This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-170162, filed on Sep. 12, 2018, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a vacuum transfer module and a vacuum transfer method.
As an apparatus for manufacturing a semiconductor device, a multi-chamber type apparatus is known in which a plurality of processing modules is connected to a vacuum transfer chamber provided with a substrate transfer mechanism. Patent Document 1 discloses a configuration in which a purge gas is supplied from a gas supply port formed in the bottom portion of a vacuum transfer chamber and is exhausted from an exhaust port formed in the bottom portion of the vacuum transfer chamber.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2003-17478
According to an embodiment of the present disclosure, there is provided a vacuum transfer module including: a housing whose interior is kept in a vacuum atmosphere, and to which a load-lock module and a processing module configured to perform a vacuum process on a workpiece are connected laterally from an outside of the housing; a transfer mechanism including a rotation body configured to rotate around a rotary shaft provided at a fixed position inside the housing, the transfer mechanism configured to transfer the workpiece between the load-lock module and the processing module through the interior of the housing kept in the vacuum atmosphere; a gas supply port opened inside the housing to supply an inert gas for purging the interior of the housing; and an exhaust port opened inside the housing and through which the interior of the housing is exhausted to form the vacuum atmosphere when the inert gas is supplied from the gas supply port, the exhaust port being formed such that an angle between a first straight line connecting the exhaust port and the rotary shaft; and a second straight line connecting the gas supply port and the rotary shaft falls within a range of 100 to 260 degrees in a plan view.
The accompanying drawings, which are incorporated in and constitute a portion of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.
Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.
A first embodiment of a vacuum processing apparatus provided with a vacuum transfer module of the present disclosure will be described with reference to
Each processing module 21 is a module that performs a vacuum process on a workpiece such as a semiconductor wafer (hereinafter, referred to as a “wafer”) W, which is a circular substrate having a diameter of 300 mm. For example, a stage on which the wafer W is mounted, a gas supply part for supplying a processing gas, and a gas exhaust part for exhausting the processing gas are provided inside the processing module 21. Examples of the process implemented by the processing module 21 may include a film forming process performed using a film forming gas, an etching process performed using an etching gas, an ashing process performed using an aching gas, and the like. In addition, an example of the film forming process may include a process of heating the wafer W in a vacuum atmosphere to form, for example, a titanium nitride (TiN) film.
The load-lock modules 231 and 232 are configured such that the interior thereof is switched between a vacuum atmosphere and a normal pressure atmosphere. The load-lock modules 231 and 232 are coupled to a loader module 26 through respective transfer ports 25. Each of the transfer ports 25 is opened and closed by a gate valve G3. The loader module 26 is kept in a normal pressure atmosphere, and includes loading/unloading ports 261 on each of which a carrier C, which is a transfer container accommodating the wafers W, is mounted. In addition, the loader module 26 is provided with a normal-pressure transfer arm 27. The normal-pressure transfer arm 27 is configured to be swingable, extendible, and movable up and down to transfer the wafer W between the carrier C and each of the load-lock modules 231 and 232.
A transfer mechanism 3 is provided inside the housing 2 to transfer the wafer W between each of the load-lock modules 231 and 232 and the respective processing module 21. As illustrated in
The first arm 32 constitutes a rotation body, and is provided on the base 31 so as to rotate about a rotary shaft 30. In
Each of the first arm 32 and the second arm 33 includes a driving force transmission system such as pulleys and belts, and is configured such that the substrate support portion 34 is rotatable and movable back and forth by, for example, a swing-purpose motor and a reciprocating-purpose motor (not illustrated). The wafer W is transferred while being held by the substrate support portion 34. Thus, as illustrated in
The vacuum transfer module 11 includes a gas supply part 4. For example, as illustrated in
The filtering portion 43 may be formed in a hollow cylindrical shape. For example, a “Break Filter” (commodity name) may be used as the filtering portion 43. As described above, when the gas supply part 4 is configured using the filtering portion 43 made of a porous body, each pore in the porous body is an ejection hole 411 for ejecting the gas. In
As illustrated in
The vacuum transfer module 11 includes an exhaust port 5 opened inside the housing 2. When the purge gas is supplied from the gas supply port 41, an internal atmosphere of the housing 2 is exhausted through the exhaust port 5 to form a vacuum atmosphere. As illustrated in
In this embodiment, the exhaust port 5 is formed slightly above a bottom surface 202 in the sidewall 201 of the housing 2. An upper end of the exhaust port 5 is positioned below the above-described transfer path 300. The exhaust port 5 is coupled to an exhaust mechanism 52 via an exhaust path 51. The exhaust mechanism 52 is constituted by a vacuum pump or the like and is provided with a pressure regulator (not illustrated) or the like. In the vacuum transfer module 11, when the wafer W is transferred, the purge gas is supplied into the housing 2 and simultaneously, is exhausted by the exhaust mechanism 52 such that the interior of the housing 2 is controlled to be kept in a predetermined vacuum atmosphere.
