JP2013124392A - Film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly carry out reaction gas switching when a plurality of types of reaction gases reacting with each other are sequentially supplied to a substrate to form a thin film.SOLUTION: In a gas forming device, a gas-flowing space P1 is formed at the outside of a position separated by 5.0-40.0 mm toward the peripheral side of the center position of a wafer W on a mounting part 3, and process gas and purge gas are supplied to the gas-flowing space P1 from a gas descending space P2 formed on the center part side of the wafer W. The height position and attitude of the mounting part 3 to a top board 4 are set such that the height dimension j for the gas-flowing space P1 is formed evenly across the surface and is 10.0 mm or less, when a film forming process is carried out on the wafer W.

Description

  The present invention relates to a film forming apparatus that forms a thin film by sequentially supplying a plurality of types of reaction gases that react with each other to a substrate.

  As a method for forming a thin film on a substrate, for example, a semiconductor wafer (hereinafter referred to as “wafer”), a so-called ALD (Atomic Layer Deposition) method or MLD (Multi) which sequentially supplies a plurality of types of reaction gases that react with each other to the wafer. A method called “Layer Deposition” method or the like is known.

As a mechanism for supplying a reactive gas to a wafer in such a film forming method, for example, in Patent Document 1, a gas supply port 221 is disposed so as to face the wafer, and conical as it goes from the upper side to the lower side. A technique is described in which a processing space 20 whose diameter is expanded is formed between a gas supply port 221 and a wafer. However, in this technique, when the reaction gas is switched, it is necessary to replace the atmosphere in the conical wide space (processing space 20). Therefore, if the atmosphere is replaced quickly, that is, high throughput is secured. Then, there is a possibility that the replacement becomes insufficient.
Although Patent Documents 2 to 4 describe an apparatus for performing a film forming process on a wafer, the above-mentioned problems are not mentioned.

JP 2010-84192 A JP 2009-88473 A Japanese Patent Laid-Open No. 9-111447 JP 2004-335892 A

  The present invention has been made under such circumstances, and an object of the present invention is to switch reactive gases when a thin film is formed by sequentially supplying a plurality of types of reactive gases that react with each other to a substrate. It is to provide a technique capable of promptly performing.

The film forming apparatus of the present invention
A plurality of kinds of reaction gases that react with each other in the vacuum vessel are sequentially supplied from the gas supply port, and a replacement gas is supplied between the supply of one reaction gas and another reaction gas. In a film forming apparatus for performing a film forming process,
A mounting portion provided in the vacuum vessel for mounting the substrate;
A top portion formed as an annular facing surface portion whose central portion is opened as the gas supply port and a portion surrounding the gas supply port is opposed to the substrate;
An exhaust mechanism for evacuating the vacuum container;
Relative to the top plate portion, the placement portion is positioned between a position when the substrate is transferred from the outside of the vacuum container to the placement portion and a processing position for performing a film forming process on the substrate. An elevating mechanism for elevating and lowering,
The opposing surface portion has a projected position of the inner peripheral edge of 5.0 mm to 40.0 mm away from the center of the substrate, and the projected position of the outer peripheral edge is the same as or outside of the outer peripheral edge of the substrate during the film forming process of the substrate. It is characterized by being set in parallel with a gap of 0.2 mm to 10.0 mm with respect to the surface of the substrate.

  The film forming apparatus may have the following configuration. The gas supply port is configured such that a plurality of gas discharge ports are formed on the upper side, and a lower side of the gas discharge port is configured as a descending space in which gas from the gas discharge port descends. A configuration in which at least one of the mounting portion and the top plate portion is provided with an inclination adjusting mechanism for adjusting the posture of the mounting portion with respect to the top plate portion. The substrate is a semiconductor wafer, and a ratio k of a diameter dimension of the gas supply port to a diameter dimension of the substrate is 0.33 or less. The height dimension of the gap between the mounting portion and the top plate portion extends in the circumferential direction outside the peripheral portion of the substrate on the mounting portion in at least one of the mounting portion and the top plate portion. For this reason, a gap regulating member that regulates the height dimension is provided. A portion of the top plate portion on the mounting portion side is made of alumina.

  According to the present invention, the central portion is provided as a gas supply port, and a portion surrounding the gas supply port is provided with a top plate portion formed as an annular facing surface portion facing the substrate on the mounting portion. When the film forming process is performed on the substrate, whether the projected position of the inner peripheral edge is 5.0 mm to 40.0 mm away from the center of the substrate and the projected position of the outer peripheral edge is the same as the outer peripheral edge of the substrate. It is located on the outer side of the substrate and is parallel to the substrate surface with a gap of 0.2 mm to 10.0 mm. Therefore, when the reaction gas is switched, the replacement gas quickly flows through the processing space, so that the atmosphere of the processing space can be replaced quickly.

It is a longitudinal cross-sectional view which shows the film-forming apparatus of this invention. It is a partially expanded longitudinal cross-sectional view which shows the said film-forming apparatus. It is the top view which looked at the top-plate part in the said film-forming apparatus from the downward side. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view for demonstrating the effect | action of the said film-forming apparatus. It is a longitudinal cross-sectional view which shows the other example of the said film-forming apparatus. It is a longitudinal cross-sectional view which shows the other example of the said film-forming apparatus. It is a longitudinal cross-sectional view which shows another example of the said film-forming apparatus. It is a longitudinal cross-sectional view which shows another example of the said film-forming apparatus. It is a longitudinal cross-sectional view which shows another example of the said film-forming apparatus.

