JP2013201235A - Heater cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater cleaning method capable of cleaning a heater well.SOLUTION: A substrate processing device includes a wafer rotation mechanism 3 which holds a wafer W and rotates it, and a heater head 35 which is arranged to face a surface of the wafer W held by the wafer rotation mechanism 3, for heating SPM liquid on the surface of the wafer W. At an upper end of a spin shaft 7 of the wafer rotation mechanism 3, a rear surface nozzle 82 is disposed. The upper end of the rear surface nozzle 82 has a rear surface liquid discharge opening 84 formed. The heater head is disposed at a position facing above the rear surface liquid discharge opening 84, and the rear surface nozzle 82 is supplied with cleaning liquid and the cleaning liquid is discharged upward from the rear surface liquid discharge opening 84. Thus, an outside surface of a housing of a heater is well cleaned, thus the outside surface of the housing is kept in a clean state.

Description

  The present invention relates to a heater cleaning method for cleaning a heater that has an infrared lamp and heat-treats a substrate. Examples of the substrate to be heat-treated include a semiconductor wafer, a glass substrate for a liquid crystal display device, a substrate for a plasma display, a substrate for FED (Field Emission Display), a substrate for an optical disk, a substrate for a magnetic disk, and a substrate for a magneto-optical disk. , Substrates such as photomask substrates, ceramic substrates, solar cell substrates and the like.

  The manufacturing process of a semiconductor device includes, for example, a step of locally implanting impurities (ions) such as phosphorus, arsenic, and boron into the main surface of a semiconductor wafer (hereinafter simply referred to as “wafer”). In this step, in order to prevent ion implantation into unnecessary portions, a resist made of a photosensitive resin is patterned on the surface of the wafer, and portions that do not require ion implantation are masked with the resist. Since the resist patterned on the surface of the wafer becomes unnecessary after the ion implantation, a resist removal process for removing the unnecessary resist on the surface of the wafer is performed after the ion implantation.

  In such a typical resist removal process, the surface of the wafer is irradiated with oxygen plasma, and the resist on the surface of the wafer is ashed. Then, a chemical solution such as a sulfuric acid / hydrogen peroxide mixture (SPM solution) which is a mixed solution of sulfuric acid and hydrogen peroxide solution is supplied to the surface of the wafer, and the ashed resist is removed. This achieves removal of the resist from the surface of the wafer.

However, irradiation with oxygen plasma for ashing the resist damages a portion of the wafer surface that is not covered with the resist (for example, an oxide film exposed from the resist).
Therefore, recently, without ashing the resist, an SPM solution is supplied to the surface of the wafer, and the strong oxidizing power of peroxomonosulfuric acid (H ₂ SO ₅ ) contained in the SPM solution causes the resist from the wafer surface. Attention has been focused on a method of peeling and removing the film.

JP 2005-93926 A

  The inventors of the present invention are considering heating the chemical solution supplied to the main surface of the substrate during the chemical solution processing in order to further increase the temperature of the chemical solution supplied to the main surface of the substrate. Specifically, a chemical solution existing on the main surface of the substrate is heated by disposing a heater having an infrared lamp and a housing that accommodates the infrared lamp at a distance from the main surface of the substrate. Are considering.

  However, when the chemical solution is heated by the infrared lamp, the chemical solution is rapidly heated, and a large amount of chemical mist is generated around the main surface of the substrate. The chemical mist generated during the heat treatment adheres to the lower surface of the heater housing facing the main surface of the substrate. If the chemical mist is left on the lower surface of the housing, not only does the amount of infrared light emitted outside the housing decrease due to the decrease in the infrared transmittance of the lower surface of the housing, but also the chemical mist dries and crystallizes. As a result, the lower surface of the housing may become a particle source. Therefore, every time one substrate is processed, it is necessary to wash away the chemical solution adhering to the lower surface of the heater housing.

As a measure for cleaning the housing of the heater, a bar nozzle in which a plurality of discharge ports directed downward in the vertical direction are arranged in one or a plurality of rows along the horizontal direction is disposed, and the processing liquid from each discharge port is supplied to the heater. A method of supplying from above can be considered. However, with such a measure, it is difficult to spread the cleaning liquid over the entire lower surface of the heater housing.
The present invention has been made under such a background, and an object of the present invention is to provide a heater cleaning method that can clean a heater satisfactorily.

  In order to achieve the above object, the invention according to claim 1 includes an infrared lamp (38) and a housing (40, 41), and an upper surface of the substrate (W) held by the substrate holding means (3). A heater cleaning method for cleaning a heater (35) disposed opposite to (upper main surface) and heating the upper surface of the heater, facing the lower surface of the substrate held by the substrate holding means and facing upward A heater disposing step (S21) for disposing the heater at a position facing the upper side of the lower nozzle (82) having the first discharge port (84) for discharging the liquid, and the substrate holding means does not hold the substrate And a lower cleaning liquid discharge step (S22) for supplying the cleaning liquid to the outer surface of the housing by supplying the cleaning liquid to the lower nozzle and discharging the cleaning liquid upward from the first discharge port. , Heater cleaning It is the law.

In addition, although the alphanumeric characters in parentheses represent corresponding components in the embodiments described later, the scope of the claims is not intended to be limited to the embodiments. The same applies hereinafter.
According to the method of the present invention, the heater is disposed at a position facing the upper side of the first discharge port. Further, the cleaning liquid is discharged upward from the first discharge port. The cleaning liquid from the first discharge port blows upward, reaches the lower outer surface of the heater housing located above the first discharge port, and is supplied to the lower outer surface.

In the heat treatment (S4) in which the substrate is heated using the heater, the lower outer surface of the housing is disposed opposite to the surface of the substrate. For this reason, after the heat treatment, there is a possibility that foreign matter adheres to the lower outer surface of the housing.
Even if foreign matter adheres to the lower outer surface of the housing, the foreign matter can be washed away by the cleaning liquid supplied from the first discharge port. The outer surface of the can be kept clean.

