JP4582929B2 - Deposition equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a film forming apparatus for forming a thin film on a wafer surface by performing epitaxial growth on the wafer.
[0002]
[Prior art]
2. Description of the Related Art A film forming apparatus that performs epitaxial growth on a semiconductor substrate such as a silicon wafer introduces a source gas into a film forming chamber and forms a thin film on the wafer by performing a gas phase reaction and / or a chemical reaction there. .
[0003]
Here, FIG. 6 and FIG. 7 are schematic sectional views showing a schematic structure of a film forming chamber of a conventional film forming apparatus. As shown in FIG. 6, in the conventional film forming apparatus, the film forming chamber 10 includes a film forming chamber upper wall 11 and a film forming chamber under the film forming chamber 10 made of quartz. A wall 15, a source gas inlet 12 for introducing a source gas into the film forming chamber 10, a source gas outlet 14 for discharging the source gas from the film forming chamber 10, and a susceptor 16 for placing and rotating a wafer in the film forming chamber 10. And a wafer rotating mechanism (susceptor rotating mechanism) 18 for rotating the susceptor 16.
[0004]
7 shows a schematic structure of a film forming chamber of a conventional film forming apparatus according to a form different from that of FIG. 6, but the film forming apparatus of FIG. 7 is similar to that of FIG. Further, a quartz film forming chamber upper wall 11, a source gas inlet 12, a source gas outlet 14, a susceptor 16, and a wafer rotating mechanism 18 are provided. However, in FIG. 7, the gate valve 13, the wafer inlet / outlet port 17, and the infrared lamp heater 19 which are not illustrated in FIG. 6 are illustrated.
[0005]
In the film forming chamber 10 having such a configuration, the wafer is transferred into the film forming chamber 10 from the wafer entrance 17 provided in the film forming chamber 10 and transferred onto the susceptor 16. Then, in the process of introducing the source gas from the source gas introduction port 12 into the film forming chamber and exhausting it from the discharge port 14, the source gas passing through the wafer surface (indicated by arrows in FIGS. 6 and 7). A thin film is formed by a chemical reaction of a part of the film, and it is deposited.
[0006]
[Problems to be solved by the invention]
In such a film forming process, the source gas is filled in the film forming chamber, and a part of the source gas is formed on the inner surfaces of the film forming chamber upper wall 11 and the film forming chamber lower wall 15 constituting the film forming chamber 10. Decomposes and adheres and accumulates. The adhered / deposited material may be peeled off and deposited as dust on the wafer during transportation or during film formation, thereby reducing film formation quality.
[0007]
Therefore, in order to maintain the film formation quality, it is necessary to remove this adhesion and deposit, and for this purpose, the inside of the film formation chamber is periodically cleaned. In this film forming apparatus, since the film forming chamber has a single structure, the apparatus must be disassembled and cleaned one by one, which is not easy.
[0008]
The present invention has been made in view of such problems, and an object, such has a simple structure but al, cleaning and reassembly, to provide a film forming apparatus which can be easily maintained There is.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a dual structure in which the functional configuration of the film forming chamber of the film forming apparatus is largely divided into two parts. The functional configuration is simplified.
[0010]
In the present invention, the mechanism inside the film forming chamber is integrated to simplify the reassembly of the chamber inside the film forming chamber, shorten the maintenance work time of the film forming chamber, and It is characterized by shortening the open time to the atmosphere exposed to the atmosphere.
[0011]
More specifically, in the present invention, the functional configuration of the film forming chamber of the film forming apparatus includes an outer chamber constituting the lower outermost wall of the film forming apparatus, an inner chamber incorporated inside the outer chamber, At the same time, by integrating the reaction gas supply / exhaust mechanism into the inner chamber, it is possible to simplify the reassembly of the chamber inside the film forming chamber, shorten the time for maintenance of the film forming chamber, and the film forming chamber. It is characterized by shortening the air opening time during which the inside is exposed to the atmosphere.