  An example of an embodiment of a film forming apparatus of the present invention will be described with reference to FIGS. As shown in FIG. 1, the film forming apparatus includes a processing container 2 that forms a vacuum container having a substantially circular planar shape, a mounting unit (mounting table) 3 provided in the processing container 2, and a mounting unit. A top plate portion 4 is provided so as to face the placement portion 3 and forms a processing space with the placement portion 3. This film forming apparatus employs an ALD (MLD) method, which is a method for sequentially supplying a plurality of types of reaction gases that react with each other to the wafer W, as will be described later. The mounting portion 3 and the top plate portion 4 are configured so that the atmosphere in the processing space can be quickly replaced when the gas (processing gas) is switched. Hereinafter, a specific configuration of the film forming apparatus will be described in detail. In FIG. 1, 5 is a transfer port for the wafer W, and 6 is a gate valve for opening and closing the transfer port 5.

  First, the top plate part 4 will be described. As shown in FIG. 1, the ceiling surface 61 of the processing container 2 is configured to be detachable from the processing container 2, and hermetically seals the inside of the processing container 2 through a sealing member 62 such as an O-ring. ing. And the above-mentioned top-plate part 4 is provided in the downward side of this ceiling surface 61. As shown in FIG. Specifically, on the lower surface side of the ceiling surface 61, a processing gas is supplied to a position facing the center portion of the wafer W on the mounting portion 3 as shown in FIG. A gas shower head 63 is provided. That is, the gas shower head 63 has a substantially cylindrical shape in which the upper surface side (ceiling surface 61 side) is open and a plurality of gas discharge ports 64 are formed on the lower surface side, and the upper end edge extends in the circumferential direction. It extends outward in a flange shape and is supported by a cap member 72 described later. FIG. 3 shows a state in which the top plate portion 4 is viewed from the wafer W side (lower side).

On the outside of the gas shower head 63, it is formed substantially concentrically with the outer edge of the mounting portion 3 so that a gap region is formed in the circumferential direction between the gas shower head 63 and the central portion. A ring-shaped member (filler) 71 is provided. The ring-shaped member 71 is made of, for example, aluminum. A cap member 72 formed along the inner peripheral surface and the lower surface of the ring-shaped member 71 is provided on the lower side of the ring-shaped member 71, and the inner peripheral edge of the cap member 72 is the ring-shaped member 71. Is extended toward the ceiling surface 61 so as to support the upper end portion of the gas shower head 63 described above and press-contact with the ceiling surface 61. The cap member 72 is made of a material having lower thermal conductivity than a metal material, such as alumina (Al ₂ O ₃ ). In FIG. 2, reference numeral 73 denotes a fixing member such as a bolt for fixing the ring-shaped member 71 to the ceiling surface 61.

  As shown in FIG. 2, the cap member 72 and the ring member 71 and the cap member are formed such that a gap region 74 having a gap dimension d of, for example, about 2 mm is formed between the ring member 71 and the ring member 71. The outer peripheral side of 72 is supported from the side peripheral surface side by a suspension member 75 extending downward from the ceiling surface 61. For example, even if the ring-shaped member 71 and the cap member 72 are thermally expanded and contracted, the gap region 74 is configured so that the ring-shaped member 71 and the cap member 72 do not interfere with each other. Between the fixing member 73 that fixes the suspension member 75 to the ceiling surface 61 and the suspension member 75, the cap member 72 is not shown so as not to be damaged by thermal expansion of the cap member 72 or the ring-shaped member 71. A spring washer is provided. Therefore, the gas shower head 63 is pressed against the ceiling surface 61 via the cap member 72 by the suspension member 75 so that the processing gas and purge gas described later do not leak from between the gas shower head 63 and the ceiling surface 61. ing.

  The lower end surface of the cap member 72 is in a region outside the position separated from the vertical line L passing through the center position of the wafer W placed on the placement unit 3 on the outer peripheral side by a separation distance D, for example, 5 mm to 100 mm. For example, the opposing surface portion 72a is formed so as to be horizontal over the surface. In other words, the opposed surface portion 72 a has a projection position of the inner peripheral edge that is separated from the center of the wafer W by a separation distance D, and a projection position of the outer peripheral edge is located outside the outer peripheral edge of the wafer W. The lower end surface of the cap member 72 is bent toward the upper gas shower head 63 on the inner peripheral side with respect to the facing surface portion 72a. Accordingly, the facing surface portion 72a has an annular shape (ring shape) along the circumferential direction of the wafer W so as to face the wafer W on the mounting portion 3.

  A cylindrical region having a diameter dimension r and a height dimension h of 40 mm and 42.2 mm, for example, is formed on the lower side of the gas shower head 63. At this time, if the region between the facing surface portion 72a and the wafer W on the mounting portion 3 and the cylindrical region below the gas shower head 63 are referred to as a gas flow space P1 and a gas descending space P2, respectively, The lower end portion of the descending space P2 forms a gas supply port for supplying gas to the wafer W. In the gas flow space P1, the mounting portion 3 is configured to be horizontal across the surface with respect to the facing surface portion 72a by a buffer mechanism 43 and a restriction mechanism 51, which will be described later.

  In the ring-shaped region between the spaces P1 and P2, the cap member 72 is bent in an arc shape with a curvature of about R20, for example, in order to relieve stress during thermal expansion and contraction of the cap member 72. The ratio (the inner diameter dimension ÷ the outer dimension) k of the inner diameter dimension r (the diameter of the gas supply port) of the gas descending space P2 to the outer dimension of the wafer W is, for example, 0.13. The gas shower head 63 and the cap member 72 constitute the top plate portion 4.