The housing may have a facing surface (52B) that faces the surface of the substrate during the heat treatment of the substrate by the infrared lamp. Further, the heat treatment may be a treatment performed in a state where a chemical solution is present on the upper surface of the substrate.
In this case, during the heat treatment, the chemical solution may be rapidly heated by the infrared lamp, and a large amount of chemical solution mist may be generated around the main surface of the substrate. And it is thought that the chemical | medical solution mist which generate | occur | produced adheres to the opposing surface of a housing.

  However, even in such a case, since the facing surface of the heater housing is cleaned with the cleaning liquid, the chemical mist adhering to the facing surface of the housing can be washed away, and the facing surface of the housing can be cleaned. Can be kept in a state. Therefore, it is possible to prevent a decrease in the amount of infrared light emitted to the outside of the housing and to prevent the housing from becoming a particle source and adversely affecting the processing of the substrate.

According to a second aspect of the present invention, in parallel with the lower cleaning liquid discharge step, the cleaning liquid is discharged downward from an upper nozzle (94) disposed above the first discharge port. The heater cleaning method according to claim 1, further comprising an upper cleaning liquid discharge step (S22) for supplying a cleaning liquid to the outer surface.
According to the method of this invention, in parallel with the discharge of the cleaning liquid from the lower nozzle, the cleaning liquid is discharged downward from the upper nozzle disposed above the heater. Therefore, the cleaning liquid can be spread over a wide range of the outer surface of the housing. Thereby, the outer surface of the heater housing can be cleaned extensively.

The upper nozzle may be a ceiling nozzle (94) disposed on the ceiling wall of the processing chamber (2) that houses the substrate holding means.
The invention described in claim 3 further includes a landing position moving step (S23) of moving a landing position of the cleaning liquid discharged from the first discharge port in parallel with the lower cleaning liquid discharging step. The heater cleaning method according to 1 or 2.

According to the method of the present invention, the cleaning liquid landing position on the outer surface of the housing is moved in parallel with the discharge of the cleaning liquid from the first discharge port. Thereby, a washing | cleaning liquid can be made to land in the wide range of the lower outer surface of a housing. Therefore, this can clean the lower outer surface of the heater housing over a wide range.
The liquid landing position moving step may include a step of reciprocating the heater in a direction (horizontal direction) that intersects the discharge direction of the cleaning liquid from the first discharge port.

The invention according to claim 4 further includes a drying step (S25, S26) in which the cleaning liquid adhering to the outer surface of the housing is removed after the lower cleaning liquid supply step is completed. The heater cleaning method according to any one of the above.
According to the method of the present invention, the cleaning liquid remaining on the outer surface of the housing is removed after the heater cleaning process. Therefore, the cleaning liquid is removed from the outer surface of the housing. Thereby, it is possible to prevent the cleaning liquid from remaining on the outer surface of the housing and adversely affecting the processing of the substrate.

The invention according to claim 5 is the invention according to claim 4, wherein the drying step further includes a heating and drying step (S26) of irradiating the housing with infrared rays from the infrared lamp to heat and dry the outer surface of the housing. The heater cleaning method described.
According to the method of the present invention, the housing is warmed by the infrared irradiation from the infrared lamp, and the cleaning liquid adhering to the outer surface of the housing is removed by evaporation. Thereby, the outer surface of a housing can be dried favorably.

  According to a sixth aspect of the present invention, the lower nozzle has a second discharge port (85) for discharging gas upward, and in the drying step, a drying gas is supplied to the lower nozzle. The method further comprises a lower drying gas spraying step (S26) for supplying the drying gas to the outer surface of the housing by supplying and blowing the drying gas upward from the second discharge port. The heater cleaning method according to 4 or 5.

  According to the method of the present invention, the drying gas from the second discharge port is sprayed onto the lower outer surface of the heater housing. The cleaning liquid adhering to the lower outer surface of the housing is blown off by the drying gas. Thereby, the outer surface of a housing can be dried favorably.

It is a figure which shows typically the structure of the substrate processing apparatus with which the heater cleaning method which concerns on one Embodiment of this invention is performed. FIG. 2 is a schematic sectional view of the heater head shown in FIG. 1. It is a perspective view of the infrared lamp shown in FIG. It is a block diagram which shows the electric constitution of the substrate processing apparatus shown in FIG. It is process drawing which shows the process example of the resist removal process which concerns on this invention. It is an illustration for explaining an SPM liquid film formation process. It is an illustration figure for demonstrating a SPM liquid film heating process. It is a top view which shows the movement range of the heater head in a SPM liquid film heating process. It is a flowchart which shows the flow of a heater head washing | cleaning drying process. It is an illustration for explaining one process in a heater head washing drying process. It is an illustration figure which shows the next process of FIG. 9A. It is a top view which shows the movement range of the heater head in a heater head washing | cleaning drying process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram schematically showing a configuration of a substrate processing apparatus 1 in which a heater cleaning method according to an embodiment of the present invention is executed. For example, the substrate processing apparatus 1 removes unnecessary resist from the surface of the wafer W after ion implantation processing or dry etching processing for injecting impurities into the surface (main surface) of the wafer W as an example of a substrate. It is a single wafer type device used for processing.

The substrate processing apparatus 1 includes a processing chamber 2 partitioned by a partition wall 2A. A fan filter unit (not shown) for sending clean air (air generated by purifying air in the clean room in which the substrate processing apparatus 1 is installed) into the processing chamber 2 is provided on the ceiling wall of the processing chamber 2. Is provided.
The substrate processing apparatus 1 has a wafer rotation mechanism (substrate holding means) 3 for holding and rotating the wafer W in the processing chamber 2, and the surface (upper surface) of the wafer W held by the wafer rotation mechanism 3. The wafer is disposed opposite to the surface of the wafer W held in the wafer rotation mechanism 3 and a peeling liquid nozzle (chemical liquid supply means) 4 for supplying an SPM liquid as an example of a resist stripping liquid as a chemical liquid. And a heater head (heater) 35 for heating the SPM liquid on the surface of W.

  As the wafer rotation mechanism 3, for example, a sandwiching type is adopted. Specifically, the wafer rotation mechanism 3 includes a spin shaft 7 that extends substantially vertically, a disk-shaped spin base 8 that is mounted substantially horizontally on the upper end of the spin shaft 7, and a plurality of peripheral portions of the spin base 8. And a plurality of clamping members 9 provided at substantially equal angular intervals. Each of the clamping members 9 is brought into contact with the end surface of the wafer W, and the wafer W is held by the plurality of clamping members 8 so that the wafer W is held in a substantially horizontal posture. It is arranged on the central axis of the.