[0012]
More specifically, the present invention provides the following.
[0013]
(1) A film forming apparatus that performs epitaxial growth on a wafer, and is divided into an outer chamber that forms a lower outer wall of the film forming apparatus, and an inner chamber that is incorporated inside the outer chamber. The outer chamber includes a gas inlet for introducing gas and a gas outlet for discharging gas, and supports and rotates a susceptor on which a wafer is placed between the inner chamber and the outer chamber. A film forming apparatus comprising a quartz plate window through which a rotating shaft passes.
[0014]
In such a film forming apparatus, an infrared lamp heater that performs heating for epitaxial growth is disposed below the outer chamber, and infrared rays from the heater pass through a lower quartz plate window built between the inner chamber and the outer chamber. Pass through and heat the wafer on the susceptor.
[0015]
In the film forming apparatus according to the present invention, the functional configuration of the film forming chamber is divided into two parts, an “outer chamber” and an “inner chamber”, and a quartz lower quartz plate window is incorporated between the outer chamber and the inner chamber. Such a configuration is a basic configuration. The outer chamber is a sophisticated device having a complicated mechanism that affects the film formation environment in the film formation chamber, such as an opening for taking in and out the substrate, a shutter for opening and closing the opening, a source gas introduction port or a discharge port. On the other hand, the inner chamber is configured to include equipment having a relatively simple structure that does not affect the film forming environment in the film forming chamber, such as a susceptor on which a wafer is placed.
[0016]
Moreover, since the configuration of the inner chamber is simplified (more specifically, it is not the present invention that the shape of the inner chamber is complicated by providing a shutter or the like outside the inner chamber), It becomes possible to provide a single inner chamber that can be easily mounted and removed.
[0017]
(2) The film forming apparatus according to (1), wherein the inner chamber is NiF ₂ coated.
[0018]
In the present invention, since the inner chamber is coated with NiF ₂ , the corrosion resistance is improved. That is, NiF ₂ which is a metal fluoride has a characteristic that itself is chemically stable and has a much lower reactivity to corrosive substances. Therefore, by covering the inner chamber with a chemical coating, the coating will not be corroded even during cleaning operations using chemicals. There will be less occurrence of peeling.
[0019]
Conventionally, equipment in the film formation chamber has been coated with chromium oxide for the purpose of rust prevention, but one of the chemical components used for cleaning metal equipment etc. in cleaning work is Si. There is hydrofluoric acid that is effective in cleaning the system by-product, and this hydrofluoric acid has etched chromium oxide, so it could not be used. However, by coating the inner chamber with NiF _2, it becomes possible to use hydrogen fluoride effective for cleaning Si-based byproducts.
[0020]
(3) The film forming apparatus according to (1) or (2), wherein an upper portion of the inner chamber is processed with a step.
[0021]
In the present invention, an upper quartz plate window as an upper lid made of quartz is formed on the upper portion of the inner chamber. By providing a step process for hooking the upper quartz plate window on the upper portion of the inner chamber. The upper quartz plate window can be hooked on the hook portion, and the upper quartz plate window can be easily attached or detached.
[0022]
In the present invention, the upper portion of the inner chamber in which the susceptor or the like is accommodated is stepped or NiF ₂ coated. The outside of the inner chamber is not equipped with a precision mechanism such as a shutter that opens and closes the opening for loading and unloading wafers, but there are simply various parts (susceptor, approach plate, etc.) necessary for film formation inside the inner chamber. It is only housed and easy to handle. Moreover, since the structure of the inner chamber is simplified as described above, the inner chamber accommodated in the outer chamber can be easily attached and detached. Therefore, in the present invention, the following inner chamber alone is also the content of the right.
[0023]
(4) An inner chamber for accommodating a susceptor on which a wafer to be subjected to epitaxial growth is placed, wherein the upper portion of the inner chamber is stepped.
