side surface 9a2 of the lower layer 9aB. Therefore, the etching solution can be brought into contact with the side surface 9a2 of the lower layer 9aB with higher cleanliness. Therefore, the etching of the side surface 9a2 of the lower layer 9aB can be promoted. That is, the throughput of the substrate processing device 1 can be improved.

Then, by removing the lower layer 9aB before the upper layer 9cB, at least the upper layer 9cB can be dropped from the substrate W as a lump. Here, for comparison, a case where the nozzle 51c is reciprocated in the radial direction and the liquid landing position PL1 is reciprocated between a predetermined position on the inner side in the radial direction and the peripheral edge of the substrate W is considered. In this case, first, all the upper layers 9c in the processing region R1 are removed by etching, then all the intermediate layers 9b in the processing region R1 are removed by etching, and then all the lower layers 9a in the processing region R1 are removed by etching. .. Even in this case, etching on the side surface 9a1 of the lower layer 9aA can be suppressed. This is because the period during which the etching solution is applied to the position adjacent to the side surface 9a1 of the lower layer 9aA is short. However, in this case, the entire volumes of the lower layer 9a, the intermediate layer 9b, and the upper layer 9c in the processing region R1 are removed by the etching action. Therefore, the time required for removing the multilayer film 9 in the processing region R1 becomes long.

On the other hand, in the first embodiment, by removing the lower layer 9aB before the upper layer 9cB, at least the upper layer 9cB can be dropped from the substrate W as a lump. That is, since the etching solution does not etch the lump, the time required for removing the multilayer film 9 can be shortened accordingly.

Further, in the above example, the control unit 130 determines whether or not the base layer 91 is exposed based on the elapsed time from the start of supplying the etching solution. According to this, the control unit 130 can more easily determine the timing of moving the nozzle 51c.

In the above example, the exposure of the base layer 91 at the bottom of the groove 92 was adopted as a trigger for starting the movement of the nozzle 51c by the nozzle movement mechanism 6. However, this is not always the case. For example, the nozzle moving mechanism 6 may move the nozzle 51c when the intermediate layer 9b or the lower layer 9a is exposed at the bottom of the groove 92. This is also because the etching on the side surface 9a1 of the lower layer 9aA can be suppressed.

<Second embodiment>
In the first embodiment, the control unit 130 determines whether or not the base layer 91 is exposed at the bottom of the groove 92 based on the elapsed time. However, the timing at which the base layer 91 is exposed may change for each treatment on the substrate W due to various factors such as variations in the thickness of the multilayer film 9 and variations in the discharge flow rate of the etching solution. Therefore, in the second embodiment, the timing at which the base layer 91 is exposed is specified with higher accuracy.

FIG. 15 is a plan view schematically showing an example of the configuration of the substrate processing apparatus 1A. The substrate processing device 1A has the same configuration as the substrate processing device 1 except for the presence or absence of the image sensor 7. The image sensor 7 is, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor. The plurality of light receiving elements included in the image sensor 7 are arranged two-dimensionally, for example, and are arranged in a matrix as a more specific example. In this case, the image sensor 7 acquires two-dimensional image data (hereinafter, simply referred to as an image).

The image sensor 7 receives the light reflected by the peripheral edge of the substrate W held by the spin chuck 21. As a specific example, the image sensor 7 images an imaging region including a part of the processing region R1 of the substrate W held by the spin chuck 21.

In the example of FIG. 15, in a plan view, the image sensor 7 is located in a region downstream of the nozzle 41 in the rotational direction AR1 and upstream of the nozzle 51c in the rotational direction AR1. That is, the image sensor 7 images the imaging region of the processing region R1 of the substrate W on the downstream side of the supply position P1 and on the upstream side of the liquid landing position PL1. In other words, the image sensor 7 receives the reflected light reflected in the peripheral portion of the substrate W on the downstream side of the supply position P1 and upstream of the liquid landing position PL1.

