JP5598407B2 - Film forming apparatus and film forming method - Google Patents

Description

  The present invention relates to an in-line film forming apparatus including a substrate preparation chamber and a film forming chamber, and a film forming method in the film forming apparatus.

  As an in-line type film forming apparatus, an apparatus including a load lock chamber and a film forming chamber as described in Patent Document 1 is known. In such a film forming apparatus, when the work is transferred between the load lock chamber and the film forming chamber, the pressure in each chamber is set to the same level (high vacuum of several Pa or less). I am doing so. After the transfer, the gate valve between the load lock chamber and the film forming chamber is closed, and the film is formed after adjusting to a pressure required for film formation in the film forming chamber.

JP 2006-96498 A

  However, since the pressure in the film forming chamber is adjusted after the work is transferred to the film forming chamber and then the gate valve is closed, the time from when the work is loaded into the film forming apparatus to when the work is unloaded. There was a problem of being long.

A film forming apparatus according to claim 1 is a film forming chamber in which a film forming process is performed on a substrate using a film forming gas, and a film forming gas introducing means for introducing the film forming gas into the film forming chamber. A substrate preparation chamber for preparing a substrate to be transferred to the film formation chamber, a gate valve for partitioning the film formation chamber and the substrate preparation chamber, and opening the gate valve to remove the substrate from the substrate preparation chamber Adjustment gas introduction means for introducing a pressure adjusting gas into the film formation chamber and increasing the pressure in the film formation chamber to the pressure during film formation during the transfer period from the transfer to the gate valve and closing the gate valve. A film forming process in the film forming chamber is performed after closing .
According to a second aspect of the present invention, in the film forming apparatus of the first aspect, when the substrate is transferred to the film forming chamber and the gate valve is closed, the introduction of the pressure adjusting gas by the adjusting gas introducing means is stopped. Gas control means for starting introduction of the film forming gas by the film gas introducing means is further provided.
According to a third aspect of the present invention, in the film forming apparatus of the first aspect, a film forming gas is used as the pressure adjusting gas.
According to a fourth aspect of the present invention, there is provided the film forming apparatus according to any one of the first to third aspects, wherein the pressure in the film forming chamber is adjusted by an evacuating apparatus for evacuating the substrate preparation chamber and an adjusting gas introducing means. And an evacuation control means for stopping the evacuation of the substrate preparation chamber by the evacuation apparatus when the working gas is introduced.
According to a fifth aspect of the present invention, there is provided a film forming chamber in which a film forming process is performed on a substrate using a film forming gas, a substrate preparing chamber in which a substrate to be transferred to the film forming chamber is prepared, a film forming chamber, A film forming method in a film forming apparatus having a gate valve for partitioning a substrate from a substrate preparation chamber, the transfer step of opening the gate valve to transfer the substrate from the substrate preparation chamber to the film forming chamber and closing the gate valve And a film forming process for forming a film on the substrate by introducing a film forming gas into the film forming chamber. In the transfer process from opening the gate valve to closing the gate valve, the pressure adjusting gas is supplied. A pressure adjusting process is performed in which the pressure in the film forming chamber is increased to the film forming pressure after being introduced into the film forming chamber.

  According to the present invention, the throughput (production amount per unit time) of the film forming apparatus can be improved.

The block diagram which shows one Embodiment of the film-forming processing apparatus by this invention. The figure explaining conveyance operation. The figure explaining conveyance operation. The figure explaining conveyance operation. The figure which shows the change of the film-forming chamber 20 internal pressure and the load-lock chamber 10 internal pressure from carrying in of the untreated board | substrate W0 to carrying out of the processed board | substrate W1 by which the film-forming process was carried out. The figure which shows the change of the film-forming chamber 20 internal pressure and the load-lock chamber 10 internal pressure in the case of the conventional apparatus. 1 is a block diagram of a film forming apparatus including a load lock chamber 10, a film forming chamber 20, and an unload chamber 40. FIG. The figure which shows the pressure change at the time of closing the gate valve G2 before the pressure of the film-forming chamber 20 becomes 100 Pa.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a film forming apparatus according to the present invention. A film forming apparatus 1 shown in FIG. 1 is a plasma CVD apparatus, and includes a film forming chamber 20, a load lock chamber 10 as a substrate preparation chamber, and a control device 30 for controlling the entire apparatus. The load lock chamber 10 is a vacuum chamber provided for carrying the substrate W into and out of the film forming chamber 20 without opening the film forming chamber 20 to the atmosphere. It is partitioned by a valve G2. The load lock chamber 10 is evacuated by a vacuum pump P1 through a valve V1. The film forming chamber 20 is evacuated by a vacuum pump P2 through a valve V2. As the valve V2, a variable valve capable of changing conductance is used. Hereinafter, an unprocessed substrate that has not been formed is referred to as an unprocessed substrate W0, and a substrate that has been formed is referred to as a processed substrate W1.