[0024]
(5) The inner chamber according to (4), wherein the inner chamber is NiF ₂ coated.
[0025]
In addition, when incorporating an inner chamber in the film-forming apparatus having a double structure according to the present invention, the following procedure (incorporation method) can be performed.
[0026]
(6) An inner chamber assembling method in which an inner chamber for housing a susceptor on which a wafer to be used for epitaxial growth is placed is placed inside an outer chamber in which an infrared lamp heater for heating for epitaxial growth is disposed below. A step of incorporating a quartz plate window through which a wafer rotation shaft for supporting and rotating the susceptor is installed inside the outer chamber; and an inner portion according to (4) or (5) above the plate window A method of assembling an inner chamber, comprising: incorporating a chamber; and hooking an upper quartz plate window made of quartz on a stepped portion of the upper portion of the inner chamber.
[0027]
In the present invention, in the step of incorporating the inner chamber into the outer chamber that is the foundation of the film forming chamber, the number of steps required for assembly can be reduced by using the inner chamber of (4) or (5), and as a result, the atmosphere is released to the atmosphere. Time can be shortened.
[0028]
Also, the process of incorporating the inner chamber into the outer chamber is simple, such as incorporating a plate window inside the outer chamber, incorporating an inner chamber above the plate window, and hanging the upper quartz plate window over the inner chamber. And can be easily reassembled.
[0029]
In addition, as a technical idea having the same effect as the present invention, the following removal method can also be provided.
[0030]
In a film forming apparatus in which an inner chamber that houses a susceptor for placing a wafer to be used for epitaxial growth is incorporated inside an outer chamber in which a heater for heating for epitaxial growth is arranged below, An inner chamber comprising: a step of removing the latched upper quartz plate window; a step of removing the inner chamber according to (4) or (5); and a step of removing the quartz chamber incorporated inside the outer chamber. How to remove.
[0031]
In such a removal method, even when removing the inner chamber that requires maintenance, the inner chamber can be easily removed by removing the upper quartz plate window that is hooked on the stepped portion of the upper portion of the inner chamber. Can do. Even when removing the lower quartz plate window incorporated between the inner chamber and the outer chamber, the lower quartz plate window can be easily removed by removing the upper quartz plate window and the inner chamber. ) Is very easy to attach and detach.
[0032]
In this regard, the conventional film forming apparatus requires a large-scale cleaning operation in which the apparatus is disassembled and cleaned one by one. However, as apparent from the removal process / assembly process as described above, the present invention relates to the present invention. Since the film forming apparatus can be easily removed and assembled, the film forming chamber can be easily cleaned without the troubles of the conventional apparatus shown in FIG.
[0033]
Further, in the apparatus shown in FIG. 7, there is no reference surface and adjustment after assembly of the reaction chamber is difficult, whereas in the present invention, the outer chamber can be made of metal such as stainless steel, The in-furnace product can be easily positioned horizontally and can be adjusted quickly after assembly of the reaction chamber.
[0034]
Further, in the conventional apparatus, various apparatuses and mechanisms (for example, a quartz jig, a thermometer, etc.) are attached to the film forming chamber, and the internal structure of the film forming chamber is complicated. It took a long time to reassemble. In addition, during cleaning work and during reassembly (during maintenance), the inside of the film forming chamber is exposed to the atmosphere, so that an increase in maintenance time causes metal contamination of the apparatus inside the film forming chamber. However, such a problem hardly occurs in the film forming apparatus according to the present invention.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a structure of an outer chamber according to a preferred embodiment of the present invention. The outer chamber 20 shown in FIG. 1 is composed of a substrate loading / unloading opening (wafer inlet / outlet) 17, an N ₂ introduction pipe 23 for purging between the inner and outer O-rings, and an O-ring 25 for latching a lower quartz plate window 30. Has been. Further, the outer chamber 20 has a quartz plate window storage area 27 and an inner chamber storage area 29.
