JP2010225740A - Substrate processing method, and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method that can suppress production of particles more excellently. <P>SOLUTION: The substrate processing method that uses a clamp ring for limiting a processing area for a workpiece to process the workpiece while limiting the processing area for the workpiece includes a process (t1) of mounting the workpiece on a mounting table having a heating mechanism, a process (t2) of heating the workpiece mounted on the mounting table up to target heating temperature using the heating mechanism, and a process (t3, A) of bringing the clamp ring for limiting the processing area for the workpiece into contact with the workpiece having reached the target heating temperature. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus, and more particularly, to a substrate processing method and a substrate processing apparatus that limit processing on a peripheral portion of an object to be processed.

  In a manufacturing process of a semiconductor device or the like, a process such as a film forming process is performed on a wafer that is a target object. In the film forming process, the film is not formed only on the upper surface of the wafer, but is also formed on the side surface of the wafer.

  In recent years, miniaturization of semiconductor devices and multi-layer structures have progressed, and demands for particle suppression have become strict.

  The film formed on the side surface of the wafer is a film that is unnecessarily adhered, and is poor in quality and fragile as compared to the film formed on the upper surface of the wafer. For this reason, it may be peeled off during the manufacturing process, causing generation of particles.

  In view of this, the peripheral edge of the wafer is covered with a clamp ring to suppress adhesion of the film to the vicinity of the peripheral edge and the side surface (bevel portion) of the wafer (for example, Patent Document 1).

JP 2000-277458 A

  However, the clamp ring contacts the wafer. For this reason, the wafer may be scraped by the clamp ring. If the wafer is scraped, new particles are generated.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a substrate processing method and a substrate processing apparatus capable of better suppressing the generation of particles.

  In order to solve the above-described problem, a substrate processing method according to a first aspect of the present invention uses a clamp ring that limits a processing area for a target object, and restricts the processing area for the target object. A substrate processing method for performing processing on a mounting table having a heating mechanism, and a step of mounting the object to be processed, and the heating mechanism is used to mount the object on the mounting table Heating the object to be processed to a target heating temperature, and contacting the object to be processed that has reached the target heating temperature with the clamp ring that limits a processing area for the object to be processed.

  A substrate processing apparatus according to a second aspect of the present invention has a heating mechanism, a mounting table on which an object to be processed is mounted, a clamp ring that limits a processing area for the object to be processed, and the clamp A clamp ring drive mechanism that drives the ring to contact and separate from the object to be processed, and after the object to be processed is mounted on the mounting table, the ring is mounted on the mounting table using the heating mechanism. Heating the workpiece to a target heating temperature, and after the workpiece reaches the target heating temperature, using the contact and release mechanism, the clamp ring is brought into contact with the workpiece. And a control unit for controlling the heating mechanism and the contact and separation mechanism.

  According to the present invention, it is possible to provide a substrate processing method and a substrate processing apparatus capable of better suppressing the generation of particles.

Sectional drawing which showed roughly an example of the substrate processing apparatus which can perform the substrate processing method which concerns on one Embodiment of this invention Timing chart showing an example of a substrate processing method according to an embodiment of the present invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention Sectional drawing which shows an example of the substrate processing method which concerns on one Embodiment of this invention The figure which shows the generation situation of the particle by comparison example The figure which shows the generation | occurence | production condition of the particle by one Embodiment

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In this description, the same parts are denoted by the same reference symbols throughout the drawings to be referred to.

  FIG. 1 is a cross-sectional view schematically showing an example of a substrate processing apparatus capable of executing a substrate processing method according to an embodiment of the present invention. This example is used for manufacturing a semiconductor device as a substrate processing apparatus, and illustrates, for example, a film forming apparatus that forms a thin film on a semiconductor wafer (hereinafter referred to as a wafer). However, the present invention is not limited to the film forming apparatus.

  As shown in FIG. 1, the film forming apparatus 100 includes a processing chamber 1 that performs a film forming process on a target object, in this example, a wafer W. In the processing chamber 1, a processing object mounting mechanism 2 on which a wafer W is mounted is disposed.