On the ceiling surface 61, gas supply ports 81 are formed, for example, at two locations so as to communicate with the internal region of the gas shower head 63. A storage portion 83 for titanium chloride (TiCl ₄ ) gas and a storage portion 84 for ammonia (NH ₃ ) gas are connected to the processing gas supply paths 82 and 82 extending upward from the gas supply ports 81 and 81, respectively. Has been. Further, a nitrogen (N 2) gas storage section 86 is connected to these processing gas supply paths 82 and 82 via a purge gas supply path 85, respectively. In FIG. 1, 87 is a flow rate adjusting unit, and 88 is a valve.

  Further, in the inside of the processing container 2, the processing container is disposed so that the region between the top panel 4 and the wafer W on the mounting unit 3 faces the side of the top panel 4 described above. 2 is formed in a ring shape along the circumferential direction of the processing vessel 2, for example. One end side of an exhaust path 92 extending from the outside of the processing container 2 toward the processing container 2 is opened as an exhaust port in the exhaust portion 91, and the other end side of the exhaust path 92 is connected via a butterfly valve 93. Are connected to a vacuum pump 94 which is an exhaust mechanism.

Subsequently, the placement unit 3 will be described. The placement unit 3 is formed in a disk shape that is slightly larger than the wafer W in order to place a circular wafer W having a diameter of, for example, 300 mm. Is formed. The mounting portion 3 is made of, for example, ceramics such as aluminum nitride (AlN) or quartz glass (SiO ₂ ), or metal such as aluminum (Al) or hastelloy, and the wafer W is formed at a film forming temperature, for example, 350 ° C. to 450 ° C. A heater 31 for heating to ° C. is embedded. An electrostatic chuck (not shown) is provided inside the mounting unit 3 as necessary in order to electrostatically attract the wafer W to the mounting unit 3.

  On the side of the mounting unit 3, a region outside the mounting region on which the wafer W is mounted and a side peripheral surface of the mounting unit 3 are covered in the circumferential direction. For example, a cover member 3a made of alumina or the like is provided as a gap regulating member. In other words, the cover member 3a is formed so as to have a substantially cylindrical shape with the upper and lower ends opened, and the upper end portion is bent horizontally in the circumferential direction so that the upper end portion is placed. It is comprised so that it may latch on the peripheral part of the part 3. FIG. As shown in FIG. 2, the thickness dimension t on the mounting portion 3 in the cover member 3a is formed to be thicker than the thickness dimension (0.8 mm) of the wafer W, specifically, 1 mm to 5 mm. In this example, it is 3 mm. In FIG. 2, the heater 31 and the like are omitted.

  On the lower side of the placement unit 3, elevation pins 7 for raising and lowering the wafer W on the placement unit 3 are provided. By the elevation pins 7, a transfer arm (not shown) outside the processing container 2 is provided. In the meantime, the wafer W is transferred via the transfer port 5. In FIG. 1, 8 is a lifting mechanism for the lifting pins 7, and 9 is a bellows body.

  One end side (upper end portion) of a support column 32 extending in the vertical direction is connected to the lower surface side central portion of the mounting portion 3, and the other end side (lower end portion) of the support column 32 is connected to the processing container 2. It is connected to a plate-like upper flange portion 33a provided so as to be substantially horizontal on the lower side. Between the lower end surface of the processing container 2 and the upper flange portion 33a, a bellows body 34 is provided for raising and lowering the support column 32 with respect to the processing container 2 while maintaining the inside of the processing container 2 airtight. . On the lower side of the upper flange portion 33a, a lower flange portion 33b formed to have substantially the same shape as the upper flange portion 33a is provided in parallel with the upper flange portion 33a. 33a and 33b are mutually fixed by the rod-shaped fixing member 34a.

  Here, the mounting portion 3 is configured to be movable up and down together with the support pillar 32 and the flange portions 33a and 33b. Specifically, on the side of the flange portions 33a and 33b, ball screws 35 extending in the vertical direction are provided at a plurality of locations, for example, two locations so as to face each other via the support pillars 32. A motor 36 for rotating the ball screw 35 around the vertical axis is provided on the lower end side of the 35. Each ball screw 35 is provided with a substantially box-shaped elevating part 37 configured to be movable up and down along the ball screw 35. That is, the elevating part 37 is threaded so that the inner peripheral surface thereof is screwed with the outer peripheral surface of the ball screw 35, and the vertical axis is rotated by the support surface 38 provided on the back side (the side opposite to the support column 32). Without being rotated (in a state where rotation is restricted).

  In the region between the flange portions 33a and 33b, there is provided an elevating plate 41 that is supported by elevating portions 37 and 37 on both the left and right sides and is formed in a substantially ring shape so as to surround the fixing member 34a. As shown in FIG. 1, a buffer mechanism 43 configured by laminating a plurality of disc springs 42 is disposed between the elevating plate 41 and the lower flange portion 33 b at a plurality of locations along the circumferential direction of the fixing member 34 a, for example. It is provided at four places so as to be equally spaced. That is, the disc spring 42 is formed so as to have a substantially cylindrical shape whose upper and lower surfaces are opened and whose diameter is increased from one end side to the other end side in the vertical direction. A restoring force that tries to return to the original (expands in the vertical direction) is generated.

