JP3915314B2 - Single wafer processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single-wafer processing apparatus that performs processing such as film formation and annealing on semiconductor wafers one by one.
[0002]
[Prior art]
In general, in order to manufacture a semiconductor integrated circuit, a desired integrated circuit is formed by repeatedly performing various processes such as a film forming process, an etching process, an oxidation diffusion process, and an annealing modification process on a substrate such as a semiconductor wafer. It is like that. When performing various processes as described above, a necessary process gas corresponding to the type of the process, for example, a film forming gas in the case of a film forming process, an ozone gas or the like in the case of an annealing reforming process. Introduce into processing container.
In this case, the atmosphere in the processing container is evacuated so as to maintain a preferable constant pressure corresponding to the type of the processing, but the flow of the evacuated gas improves the in-plane uniformity of the processing. In order to maintain high, it is required to flow evenly with respect to the surface of the semiconductor wafer.
[0003]
Here, a conventional general processing apparatus will be described. 6 is a schematic configuration diagram showing a conventional general annealing reformer, FIG. 7 is a cross-sectional view taken along line AA in FIG. 6, and FIG. 8 is a cross-sectional view taken along line BB in FIG. It is a figure which shows the simulation result of the gas flow in. As shown in FIG. 6, this annealing reformer has a processing vessel 2 made of aluminum having a square cross section, for example, and the processing vessel 2 is erected from the bottom of the vessel via a support column 4 inside. A mounting table 6 is provided. A heater 8 is embedded in the mounting table 6 so that the semiconductor wafer W as the object to be processed mounted on the upper surface of the mounting table 6 can be heated. A quartz ring-shaped shower head 10 for introducing, for example, ozone as a processing gas into the processing container 2 is provided above the mounting table 6, and a transmission window 12 is provided on the ceiling. Is provided, and the wafer surface is irradiated with ultraviolet rays UV emitted from an ultraviolet lamp 14 provided on the outside.
[0004]
On the other hand, four vacuum exhaust ports 18 (see FIG. 7) are provided at the bottom 16 of the processing container 2 so as to be positioned obliquely below the mounting table 6 in the illustrated example. Further, exhaust pipes 20 are connected to the respective vacuum exhaust ports 18, and these exhaust pipes 20 are joined at the downstream side thereof, and a vacuum pump (not shown) is interposed to evacuate the processing container 2. It can be done.
In such an annealing reforming apparatus, the wafer W on the mounting table 6 is heated and irradiated with ultraviolet UV, and ozone gas is applied to the wafer W, for example, to form TaOx (tantalum oxide film) formed on the surface of the wafer W. And the like are subjected to an annealing modification treatment.
[0005]
[Problems to be solved by the invention]
By the way, in the apparatus described above, the processing gas such as ozone introduced into the processing chamber 2 flows down the processing space S and then flows outwardly in the radial direction on the surface of the wafer W, and obliquely below the mounting table 6. The four vacuum exhaust ports 18 arranged in the are exhausted substantially evenly.
However, when the actual flow of the processing gas in the processing space S is examined in detail, it does not flow uniformly outward in the radial direction of the wafer W, but is arranged in the direction in which the vacuum exhaust port 18 is arranged. There is a considerable difference in the gas flow from the direction in which it is not, and this has caused a problem that the uniformity of processing on the wafer surface cannot be maintained sufficiently high.
[0006]
FIG. 8 is a diagram showing a simulation result of the flow of the processing gas in the processing container. In the direction X1 in which the vacuum exhaust port 18 is disposed, the processing gas flows smoothly, but the vacuum exhaust port 18 is disposed. In the direction X2 that is not, it is found that a slight retention of the processing gas has occurred.
In order to prevent the non-uniformity of the gas flow, it is conceivable to arrange a larger number of vacuum exhaust ports 18 in a circumferential shape, but in this case, not only the structure becomes complicated but also the current state Even if only four exhaust pipes 20 are provided, maintenance is difficult, and if the number of exhaust pipes 20 is further increased, maintenance work becomes very difficult, and thus cannot be adopted.