A rotational force is input to the spin shaft 7 from a chuck rotation drive mechanism 6 including a motor (not shown). With this rotational force input, the spin shaft 7 rotates, and the spin base 8 rotates about a predetermined rotation axis (vertical axis) C with the wafer W held by the holding member 9 maintained in a substantially horizontal posture. To do.
The spin shaft 7 is a hollow shaft, and a back side liquid supply pipe 80 and a back side gas supply pipe 81 extending in the vertical direction are inserted through the spin shaft 7. The upper end of the back side liquid supply pipe 80 and the upper end of the back side gas supply pipe 81 are connected to a back nozzle (lower nozzle) 82 provided at the upper end of the spin shaft 7, respectively. The back surface nozzle 82 has a circular back surface liquid discharge port (first discharge port) 84 and a circular back surface gas discharge port (second discharge port) 85 at its upper end. The back surface liquid discharge port 84 and the back surface gas discharge port 85 are arranged close to each other. Each of the discharge ports 84 and 85 is opposed to the rotation center of the lower surface of the wafer W held by the wafer rotation mechanism 3. The back surface liquid discharge port 84 and the back surface gas discharge port 85 have the same height in the vertical direction.

A cleaning liquid lower supply pipe 86 to which DIW (deionized water) as an example of the cleaning liquid is supplied is connected to the back surface side liquid supply pipe 80. The lower cleaning solution supply pipe 86 is provided with a lower cleaning solution valve 87 for opening and closing the lower cleaning solution supply pipe 86.
A drying gas lower supply pipe 88 to which nitrogen gas as an example of the drying gas is supplied is connected to the back side gas supply pipe 81. The drying gas lower supply pipe 88 is provided with a drying gas lower valve 89 for opening and closing the drying gas lower supply pipe 88.

  The stripping liquid nozzle 4 is, for example, a straight nozzle that discharges the SPM liquid in a continuous flow state. The stripping liquid nozzle 4 is attached to the tip of the first liquid arm 11 extending substantially horizontally with its discharge port directed downward. The first liquid arm 11 is provided so as to be rotatable around a predetermined swing axis extending in the vertical direction. The first liquid arm 11 is coupled to a first liquid arm swinging mechanism 12 for swinging the first liquid arm 11 within a predetermined angle range. As the first liquid arm 11 swings, the stripping liquid nozzle 4 moves to a position on the rotation axis C of the wafer W (position facing the rotation center of the wafer W) and a home set on the side of the wafer rotation mechanism 3. Moved between positions.

A stripping solution supply pipe 15 to which an SPM solution from an SPM supply source is supplied is connected to the stripping solution nozzle 4. In the middle of the stripping solution supply pipe 15, a stripping solution valve 23 for switching supply / stop of supply of the SPM solution from the stripping solution nozzle 4 is interposed.
The substrate processing apparatus 1 also applies a DIW nozzle 24 for supplying DIW as a rinsing liquid to the surface of the wafer W held by the wafer rotation mechanism 3 and the surface of the wafer W held by the wafer rotation mechanism 3. SPM that surrounds the periphery of the wafer rotation mechanism 3 and flows down or scatters from the wafer W, and the SC1 nozzle 25 for supplying SC1 (ammonia-hydrogen peroxide mixture) as a cleaning chemical. And a cup 5 for receiving liquid, SC1, and DIW.

  The DIW nozzle 24 is, for example, a straight nozzle that discharges DIW in a continuous flow state. The DIW nozzle 24 is fixedly disposed above the wafer rotation mechanism 3 with its discharge port directed toward the vicinity of the rotation center of the wafer W. A DIW supply pipe 26 to which DIW is supplied from a DIW supply source is connected to the DIW nozzle 24. A DIW valve 27 for switching supply / stop of supply of DIW from the DIW nozzle 24 is interposed in the middle of the DIW supply pipe 26.

  The SC1 nozzle 25 is, for example, a straight nozzle that discharges SC1 in a continuous flow state. The SC1 nozzle 25 is attached to the tip of the second liquid arm 28 that extends substantially horizontally with its discharge port directed downward. The second liquid arm 28 is provided so as to be rotatable around a predetermined swing axis extending in the vertical direction. The second liquid arm 28 is coupled to a second liquid arm swing mechanism 29 for swinging the second liquid arm 28 within a predetermined angle range. As the second liquid arm 28 swings, the SC1 nozzle 25 moves to a position on the rotation axis C of the wafer W (a position facing the rotation center of the wafer W) and a home position set to the side of the wafer rotation mechanism 3. Moved between.

An SC1 supply pipe 30 to which SC1 from an SC1 supply source is supplied is connected to the SC1 nozzle 25. An SC1 valve 31 for switching supply / stop of supply of SC1 from the SC1 nozzle 25 is interposed in the middle of the SC1 supply pipe 30.
A support shaft 33 extending in the vertical direction is disposed on the side of the wafer rotation mechanism 3. A heater arm 34 extending in the horizontal direction is coupled to the upper end portion of the support shaft 33, and a heater head 35 that houses and holds the infrared lamp 38 is attached to the tip of the heater arm 34. The support shaft 33 is coupled with a swing drive mechanism 36 for rotating the support shaft 33 around the central axis, and an elevating drive mechanism 37 for moving the support shaft 33 up and down along the central axis. ing.

  A driving force is input to the support shaft 33 from the swing drive mechanism 36 and the support shaft 33 is rotated within a predetermined angle range, whereby the heater arm 34 is located above the wafer W held by the wafer rotation mechanism 3. Is swung around the support shaft 33 as a fulcrum. By the swinging of the heater arm 34, the heater head 35 is moved to a position including the rotation axis C of the wafer W (position facing the rotation center of the wafer W), and a home position set to the side of the wafer rotation mechanism 3. Moved between. Further, by inputting a driving force from the lifting drive mechanism 37 to the support shaft 33 and moving the support shaft 33 up and down, the proximity position close to the surface of the wafer W held by the wafer rotation mechanism 3 (first described later). Between the proximity position and the second proximity position of FIG. 1. A position indicated by a two-dot chain line in FIG. 1) and a retreat position (position indicated by a solid line in FIG. 1) for retreating above the wafer W, The heater head 35 is moved up and down. In this embodiment, the proximity position is set to a position where the distance between the surface of the wafer W held by the wafer rotation mechanism 3 and the lower surface (opposing surface) 52B of the heater head 35 is 3 mm, for example.