  And about two disc springs 42 and 42, wide opening parts are made to mutually oppose among two opening parts of each up-and-down direction, and it constitutes as a set of spring members 42a, and this spring member 42a is made into the up-and-down direction, for example Three layers are stacked. Further, a bar-shaped guide member 44 extending vertically from the lower flange portion 33b toward the lifting plate 41 is disposed so as to penetrate the opening portions of the disc springs 42 in the vertical direction. 42 is prevented from being displaced laterally. At this time, the opening 45 is formed at a position corresponding to the tip of the guide member 44 in the elevating plate 41. And even if each disc spring 42 is in the fully extended state (the state where no restoring force is generated) so that the lower flange portion 33b is not displaced laterally with respect to the elevating plate 41, the guide member 44. The front end portion of the head is located in the opening 45.

  Here, the operation of the buffer mechanism 43 will be briefly described. When the inside of the processing container 2 is in an atmospheric atmosphere, the placement unit 3 tends to descend downward due to the weight of the placement unit 3. Therefore, a base 46 for receiving the mounting portion 3 is provided below the lower flange portion 33b. At this time, each disc spring 42 is in a state where no restoring force is generated (not contracted). In FIG. 1, reference numeral 47 denotes a receiving portion provided at a position corresponding to the base portion 46 on the lower surface of the lower flange portion 33b.

  On the other hand, when the inside of the processing container 2 is set to a vacuum atmosphere, a differential pressure is generated between the internal atmosphere of the processing container 2 and the atmosphere outside the processing container 2 (atmospheric atmosphere). It is attracted by the vacuum atmosphere in the container 2 (pressed by the air atmosphere). When the inside of the processing container 2 reaches a vacuum state of, for example, about 13.3 Pa (0.1 Torr), the suction force of the mounting portion 3 that is about to rise due to the differential pressure rather than the load that is about to descend due to its own weight. The direction becomes larger, and the mounting portion 3 tends to rise. Therefore, the elevating plate 41 is provided with a restricting portion 48 for receiving the lower flange portion 33b and restricting the rising of the placement portion 3. At this time, each of the disc springs 42 receives a stress compressed in the vertical direction between the elevating plate 41 and the lower flange portion 33b. In FIG. 1, reference numeral 49 denotes a receiving portion provided at a position corresponding to the restricting portion 48 in the lower flange portion 33b.

  In the state where the inside of the processing container 2 is set to a vacuum atmosphere, that is, in the state where the lower flange portion 33b is received by the lift plate 41, when the lift unit 37 is lifted and lowered, the lower flange portion 33b and the lift plate 41 and The placement unit 3 moves up and down via the buffer mechanism 43. As will be described later, the mounting portion 3 can be swung with respect to the top plate portion 4 by the buffer mechanism 43.

  The lower flange portion 33 b is provided with a restriction mechanism 51 for restricting the posture of the placement portion 3 with respect to the lifting plate 41. Specifically, as shown in FIG. 1, on the lower side of the lower flange portion 33b, there is provided a push screw 52 extending in the vertical direction so as to penetrate the lower flange portion 33b from the lower side. An upper end portion of the push screw 52 is configured such that a gap dimension with the lifting plate 41 is adjustable. A motor 54 that rotates the push screw 52 around the vertical axis is connected to the lower side of the push screw 52.

  The inner peripheral surface of the portion of the lower flange portion 33 b through which the push screw 52 passes is threaded so as to be screwed with the outer peripheral surface of the push screw 52. A push screw 52 is inserted through the lower flange portion 33b, and a nut 53 that is screwed with the push screw 52 is provided. The nut 53 is tightened toward the lower flange portion 33b. Thus, the height position of the upper end portion of the push screw 52 can be regulated. The restriction mechanisms 51 are provided at a plurality of places, for example, four places so as to be separated from each other along the circumferential direction of the support pillar 32. A restriction mechanism 51 is constituted by the push screw 52 and the nut 53. A method for regulating the posture of the placement unit 3 using the regulation mechanism 51 will be described later.

  In addition, the film forming apparatus is provided with a control unit 100 including a computer for controlling the operation of the entire apparatus. In the memory of the control unit 100, the posture adjustment of the wafer W and the film forming process are performed. Stores a program for performing That is, this program sets the posture by the posture adjustment program 101 for setting the posture of the mounting portion 3 horizontally with respect to the top plate portion 4 and the program 101 at the time of maintenance of the film forming apparatus, for example. A film forming program 102 for mounting the wafer W on the mounting unit 3 and performing a film forming process. These programs 101 and 102 are installed in the control unit 100 from the storage unit 110 which is a storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, and a flexible disk.

  Subsequently, the operation of the film forming apparatus according to the present embodiment will be described with reference to FIGS. At this time, the processing container 2 is maintained in a vacuum atmosphere, the maintenance described later has already been performed, and the posture of the mounting portion 3 is horizontal with respect to the top plate portion 4. To do. Accordingly, as shown in FIG. 1 described above, the upper end portion of the push screw 52 is in contact with the lifting plate 41, and the posture of the lower flange portion 33 b (mounting portion 3) with respect to the lifting plate 41. Is in a regulated state.

  First, the placement unit 3 is positioned on the lower side, the gate valve 6 is opened, a transfer arm (none of which is shown) provided in the outside (vacuum transfer chamber) of the processing container 2 and the lifting pin 7. Then, the wafer W is placed on the placement unit 3 heated to the film forming temperature by the heater 31. Next, the gate valve 6 is closed, and the placement unit 3 is raised to the processing position. At this processing position, the height dimension of the gas flow space P1 (the distance dimension between the facing surface portion 72a and the surface of the wafer W on the mounting portion 3) j is aligned in the plane, and the height dimension. j is set to be 0.2 mm to 10.0 mm and 0.5 mm in this example. In FIG. 2 described above, the height dimension j is schematically drawn larger.