  In the film forming apparatus 1 shown in FIG. 1, the load lock chamber 10 is provided with two transfer mechanisms 100 </ b> A and 100 </ b> B at the top and bottom. For example, Japanese Patent Application Laid-Open No. 2006-96498 discloses a configuration in which the transport mechanism is provided in two stages in the load lock chamber. The upper transfer mechanism 100A is for transferring the cart 101 on which the unprocessed substrate W0 is placed from the load lock chamber 10 to the film forming chamber 20. On the other hand, the lower transfer mechanism 100 </ b> B is for transferring the cart 101 on which the processed substrate W <b> 1 is placed from the film forming chamber 20 to the load lock chamber 10. The film forming chamber 20 is also provided with a transport mechanism 100C. Each of the transport mechanisms 100A to 100C can be switched between a horizontal state shown in FIG. 1 and an inclined state as indicated by a two-dot chain line. As will be described later, at the time of the transport operation, the cart 101 is moved with each transport mechanism tilted.

  The load lock chamber 10 includes a gate valve G1 that is opened and closed when the substrate is carried in, and a gate valve G3 that is opened and closed when the substrate is carried out. The load lock chamber 10 also serves as a preheating chamber, and includes a heater 102 for heating the loaded unprocessed substrate W0. Although not shown in FIG. 1, an external station is provided for supplying the unprocessed substrate W0 to the load lock chamber 10 and temporarily storing the processed substrate W1 unloaded from the load lock chamber 10. When the load lock chamber 10 is opened to the atmosphere, purge gas is supplied into the load lock chamber 10 via the valve V3.

  A film forming material gas is supplied into the film forming chamber 20 via the mass flow controllers 204A to 204C. For example, in the case of an apparatus for forming a silicon nitride film, nitrogen (N2), silane (SiH4), and ammonia (NH3) are supplied as material gases. Reference numerals 105 and 205 denote vacuum gauges for measuring pressures in the load lock chamber 10 and the film forming chamber 20.

  An RF antenna 201 is provided outside the film formation chamber 20, and a high frequency power source 202 is connected to the RF antenna 201. By supplying high frequency power to the RF antenna 201, electromagnetic waves are incident on the film forming chamber 20. The electromagnetic wave incident on the film forming chamber 20 ionizes the gas in the film forming chamber 20 to generate plasma.

  Next, the substrate transfer operation will be described with reference to FIGS. In the film formation processing apparatus 1 shown in FIG. 1, the substrate W and the cart 101 are transported as a single unit while the substrate is placed on the cart 101 and transported, formed, and carried out. 2 to 4 show the position of the cart 101 in the film formation processing apparatus 1. Of the configurations shown in FIG. FIG. 5 is a diagram for explaining the pressure in the load lock chamber 10 (FIG. 5B) and the film forming chamber 20 (FIG. 5A) in each step.

  In the film forming apparatus 1, a series of processes of (carrying in from outside the apparatus) → (preliminary heating) → (film forming) → (carrying out of the apparatus) is repeated. Here, the operation will be described in order from the point in time when the substrate carrying into the film forming apparatus 1 is completed, that is, from the point A in FIG. By opening and closing the gate valve G1, the cart 101 on which the unprocessed substrate W0 is placed is carried into the upper transfer mechanism 100A from the outside of the apparatus (see FIG. 2A). Then, the valve V1 is opened at the point A in FIG. 5, and the load lock chamber 10 is evacuated by the vacuum pump P1. The valve V3 is closed. As a result, as shown in FIG. 5, the load lock chamber 10 is evacuated from atmospheric pressure to a high vacuum state. Here, it is assumed that the air is exhausted to about 5 Pa.