On the lower surface of the ceiling wall of the processing chamber 2, a cleaning liquid upper nozzle (ceiling nozzle) 94 and a drying gas upper nozzle (ceiling nozzle) 95 are laterally adjacent to each other above the rotation axis C of the wafer rotating mechanism 3. Are arranged.
The cleaning liquid upper nozzle 94 has a discharge port for discharging the liquid downward in a shower shape. A cleaning liquid supply pipe 90 to which the cleaning liquid is supplied is connected to the cleaning liquid upper nozzle 94. A cleaning liquid upper valve 91 for opening and closing the cleaning liquid upper supply pipe 90 is interposed in the cleaning liquid upper supply pipe 90.

The drying gas upper nozzle 95 has a discharge port for discharging gas vertically downward. The drying gas upper nozzle 95 is connected to a drying gas upper supply pipe 92 to which nitrogen gas as an example of the drying gas is supplied. The drying gas upper supply pipe 92 is provided with a drying gas upper valve 93 for opening and closing the drying gas upper supply pipe 92.
FIG. 2 is a schematic sectional view of the heater head 35.

  The heater head 35 has an infrared lamp 38, an opening 39 in the upper part, a bottomed container-like lamp housing (housing) 40 that houses the infrared lamp 38, and the infrared lamp 38 is suspended inside the lamp housing 40. And a support member 42 for supporting the lamp housing 40 and a lid (housing) 41 for closing the opening 39 of the lamp housing 40. In this embodiment, the lid 41 is fixed to the tip of the heater arm 34.

  FIG. 3 is a perspective view of the infrared lamp 38. As shown in FIGS. 2 and 3, the infrared lamp 38 includes an annular (arc-shaped) annular portion 43 and a pair extending from both ends of the annular portion 43 along the central axis of the annular portion 43. Infrared lamp heater having the straight portions 44 and 45, and the annular portion 43 mainly functions as a light emitting portion. In this embodiment, the diameter (outer diameter) of the annular portion 43 is set to about 60 mm, for example. In a state where the infrared lamp 38 is supported by the support member 42, the annular portion 43 is in a horizontal posture. In other words, the central axis of the annular portion 43 is an axis (vertical axis) perpendicular to the surface of the wafer W held by the wafer rotation mechanism 3.

The infrared lamp 38 is configured by arranging a filament in a quartz pipe. An amplifier 54 for supplying voltage is connected to the infrared lamp 38. As the infrared lamp 38, a short, medium and long wavelength infrared heater represented by a halogen lamp and a carbon heater can be adopted.
As shown in FIG. 2, the lid 41 has a disk shape and is fixed in a horizontal posture with respect to the heater arm 34. The lid 41 is formed using a fluororesin material such as PTFE (polytetrafluoroethylene). In this embodiment, the lid 41 is formed integrally with the heater arm 34. However, the lid 41 may be formed separately from the heater arm 34. In addition to a resin material such as PTFE, a material such as ceramics or quartz can also be used as the material of the lid 41.

  A groove portion 51 (substantially cylindrical) is formed on the lower surface 49 of the lid 41. The groove 51 has an upper bottom surface 50 formed of a horizontal flat surface, and the upper surface 42A of the support member 42 is fixed to the upper bottom surface 50 in contact therewith. The lid 41 is formed with insertion holes 58 and 59 that penetrate the upper bottom surface 50 and the lower surface 42B in the vertical direction (vertical direction). The insertion holes 58 and 59 are for insertion of the upper ends of the linear portions 44 and 45 of the infrared lamp 38.

The lamp housing 40 has a bottomed cylindrical container shape. The lamp housing 40 is formed using quartz.
The lamp housing 40 is fixed to the lower surface 49 of the lid 41 (the lower surface excluding the groove portion 51 in this embodiment) with the opening 39 facing upward. An annular flange 40A projects radially outward (in the horizontal direction) from the peripheral edge on the opening side of the lamp housing 40. The lamp housing 40 is supported by the lid 41 by fixing the flange 40A to the lower surface 49 of the lid 41 using a fixing means (not shown) such as a bolt.

  In this state, the bottom plate portion 52 of the lamp housing 40 is in the shape of a horizontal disk. Each of the upper surface 52A and the lower surface 52B of the bottom plate portion 52 forms a horizontal flat surface. In the lamp housing 40, the infrared lamp 38 is disposed so that the lower portion of the annular portion 43 is close to the upper surface 52 </ b> A of the bottom plate portion 52. The annular portion 43 and the bottom plate portion 52 are provided in parallel to each other. In other words, the bottom of the annular portion 43 is covered with the bottom plate portion 52 of the lamp housing 40. In this embodiment, the outer diameter of the lamp housing 40 is set to about 85 mm, for example. Further, the vertical distance between the infrared lamp 38 (the lower portion of the annular portion 43) and the upper surface 52A is set to about 2 mm, for example.

  The support member 42 has a thick plate shape (substantially disk shape), and is attached and fixed to the lid 41 from below with a bolt 56 and the like in a horizontal posture. The support member 42 is formed using a heat-resistant material (for example, ceramics or quartz). The support member 42 has two insertion holes 46 and 47 that penetrate the upper surface 42A and the lower surface 42B in the vertical direction (vertical direction). The insertion holes 46 and 47 are for the insertion of the straight portions 44 and 45 of the infrared lamp 38.

An O-ring 48 is fitted and fixed to the middle part of each straight part 44, 45. In a state where the straight portions 44 and 45 are inserted through the insertion holes 46 and 47, the outer periphery of each O-ring 48 is in pressure contact with the inner walls of the insertion holes 46 and 47, whereby the insertion holes 46 and 47 of the straight portions 44 and 45 are connected. 47 is achieved, and the infrared lamp 38 is suspended and supported by the support member 42.
When a voltage is supplied from the amplifier 54 to the infrared lamp 38, the infrared lamp 38 emits infrared rays and is emitted toward the lower side of the heater head 35 via the lamp housing 40.
Infrared rays emitted through the bottom plate portion 52 of the lamp housing 40 heat the SPM liquid.