  Then, the pressure in the processing container 2 is set to a set pressure, and as shown in FIG. 4, titanium chloride gas is supplied as a processing gas from the gas shower head 63 toward the lower wafer W. The processing gas descends quickly in the gas descending space P2 and spreads radially along the circumferential direction at a position near the wafer W. At this time, since the facing surface portion 72a and the wafer W on the mounting portion 3 are parallel to each other, the processing gas flows at a uniform flow velocity (concentration) along the circumferential direction of the wafer W. When the wafer W comes into contact with this processing gas, the components of the processing gas are adsorbed on the wafer W. Further, since the size of the gap between the top plate portion 4 and the cover member 3a is extremely small, the pressure of the processing gas in the processing space, which is the upper region of the wafer W, is the pressure in the processing chamber 2 (mounting). Therefore, the adsorption amount of the processing gas is uniform over the entire surface.

  Next, the supply of the processing gas is stopped, and a purge gas (substitution gas) is supplied from the gas shower head 63 into the processing container 2 as shown in FIG. At this time, since the gas descending space P2 is set to be thin as described above (the inner diameter dimension r is small), vertical vortex flow (gas flow rotating around the horizontal axis) hardly occurs in the gas descending space P2. . Further, since the height dimension j of the gas flow space P1 is set to be small, the volume of the processing space that is the region above the wafer W is extremely small. Accordingly, the processing gas in this processing space is quickly exhausted toward the exhaust part 91 by the purge gas and is replaced with the purge gas.

  Thereafter, as shown in FIG. 6, the gas is switched to ammonia gas, and the component of the titanium chloride gas adsorbed on the wafer W is nitrided. At this time, since the volumes of the spaces P1 and P2 are small as described above, the pressure of the processing space above the wafer W is higher than the pressure below the mounting portion 3. Therefore, the nitriding reaction occurs efficiently over the surface of the wafer W. Thus, as shown in FIG. 7, after the atmosphere in the processing space is again replaced with the purge gas, the titanium chloride gas and the ammonia gas are alternately supplied to the wafer W as described above, for example, titanium nitride (TiN). A thin film made of the above is formed on the wafer W.

  Here, when the orientation of the mounting unit 3 is set horizontally with respect to the top plate unit 4 before the film forming process is started on the wafer W, a series of steps described below are performed. That is, when performing the film forming process, the posture of the mounting unit 3 is adjusted in advance, so that the posture of the mounting unit 3 with respect to the top plate unit 4 is kept horizontal. Specifically, if the setting unit 3 is set to be horizontal with respect to the top plate part 4, the setting unit 3 moves up and down together with the elevating unit 37, and therefore the encoder value of the motor 36 of the elevating unit 37. The horizontal posture of the mounting portion 3 can be maintained via

  On the other hand, for example, when the maintenance of the inside of the processing container 2 is performed or when the substrate processing apparatus including the film forming apparatus is started up, the posture of the mounting unit 3 is not horizontal with respect to the top plate unit 4. There is a risk of tilting. That is, the mounting portion 3 may be connected to the support column 32 with a slight inclination, or the ball screw 35 may be slightly distorted. If used, the processing on the wafer W may be non-uniform in the surface. Therefore, before starting the film forming process on the wafer W, the posture of the mounting unit 3 is adjusted to be horizontal with respect to the top plate unit 4 as described below.

  First, when the processing container 2 is in an air atmosphere, the lower flange portion 33 b is supported by the base portion 46. Further, the push screw 52 is set at a position where the upper end portion is spaced downward from the lower surface of the elevating plate 41.

  And if the inside of the said processing container 2 is pressure-reduced more than the vacuum degree which started vacuuming in the processing container 2, as above-mentioned, the difference of the inside and outside of the processing container 2 rather than the load of the mounting part 3 will be mentioned. Since the suction force based on the pressure becomes larger, the lower flange portion 33b rises together with the mounting portion 3 while contracting the disc spring 42, and comes into contact with the lifting plate 41 (the regulating portion 48). Next, when the mounting portion 3 is raised through the lifting plate 41 until the cover member 3 a comes into contact with the top plate portion 4, the mounting portion 3 is inclined with respect to the top plate portion 4. In this case, as shown in FIG. 8, one end side (for example, the left end in FIG. 8) of the cover member 3 a contacts the top plate portion 4. In FIG. 8, the state in which the mounting portion 3 is inclined is exaggerated and drawn greatly.

  Subsequently, when the elevating part 37 is further raised by, for example, about 1 mm, the portion of the cover member 3a that has already been in contact with the top plate part 4 (left side in FIG. 8) cannot be raised any further, so the lower flange part The left part of 33b cannot follow the ascent of the left elevating part 37, but is separated from the elevating plate 41 downward when viewed relatively. Accordingly, the buffer mechanism 43 on the left side is slightly extended to reduce the restoring force. On the other hand, the portion of the cover member 3a that is not in contact with the top plate portion 4 (the right side in FIG. 8) is separated from the top plate portion 4, so that until the top plate portion 4 comes into contact, It moves as the elevating unit 37 moves up. Thus, as shown in FIG. 9, since the cover member 3 a is in contact with the top plate portion 4 over the surface, the wafer W on the mounting portion 3 and the bottom surface of the top plate portion 4 are parallel to each other.