The image sensor 7 may be provided directly above the imaging region. In this case, the image sensor 7 images the imaging region from directly above. Alternatively, the image sensor 7 may image the imaging region from an oblique direction. For example, the image sensor 7 may be provided radially inside the imaging region in a plan view. According to this, the processing liquid flowing through the processing region R1 or the gas evaporated from the processing liquid is unlikely to adhere to the image sensor 7. Therefore, contamination or corrosion of the light receiving surface of the image sensor 7 by the treatment liquid or gas can be suppressed.

If there is a possibility that the image sensor 7 physically interferes with the center robot CR when the substrate W is carried in and out, a sensor moving mechanism for moving the image sensor 7 between the imaging position and the retracted position is provided. It would be nice to be done. The imaging position is a position when the image sensor 7 images an imaging region. The retracted position is a position where the image sensor 7 does not face the substrate W in the vertical direction.

The image sensor 7 is controlled by the control unit 130, and outputs the acquired image (image data) to the control unit 130. The image sensor 7 repeatedly acquires an image for at least a period during which the etching solution is supplied to the substrate W.

The image acquired by the image sensor 7 is input to the control unit 130. Based on this image, the control unit 130 determines whether or not the underlying layer 91 directly under the multilayer film 9 is exposed.

FIG. 16 is a diagram schematically showing an example of the image IM1 acquired by the image sensor 7. In the example of FIG. 16, the image IM1 includes only a part of the peripheral edge of the substrate W in the circumferential direction. Image IM1 includes a groove 92. The color of the groove 92 changes as the etching progresses. For example, the color of the groove 92 may change as the exposed layer at the bottom of the groove 92 changes, or as the depth of the groove 92 changes. Generally, the deeper the groove 92, the darker the color of the groove 92. The color of the groove 92 when the base layer 91 is exposed at the bottom of the groove 92 can be known in advance by, for example, simulation or experiment.

Therefore, the control unit 130 determines whether or not the base layer 91 is exposed based on the image IM1 acquired by the image sensor 7, that is, the light received by the image sensor 7.

FIG. 17 is a flowchart showing an example of a specific operation of the determination process for the exposure of the base layer 91. This series of processes corresponds to an example of the specific processes in step S5 of FIG. First, the image sensor 7 acquires the image IM1 and outputs it to the control unit 130 (step S51). Next, the control unit 130 acquires the first color information of the groove 92 from the image IM1 (step S52). The first color information may be the color information of one pixel in the pixel group indicating the groove 92, or may be the average value of the color information of a plurality of pixels in the pixel group indicating the groove 92. Since the position where the groove 92 is formed is known in advance, the positions of the plurality of pixels indicating the groove 92 in the image IM1 may be set in advance. Alternatively, the control unit 130 may specify a plurality of pixels indicating the groove 92 by performing image processing on the image IM1.

Next, the control unit 130 acquires the second color information of the region of the upper surface of the substrate W (that is, the upper surface of the multilayer film 9) different from the groove 92 from the image IM1 (step S53). As the region, for example, an arbitrary region located on the inner surface of the upper surface of the substrate W in the radial direction with respect to the groove 92 may be adopted. The second color information may be the color information of one pixel in the pixel group indicating the region, or may be the average value of the color information of a plurality of pixels in the pixel group indicating the region. The positions of a plurality of pixels indicating the region in the image IM1 may be preset.

Next, the control unit 130 obtains the difference (color difference) between the first color information and the second color information (step S54). When the image sensor 7 is a color sensor, for example, a color distance can be adopted as the color difference. Alternatively, a difference (or ratio) in luminance value may be adopted as the difference in color. When the image sensor 7 is a grayscale sensor, a difference (or ratio) in pixel values can be adopted as the difference in color. In gray scale, it can be understood that the pixel value indicates the luminance value. Here, as the difference in the colors, the ratio of the luminance value of the first color information to the luminance value of the second color information (= second color information / first color information) is adopted. This ratio indicates contrast.