In particular, the above-described problems have become apparent as the size of a semiconductor wafer increases from 6 inches or 8 inches to 12 inches, and an early solution is desired.
[0007]
The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a single-wafer processing apparatus capable of uniformizing the flow of processing gas discharged from the processing space to the outside of the object in the radial direction without complicating the structure. It is in.
[0008]
[Means for Solving the Problems]
The invention defined in claim 1 is a single wafer in which a predetermined gas is supplied into a processing container that can be evacuated to perform a predetermined process on an object to be processed placed on a mounting table. In the processing apparatus of the above type, an inlet opening having a diameter smaller than the diameter of the mounting table is formed at the bottom of the processing container, and the gas dropping space communicating with the processing container is formed in order to form the gas dropping space. A cylindrical partition wall having a bottomed cylindrical shape is connected to the inlet opening, and the mounting table is supported by a support column provided upright on the bottom of the cylindrical partition wall, and an outer diameter is provided at the bottom of the cylindrical partition wall. A pipe-shaped baffle pipe having a flange portion set to be the same as the inner diameter of the cylindrical partition wall and inscribed in the cylindrical partition wall, the inner diameter of which is smaller than the inner diameter of the cylindrical partition wall; In the main body and in the center The two gases flow port disposed so as to face provided, in the lower side wall of the cylindrical partition wall, set the evacuation outlet for evacuating at a position that does not face directly to the gas flow opening The gas flow port is formed in a different direction at an angle of 90 degrees with respect to the direction in which the vacuum exhaust port is located .
[0009]
As described above, since the atmosphere in the processing space is evacuated toward the gas drop-in space where the inlet opening portion is reduced, the atmosphere in the processing space should be exhausted by flowing down the outer periphery of the target object evenly. Is possible.
Moreover, since the drift of the exhaust gas is suppressed by the action of the baffle pipe, the flow of the processing gas discharged from the processing space to the outside of the object to be processed in the radial direction can be made more uniform .
[0010]
In this case, for example, as defined in claim 2 , for example, the flange portion of the baffle pipe is installed at the bottom of the cylindrical partition wall with the flange portion facing upward.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a single wafer processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
1 is a cross-sectional view showing a single-wafer processing apparatus according to the present invention, FIG. 2 is a cross-sectional view taken along line CC in FIG. 1, and FIG. 3 is a perspective view showing a baffle pipe provided in a gas dropping space. FIG. Here, a single wafer type annealing reforming apparatus will be described as an example of the processing apparatus. As shown in the figure, the annealing reformer 22 has a processing vessel 24 made of aluminum having a substantially square cross section, for example. A quartz ring-shaped shower head portion 26 for introducing, for example, ozone as a processing gas is provided on the ceiling portion in the processing container 24, and a processing space is provided from a number of gas injection ports 28 provided on the lower surface. The processing gas is jetted toward S.
[0012]
A large opening 30 is formed in the ceiling portion of the processing container 24, and a transparent window 32 made of, for example, a quartz plate that is transparent to ultraviolet rays is formed in the opening 30, and a sealing member 34 such as an O-ring. It is attached airtight through. A lamp chamber 38 covered with a casing 36 is formed above the transmission window 32, and a plurality of ultraviolet lamps 40 are provided in the lamp chamber 38. The emitted UV light UV is transmitted through the transmission window 32 and introduced into the processing space S.
In addition, a loading / unloading port 42 for loading / unloading a semiconductor wafer W as an object to be processed is provided on the side wall of the processing chamber 24, and the loading / unloading port 42 is hermetically opened and closed. An enabled gate valve 44 is provided.