  Further, an air supply path 60 for supplying air to the inside of the lamp housing 40 and an exhaust path 61 for exhausting the atmosphere inside the lamp housing 40 are formed in the lid 41. The air supply path 60 and the exhaust path 61 have an air supply port 62 and an exhaust port 63 that open on the lower surface of the lid 41. One end of an air supply pipe 64 is connected to the air supply path 60. The other end of the air supply pipe 64 is connected to an air supply source. One end of an exhaust pipe 65 is connected to the exhaust path 61. The other end of the exhaust pipe 65 is connected to an exhaust source.

  FIG. 4 is a block diagram showing an electrical configuration of the substrate processing apparatus 1. The substrate processing apparatus 1 further includes a control device 55 configured to include a microcomputer. The control device 55 includes a chuck rotation drive mechanism 6, an amplifier 54, a swing drive mechanism 36, a lift drive mechanism 37, a first liquid arm swing mechanism 12, a second liquid arm swing mechanism 29, a stripping liquid valve 23, DIW. The valve 27, the SC1 valve 31, the cleaning liquid lower valve 87, the drying gas lower valve 89, the cleaning liquid upper valve 91, the drying gas nozzle 93, and the like are connected as control targets.

FIG. 5 is a process diagram showing an example of a resist removal process according to the present invention. FIG. 6A is an illustrative view for explaining an SPM liquid film forming step described later. FIG. 6B is an illustrative view for explaining an SPM liquid film heating step to be described later. FIG. 7 is a plan view showing a moving range of the heater head 35 in an SPM liquid film heating step to be described later.
Hereinafter, an example of the resist removal process will be described with reference to FIGS.

  During the resist removal process, a transfer robot (not shown) is controlled, and the wafer W after the ion implantation process is loaded into the processing chamber 2 (see FIG. 1) (step S1: wafer loading). The wafer W is delivered to the wafer rotating mechanism 3 with its surface facing upward. At this time, the heater head 35, the stripping solution nozzle 4 and the SC1 nozzle 25 are each arranged at the home position so as not to hinder the loading of the wafer W.

  When the wafer W is held by the wafer rotation mechanism 3, the controller 55 controls the chuck rotation drive mechanism 6 to start rotation of the wafer W (step S2). The rotation speed of the wafer W is increased to a liquid buildup speed (in the range of 30 to 300 rpm, for example, 60 rpm) that can cover the wafer W with the SPM liquid, and then maintained at the liquid buildup speed. Further, the control device 55 controls the first liquid arm swing mechanism 12 to move the stripping liquid nozzle 4 to a position above the wafer W.

  After the rotation speed of the wafer W reaches the liquid buildup speed, the controller 55 opens the stripping liquid valve 23 and supplies the SPM liquid to the surface of the wafer W from the stripping liquid nozzle 4 as shown in FIG. 6A. The SPM liquid supplied to the surface of the wafer W is accumulated on the surface of the wafer W, and an SPM liquid film 70 covering the entire surface of the wafer W is formed on the surface of the wafer W (step S3: SPM liquid film forming step).

  As shown in FIG. 6A, at the start of the SPM liquid film forming process, the control device 55 controls the first liquid arm swinging mechanism 12 so that the stripping liquid nozzle 4 is placed on the rotation center of the wafer W and stripping is performed. SPM liquid is discharged from the liquid nozzle 4. Thereby, the liquid film 70 of the SPM liquid can be formed on the surface of the wafer W, and the SPM liquid can be spread over the entire surface of the wafer W. Thereby, the entire surface of the wafer W can be covered with the liquid film 70 of the SPM liquid.

When a predetermined liquid film formation period elapses from the start of the discharge of the SPM liquid from the stripping liquid nozzle 4, the control device 55 controls the chuck rotation driving mechanism 6 so that the rotation speed of the wafer W is smaller than the liquid buildup speed. Reduce to the heat treatment speed. Thereby, the SPM liquid film heating process (heating process) of step S4 is performed.
The heat treatment speed is a speed (within a range of 1 to 20 rpm, for example, 15 rpm) at which the liquid film 70 of the SPM liquid can be held on the surface of the wafer W without supplying the SPM liquid to the wafer W. Further, in synchronization with the deceleration of the wafer W by the chuck rotation driving mechanism 6, as shown in FIG. 6B, the control device 55 closes the stripping solution valve 23 and stops the supply of the SPM solution from the stripping solution nozzle 4. At the same time, the first liquid arm swinging mechanism 12 is controlled to return the stripping liquid nozzle 4 to the home position. Although the supply of the SPM liquid to the wafer W is stopped, the liquid film 70 of the SPM liquid is continuously held on the surface of the wafer W by reducing the rotation speed of the wafer W to the heat treatment speed.

  Further, as shown in FIGS. 6B and 7, the control device 55 controls the amplifier 54 to emit infrared rays from the infrared lamp 38, and controls the swing drive mechanism 36 and the lift drive mechanism 37, thereby heating the heater. The head 35 has a first proximity position (position indicated by a solid line in FIG. 7) facing the rotation center of the wafer W and a second proximity position (indicated by a two-dot chain line in FIG. 7) facing the peripheral edge of the wafer W. Move back and forth. By irradiation of infrared rays by the infrared lamp 38, the wafer W and the SPM liquid immediately below the infrared lamp 38 are rapidly heated, and the SPM liquid near the boundary with the wafer W is heated. Then, a region facing the lower surface 52B of the bottom plate portion 52 on the surface of the wafer W (a region facing the infrared lamp 38) has a circular arc in a range from the region including the rotation center of the wafer W to the region including the peripheral edge of the wafer W. Reciprocates while drawing a belt-like trajectory. As a result, the entire surface of the wafer W can be heated.