[0036]
FIG. 2 is a diagram showing a structure of an inner chamber according to a preferred embodiment of the present invention. The inner chamber 40 shown in FIG. 2 includes a step portion 41 that has been stepped, a cooling water introduction pipe 43, and a cooling water discharge pipe 44.
[0037]
That is, in the film forming apparatus according to the present invention, the inner chamber 40 of FIG. 2 is incorporated and integrated in the inner chamber housing region 29 of the outer chamber shown in FIG. In the present invention, the inner chamber 40 is configured to be easily detachable so that the reaction chamber can be cleaned basically by cleaning only the inner chamber 40 outside the apparatus. . Furthermore, since the structure of the inner chamber 40 is simplified, it is possible to reduce the number of assembling steps and reduce the occurrence of failure, thereby improving the efficiency of maintenance.
[0038]
FIG. 3 is a diagram for explaining an inner chamber assembling method according to a preferred embodiment of the present invention. FIG. 3 (a) is a diagram for explaining the assembling order, and FIG. It is a completed assembly drawing.
[0039]
In the film forming apparatus, the infrared lamp heater 19 and the outer chamber 20 are fixed to the film forming apparatus, and the attachment / detachment thereof is not as easy as the inner chamber 40. That is, the outer chamber 20, the flange 21, is sufficiently fixed to the shutter are close, the film formation apparatus for opening and closing the entrance to the flange 21.
[0040]
In this manner, first, the lower quartz plate window 30 is incorporated inside the outer chamber 20 to be the base of the film forming chamber of the film forming apparatus (step 1). Next, the inner chamber 40 is assembled inside the outer chamber 20 (inner chamber storage area 29 ) (step 2). In this case, the lower quartz plate window 30 is sandwiched between the O-ring provided on the O-ring 25 and the inner chamber bottom provided on the outer chamber, it is held in a quartz plate window housing area 27. At this time, the wafer entrance / exit of the outer chamber 20 and the wafer entrance / exit of the inner chamber 40 are matched.
[0041]
After the inner chamber 40 is assembled inside the outer chamber 20 in this way, various parts are accommodated in the inner chamber (steps 3 to 5 ). Specifically, the wafer rotation axis of the wafer rotating mechanism 18 provided in the deposition chamber is projected to the inner chamber 40, for supporting the susceptor 16 to the upper portion of the rotary shaft (Step 4). In addition to the susceptor 16, there are an approach plate 50 (step 3), a susceptor ring 51 (step 5), and the like, which are appropriately changed depending on the characteristics and functions of the apparatus.
[0042]
Then, after receiving all necessary components in the inner chamber 40, the upper quartz plate window 11 and placed on the O-ring disposed in the stepped portion 41 of the upper surface of the inner chamber 40 (upper), abolish hanging (Step 6 ). In this way, when the upper quartz plate window 11 is installed as the upper lid of the inner chamber 40, the film formation composed of the inner chamber 40, the lower quartz plate window 30, and the upper quartz plate window 11 inside the outer chamber 20. A chamber can be provided.
[0043]
As a preferred embodiment of the present invention, after step 6 , the holding flange 60 is arranged on the upper part of the upper quartz plate window 11 (step 7 ).
[0044]
4A and 4B are diagrams showing an outline of a film forming chamber of a film forming apparatus according to a preferred embodiment of the present invention. FIG. 4A is a plan view and FIG. 4B is a cross-sectional view.
[0045]
The film forming chamber shown in FIG. 4A has an inner chamber 40 incorporated inside the outer chamber 20, a wafer inlet / outlet 17 on the right side surface of the outer chamber 20, and a cooling water introduction pipe on each of the upper side surface and the lower side surface. 43 and a cooling water discharge pipe 44 are provided. A susceptor 16 is provided in the center of the film forming chamber. The gas introduction pipe / discharge pipe are respectively connected to a gas inlet and a gas outlet (not shown) connected to the outer chamber.