Next, a relative positional relationship between the gas supply port 41 at the tip end of the gas supply path 42 of the gas supply part 4 and the exhaust port 5 will be described. As illustrated in
More specifically, as illustrated by the solid line in
Specifically describing the second straight line L2, an end point of the straight line L2 is the center O3 of the gas supply port 41 in a plan view. If there are a plurality of gas supply ports 41, one located farthest from the exhaust port 5 when viewed in a direction in which the rotary shaft 30 rotates, corresponds to a gas supply port cited in the accompanying claims. More specifically, the gas supply port 41 disposed closest to the angle θ=180 degrees corresponds to a gas supply port cited in the accompanying claims. The reason for this is to reduce a concentration of oxygen inside the housing 2 (to be described later) by forming the gas supply port 41 at a position far away from the exhaust port 5. Accordingly, in the case where two gas supply ports 41 are formed, even if one is formed at the angle θ less than 100 degrees, the other may be formed at the angle θ ranging from 100 to 260 degrees.
In this embodiment, the gas supply port 41 is formed at a position where the angle θ is about 190 degrees. Since the angle θ is set in this manner, in the first embodiment, the gas supply port 41 and the exhaust port 5 are arranged such that the base 31 on which the rotary shaft 30 is provided is interposed between the gas supply port 41 and the exhaust port 5 in a plan view. Accordingly, the purge gas is supplied into all of the plurality of ejection holes 411 of the filtering portion 43 through the gas supply port 41.
As illustrated in
Next, the operation of the above-described vacuum processing apparatus 1 will be described. First, in the vacuum transfer module 11, the nitrogen gas as a purge gas is supplied from the plurality of ejection holes 411 of the filtering portion 43 through the gas supply port 41. Meanwhile, the purge gas is exhausted by the exhaust mechanism 52 through the exhaust port 5 so that a vacuum atmosphere having a regulated pressure is formed inside the housing 2. As described above, the gas supply port 41 and the exhaust port 5 are provided such that the angle between the first straight line L1 connecting the exhaust port 5 and the rotary shaft 30 and the second line L1 connecting the gas supply port 41 and the rotary shaft 30 falls within a range of 100 to 260 degrees. Accordingly, the gas supply port 41 and the exhaust port 5 are provided so as to face each other inside the housing 2 with the rotary shaft 30 interposed between the gas supply port 41 and the exhaust port 5.
With this configuration, a distance between the gas supply port. 41 and the exhaust port 5 is relatively long. Thus, the purge gas supplied from the plurality of ejection holes 411 of the filtering portion 43 through the gas supply port 41 sufficiently spreads throughout the interior of the housing 2 and is exhausted through the exhaust port 5. This replaces the internal atmosphere of the housing 2 by the purge gas. Thus, since the time oxygen stays inside the housing 2 is suppressed, it is possible to transfer the wafer W while maintaining the concentration of oxygen at a relatively low level. An internal pressure of the housing 2 during the wafer transfer may be 1.50 to 250 Pa, and the oxygen concentration may be 0.1 ppm or lower. Inside the housing 2, the supply of the purge gas from the gas supply port 41 and the exhaust of the purge gas from the exhaust port 5 are continuously performed until a series of processes on the wafer W are completed.
The wafers W accommodated in the carrier C on the loading/unloading port 261 are sequentially taken out by the normal-pressure transfer arm 27 and are transferred into the load-lock module 231 (or 232) kept in a normal pressure atmosphere. The interior of the load-lock module 231 (or 232) is switched to a vacuum atmosphere and subsequently, the wafer W is taken out by the transfer mechanism 3. The transfer mechanism 3 moves through the interior of the housing 2 to transfer the taken-out wafer W toward a respective processing module 21 and deliver on the stage of the respective processing module 21.