  If the pressure in the load lock chamber 10 has sufficiently decreased (for example, about 15 Pa), the heater 102 is turned on to preheat the unprocessed substrate W0. When the pre-heating of the unprocessed substrate W0 is performed in the load lock chamber 10, the film forming process is performed in the film forming chamber 20. During the film formation process, a mixed gas of nitrogen (N 2), silane (SiH 4), and ammonia (NH 3) is introduced into the film formation chamber 20, and the opening degree (conductance) of the valve V 2 is adjusted to form the film formation chamber 20. The internal pressure is maintained at a predetermined film forming pressure (here, 100 Pa).

  When the film forming process in the film forming chamber 20 is completed, the introduction of the mixed gas into the film forming chamber 20 is stopped and the opening of the valve V2 is increased so that the inside of the film forming chamber 20 is in a high vacuum state. Exhaust. As shown in FIG. 2 (b), the gate valve G2 is opened at the point B (see FIG. 5 (a)) where the pressure in the film forming chamber 20 is the same as or similar to the pressure (5Pa) in the load lock chamber 10. To start the transfer operation.

  In parallel with the transfer operation, introduction of nitrogen (N 2) gas (pressure adjusting gas) into the film formation chamber 20 is started, and the pressure in the film formation chamber 20 and the load lock chamber 10 is the pressure at the time of film formation. The pressure adjustment operation is performed so as to be the same 100 Pa. In this pressure adjustment operation, the gas flow rate is adjusted by the mass flow controller 204A, and the opening degree of the valve V2 is reduced (for example, the same opening degree as at the time of film formation) so that the pressure adjustment is performed in a shorter time. To do. The valve V1 is closed.

  If the valve V1 is open during the pressure adjustment operation, a part of the pressure adjustment gas (N2 gas) introduced into the film forming chamber 20 is exhausted by the vacuum pump P1, and the pressure is increased to 100 Pa. Adjustment time becomes longer. Therefore, it is preferable to close the valve V1 during the pressure adjustment operation. Of course, it may be in an open state.

  In the transfer operation performed in parallel with the pressure adjustment, first, the gate valve G2 is opened, the transfer mechanisms 100B and 100C are inclined as shown in FIG. 2B, and the cart 101 in the film forming chamber 20 is loaded into the load lock chamber. 10 transport mechanisms 100B. As a result, the processed substrate W <b> 1 formed into a film is transferred to the load lock chamber 10. Next, as shown in FIG. 3A, the transport mechanisms 100 </ b> A and 100 </ b> C are tilted, and the cart 101 in the load lock chamber 10 is moved to the transport mechanism 100 </ b> C in the film forming chamber 20. Thereafter, the gate valve G2 is closed. Thus, the preheated unprocessed substrate W0 is transferred to the film forming chamber 20. In the example shown in FIG. 5, the time required for pressure adjustment (T2) is shorter than the time required for the transport operation (T1), and the pressure adjustment operation is completed during the transport operation.

  When the transfer operation is completed, an operation of introducing a mixed gas into the film forming chamber 20 and replacing the nitrogen gas in the film forming chamber 20 with a mixed gas used for film formation is performed. Note that switching between introducing nitrogen gas or mixed gas into the film forming chamber 20 is performed by controlling the mass flow controllers 204A to 204C shown in FIG. When the gas replacement is completed, the film forming process is started. The management of the completion of the gas replacement may be performed based on the replacement time determined by testing in advance, or a gas analyzer that analyzes the gas components in the film forming chamber 20 is provided and is performed based on the analysis result. Also good.

  On the other hand, in the load lock chamber 10, when the transfer operation is completed, as shown in FIG. 3B, the valve V3 is opened to introduce the purge gas, and the pressure in the load lock chamber 10 is returned to the atmospheric pressure. After that, as shown in FIG. 4, the gate valves G1 and G3 are opened, and the cart 101 on which the unprocessed substrate W0 is placed is carried into the transfer mechanism 100A of the load lock chamber 10 from outside the apparatus, and the processed substrate W1 is The placed cart 101 is carried out of the apparatus from the transport mechanism 100B.

  Next, the operational effects in the present embodiment will be described in comparison with a transport operation in a conventional apparatus. In the conventional apparatus, as shown in FIG. 6, the transfer operation between the load lock chamber 10 and the film formation chamber 20 is performed in a high vacuum state (5 Pa), the mixed gas is introduced after the gate valve G2 is closed. Thus, the pressure in the film forming chamber 20 is adjusted. For this reason, the time required from the start of the transfer operation to the start of the film forming process is the sum of the time T1 required for the transfer operation and the time T2 required for pressure adjustment (T1 + T2).