  Next, the posture of the lower flange portion 33b (mounting portion 3) with respect to the lifting plate 41 is restricted. That is, the push screw 52 is raised toward the lift plate 41 until the upper end portion of the push screw 52 contacts the lift plate 41. Specifically, each motor 54 is driven until the load (torque) applied to the push screw 52 from the motor 54 below the push screw 52 is uniform between the push screws 52. Then, for example, the nut 53 is tightened toward the lower flange portion 33b by an operator, and each push screw 52 is fixed.

  Then, as shown in FIG. 10, when the mounting portion 3 is lowered by, for example, 10 mm, the restriction portion 48 and the receiving portion 49 on the left side in FIG. 8 described above are separated from each other. The lower flange portion 33b of the left side tends to rise until the restricting portion 48 and the receiving portion 49 come into contact with each other. However, since the push screw 52 is disposed between the lower flange portion 33b and the lifting plate 41, the separation distance between the lifting plate 41 and the lower flange portion 33b is maintained, that is, the ceiling. The mounting unit 3 is lowered while the horizontal position of the mounting unit 3 with respect to the plate unit 4 is maintained. In this way, the gas flow space P1 described above has the above-described dimensions while the height dimension j is aligned in the plane. Then, the pulse value of the encoder of each motor 36 at this time is stored and set as a processing position when film formation processing is performed on the wafer W.

  According to the above-described embodiment, the gas flow space P <b> 1 is formed on the outer side of the position away from the center position of the wafer W on the placement unit 3 by the separation distance D on the outer peripheral side. And when performing the film-forming process with respect to the wafer W, the height dimension j of this gas flow space P1 is equal over the surface, and it is set to 0.2 mm-10.0 mm. Therefore, when the reaction gas is switched, the purge gas quickly flows through the gas flow space P1, and the vertical flow vortex is not easily formed in the gas descending space P2, so that the atmosphere of the gas descending space P2 can be replaced quickly. Therefore, film formation using the ALD method can be performed with a good throughput.

Further, since a narrow space is formed between the top plate portion 4 and the mounting portion 3, the pressure of the processing gas in the vicinity of the wafer W is increased so that the processing gas is uniformly adsorbed over the surface. And good coverage can be obtained. At this time, since the cover member 3a is used as a leveling reference when setting the mounting portion 3 horizontally with respect to the top plate portion 4, the posture of the mounting portion 3 can be easily adjusted. Furthermore, since the buffer mechanism 43 is provided, the mounting portion 3 can be configured to be swingable.
Furthermore, since the portion (cap member 72) on the mounting plate 3 side of the top plate portion 4 is made of alumina having a lower thermal conductivity than metal or the like, even if the cap member 72 is brought close to the wafer W, It is possible to suppress the heat of the wafer W from being radiated through the cap member 72.

  Here, the cover member 3a is provided on the placement unit 3 side as the height adjustment member, but such a height adjustment member may be provided on the top plate unit 4 side. In this case, the top plate portion 4 is provided with a ring-shaped member surrounding the region in the circumferential direction, for example, on the outer peripheral side of the region where the wafer W is placed on the placement unit 3.

  Further, when adjusting the placement unit 3 to be horizontal with respect to the top plate unit 4, the following configuration may be adopted. That is, as shown in FIG. 11, projections 120 each having a height dimension set to about 20 mm, for example, instead of the cover member 3a outside the region where the wafer W is placed on the placement unit 3 are provided. You may provide in four places along the circumferential direction, for example.

In the apparatus having such a configuration, when the mounting unit 3 on which the wafer W is mounted is raised, when the mounting unit 3 is inclined with respect to the top plate unit 4, one end of the mounting unit 3. The protruding portion 120 on the side abuts the top plate portion 4. Next, when the mounting portion 3 is further raised, the protrusion 120 comes into contact with the top plate portion 4 over the surface by the buffering action of the buffer mechanism 43, and the top plate portion 4 and the mounting portion 3. And become parallel. In this way, by supplying the processing gas and the purge gas to the wafer W on the mounting unit 3, the above-described film forming process is performed. These gases flow through the side of the projecting portion 120 toward the exhaust portion 91. Therefore, in addition to the function as the gap regulating member of the cover member 3a described above, the protrusion 120 plays a role of regulating the height dimension j between the facing surface portion 72a and the wafer W on the mounting portion 3. have.
The protruding portion 120 may also be provided on the lower surface of the top plate portion 4 instead of being provided on the placement portion 3.

  In addition, as shown in FIG. 12, the diameter dimension r of the gas descending space P2 may be adjusted such that the diameter of the gas descending space P2 increases from the upper side toward the lower side and becomes a substantially conical shape. Also in this case, the gas flow space P1 is horizontal across the plane, for example, in a region outside the position separated from the center position of the wafer W on the placement unit 3 by the separation distance D from the outer peripheral side. Formed as follows. In FIG. 12, the top plate portion 4 is simplified. The same applies to FIG. 13 below.

  Furthermore, as shown in FIG. 13, the top plate portion 4 (cap member 72) may be configured to have a diameter dimension substantially the same as the outer dimension of the wafer W on the mounting portion 3. In other words, the projection position of the outer peripheral edge of the facing surface portion 72 a is the same as the outer peripheral edge of the wafer W during the film formation process of the wafer W. In this case, when the mounting unit 3 is leveled with respect to the top plate unit 4, the mounting surface on which the wafer W is mounted without placing the wafer W on the mounting unit 3. Is brought into contact with the top plate portion 4.