The control unit 130 determines whether or not the color difference is equal to or greater than the color reference value (step S55). The color reference value is a difference in the color when the base layer 91 is exposed, and is set in advance by, for example, a simulation or an experiment. When the color difference is less than the color reference value, the base layer 91 is not yet exposed, so the control unit 130 executes step S51 again. When the color difference is equal to or greater than the color reference value, the control unit 130 determines that the base layer 91 is exposed (step S56).

As described above, according to the second embodiment, the image sensor 7 receives the reflected light reflected on the upper surface of the substrate W, and the control unit 130 exposes the base layer 91 based on the reflected light. Judge whether or not. Therefore, the exposure timing of the base layer 91 can be specified with high accuracy. In other words, since the etching state of the substrate 7 can be confirmed by the image sensor 7, the liquid landing position PL1 can be moved at a more appropriate timing.

Further, in the above example, the control unit 130 makes the above determination based on the difference between the first color information of the groove 92 and the second color information of the region other than the groove 92. For comparison, consider the case where only the first color information is used. Although the color of the groove 92 differs depending on the depth of the groove 92, it also changes due to other factors. For example, if the periphery of the substrate W is bright, the color of the groove 92 is bright, and if the periphery of the substrate W is dark, the color of the groove 92 is dark. Therefore, for example, when the substrate processing device 1 is provided with an illumination that illuminates the substrate W, the groove 92 becomes dark when the illumination becomes dark due to deterioration over time. In this case, the brightness of the illumination affects the determination of whether or not the base layer 91 of the control unit 130 is exposed.

On the other hand, if the difference between the first color information of the groove 92 and the second color information of the region other than the groove 92 is calculated, the influence of the brightness of such illumination can be suppressed. That is, although the first color information and the second color information commonly include the influence of the brightness of the illumination, the influence is almost canceled in these differences. Therefore, the control unit 130 can determine with high accuracy whether or not the base layer 91 is exposed, regardless of the surrounding lighting environment.

Further, in the above example, the color of the region located radially inside the groove 92 is adopted as the second color information. For comparison, a case where a region located radially outside the groove 92 (hereinafter referred to as an outer region) is adopted as the second color information will be described. Since this outer region is etched by the etching solution, the color of the outer region can change as the etching progresses. Therefore, the difference between the first color information and the second color information changes depending not only on the depth of the groove 92 but also on the amount of etching on the outer region. Therefore, the accuracy of determining the exposure of the base layer 91 is lowered.

On the other hand, the region radially inner of the groove 92 (hereinafter referred to as the inner region) is hardly etched. Therefore, the color of the inner region is almost constant regardless of the progress of etching. Therefore, if the color of the inner region is adopted for the second color information, the accuracy of determining whether or not the base layer 91 is exposed can be improved.

Further, in the above example, the image sensor 7 captures a region on the downstream side of the rotation direction AR1 from the nozzle 41 and on the upstream side of the rotation direction AR1 from the nozzle 51c in a plan view. That is, the image sensor 7 images the region of the processing region R1 of the substrate W on the downstream side of the supply position P1 and on the upstream side of the liquid landing position PL1. In this region, most of the etching solution is blown out of the substrate W by the gas flow G1 at the supply position P1. Therefore, the image IM1 does not contain much etching solution. Therefore, the color information of each pixel of the image IM1 is not so affected by the etching solution. As a result, it is possible to suppress a decrease in judgment accuracy due to the inclusion of the etching solution in the image. In other words, the control unit 130 can acquire the color information of the groove 92 with high accuracy.