In the processing module 21, a film forming process of forming a TiN film is performed in the state in which the wafer W is heated to a predetermined temperature in a vacuum atmosphere of a predetermined pressure. When the process on the wafer W is completed in the processing module 21, the transfer mechanism 3 receives the wafer W from the processing module 21. The transfer mechanism 3 holding the processed wafer W moves through the interior of the housing 2 and delivers the processed wafer W to the load-lock module 231 (or 232) switched to the vacuum atmosphere. Subsequently, the load-lock module 231 (or 232) is switched into the normal pressure atmosphere, and then, the processed wafer W is returned to, for example, the original carrier C by the normal-pressure transfer arm 27.
According to the embodiment described above, since the positional relationship between the gas supply port 41 and the exhaust port 5 is set as described above, the purge gas sufficiently spreads throughout the interior of the housing 2 to suppress the staying of oxygen, thus reducing the oxygen concentration. As a result, when the wafer W subjected to the film forming process in the processing module 21 is transferred to the load-lock module 231 (or 232) through the interior of the housing 2, the oxidation of the thin film is suppressed, which makes it possible to maintain a sheet resistance value at a low level.
The gas supply port 41, the plurality of ejection holes 411 formed in the filtering portion 43, and the exhaust port 5 are provided below the transfer path 300 for the wafer W inside the housing 2. In this configuration, the purge gas is supplied downward of the wafer W which is being transferred by the transfer mechanism 3, and flows through the interior of the housing 2 toward the exhaust port 5. This makes it possible to prevent the position of the wafer W, which is being transferred, from being deviated by being exposed to a gas flow flowing from the gas supply port 41 toward the exhaust port 5 through the plurality of ejection holes 411 of the filtering portion 43. In addition, since the interior of the housing 2 is replaced with the purge gas which is not provided from above the wafer W, it is possible to suppress the contamination of the wafer W due to particles. However, the gas supply port 41, the filtering portion 43, and the exhaust port 5 are not limited to be arranged in the aforementioned manner. In some embodiments, the gas supply port 41 located at the tip end of the gas supply path 42 may be formed in a ceiling surface, the bottom surface 202, and the sidewall 201 of the housing 2.
Next, a second embodiment of the present disclosure will be described with reference to
Even in the second embodiment, an angle θ between a first straight line L1a connecting the exhaust port 5 and the rotary shaft 30 and a second straight line L2a connecting the gas supply port 41 and the rotary shaft 30 may fall within a range of 120 to 260 degrees, specifically about 215 degrees.
In the second embodiment, an ejection hole 412 formed at the base end side of the filtering portion 43 is located closest to the exhaust port 5 when viewed in the rotational direction. A straight line connecting the ejection hole 412 and the center O1 of the rotary shaft 30 is indicated as L0. A length of the straight line L0 is about 640 mm, and a length of the straight line L1a is about 360 mm. In addition, an angle θ1 between the straight line L1a and the straight line L0 may be 140 degrees.
As described above, even in the case where the exhaust port 5 is formed in the bottom surface 202 of the housing 2, the positional relationship between the gas supply port 41 and the exhaust port 5 is set as in the first embodiment. With this configuration, it is possible to sufficiently spread the purge gas throughout the interior of the housing 2, thus suppressing the staying of oxygen and reducing the oxygen concentration.
It has been confirmed that the effect of reducing the oxygen concentration inside the housing 2 as described above is obtained in the layout of the gas supply port 41 and the exhaust port 5 in the first and second embodiments. The layout of the gas supply port 41 and the exhaust port 5 in each of these embodiments will be described in more detail with reference to a schematic view illustrated in
In
In the first embodiment, the length of the straight line L1 is about 700 mm, and the exhaust port 5 is provided in the sidewall 201. Thus, a ratio of the straight line L1 to the straight line L3 in length is 1. In the first embodiment, the length of the straight line L2 is about 500 mm. Even if the length L2 is slightly smaller than 500 mm, it is considered that the gas is capable of being sufficiently spread throughout the interior of the housing 2. Thus, the length of the straight line L2 may be 400 mm or more. In the first embodiment, a ratio of the straight line L2 to the straight line L4 in length is about 0.8. it is considered that, even if the ratio of the straight line L2 to the straight line IA in length is slightly smaller than 0.8, the same effect can be obtained. Thus, the ratio of the straight line L2 to the straight line L4 in length may be 0.7 or more.