[0013]
A gas dropping space 50 that is a feature of the present invention is formed in the bottom 48 of the processing container 24. Specifically, a large opening 52 is formed in the central portion of the container bottom 48, and a cylindrical partition wall 54 having a bottomed cylindrical shape extending downward is connected to the opening 52 and the above described inside is connected to the inside. A gas dropping space 50 is formed. Further, for example, a cylindrical column 56 is provided on the bottom 54A of the cylindrical partition wall 54 that partitions the space 50, and a disk-shaped mounting table 58 is fixed to the upper end. ing. The mounting table 58 includes, for example, a heater 60 arranged in a predetermined pattern shape inside, and the outside is made of sintered ceramics such as AlN, and the semiconductor wafer W is mounted on the upper surface. It can be placed.
[0014]
The mounting table 58 is formed with a plurality of pin holes 62 penetrating in the vertical direction, and a push-up pin 64 made of quartz, for example, commonly connected to the operating rod 66 is idled in each pin hole 62. It is housed in a fitted state. The actuating rod 66 is connected to an in / out rod 68B of an air cylinder 68 provided on the lower surface of the container bottom 48, and the push-up pins 64 are indented upward from the upper ends of the pin holes 62 when the wafer W is transferred. It is supposed to let you. A bellows 70 is interposed between the air cylinder 68 and the lower surface of the container bottom 48 so that the retracting rod 68B can be moved up and down while maintaining the airtightness in the processing container 24.
[0015]
The diameter L1 of the inlet opening 50A of the gas dropping space 50 is set to be smaller than the diameter of the mounting table 58, and the processing gas flowing down outside the peripheral edge of the mounting table 58 is It goes down and flows into the inlet opening 50A. A vacuum exhaust port 72 is formed on the lower side wall of the cylindrical partition wall 54 so as to face the gas dropping space 50, and a vacuum pump (not shown) is interposed in the vacuum exhaust port 72. An exhaust pipe 74 is connected so that the atmosphere in the processing container 24 and the gas dropping space 50 can be evacuated. A pipe-shaped baffle tube 76 is provided in the vicinity of the vacuum exhaust port 72, that is, in the bottom portion 54 </ b> A of the cylindrical partition wall 54.
[0016]
Specifically, the diameter of the baffle pipe 76 is set to about ½ of the inner diameter of the cylindrical partition wall 54, and the baffle pipe 76 has the same size as the inner diameter of the gas dropping space 50 at its upper end. The ring-shaped flange portion 78 is provided so as to be inscribed in the cylindrical partition wall 54 (see FIG. 3). Further, two gas circulation ports 82 are formed in the main body portion 80 of the baffle pipe 76 so as to face the central portion (see FIG. 2). These two gas circulation ports 82 are arranged so as not to directly face the vacuum exhaust port 72. For example, in the case shown in FIG. The two gas circulation ports 82 are formed in different directions at an angle of 90 degrees so that the two gas circulation ports 82 are uniformly evacuated without being pulled from either one of the gas circulation ports 82. It has become.
A ring-shaped rectifying plate 86 having a large number of gas ports 84 is provided between the peripheral edge of the mounting table 58 and the inner wall of the processing container 24. Reference numeral 90 denotes a power supply line disposed in the support column 56 for supplying electric power to the heater 60.
[0017]
Next, the operation of the present embodiment configured as described above will be described.
First, an unprocessed semiconductor wafer W is loaded into the processing container 24 through a gate valve 44 and a loading / unloading port 42 which are held by a transfer arm (not shown) and opened, and this wafer W is received by push-up pins 64. After being transferred, the push-up pin 64 is lowered to place and hold the wafer W on the mounting table 58.