  Furthermore, as shown in FIG. 14, the top plate portion 4 may be supported from above at a position where the top plate portion 4 is spaced apart from the ceiling surface 61. Specifically, as shown in FIG. 5A, a disk-shaped gas diffusion plate 131 having a large number of gas discharge ports 64 is arranged inside a gas supply pipe 130 that extends in a cylindrical shape in the vertical direction. To do. The gas supply pipe 130 and the cap member 72 are configured so that the outer peripheral surface on the lower end side of the gas supply pipe 130 and the inner peripheral surface of the cap member 72 are screwed together. Then, as shown in FIG. 14 (b), the opening on the upper surface side of the processing container 2 is closed by the ceiling surface 61 in a state where the top plate portion 4 is housed in the processing container 2, and the upper side of the ceiling surface 61. The gas supply pipe 130 is inserted into the processing container 2. In this way, the top plate portion 4 is supported by the gas supply pipe 130 and the outer peripheral surface of the gas supply pipe 130 and the through-hole provided in the ceiling surface 61 are screwed together to fix the gas supply pipe 130 to the processing container 2. To do. A seal member (not shown) is provided between the outer peripheral surface of the gas supply pipe 130 above the ceiling surface 61 and the ceiling surface 61. Moreover, in FIG. 14, the processing container 2, the ceiling surface 61, and the top plate part 4 are simplified.

  Further, as the regulation mechanism 51, the rise of the mounting portion 3 is regulated against the pressure difference between the inside of the processing container 2 and the atmospheric atmosphere, but it is opposed to the restoring force of the buffer mechanism 43. In addition, the layout of the buffer mechanism 43 may be changed. Specifically, the film forming apparatus of FIG. 1 will be described as an example. The buffer mechanism 43 is shown in FIG. 15 instead of being provided between the elevating plate 41 and the lower flange portion 33b. Thus, it is provided between the upper flange portion 33 a and the lifting plate 41.

  In the film forming apparatus having this configuration, while the inside of the processing container 2 is kept in an air atmosphere, the mounting unit 3 is lifted via the lifting plate 41 and the buffer mechanism 43 so that the mounting unit 3 (the cover member 3a) is placed on the ceiling. It abuts on the plate part 4. Thereafter, when the mounting portion 3 is further raised slightly, the mounting portion 3 takes a horizontal posture with respect to the top plate portion 4 as in the above-described examples. At this time, for example, the right disc spring 42 in FIG. 15 receives a compressive stress between the upper flange portion 33a and the lifting plate 41 by the lifting plate 41, and thus has a restoring force to stretch.

  Subsequently, when the spacing mechanism between the lifting plate 41 and the lower flange portion 33b is restricted by the restriction mechanism 51 and the mounting portion 3 is lowered, the right disc spring 42 tends to extend due to the restoring force. . However, the lowering plate 41 among the members sandwiching the right disc spring 42 from above and below is restricted by the restricting mechanism 51 from being lowered with respect to the upper flange portion 33a. In addition, with respect to the upper upper flange portion 33a of the upper and lower members of the disc spring 42, the distance between the upper flange portion 33b and the lower flange portion 33b is fixed by the fixing member 34a. Accordingly, the restoring force of the right disc spring 42 is restricted, so that the placing portion 3 maintains a horizontal posture with respect to the top plate portion 4. In this way, a thin film is formed by alternately supplying process gases that react with each other to the wafer W while replacing the atmosphere with a purge gas in an air atmosphere or an atmosphere slightly depressurized from the air atmosphere.

  The diameter r of the gas descending space P2 may be smaller than the dimension described above. Accordingly, the gas flow space P1 may be larger than the dimensions described above. Specifically, if the ratio of the inner diameter dimension r of the gas descending space P2 to the outer dimension of the wafer W (the inner diameter dimension ÷ the outer dimension) k is too large, a vertical vortex tends to occur in the gas descending space P2. On the other hand, if it is too small, it becomes difficult for the gas to flow, so it is preferably 0.01 to 0.33, more preferably 0.02 to 0.13 (5.0 mm to 40.0 mm in actual dimensions).

  Further, instead of raising and lowering the placement unit 3 with respect to the top plate unit 4, the top plate unit 4 may be raised and lowered with respect to the placement unit 3. Although the buffer mechanism 43 and the regulation mechanism 51 are provided on the placement unit 3 side, they may be provided on the top plate unit 4 side. Further, as the buffer mechanism 43, an elastic member such as a spring or rubber may be used instead of the disc spring 42. Furthermore, as the raising / lowering part 37 and the buffer mechanism 43, you may arrange | position in three or more places, respectively, and the raising / lowering part 37 may be one place.

  Further, the timing for adjusting the posture of the wafer W has been described by taking as an example the time of maintenance of the apparatus and the time of startup of the substrate processing apparatus. When the height dimension j between the top plate part 4 and the wafer W on the mounting part 3 is changed according to the processing recipe at the time (when the inside of the processing container 2 is maintained in a vacuum atmosphere), or It may be performed each time a predetermined number of wafers W are formed. Further, when the horizontal position of the mounting unit 3 is adjusted with respect to the top plate unit 4 in a vacuum atmosphere, the wafer W is previously mounted on the mounting unit 3 and the mounting unit 3 is leveled. The film forming process may be started immediately.