  In this example, the workpiece mounting mechanism 2 includes a support member 21 disposed on the center of the bottom of the processing chamber 1, a base 22 provided on the upper end of the support member 21, and a base 22. A mounting table 23 having a heating mechanism 24, for example, a stage heater, on which the wafer W is mounted is provided. The heating mechanism 24 is connected to the heater power source 3. A side wall 23a is provided on the periphery of the base 22 so as to surround the mounting table 23, and a clamp ring (also referred to as a cover ring) 25 that limits a processing area for the wafer W can be moved up and down on the side wall 23a. Is provided. The planar shape of the clamp ring 25 is a ring shape having an opening 25a at the center. The clamp ring 25 is brought into contact with the peripheral edge of the wafer W placed on the placement table 23. The contact amount is arbitrary, but for example, the contact is made so as to cover about 3 mm to 5 mm from the edge of the wafer W. As a result, the processing area for the wafer W is limited within the opening 25a, and a film is selectively formed on the wafer W on an area 3 mm to 5 mm inside from the edge of the wafer W. No film is formed on the portion of the wafer W covered by the clamp ring 25. The clamp ring 25 is driven by a clamp ring drive mechanism 26 that drives the clamp ring 25 to come into contact with and separate from the wafer W. The clamp ring drive mechanism 26 of this example drives the clamp ring 25 up and down in the vertical direction.

  Further, the base 22 and the mounting table 23 are formed with lift pin holes 27 penetrating them, and lift pins 28 provided so as to be movable up and down are inserted into the lift pin holes 27. The lift pin 28 is driven by a lift pin drive mechanism 29. The lift pin drive mechanism 29 is driven to lower the lift pins 28 so as to contact the wafer W with the mounting table 23 and to lift the lift pins 28 so as to be detached from the mounting table 23.

  A raw material gas supply unit 4 is provided in the upper part of the processing chamber 1. The source gas supply unit 4 is connected to a source gas supply mechanism 5. The source gas supply mechanism 5 supplies a gas 51 containing a source material for a film to be formed to the source gas supply unit 4 via a gas supply pipe 52. The source gas supply unit 4 is a shower head in this example, and is connected to the gas supply pipe 52 and formed on the diffusion space 41 in which the gas 51 containing the source is diffused and the surface of the diffusion space 41 facing the wafer W. A plurality of gas discharge holes 42 are provided.

The gas 51 containing the raw material is decomposed in the vicinity of the surface of the wafer W heated by the heating mechanism 24 to form a film on the wafer W. As an example of such a film formation, a ruthenium (Ru) film formation using Ru ₃ (CO) ₁₂ gas as the gas 51 containing the raw material can be given. The Ru ₃ (CO) ₁₂ gas is thermally decomposed into Ru and CO gas as described below, and Ru is deposited on the surface of the wafer W as a metal solid to form a Ru film.

Ru ₃ (CO) ₁₂ ↑ ⇔ Ru ₃ (CO) _12−x ↑ + XCO ↑
Ru ₃ (CO) _12−x ↑ + Q → 3Ru + (12−X) CO ↑
Here, “⇔” indicates reversible, “↑” indicates a gas state, those without “↑” indicate a solid state, and “Q” indicates an amount of heat. It is shown that.

  An exhaust device 6 is connected to the processing chamber 1. For example, the exhaust device 6 exhausts the processing space S in the processing chamber 1 during processing so that the pressure of the processing space S is maintained at an appropriate pressure.

  The control unit 7 includes a process controller 71 composed of a microprocessor (computer), a keyboard on which an operator inputs commands to manage the film forming apparatus, and a display that visualizes and displays the operating status of the substrate processing system. And the like, and a control program for realizing various processes executed by the film forming apparatus under the control of the process controller 71, various data, and causing the film forming apparatus to execute processes according to processing conditions. And a storage unit 73 in which a recipe is stored.

  The recipe is stored in a storage medium in the storage unit 73. The storage medium may be a hard disk or a portable medium such as a CD-ROM, DVD, or flash memory. Moreover, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example. If necessary, an arbitrary recipe is called from the storage unit 73 by an instruction from the user interface 72 and is executed by the process controller 71, so that a desired process in the film forming apparatus is performed under the control of the process controller 71. Is done.

  Next, an example of a substrate processing method according to an embodiment of the present invention will be described.

  FIG. 2 is a timing chart showing an example of a substrate processing method according to an embodiment of the present invention, and FIGS. 3 to 9 are sectional views showing an example of a substrate processing method according to an embodiment of the present invention.

  First, as shown in FIGS. 2 and 3, the wafer W is loaded into the processing chamber using a transfer device (not shown), and the wafer W is placed on the lift pins 28 raised (time t0).

  Next, as shown in FIGS. 2 and 4, the lift pins 28 are lowered and the wafer W is placed on the mounting table 23 (time t1).