[0046]
FIG. 5 is an enlarged view of the film formation region 39 of the film formation chamber. A film formation region 39 shown in FIG. 5 formed by incorporating an inner chamber 40 containing a susceptor or the like into the outer chamber 20 is composed of an upper quartz plate window 11 and a lower quartz plate window 30. In such a film formation region 39, the source gas flows from the right direction to the left direction (arrow direction in FIG. 5).
[0047]
The space formed by the outer peripheral surface of the susceptor ring 51 and the inner peripheral surface of the approach plate 50 has a crank shape, so that the source gas is less likely to contact the lower quartz plate window 30 (labyrinth effect). . For this reason, the wall deposit on the lower quartz plate window 30 is reduced, and the maintenance frequency of the lower quartz plate window 30 can be suppressed. Further, since the disturbance of the source gas flow is eliminated, the source gas flow becomes a stable parallel flow, and the film thickness can be expected to be flattened, so that the film forming quality is stabilized.
[0048]
In addition, the inner chamber 40 according to the present invention is coated with NiF ₂ and has a characteristic that the reactivity with respect to corrosive substances and the like is much lower, and can withstand cleaning using an etchant containing HF. It is superior to chromium oxide-based coatings.
[0049]
【The invention's effect】
As described above, according to the present invention, the functional configuration of the film forming chamber is largely divided into the outer chamber and the inner chamber. Therefore, in the disassembly and cleaning operation of the inner chamber that requires maintenance, the disassembly operation can be simplified. The efficiency of the disassembly and cleaning work can be improved, and the loss associated with the disassembly and cleaning work can be reduced.
[0050]
Further, by enhancing the corrosion resistance of the inner chamber, the consumption rate of the inner chamber can be kept low.
[Brief description of the drawings]
FIG. 1 is a diagram showing a structure of an outer chamber according to a preferred embodiment of the present invention.
FIG. 2 is a diagram showing a structure of an inner chamber according to a preferred embodiment of the present invention.
FIG. 3 is a view for explaining an inner chamber assembling method according to a preferred embodiment of the present invention.
FIG. 4 is a diagram showing an outline of a film forming chamber of a film forming apparatus according to a preferred embodiment of the present invention.
FIG. 5 is an enlarged view of a film formation region of a film formation chamber.
FIG. 6 is a view showing a schematic structure of a film forming chamber of a conventional film forming apparatus.
FIG. 7 is a view showing a schematic structure of a film forming chamber of a conventional film forming apparatus.
[Explanation of symbols]
10 Deposition chamber 11 Upper quartz plate window (deposition chamber upper wall)
12 Source gas inlet 13 Gate valve 14 Source gas outlet 15 Deposition chamber lower wall 16 Susceptor 17 Wafer inlet / outlet 18 Wafer rotation mechanism (susceptor rotation mechanism)
19 Infrared lamp heater 20 Outer chamber 21 Flange 23 Purge N ₂ introduction pipe 25 O-ring 27 Quartz plate window storage area 29 Inner chamber storage area 30 Lower quartz plate window 39 Film formation area 40 Inner chamber 41 Stepped portion 43 Cooling water introduction pipe 44 Cooling water discharge pipe 50 Approach plate 51 Susceptor ring 60 Presser flange

Claims (3)

  A film forming apparatus that performs epitaxial growth on a wafer, and is configured by being divided into an outer chamber that forms a lower outer wall of the film forming apparatus, and an inner chamber that is incorporated inside the outer chamber, The outer chamber includes a gas inlet for introducing gas and a gas outlet for discharging gas. Between the inner chamber and the outer chamber, a rotating shaft that supports and rotates a susceptor on which a wafer is placed is provided. A film forming apparatus, wherein a quartz plate window to be penetrated is incorporated. The film forming apparatus according to claim 1, wherein the inner chamber is NiF ₂ coated.   The film forming apparatus according to claim 1, wherein an upper portion of the inner chamber is processed with a step.

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