  On the other hand, in the present embodiment, the pressure in the film forming chamber 20 is increased during the transfer period from opening the gate valve G2 to transferring the unprocessed substrate W1 from the load lock chamber 10 to the film forming chamber 20 and closing the gate valve G2. A pressure adjusting gas (N 2 gas) for setting the film forming pressure (100 Pa) was introduced into the film forming chamber 20. In the example shown in FIG. 5, (transportation time T1)> (pressure adjustment time T2) is described. However, the time T1 in the case of the apparatus having the two-stage load lock chamber 10 as shown in FIG. , T2 shows an example in which the transport time T1 is about 40 seconds, while the pressure adjustment time T2 is about 20 seconds, which is shorter than the transport time T1. Therefore, the time from the start of the transfer operation to the start of the film forming process in this embodiment is the sum (T1 + T3) of the transfer time T1 and the time T3 required for gas replacement. In addition, compared with the case where the gas is replaced with the same pressure, the pressure adjustment until the pressure is stably increased to 100 Pa by introducing the gas is generally longer. T3) <(pressure adjustment time T2). That is, when the required time from the start of the transfer operation to the start of the film forming process is compared, the difference ΔT between (conventional required time) and (required time in the present embodiment) is ΔT = T2−T3, and the difference ΔT It can be seen that the time from the start of the transfer operation to the start of the film formation process can be shortened. That is, it is possible to shorten the processing time from the loading of the unprocessed substrate into the film forming apparatus 1 until the film forming process is performed on the unprocessed substrate and the unprocessed substrate is unloaded from the film forming apparatus 1. 1 throughput (a production amount per unit time) can be improved.

  As shown in FIG. 5, in the above-described embodiment, nitrogen (N 2) gas is introduced when adjusting the pressure during the transfer operation, and the gate between the load lock chamber 10 and the film formation chamber 20 is introduced. After the valve G2 was closed, the gas was replaced with the mixed gas. This is the result of such processing from the viewpoint of safety. For example, when pressure adjustment is performed using a mixed gas from the beginning, oxygen in the atmosphere reacts rapidly with silane contained in the mixed gas when the load lock chamber 10 is opened to the atmosphere for unloading and loading. The problem will arise.

  Therefore, if the film forming apparatus uses a material gas that does not cause a problem when released to the atmosphere, the pressure may be adjusted using a mixed gas from the beginning. In this case, since the gas replacement operation as shown in FIG. 5 is not required, the time from the start of the transfer operation to the start of the film forming process can be further shortened from T1 + T3 to T1.

  In the embodiment described above, the load lock chamber 10 is provided with two transport mechanisms 100A and 100B as shown in FIG. 1, but the present invention is similarly applied even when only one transport mechanism is provided. Can be applied. In that case, a transport mechanism that simultaneously transports the processed substrate W1 and the unprocessed substrate W0 is provided. Further, as shown in FIG. 7, the present invention is also applicable to a film forming apparatus having a configuration in which a load lock chamber and an unload chamber 40 are provided on both sides of the film forming chamber and the processed substrate W1 is transferred to the unload chamber 40. it can. The unload chamber 40 is provided with a gate valve G4 for carrying out, a vacuum pump P3 and a valve V5 for evacuation, and a valve V4 for gas purging.

  In any case, if the transfer time required to transfer the unprocessed substrate W0 to the film forming chamber is T10, if T10> T2, the required time in the conventional case is T10 + T2, and the transfer operation is performed as described above. The time required for performing the pressure adjustment operation in parallel is T10 + T3.

  Further, when T10 <T2, as shown in FIG. 8, when the transfer operation is completed, the gate valve G2 is closed even if the pressure adjustment is not completed, and the gas replacement with the mixed gas is started immediately. The pressure adjustment up to 100 Pa may be performed. By performing such control, even when T10 <T2, the time from the start of the transfer operation to the start of the film formation process can be reliably shortened.