From this viewpoint, the image sensor 7 may image a region on the downstream side of the rotation direction AR1 from the nozzle 51d and on the upstream side of the rotation direction AR1 from the nozzle 51c in a plan view. That is, the image sensor 7 may image a region of the processing region R1 of the substrate W that is downstream of the supply position P5 and upstream of the liquid landing position PL1. Since the etching solution on the processing region R1 of the substrate W is further blown off by the gas flow G5 at the supply position P5, the etching solution remaining in this region is further reduced. Therefore, the etching solution contained in the image IM1 can be further reduced. Therefore, the control unit 130 can acquire the color information of the groove 92 with higher accuracy.

In the above example, the control unit 130 determines whether or not the base layer 91 is exposed based on the color of the groove 92 (specifically, the difference in color between the groove 92 and the inner region). However, this is not always the case. As described above, the color of the outer region outside the groove 92 may change as the etching progresses. In this case, the control unit 130 may determine whether or not the base layer 91 is exposed based on the color of the outer region (for example, the difference in color between the outer region and the inner region).

<Groove width>
The radial width of the groove 92 increases as the etching progresses. The width of the groove 92 when the base layer 91 is exposed at the bottom of the groove 92 can be known in advance by, for example, simulation or experiment.

Therefore, the control unit 130 may determine the width of the groove 92 based on the image IM1 acquired by the image sensor 7, and determine whether or not the base layer 91 is exposed based on the width of the groove 92. FIG. 18 is a flowchart showing an example of the operation of the determination process for the exposure of the base layer 91. This series of processes also corresponds to an example of the processes in step S5 of FIG.

First, similarly to step S51, the image sensor 7 acquires the image IM1 and outputs the image IM1 to the control unit 130 (step S501).

Next, the control unit 130 obtains the width of the groove 92 based on the image IM1 (step S502). For example, the control unit 130 acquires an edge-extracted image by performing an edge-extracting process such as the Canny method on the image IM1. The edge extraction image includes the contour of the groove 92 as an edge. The control unit 130 may appropriately perform mask processing in order to remove edges other than the contour of the groove 92 from the edge extracted image. Since the radial direction is predetermined in the image IM1, the control unit 130 calculates the width of the groove 92 based on the contour of the groove 92.

Next, the control unit 130 determines whether or not the width of the groove 92 is equal to or greater than a predetermined width reference value (step S503). The width reference value is the width of the groove 92 when the base layer 91 is exposed, and can be set in advance by simulation, experiment, or the like. When the width of the groove 92 is less than the width reference value, the base layer 91 is not yet exposed, so the control unit 130 executes step S501 again. When the width of the groove 92 is equal to or larger than the width reference value, the control unit 130 determines that the base layer 91 is exposed (step S504).

As described above, the control unit 130 determines whether or not the base layer 91 is exposed based on the width of the groove 92. Also with this, it is possible to determine with high accuracy whether or not the base layer 91 is exposed.

In the above example, although the control unit 130 determines whether or not the base layer 91 is exposed, similarly determines whether or not the intermediate layer 9b or the lower layer 9a is exposed, and the nozzle moves according to the determination. The mechanism 6 may move the liquid landing position PL1 radially outward.

<Third embodiment>
The configuration of the substrate processing apparatus 1 according to the third embodiment is the same as that of the first and second embodiments. Also in the third embodiment, the nozzle moving mechanism 6 gradually moves the nozzle 51c radially outward with the passage of time after the base layer 91 (or the intermediate layer 9b or the lower layer 9a) is exposed. That is, the nozzle movement mechanism 6 moves the nozzle 51c radially outward by a predetermined movement amount at predetermined time intervals. However, in the third embodiment, the predetermined time is set shorter as the liquid landing position PL1 is on the outer side in the radial direction. FIG. 19 is a graph schematically showing an example of the time change of the liquid landing position PL1. In the example of FIG. 19, the liquid landing position PL1 changes stepwise, and the predetermined time T is set shorter as the liquid landing position PL1 approaches the peripheral edge of the substrate W.