  Next, as shown in FIGS. 2 and 5, the heating mechanism 24 is turned on, and heating of the wafer W placed on the placement table 23 is started (time t2). Alternatively, the heating mechanism 24 is turned on before the wafer W is mounted on the mounting table 23, and the heating of the wafer W is started (time t2). In this example, the pressure in the processing chamber is increased to, for example, 5 Torr until the wafer W reaches the target heating temperature.

  Next, as shown in FIGS. 2 and 6, when the temperature of the wafer W reaches the target heating temperature, which is 200 ° C. in this example, the clamp ring 25 is lowered and the clamp ring 25 is brought into contact with the peripheral portion of the wafer W. (Time t3, see circle A in the figure). In this example, when the wafer W reaches the target heating temperature, the pressure in the processing chamber is reduced to a predetermined process pressure, for example, 0.1 Torr.

  Next, as shown in FIG. 2 and FIG. 7, the film forming process of the film 8 is started in a state where the peripheral edge portion of the wafer W is covered by the clamp ring 25 (time t4).

  Next, as shown in FIGS. 2 and 8, when the film forming process is completed, the heating mechanism 24 is turned off, the clamp ring 25 is raised, and the clamp ring 25 is detached from the peripheral edge of the wafer W (time t5). .

  Next, as shown in FIGS. 2 and 9, the lift pins 28 are raised, and the wafer W is detached from the mounting table 23. Thereafter, the wafer W is unloaded from the processing chamber using a transfer device (not shown), and the processing is terminated (time t6).

  FIG. 10 is a diagram illustrating a particle generation state according to a comparative example, and FIG. 11 is a diagram illustrating a particle generation state according to an embodiment.

  In the comparative example, as shown by a circle B in FIG. 2, the clamp ring 25 is brought into contact before the wafer W is heated.

  As shown in FIG. 10, in the comparative example, the generation state of particles greatly increases from the initial state to after the processing. In particular, generation of particles is remarkable at the peripheral edge of the wafer W.

  On the other hand, as shown in FIG. 11, in one embodiment, the generation state of particles hardly increases from the initial state to after the processing.

  In the comparative example, since the clamp ring 25 is in contact with the peripheral edge of the wafer W before the wafer W is heated, the clamp ring 25 and the wafer W rub against each other when the wafer W is thermally expanded. This is because the wafer W has been shaved. In fact, in the comparative example, as a result of observing the surface of the generated particles and the surface of the wafer W, scratch marks were observed.

  On the other hand, in one embodiment, after the wafer W is heated, the clamp ring 25 is brought into contact with the peripheral portion of the wafer W after the temperature of the wafer W reaches the target heating temperature and the wafer W is sufficiently thermally expanded. . Therefore, friction between the clamp ring 25 and the wafer W due to the thermal expansion of the wafer W can be reduced as compared with the comparative example. Therefore, according to the embodiment, it is possible to obtain a substrate processing method that can suppress the wafer W from being scraped and can better suppress the generation of particles.

  Further, by causing the control unit 7 to perform the operation shown in the timing chart shown in FIG. 2 and the operation of the clamp ring 25 shown in FIGS. It is possible to obtain a substrate processing apparatus capable of better suppressing the occurrence.

  It is also conceivable that the particles are washed away after the processing is completed. However, the scratch marks on the surface of the wafer W generated in the comparative example cannot be erased by cleaning. The scratch marks are those in which the wafer W is mechanically cut. For this reason, scratch marks can cause new particles to be generated during processing. If new particles are generated during the processing and taken into the film being formed, for example, it may cause a film failure, for example, a short circuit, or, for example, the etching surface of the wafer W during etching. If it adheres to the top, it may cause a shape defect such as etch pits. For this reason, the generation of scratch marks on the wafer W can be a factor that deteriorates the manufacturing yield of the semiconductor device.

  In this regard, an embodiment capable of suppressing the generation of scratch marks on the wafer W is also advantageous in maintaining and improving the manufacturing yield of the semiconductor device.

  In the embodiment, in the step of heating the wafer W to the target heating temperature, in order to improve the thermal conductivity to the wafer W, the pressure in the processing chamber in which processing is performed is increased, and the temperature of the wafer W is increased. After reaching the target heating temperature, the pressure in the processing chamber is reduced to the process pressure. At this time, the clamp ring 25 is brought into contact with the wafer W after the pressure in the processing chamber drops to the process pressure.