Due to the irradiation of infrared rays from the infrared lamp 38, the SPM liquid immediately below the infrared lamp 38 is rapidly heated, and bumping occurs. Therefore, a large amount of SPM liquid mist is generated around the surface of the wafer W.
Note that the second proximity position is such that when the heater head 35 is viewed from above, a part of the lower surface 52B of the bottom plate portion 52, more preferably the annular portion 43 of the infrared lamp 38, is more than the outer periphery of the wafer W. It is a position that projects in the radial direction.

In the SPM liquid film heating step of step S4, the liquid film 70 of the SPM liquid is heated near the boundary with the surface of the wafer W. During this time, the reaction between the resist on the surface of the wafer W and the SPM solution proceeds, and the resist peels off from the surface of the wafer W.
Thereafter, when a predetermined liquid film heating time elapses after the rotation speed of the wafer W is reduced, the control device 55 controls the amplifier 54 to stop the infrared radiation from the infrared lamp 38. The control device 55 controls the swing drive mechanism 36 and the lift drive mechanism 37 to return the heater head 35 to the home position. At the end of this SPM liquid film heating step, a large amount of SPM liquid mist is attached to the lower surface 52B of the lamp housing 40 of the heater head 35.

  Then, the control device 55 controls the chuck rotation drive mechanism 6 to increase the rotation speed of the wafer W to a predetermined liquid processing rotation speed (for example, 1000 rpm in the range of 300 to 1500 rpm) and open the DIW valve 27. Then, DIW is supplied from the discharge port of the DIW nozzle 24 toward the vicinity of the rotation center of the wafer W (step S5: intermediate rinsing process). The DIW supplied to the surface of the wafer W receives centrifugal force due to the rotation of the wafer W and flows on the surface of the wafer W toward the periphery of the wafer W. Thereby, the SPM liquid adhering to the surface of the wafer W is washed away by DIW.

When the DIW supply is continued for a predetermined intermediate rinse time, the DIW valve 27 is closed and the supply of DIW to the surface of the wafer W is stopped.
While maintaining the rotation speed of the wafer W at the liquid processing rotation speed, the controller 55 opens the SC1 valve 31 and supplies SC1 from the SC1 nozzle 25 to the surface of the wafer W (step S6). Further, the control device 55 controls the second liquid arm swing mechanism 29 to swing the second liquid arm 28 within a predetermined angle range, so that the SC1 nozzle 25 is placed on the rotation center and the peripheral portion of the wafer W. Move back and forth between the top and bottom. As a result, the supply position on the surface of the wafer W to which SC1 is guided from the SC1 nozzle 25 is in the range from the rotation center of the wafer W to the peripheral edge of the wafer W in an arc shape that intersects the rotation direction of the wafer W. Move back and forth while drawing a trajectory. Thereby, SC1 is supplied uniformly over the entire surface of the wafer W, and foreign substances such as resist residues and particles adhering to the surface of the wafer W can be removed by the chemical ability of SC1.

  When the supply of SC1 is continued for a predetermined SC1 supply time, the controller 55 closes the SC1 valve 31 and controls the second liquid arm swing mechanism 29 to return the SC1 nozzle 25 to the home position. In the state where the rotation speed of the wafer W is maintained at the liquid processing rotation speed, the controller 55 opens the DIW valve 27 and supplies DIW from the discharge port of the DIW nozzle 24 toward the vicinity of the rotation center of the wafer W. (Step S7: rinsing process). The DIW supplied to the surface of the wafer W receives centrifugal force due to the rotation of the wafer W and flows on the surface of the wafer W toward the periphery of the wafer W. Thereby, SC1 adhering to the surface of the wafer W is washed away by DIW.

When the supply of DIW is continued for a predetermined rinse time, the DIW valve 27 is closed and the supply of DIW to the surface of the wafer W is stopped.
When a predetermined time has elapsed from the start of the rinsing process, the control device 55 closes the DIW valve 27 and stops the supply of DIW to the surface of the wafer W. Thereafter, the control device 55 drives the chuck rotation driving mechanism 6 to increase the rotation speed of the wafer W to a predetermined high rotation speed (for example, 1500 to 2500 rpm), and shakes off the DIW adhering to the wafer W to be dried. The spin dry process is performed (step S8).

When the spin dry process is performed for a predetermined spin dry process time, the control device 55 drives the chuck rotation drive mechanism 6 to stop the rotation of the wafer rotation mechanism 3. As a result, the resist removal process for one wafer W is completed, and the processed wafer W is unloaded from the processing chamber 2 by the transfer robot (step S9).
After unloading the wafer W, the heater head 35 is cleaned, and a heater head cleaning / drying process is performed in which the cleaned heater head 35 is dried (step S10). In the heater head cleaning / drying step, a cleaning process for cleaning the heater head 35 is performed, and a drying process is performed on the heater head 35 after the cleaning process.

FIG. 8 is a flowchart showing the flow of the heater head cleaning and drying process. FIG. 9A is a schematic diagram for explaining the cleaning process of the heater head cleaning / drying process, and FIG. 9B is a schematic diagram for explaining the drying process of the heater head cleaning / drying process. FIG. 10 is a plan view showing a moving range of the heater head 35 in the heater head cleaning / drying step.
In the cleaning process of the heater head cleaning / drying process, the control device 55 controls the swing drive mechanism 36 to swing the heater arm 34 and also controls the lift drive mechanism 37 to lift the heater head 35 up and down. Is moved above the wafer rotation mechanism 3 from the home position. At this time, the wafer W is not held by the wafer rotation mechanism 3. Therefore, the heater head 35 is disposed opposite to the upper surface of the spin base 8 (step S21, heater arrangement step). More specifically, the circular lower surface 52B of the heater head 35 (lamp housing 40) is positioned above the rotation center (on the rotation axis C) by the wafer rotation mechanism 3. The heater head 35 at this time is preferably at a height position such that the cleaning liquid blown from the back surface liquid discharge port 84 reaches the lower surface 52B.

  9A, the control device 55 opens the cleaning liquid upper valve 91 (see FIG. 1 and the like), and discharges the cleaning liquid downwardly from the cleaning liquid upper nozzle 94 (step S22, upper cleaning liquid discharge step). ). Thus, the cleaning liquid that has flowed downward from the cleaning liquid upper nozzle 94 falls on the heater head 35. That is, the liquid is deposited on the upper surface of the heater head 35 (for example, the upper surface of the lid 41).