By the way, the multilayer film 9B of the substrate W becomes thinner as the etching progresses. Then, as the multilayer film 9B becomes thinner, the side surfaces 9a2, 9b2, and 9c2 of the multilayer film 9B are quickly retracted to the outside in the radial direction by etching. In the third embodiment, the liquid landing position PL1 is moved radially outward at shorter time intervals as the etching progresses. Therefore, the liquid landing position PL1 can be moved so as to appropriately follow the lateral movement (evacuation) of the side surfaces 9a2, 9b2, and 9c2 in the radial direction. Therefore, the etching solution can be brought into contact with the side surfaces 9a2, 9b2, and 9c2 of the multilayer film 9B with higher cleanliness. Therefore, the throughput can be further improved.

In the above example, the predetermined time (that is, the time pitch) is set shorter as the liquidation position PL1 approaches the peripheral edge of the substrate W, but the predetermined movement amount as the liquidation position PL1 approaches the substrate W. (That is, the movement pitch) may be set large. This also allows the liquid landing position PL1 to be moved so as to appropriately follow the lateral movement (evacuation) of the side surfaces 9a2, 9b2, and 9c2 in the radial direction. Therefore, the etching solution can be brought into contact with the side surfaces 9a2, 9b2, and 9c2 of the multilayer film 9B with higher cleanliness.

Although the embodiment has been described above, the substrate processing apparatus 1 and the substrate processing method can be modified in various ways other than those described above as long as the purpose is not deviated. Within the scope of the disclosure, the present embodiment can be freely combined with each embodiment, modified any component of each embodiment, or can omit any component in each embodiment. is there.

For example, in the above example, the etching rate of the multilayer film 9 with respect to the upper layer 9c is higher than that of the lower layer 9a and the intermediate layer 9b, but is not necessarily limited to this. Further, for example, the substrate processing apparatus 1 may be provided with a heating mechanism for heating the substrate W. Further, for example, an inert gas supply unit for supplying the inert gas may be provided on the lower surface of the substrate W.

Further, in the above example, the nozzle moving mechanism 6 moves the nozzle 51c in the horizontal direction to move the liquid landing position PL1. However, if the nozzle 51c is provided so as to be able to move up and down, the nozzle 51c may be raised. Since the discharge direction of the nozzle 51c is inclined outward in the radial direction, when the nozzle 51c rises, the liquid landing position PL1 moves outward in the radial direction. Alternatively, the posture of the nozzle 51c may be changeable. For example, when the nozzle 51c is rotatably attached, the nozzle 51c can be tilted by a slight rotation of the nozzle 51c. As a result, the ejection direction of the nozzle 51c changes. For example, when the nozzle 51c is tilted so that the tip (discharge port) of the nozzle 51c is located radially outward with respect to the upper end thereof, the discharge direction is tilted more radially outward. This also makes it possible to move the liquid landing position PL1 to the outside in the radial direction.

6 Nozzle movement mechanism 7 Image sensor 9 Multilayer film 9a 1st layer (lower layer)
9c 2nd layer (upper layer)
21 Substrate holder (spin chuck)
231 Rotation mechanism 51c Nozzle 91 Third layer (base layer)
130 Control unit W board

Claims (15)