In the second embodiment, a length of the straight line L1a is about 360 mm. It is considered that, even if the length of the straight line L1a is slightly smaller than 360 mm, the gas is capable of being sufficiently spread throughout the interior of the housing 2. Thus, the length of the straight line L1a may be 300 mm or more. In the second embodiment, a ratio of the straight line L1a to the straight line L3a in length is about 0.8. It is considered that, even if the ratio of the straight line L1a to the straight line L3a in length is slightly smaller than 0.8, the same effect can be obtained. Thus, the ratio of the straight line L1a to the straight line L3a in length may be 0.7 or more.
In the second embodiment, a length of the straight line L2a is about 640 mm. It is considered that, even if the length of the straight line L2a is slightly smaller than 640 mm, the gas is capable of being sufficiently spread throughout the interior of the housing 2. Thus, the length of the straight line L2a may be 600 mm or more. In the second embodiment, a ratio of the straight line L2a to the straight line L4a in length is closer to 1 compared with that in the first embodiment. Thus, in consideration of the layouts of the first embodiment and the second embodiment, the lengths of the straight lines L1 and L1a may be 300 mm or more, and the lengths of the straight lines L2 and L2a may be 400 mm or more.
A ratio of the straight line L1 to the straight line L2 (ratio of the straight line L1a to the straight line L2a) in length is about 1 in the first embodiment, and about 0.6 in the second embodiment. When the values of the straight line L1 (L1a) and the straight line L2 (L2a) are set as large as possible in the internal space of the housing 2, the ratio of the straight line L1 to the straight line L2 (the ratio of the straight line L1a to the straight line L2a) in length becomes a value close to 1. In this case, in the second embodiment, the above-described effect of reducing the oxygen concentration is obtained even at a value relatively greatly deviated from 1. That is to say, it is estimated that it is possible to obtain the same effect as long as the ratio of the straight line L1 to the straight line L2 (the ratio of the straight line L1a to the straight line 12a) in length is close to 0.6, which is the value in the second embodiment. Accordingly, it is considered that the ratio of the straight line L1 to the straight line L2 (the ratio of the straight line L1a to the straight line L2a) in length may be 0.5 to 1. In addition, even if the gas supply part 4 is provided at the position where the exhaust port 5 is provided and the exhaust port 5 is provided at the position where the gas supply part 4 is provided in the second embodiment, it is considered that the distribution state of the gas inside the housing 2 does not greatly change. Therefore, it is considered that the ratio of the straight line L1 to the straight line L2 (the ratio of the straight line L1a to the straight line L2a) in length may be 0.5 to 15.
As described above, in the vacuum transfer module 11 according to the present disclosure, the gas supply port 41 at the tip end of the gas supply path 42 may be located at a position where the angle θ between the first straight line and the second straight line falls within a range of 100 to 260 degrees in a plan view. Therefore, even if the connection portion between the gas supply path 42 and the housing 2 falls outside the range of the angle θ in a plan view, the gas supply path 42 may be disposed inside the housing 2 and the gas supply port 41 of at the tip end thereof may be disposed at a position within the range of the angle θ. In addition, the gas supply part 4 has a configuration in which the gas supply port 41 is opened inside the housing 2. Thus, the gas supply port 41 may be configured to be opened in the sidewall 201, the bottom surface 202, or the ceiling surface of the housing 2 instead of extending the gas supply path 42 inside the housing 2. Furthermore, it is not necessarily required to provide the filtering portion 43. For example, the gas supply port 41 may be covered with a sheet-type porous body. Alternatively, a filtering member made of a porous body may be provided inside the gas supply path 42 or outside the housing 2.