The mounting table 58 is preheated to a predetermined temperature in advance, and after the wafer W is mounted, the power supplied to the heater 60 is increased to raise the temperature of the wafer W to a predetermined process temperature and maintain the process temperature. To do. In addition, an ultraviolet lamp 40 provided above the ceiling is driven, and ultraviolet rays UV emitted from the ultraviolet lamp 40 are transmitted through the transmission window 32 of the container ceiling to irradiate the surface of the wafer W. At the same time, for example, ozone is jetted and supplied from the shower head unit 26 to the processing space S as a processing gas, and a vacuum pump (not shown) provided in the exhaust pipe 74 is driven to drive the inside of the processing container 24 and the gas dropping space 50. The atmosphere inside is evacuated and the atmosphere of the processing space S is maintained at a predetermined process pressure. As a result, a film such as TaOx formed on the surface of the semiconductor wafer W is modified by ozone activated by the ultraviolet rays UV, and is annealed.
[0018]
In this case, the processing gas (ozone) supplied from the shower head unit 26 to the processing space S flows almost evenly to the peripheral edge of the wafer W and hardly flows, so the processing uniformity, here In-plane uniformity of the annealing modification treatment can be maintained high. That is, here, a gas dropping space 50 in which the inlet opening 50A is slightly narrowed is provided below the mounting table 58, and evacuation is performed through this space 50. Therefore, as shown in FIG. Unlike the case of the conventional apparatus, the processing gas ejected from the shower head portion 26 flows and diffuses substantially uniformly from the center side of the upper surface of the wafer to the outer side in the radial direction. It passes through the gas ports 84 of the rectifying plate 86 arranged on the outer side of the plate substantially evenly and goes around the mounting table 58. The processing gas that has flowed in flows into the gas dropping space 50 through the inlet opening 50A and flows down, and further, the processing gas passes through the two gas flow ports 82 from the center of the baffle pipe 76. And then exhausted from the exhaust pipe 74 through the vacuum exhaust port 72.
[0019]
As described above, since the atmosphere of the processing space S can be dropped into the gas dropping space 50 via the outer peripheral edge of the mounting table 58, a drift is generated from the center side of the wafer upper surface outward in the radial direction. The processing gas can be made to flow substantially evenly without causing it. For this reason, it is possible to maintain high in-plane uniformity of processing such as annealing modification processing.
Also, when evacuating the atmosphere in the gas drop-in space 50, as shown in FIG. 2, the vacuum exhaust port 72 and the two gas flow ports 82 are not directly opposed to each other. Vacuum is not mainly evacuated from the gas flow ports 82, but can be evacuated from both gas flow ports 82 substantially equally. Therefore, the gas distribution flowing into the inlet opening 50A of the gas dropping space 50 is in a uniform state, and the processing gas flowing on the upper surface of the wafer can be further equalized.
[0020]
Conventionally, four exhaust pipes 20 (see FIG. 6) are required. However, in the case of this embodiment, only one exhaust pipe 74 is required, and not only the structure of this part can be simplified but also the space. Maintenance work can be easily performed in combination with the increase in the number of parts.
FIG. 4 is a diagram showing a simulation result of the flow of the processing gas in the processing container 24 and the gas dropping space 50 of the apparatus of the present invention described above. As is clear from this figure, the case of the conventional apparatus shown in FIG. In contrast, in the case of the apparatus of the present invention, it has been found that the processing gas flows substantially uniformly from the substantially central side of the wafer surface toward the peripheral portion, and that the stagnant gas is hardly generated.
The diameter of the baffle tube 76 and the number of gas flow ports 82 provided in the baffle tube in the above embodiment are merely examples, and are not limited to those described above. Of course, even when the baffle tube 76 is not provided, the above-described substantially the same effect can be obtained.
[0021]
Furthermore, although the annealing reforming apparatus has been described as an example of the processing apparatus here, the present invention is not limited thereto, and the apparatus of the present invention can be applied to a film forming apparatus, an etching apparatus, an oxidation diffusion apparatus, and a processing apparatus using plasma. Of course. For example, when the apparatus of the present invention is used for a CVD film forming apparatus, the ultraviolet lamp 40 and the transmission window 32 are excluded from the apparatus shown in FIG. 1, and further replaced with a ring-shaped shower head unit 26 as shown in FIG. A disc-shaped normal shower head portion 94 having a large number of gas injection ports 92 on the lower surface may be provided.