A substrate processing method in which an etching process for etching the multilayer film is performed on a peripheral edge of a substrate on which a multilayer film including a first layer and a second layer above the first layer is formed.
The first step of holding the substrate and
The second step of starting the rotation of the substrate around the rotation axis along the vertical direction, and
A third step of ejecting an etching solution for etching the multilayer film from a nozzle and landing it at a position inside a predetermined width from the peripheral edge of the substrate.
A fourth step of determining whether or not the first layer or the third layer immediately below the multilayer film is exposed.
A substrate processing method comprising a fifth step of moving the landing position of the etching solution to the peripheral side of the substrate when it is determined that the first layer or the third layer is exposed. The substrate processing method according to claim 1.
A substrate processing method in which, in the fifth step, the liquid landing position is moved to the peripheral edge side of the substrate with the passage of time within the range in which the etching solution is landed on the upper surface of the third layer. The substrate processing method according to claim 2.
In the fifth step, the liquid landing position is moved to the peripheral edge side of the substrate by a predetermined movement amount at predetermined time intervals.
A substrate processing method in which the predetermined time is set shorter as the liquid landing position is closer to the peripheral side, or the predetermined movement amount is set larger as the liquid landing position is closer to the peripheral side. The substrate processing method according to any one of claims 1 to 3.
In the fourth step, when it is determined that the elapsed time from the start of the third step is equal to or longer than a predetermined reference time, it is determined that the first layer or the third layer is exposed. Method. The substrate processing method according to any one of claims 1 to 3.
In the fourth step, the substrate receives the reflected light from the substrate by the image sensor, and determines whether or not the first layer or the third layer is exposed based on the received reflected light. Processing method. The substrate processing method according to claim 5.
In the fourth step, the image sensor obtains a first color of a groove formed on the substrate by etching at the liquid landing position of the rotating substrate and a second color of a region different from the groove. A substrate processing method for determining whether or not the first layer or the third layer is exposed based on the difference between the first color and the second color, which is acquired based on the image acquired by. The substrate processing method according to claim 6.
The substrate processing method, wherein the region different from the groove is a region on the rotation axis side of the groove. The substrate processing method according to any one of claims 5 to 7.
In the fourth step, the width of the groove formed on the substrate by etching at the liquid landing position of the rotating substrate is obtained based on the image acquired by the image sensor, and is based on the width of the groove. A substrate processing method for determining whether or not the first layer or the third layer is exposed. The substrate processing method according to any one of claims 5 to 8.
In the third step and the fifth step, the inert gas is supplied to the supply position on the upstream side of the substrate in the rotational direction from the liquid landing position, and the etching solution is blown off from the peripheral edge of the substrate.
The image sensor is a substrate processing method that receives reflected light reflected in a region of the peripheral edge of the substrate that is upstream of the liquid landing position and downstream of the supply position. The substrate processing method according to any one of claims 1 to 9.
The etching rate of the second layer by the etching solution is higher than the etching rate of the first layer by the etching solution.
A substrate processing method in which the second layer is thicker than the first layer. The substrate processing method according to any one of claims 1 to 10.
A substrate treatment method, wherein the multilayer film includes a titanium layer, a titanium nitride layer provided on the titanium layer, and a tungsten layer provided on the titanium nitride layer. The substrate processing method according to any one of claims 1 to 11.
A substrate processing method in which the ejection direction of the nozzle is an oblique direction toward the peripheral edge of the substrate as it goes downward. The substrate processing method according to any one of claims 1 to 12.
The etching solution contains ammonium hydroxide, hydrogen peroxide solution and pure water.
A substrate treatment method in which the ratio of the combination of ammonium hydroxide and hydrogen peroxide solution to pure water is set in the range of 6: 1 to 11:10. The substrate processing method according to any one of claims 1 to 13.
A substrate processing method in which in the fifth step, the liquid landing position is moved in only one direction toward the peripheral edge of the substrate. A substrate processing apparatus that performs an etching process for etching the multilayer film on the peripheral edge of the substrate on which the multilayer film including the first layer and the second layer above the first layer is formed.
A substrate holding portion that holds the substrate and
A rotation mechanism that rotates the substrate held by the substrate holding portion around a rotation axis along the vertical direction, and a rotation mechanism.
A nozzle that discharges an etching solution that etches the multilayer film and causes it to land at a position inside a predetermined width from the peripheral edge of the substrate.
A substrate processing apparatus including a nozzle moving mechanism that moves the landing position of the etching solution to the peripheral edge side of the substrate when the first layer or the third layer immediately below the multilayer film is exposed.

Images