In some embodiments, a plurality of exhaust ports may be provided. In the case where the plurality of exhaust ports are provided, the exhaust port located farthest from the gas supply port in the rotational direction of the rotary shaft corresponds to an exhaust port cited in the accompanying claims. The housing is not limited to have the illustrated heptagonal shape in a plan view. In some embodiments, the housing may have a hexagonal shape or a quadrilateral shape in a plan view. The rotary shaft of the transfer mechanism may not be provided in the central portion of the housing, but may be provided at a position near either the front, rear, left, or right. The rotary shaft of the transfer mechanism is provided at a fixed position inside the housing, but is not limited thereto. In some embodiments, the rotary shaft of the transfer mechanism may be configured to move upward and downward in the vertical direction as long as a horizontal position of the rotary shaft (in a lateral direction is fixed.
In the apparatus of the first embodiment shown in
The measurement result of Example 1 is represented in
Moreover, the similar measurement was performed in the vacuum processing apparatus 1 provided with the vacuum transfer module 11 of the second embodiment illustrated in
The angle θ between the first straight line and the second straight line in Example 1 was about 190 degrees, the angle θ in Example 2 was about 215 degrees, and the angle θ in Comparative Example 1 was about 50 degrees. Accordingly, it was confirmed from the above measurement results that the oxygen concentration side the housing 2 changes depending on the formation locations of the gas supply port 41 and the exhaust port 5. As described in the above embodiments, it was confirmed that the oxygen concentration inside the housing 2 is decreased when the angle θ that represents the positional relationship between the gas supply port 41 and the exhaust port 5 is relatively large. It is considered that the oxygen concentration changes depending on the change in the angle θ because the distribution of the purge gas inside the housing 2 changes as described above.
From the measurement results, it was considered effective to arrange the gas supply port 41 and the exhaust port 5 so as to be greatly separated from each other as described above. Thus, it was considered effective to set the angle θ to a value close to 180 degrees when viewed from the rotary shaft 30 provided inside the housing 20. The position indicated by the angle θ in Example 2 is substantially the same as the position indicated by the angle θ1 in
In addition, from the viewpoint of a practical use, the oxygen concentration inside the housing 2 may be 0.1 ppm or lower. The oxygen concentration was about 0.02 ppm when the angle θ in Example is about 140 degrees. The oxygen concentration was 0.12 ppm when the angle θ in Comparative Example 1 was about 50 degrees. Assuming that the oxygen concentration changes depending on the angle θ, it is considered that the oxygen concentration becomes about 0.1 ppm at 100 degrees, which is approximately halfway between 50 degrees and 140 degrees. Accordingly, it is considered effective if the angle θ falls within a range of 100 to 180 degrees. The arrangement in which the angle θ falls within the range of 100 to 180 degrees is symmetrical to the arrangement in which the angle θ falls within the range of 180 to 260 degrees. Therefore, it is effective to set the angle θ in the range of 100 to 260 degrees.
Furthermore, in the vacuum processing apparatus according to Example 1, TiN films were sequentially formed on the plurality of wafers W in the respective processing modules 21. The sheet resistance value (Rs resistance value) of the TiN film formed on each wafer W was measured. Each TiN film was formed by the method described above. The nitrogen gas was supplied into the housing 2 from the ejection holes 411 of the filtering portion 43 through the gas supply port 41. The nitrogen gas was exhausted from the exhaust port 5 so that the internal pressure of the housing 2 was adjusted to a predetermined pressure (Example 3). The similar measurement was also performed in the conventional vacuum processing apparatus provided with the conventional vacuum transfer module illustrated in
As a result, compared with the sheet resistance value in Comparative Example 2, the average value of the sheet resistance value in Example 3 was improved by about 4.5%. In the vacuum processing apparatus illustrated in
In the forgoing, the vacuum transfer module of the present disclosure is not limited to the above embodiments. The shape and formation location of the gas supply port, and the shape and formation location of the exhaust port are not limited to the configurations described above as long as the angle between the first straight line connecting the exhaust port and the rotary shaft and the second straight line connecting the gas supply port and the rotary shaft falls within the range of 100 to 260 degrees. In addition, the vacuum transfer module of the present disclosure is an example, and the layouts and shapes of the housing, the load-lock module, and the processing module are appropriately changeable.
According to the present disclosure, it is possible to reduce the oxygen concentration of a vacuum transfer module.
It should be noted that the embodiments disclosed herein are exemplary in all respects and are not restrictive. The above-described embodiments may be omitted, replaced or modified in various forms without departing from the scope and spirit of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-170162 | Sep 2018 | JP | national |