In this embodiment, the semiconductor wafer is described as an example of the object to be processed. However, the present invention is not limited to this, and can be applied to an LCD substrate, a glass substrate, and the like.
[0022]
【The invention's effect】
As described above, according to the single wafer processing apparatus of the present invention, the following excellent operational effects can be exhibited.
Since a gas dropping space is formed under the mounting table and the atmosphere in the processing container is evacuated through this space, the atmosphere of the processing space (processing gas) is radially directed from the center side of the object to be processed. The liquid can flow substantially uniformly toward the outside, and can be discharged substantially uniformly on the outer periphery (outside of the peripheral edge). For this reason, the in-plane uniformity of the process of the to-be-processed object surface can be improved.
In addition, since the number of exhaust pipes can be reduced, not only the structure can be simplified, but also the maintenance work can be simplified and the efficiency can be improved.
Further, a baffle pipe is provided in the gas drop-in space, and two baffle pipes are provided in the baffle pipe so that the baffle pipe is not directly desired with respect to the vacuum exhaust port. Since it is directed to a different direction at an angle of 90 degrees with respect to the direction in which it is positioned, as a result, it is possible to further suppress the drift of the processing gas exhausted from the processing space. The flowing process gas can be discharged in a more uniform state.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram showing a single wafer processing apparatus according to the present invention.
FIG. 2 is a cross-sectional view taken along the line CC in FIG.
FIG. 3 is a perspective view showing a baffle pipe provided in a gas dropping space.
FIG. 4 is a diagram showing a simulation result of a flow of processing gas in a processing container and a gas dropping space of the apparatus of the present invention.
FIG. 5 is a cross-sectional configuration diagram showing a modification of the device of the present invention.
FIG. 6 is a schematic configuration diagram showing a conventional general annealing reforming apparatus.
7 is a cross-sectional view taken along line AA in FIG.
FIG. 8 is a diagram showing a gas flow simulation result in a cross-sectional view along the line BB in FIG. 7;
[Explanation of symbols]
22 Annealing reformer (processing equipment)
24 Processing container 26 Shower head part 32 Transmission window 40 Ultraviolet lamp 50 Gas drop-in space 50A Entrance opening 54 Inner cylinder partition wall 54A Bottom 56 Support column 58 Mounting table 60 Heater 72 Vacuum exhaust port 74 Exhaust pipe 76 Baffle pipe 82 Gas flow Mouth S Processing space W Semiconductor wafer (object to be processed)

Claims (2)

In a single-wafer type processing apparatus that supplies a predetermined gas into a processing container that is evacuated and performs a predetermined process on an object to be processed placed on a mounting table.
Forming an inlet opening whose diameter is smaller than the diameter of the mounting table at the bottom of the processing vessel,
A cylindrical partition wall having a bottomed cylindrical shape is connected to the inlet opening to form a gas dropping space communicating with the processing container,
Supporting the mounting table by a column provided standing on the bottom of the cylindrical partition wall,
The bottom of the cylindrical partition wall has a flange portion whose outer diameter is set to be the same as the inner diameter of the cylindrical partition wall and is inscribed in the cylindrical partition wall, and the inner diameter is made smaller than the inner diameter of the cylindrical partition wall. A pipe-shaped baffle pipe
Provided in the body part of the baffle tube with two gas circulation ports arranged so as to face the center part,
The lower sidewall of the cylindrical partition wall, set the evacuation outlet for evacuating at a position that does not face directly to the gas circulation port,
The single-wafer processing apparatus , wherein the gas circulation port is formed in a different direction at an angle of 90 degrees with respect to a direction in which the vacuum exhaust port is located . The single-wafer processing apparatus according to claim 1 , wherein the flange portion of the baffle pipe is installed at a bottom portion in the cylindrical partition wall with the flange portion facing upward.

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