  Further, the control device 55 opens the cleaning liquid lower valve 87 (see FIG. 1 and the like), and discharges the cleaning liquid vertically upward from the back surface liquid discharge port 84 of the back surface nozzle 82 (step S22, lower cleaning liquid discharge process). As a result, the cleaning liquid is greatly blown upward from the back surface liquid discharge port 84. The cleaning liquid blown from the back surface liquid discharge port 84 lands on the lower surface 52B of the bottom plate portion 52 of the lamp housing 40 that constitutes the lower surface of the heater head 35.

  Further, the control device 55 controls the swing drive mechanism 36 to swing the heater arm 34, so that the heater head 35 is moved from the center of the spin base 8 to the center of the spin base 8 and one peripheral portion of the spin base 8. Is moved to a first intermediate position (position indicated by a solid line in FIG. 10). Next, the control device 55 controls the swing drive mechanism 36 to swing the heater arm 34 within a predetermined angular range, so that the heater head 35 is moved over the first intermediate position, the center of the spin base 8 and the spin. The base 8 is reciprocated between the second intermediate position (the position indicated by the two-dot chain line in FIG. 10) with respect to the other peripheral edge of the base 8 (step S23, liquid landing position moving step). The first intermediate position is a position where one peripheral edge portion of the lower surface 52B of the lamp housing 40 is on the rotation center (on the rotation axis C) of the spin base 8. In the second intermediate position, the other peripheral edge of the lower surface 52B of the heater head 35 (the one peripheral edge and the peripheral edge on the opposite side across the center of the lower surface 52B) is on the rotation center of the spin base 8 (on the rotation axis C). ). As a result, the landing position of the lower surface 52B through which the cleaning liquid from the back surface liquid discharge port 84 is guided crosses the circumferential direction of the lower surface 52B within a range from one peripheral edge portion of the lower surface 52B to the other peripheral edge portion. It moves back and forth while drawing an arcuate trajectory.

As a result, the cleaning liquid is uniformly supplied to the entire area of the lower surface 52B of the lamp housing 40, and foreign substances such as SPM liquid mist adhering to the lower surface 52B of the lamp housing 40 are washed away by the cleaning liquid.
Further, the liquid landing position on the upper surface of the heater head 35 (the upper surface of the lid 41) to which the cleaning liquid is guided from the back surface liquid discharge port 84 also reciprocates while drawing an arcuate locus. The cleaning liquid supplied to the upper surface of the heater head 35 spreads over the entire upper surface of the heater head 35 and spreads to the side wall of the heater head 35.

As described above, the cleaning liquid is evenly distributed over the entire outer surface of the heater head 35, and the entire outer surface of the heater head 35 can be cleaned well.
The discharge of the cleaning liquid from the cleaning liquid upper nozzle 94 and the back surface liquid discharge port 84 and the reciprocating swing of the heater arm 34 are continued until a predetermined cleaning processing time elapses.
When the predetermined cleaning process time ends (YES in step S24), the control device 55 closes the cleaning liquid upper valve 91 and the cleaning liquid lower valve 87 (step S25), and the cleaning liquid from the cleaning liquid upper nozzle 94 and the back surface liquid discharge port 84. Stop discharging.

Further, as shown in FIG. 9B, the control device 55 opens the drying gas upper valve 93 (step S26). As a result, the drying gas from the drying gas upper nozzle 95 is sprayed onto the upper surface of the heater head 35. The cleaning liquid adhering to the upper surface of the heater head 35 is blown off by the drying gas.
The control device 55 opens the drying gas lower valve 89 (step S26, lower drying gas spraying step). Thereby, the drying gas from the back surface gas discharge port 85 of the back surface nozzle 82 is sprayed onto the lower surface 52 </ b> B of the lamp housing 40.

  At this time, the control device 55 controls the swing drive mechanism 36 to swing the heater arm 34 to reciprocate the heater head 35 between the first intermediate position and the second intermediate position. As a result, the spraying position of the drying gas from the back surface gas discharge port 85 on the lower surface 52B intersects the circumferential direction of the lower surface 52B within a range from one peripheral edge portion of the lower surface 52B to the other peripheral edge portion. It moves back and forth while drawing an arcuate trajectory.

Thereby, the drying gas is uniformly supplied to the entire area of the lower surface 52B of the lamp housing 40, and the cleaning liquid adhering to the lower surface 52B of the lamp housing 40 is blown off by the drying gas.
Further, the control device 55 controls the amplifier 54 to emit infrared rays from the infrared lamp 38 (step S26, heat drying step). Thereby, the lamp housing 40 is warmed, and the cleaning liquid adhering to the lower surface 52B or the outer periphery of the lamp housing 40 is evaporated and removed.

The discharge of the drying gas from the drying gas upper nozzle 95 and the back nozzle 82 and the emission of infrared rays from the infrared lamp 38 are continued until a predetermined drying processing time elapses.
When the predetermined drying processing time ends (YES in step S27), the control device 55 closes the drying gas upper valve 93 and the drying gas lower valve 89 (step S28), and the drying gas upper nozzle 95 and the backside gas. The discharge of the drying gas from the discharge port 85 is stopped.

Further, the control device 55 controls the swing drive mechanism 36 to swing the heater arm 34 and return the heater head 35 after the cleaning process to the home position.
A series of resist removal processing is completed by the end of the heater head cleaning and drying process.
As described above, according to this embodiment, the cleaning process for cleaning the heater head 35 is executed in each resist removal process. In this cleaning process, the heater head 35 is disposed at a position facing the upper side of the back surface liquid discharge port 84. Further, the cleaning liquid is discharged vertically upward from the back surface liquid discharge port 84. The cleaning liquid from the back surface liquid discharge port 84 is blown up vertically and is deposited on the lower surface 52 </ b> B of the lamp housing 40. In the SPM liquid film heating step, a large amount of generated SPM liquid mist may adhere to the lower surface 52B of the lamp housing 40.