  Of course, the clamp ring 25 may be brought into contact with the wafer W while the pressure in the processing chamber is lowered to the process pressure. However, the clamp ring 25 is preferably brought into contact with the wafer W after the pressure in the processing chamber has dropped to the process pressure. This is because when the pressure around the wafer W changes, the wafer W slightly deforms according to the change in pressure. During this deformation, scratch marks may occur on the wafer W. Such a possibility can be eliminated by bringing the clamp ring 25 into contact with the wafer W after the pressure around the wafer W is stabilized.

  The present invention has been described according to the embodiment. However, the present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit of the invention. In the embodiment of the present invention, the above-described embodiment is not the only embodiment.

  For example, in the above-described embodiment, when the temperature of the wafer wafer W reaches the target heating temperature, the clamp ring is lowered. From the viewpoint of increasing the throughput, the clamp ring is removed when the temperature of the wafer W approaches the target heating temperature. It may be lowered. This is because when the wafer W is silicon, the change in the coefficient of thermal expansion is large at a low temperature, but the change in the coefficient of thermal expansion is small (saturates) at a high temperature of, for example, 150 ° C. or higher.

  In the above embodiment, the example in which the substrate processing method according to the present invention is applied to a film forming apparatus has been described. However, the substrate processing method can be applied to a substrate processing apparatus other than the film forming apparatus, for example, an etching apparatus, The present invention can also be applied to an oxidation apparatus or an annealing apparatus that heats the wafer W and thermally expands the wafer W.

  Further, as an example of the mounting table 23 having the heating mechanism 24, the stage heater provided with the heating mechanism 24 is illustrated, but the stage heater is not limited to the stage heater, and the heating mechanism 24 can heat the wafer W. For example, a lamp heating type mounting table may be used.

  Moreover, although the semiconductor wafer was illustrated as a to-be-processed object, the to-be-processed object may be the glass substrate used for manufacture of FPD and a solar cell, and what kind of to-be-processed object will be thermally expanded? The present invention can be applied even to an object to be processed.

  DESCRIPTION OF SYMBOLS 1 ... Processing chamber, 2 ... To-be-processed object mounting mechanism, 21 ... Support member, 22 ... Base, 23 ... Mounting base, 23a ... Side wall of mounting base, 24 ... Heating mechanism, 25 ... Clamp ring, 25a ... Clamp ring 26 ... Clamp ring drive mechanism, 27 ... Lift pin hole, 28 ... Lift pin, 29 ... Lift pin drive mechanism, 3 ... Heater power supply, 4 ... Source gas supply unit, 41 ... Diffusion space, 42 ... Gas discharge hole, 5 ... Source gas supply mechanism 51... Gas containing raw material 52. Gas supply pipe 6. Exhaust device 7. Control unit 71. Process controller 72 72 User interface 73 Storage unit S Processing space

Claims (6)

A substrate processing method using a clamp ring that limits a processing area for a target object, and processing the target object while limiting a processing area for the target object,
A step of mounting the object to be processed on a mounting table having a heating mechanism;
Using the heating mechanism, heating the target object placed on the mounting table to a target heating temperature;
Contacting the clamp ring that limits a processing area for the object to be processed, which has reached the target heating temperature;
A substrate processing method.   The substrate processing method according to claim 1, wherein the clamp ring covers a peripheral edge of the object to be processed.   The substrate processing method according to claim 1, wherein the process is a film forming process. In the step of heating the object to be processed to a target heating temperature, the pressure in the processing chamber for performing the processing is increased,
4. The substrate processing method according to claim 1, wherein after the temperature of the object to be processed reaches the target heating temperature, the pressure in the processing chamber is lowered to a process pressure. 5.   The substrate processing method according to claim 4, wherein the clamp ring is brought into contact with the object to be processed after the pressure in the processing chamber is lowered to a process pressure. A mounting table having a heating mechanism on which the object to be processed is mounted;
A clamp ring for limiting a processing area for the object to be processed;
A clamp ring drive mechanism for driving the clamp ring so as to contact and detach from the object to be processed;
After the object to be processed is mounted on the mounting table, the target object mounted on the mounting table is heated to a target heating temperature using the heating mechanism, and the target object is heated to the target heating temperature. A control unit that controls the heating mechanism and the contact and release mechanism so that the clamp ring is brought into contact with the workpiece using the contact and release mechanism,
A substrate processing apparatus comprising:

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