Furthermore, in the example described above, the example in which the film forming apparatus is incorporated in the substrate processing apparatus has been described. However, the film forming apparatus may be configured as a stand-alone apparatus. In this case, each wafer W is carried into the processing container 2 set to an atmospheric atmosphere and then evacuated, so that the top plate portion 4 is applied to each wafer W before the film forming process is performed. The posture of the mounting unit 3 with respect to is set to be horizontal.
Further, when the dimensions of the mounting portion 3 and the height position of the base portion 46 can be set with extremely high accuracy (the mounting portion 3 is in a horizontal position with respect to the top plate portion 4 without adjusting the posture of the mounting portion 3. In the case of taking the above), the restriction mechanism 51 and the buffer mechanism 43 described above may not be provided.

Furthermore, in the film forming apparatus of the present invention, in addition to the above-described TiN film formation, a metal element, for example, an element of the fourth period of the periodic table, such as Al or Si, which is an element of the third period of the periodic table, is used. Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, etc. Zr, Mo, Ru, Rh, Pd, Ag, etc., which are the elements of the fifth period of the periodic table, etc. A thin film containing an element such as Ba, Hf, Ta, W, Re, lr, or Pt may be formed. Examples of the metal raw material to be adsorbed on the surface of the wafer W include a case where an organic metal compound or an inorganic metal compound of these metal elements is used as a reaction gas (raw material gas). Specific examples of the metal raw material include, in addition to TiCl ₄ described above, BTBAS ((Bistial Butylamino) silane), DCS (dichlorosilane), HCD (hexadichlorosilane), TMA (trimethylaluminum), 3DMAS (Trisdimethyl). Aminosilane).

Further, for the reaction to obtain a desired film by reacting the raw material gas adsorbed on the surface of the wafer W, for example, an oxidation reaction using O ₂ , O ₃ , H ₂ O, etc., H ₂ , HCOOH, CH ₃ COOH, etc. Reduction reaction using alcohols such as organic acids, CH ₃ OH, C ₂ H ₅ OH, etc., carbonization reaction using CH ₄ , C ₂ H ₆ , C ₂ H ₄ , C ₂ H _2, etc., NH ₃ Various reactions such as nitriding reaction using NH ₂ NH ₂ , N ₂ or the like may be used.

Further, three types of reactive gases or four types of reactive gases may be used as the reactive gases. For example, as an example of a case of using three kinds of the reaction gases, and the like when forming a strontium titanate (SrTiO _3), for example, a Sr material Sr and _{(THD) 2} (strontium bis tetramethylheptanedionate isocyanatomethyl) Ti (OiPr) ₂ (THD) ₂ (titanium bisisopropoxide bistetramethylheptanedionate) which is a Ti raw material and ozone gas which is an oxidizing gas thereof are used. In this case, the gas is switched in the order of Sr source gas → purge gas → oxidizing gas → purge gas → Ti source gas → purge gas → oxidizing gas → purge gas. In addition, although the circular wafer W has been described as the substrate on which the film formation process is performed, the present invention may be applied to, for example, a rectangular glass substrate (LCD substrate).

W Semiconductor wafer 2 Processing container 3 Placement part 3a Cover member 4 Top plate part 35 Ball screw 43 Buffer mechanism 51 Control mechanism 64 Gas discharge port 71 Ring-shaped member 72 Cap member 72a Opposing surface part

Claims (6)

A plurality of kinds of reaction gases that react with each other in the vacuum vessel are sequentially supplied from the gas supply port, and a replacement gas is supplied between the supply of one reaction gas and another reaction gas. In a film forming apparatus for performing a film forming process,
A mounting portion provided in the vacuum vessel for mounting the substrate;
A top portion formed as an annular facing surface portion whose central portion is opened as the gas supply port and a portion surrounding the gas supply port is opposed to the substrate;
An exhaust mechanism for evacuating the vacuum container;
Relative to the top plate portion, the placement portion is positioned between a position when the substrate is transferred from the outside of the vacuum container to the placement portion and a processing position for performing a film forming process on the substrate. An elevating mechanism for elevating and lowering,
The opposing surface portion has a projected position of the inner peripheral edge of 5.0 mm to 40.0 mm away from the center of the substrate, and the projected position of the outer peripheral edge is the same as or outside of the outer peripheral edge of the substrate during the film forming process of the substrate. A film forming apparatus, wherein the film forming apparatus is positioned parallel to the surface of the substrate with a gap of 0.2 mm to 10.0 mm.   2. The gas supply port according to claim 1, wherein a plurality of gas discharge ports are formed on an upper side, and a lower side of the gas discharge port is configured as a descending space in which gas from the gas discharge port descends. The film-forming apparatus of description.   The tilt adjustment mechanism for adjusting the attitude | position of the said mounting part with respect to the said top-plate part is provided in at least one of the said mounting part and the said top-plate part, The Claim 1 or 2 characterized by the above-mentioned. The film-forming apparatus of description.   4. The composition according to claim 1, wherein the substrate is a semiconductor wafer, and a ratio k of a diameter dimension of the gas supply port to a diameter dimension of the substrate is 0.33 or less. Membrane device.   The height dimension of the gap between the mounting portion and the top plate portion extends in the circumferential direction outside the peripheral portion of the substrate on the mounting portion in at least one of the mounting portion and the top plate portion. 5. The film forming apparatus according to claim 1, further comprising a gap regulating member that regulates the height dimension.   6. The film forming apparatus according to claim 1, wherein a portion on the mounting portion side of the top plate portion is made of alumina.

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