  Since the SPM liquid mist adhering to the lower surface 52B of the lamp housing 40 can be washed away by the cleaning liquid supplied from the back surface liquid discharge port 84 to the lower surface 52B of the lamp housing 40, the lower surface 52B of the lamp housing 40 is excellent. Can be washed. And the lower surface 52B of the lamp housing 40 can be maintained in a clean state. As a result, it is possible to prevent a decrease in the amount of infrared light emitted to the outside of the lamp housing 40 and to prevent the lower surface 52B of the lamp housing 40 from becoming a particle source.

Further, after the heater head 35 is cleaned, the outer surface of the heater head 35 is dried. Thereby, it is possible to prevent the cleaning liquid from remaining on the outer surface of the heater head 35 and adversely affecting the processing of the wafer W.
Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms.

  For example, in the above-described embodiment, the cleaning liquid is supplied from both the cleaning liquid upper nozzle 94 and the back surface liquid discharge port 84 to the heater head 35 in the cleaning process of the heater head 35. The heater head 35 may be cleaned only by supplying the cleaning liquid from the back surface liquid discharge port 84 to the heater head 35 without supplying the cleaning liquid from the nozzle 94. In this case, in the drying process of the heater head 35, it is not necessary to spray the drying gas upper nozzle 95 on the heater head 35.

  Further, in the above-described embodiment, the position where the cleaning liquid is deposited on the lower surface 52B of the heater head 35 is moved by reciprocating the heater head 35 in the horizontal direction. When a nozzle having a discharge port capable of changing the discharge direction is employed, the cleaning liquid landing position on the lower surface 52B of the heater head 35 is moved by changing the discharge direction of the cleaning liquid from the discharge port. You can also.

  In the drying process of the heater head 35, the cleaning liquid adhering to the heater head 35 is blown and dried by blowing the drying gas from the drying gas upper nozzle 95 and the back nozzle 82, and the lamp housing 40 is warmed by the infrared lamp 38. Although the case of drying by both heat drying has been described as an example, the heater head 35 may be dried only by heat drying with the infrared lamp 38 without performing blow-drying with a drying gas.

Further, the back nozzle 82 may employ a configuration in which the cleaning liquid and the dry gas are selectively discharged from one discharge port without separately providing the back surface liquid discharge port 84 and the back surface gas discharge port 85. it can.
In addition, the heater arm 34 may be cleaned together with the heater head cleaning / drying step (step S10 shown in FIG. 5). Although the cleaning of the heater arm 34 can be performed using the cleaning liquid discharged from the cleaning liquid upper nozzle 94, the heater arm 34 is cleaned using a bar nozzle (not shown) separately provided in the processing chamber 2. be able to. In the bar nozzle, a large number of discharge ports directed vertically downward are arranged in one or a plurality of rows along the horizontal direction, and are arranged in an upper region in the processing chamber 2. In the state where the heater arm 34 (and the heater head 35) is disposed below the bar nozzle, the cleaning liquid is discharged from each discharge port of the bar nozzle. The cleaning liquid falls on the outer surface of the heater arm 34, and the heater arm 34 The outer surface is cleaned.

Further, cleaning (chamber cleaning) in the processing chamber 2 may be performed in combination with the heater head cleaning / drying step (step S10 shown in FIG. 5).
Further, the case where DIW is used as the cleaning liquid used in the cleaning process has been described as an example. However, the cleaning liquid is not limited to DIW, and a dilute hydrofluoric acid aqueous solution, carbonated water, electrolytic ion water, ozone water, or the like may be employed as the cleaning liquid. Further, when a chemical solution such as a dilute hydrofluoric acid aqueous solution is used as the cleaning liquid, after the cleaning liquid is supplied to the heater head 35, a rinse treatment for washing the cleaning liquid from the heater head 35 using DIW or carbonated water is performed. Also good.

Moreover, although nitrogen gas was mentioned as an example of drying gas, clean air and other inert gas can be used as drying gas.
The present invention can also be applied to a heater cleaning method provided in a substrate processing apparatus that selectively etches a nitride film on a main surface of a substrate using a high-temperature etching solution such as phosphoric acid.
In addition, various design changes can be made within the scope of matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 2 Processing chamber 3 Wafer rotation mechanism (substrate holding means)
35 Heater head (heater)
38 Infrared lamp 40 Lamp housing (housing)
41 Lid (housing)
52B Bottom (opposite surface)
82 Back nozzle (lower nozzle)
84 Back side liquid outlet (first outlet)
85 Backside gas outlet (second outlet)
94 Nozzle for cleaning liquid (ceiling nozzle)
W Wafer (Substrate)

Claims (6)

A heater cleaning method for cleaning a heater having an infrared lamp and a housing and disposed opposite to the upper surface of the substrate held by the substrate holding means to heat the upper surface,
A heater disposing step of disposing the heater at a position facing the lower surface of the lower nozzle having a first discharge port that discharges the liquid upward, facing the lower surface of the substrate held by the substrate holding means;
The cleaning liquid is supplied to the outer surface of the housing by supplying the cleaning liquid to the lower nozzle and discharging the cleaning liquid upward from the first discharge port in a state where the substrate is not held by the substrate holding means. A heater cleaning method including a lower cleaning liquid discharging step.   In parallel with the lower cleaning liquid discharge step, an upper cleaning liquid discharge step of supplying the cleaning liquid to the outer surface of the housing by discharging the cleaning liquid downward from an upper nozzle disposed above the first discharge port. The heater cleaning method according to claim 1, further comprising:   3. The liquid landing position moving step of moving the liquid landing position of the cleaning liquid discharged from the first discharge port on the outer surface of the housing in parallel with the lower cleaning liquid discharging step. Heater cleaning method.   The heater cleaning method according to any one of claims 1 to 3, further comprising a drying step in which the cleaning solution adhering to the outer surface of the housing is removed after the lower cleaning solution supply step.   5. The heater cleaning method according to claim 4, wherein the drying step further includes a heating drying step of irradiating the housing with infrared rays from the infrared lamp to heat dry the outer surface of the housing. The lower nozzle has a second discharge port for discharging gas upward;
The drying step supplies the drying gas to the lower nozzle and blows the drying gas upward from the second discharge port, thereby supplying the drying gas to the outer surface of the housing. The heater cleaning method according to claim 4, further comprising a gas spraying step.

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