  As described above, in the film forming apparatus of the present invention described above, the film forming chamber 20 in which the film forming process is performed on the substrate using the film forming gas (mixed gas), and the film forming in the film forming chamber 20 are performed. A film forming gas introducing means (for example, mass flow controllers 204A to 204C) for introducing a working gas, a substrate preparation chamber (for example, the load lock chamber 10) in which a substrate W0 to be transferred to the film forming chamber 20 is prepared, The gate valve G2 for partitioning between the film chamber 20 and the substrate preparation chamber, and the pressure adjustment during the transfer period from opening the gate valve G2 to transferring the substrate from the substrate preparation chamber to the film formation chamber 20 and closing the gate valve G2. And adjustment gas introduction means (for example, a mass flow controller 204A) for introducing a working gas (for example, N 2 gas) into the film forming chamber 20. By introducing such a pressure adjusting gas, the pressure in the film forming chamber 20 is increased during the transfer period, so that the time required for raising the pressure in the film forming chamber to be increased to the pressure during film formation can be shortened. . As a result, the time from the start of the transfer operation to the start of the film forming process is shortened as compared with the prior art, and the throughput (production amount per unit time) of the film forming apparatus can be improved.

  Further, when the substrate W0 is transported to the film forming chamber 20 and the gate valve G2 is closed, the introduction of the pressure adjusting gas by the adjusting gas introducing means (for example, the mass flow controller 204A for introducing N 2 gas) is stopped. You may make it provide the control apparatus 30 which starts the introduction of the gas for film-forming by the film gas introduction means (for example, mass flow controllers 204A-204C for introducing mixed gas). Safety can be improved by using a gas that is safe even if released into the atmosphere as the pressure adjusting gas.

  Further, if the film forming gas used for film formation is a safe gas even when released into the atmosphere, the film forming gas may be used as the pressure adjusting gas.

  Furthermore, it is preferable to stop the vacuum evacuation of the substrate preparation chamber by the vacuum evacuation apparatus when the pressure evacuation apparatus for evacuating the substrate preparation chamber and the introduction of the pressure adjusting gas to the film forming chamber by the pressure adjusting means. As a result, the pressure increase in the film forming chamber is accelerated, and the time from the start of the transfer operation to the start of the film forming process is further shortened.

  Each of the embodiments described above may be used alone or in combination. This is because the effects of the respective embodiments can be achieved independently or synergistically. In addition, the present invention is not limited to the above embodiment as long as the characteristics of the present invention are not impaired.

  1: film forming apparatus, 10: load lock chamber, 20: film forming chamber, 30: control device, 40: unload chamber, 100A to 100C: transfer mechanism, 101: cart, 204A to 204C: mass flow controller, G1 G4: Gate valve, P1-P3: Vacuum pump, V1-V5: Valve, W0: Untreated substrate, W1: Treated substrate

Claims (5)

A film forming chamber in which a film forming process is performed on the substrate using a film forming gas;
A film forming gas introducing means for introducing the film forming gas into the film forming chamber;
A substrate preparation chamber in which a substrate for transporting to the film formation chamber is prepared;
A gate valve that partitions the film formation chamber and the substrate preparation chamber;
During the transfer period from opening the gate valve to transferring the substrate from the substrate preparation chamber to the film formation chamber and closing the gate valve, a pressure adjusting gas is introduced into the film formation chamber. Adjusting gas introduction means for increasing the pressure to the pressure during film formation ,
A film forming apparatus in which a film forming process is performed in the film forming chamber after the gate valve is closed . In the film-forming processing apparatus of Claim 1,
When the substrate is transported to the film forming chamber and the gate valve is closed, the gas for stopping the introduction of the pressure adjusting gas by the adjusting gas introducing means and starting the introduction of the film forming gas by the film forming gas introducing means A film forming apparatus, further comprising a control means. In the film-forming processing apparatus of Claim 1,
A film forming apparatus using the film forming gas as the pressure adjusting gas. In the film-forming processing apparatus as described in any one of Claims 1 thru | or 3,
An evacuation apparatus for evacuating the substrate preparation chamber;
Exhaust gas control means for stopping vacuum exhaust of the substrate preparation chamber by the vacuum exhaust device when the pressure adjusting gas is introduced into the film forming chamber by the adjustment gas introducing means. Membrane processing equipment. A film forming chamber in which a film forming process is performed on the substrate using a film forming gas, a substrate preparing chamber in which a substrate to be transported to the film forming chamber is prepared, the film forming chamber, and the substrate preparing chamber; A film formation method in a film formation processing apparatus provided with a gate valve for partitioning,
A transfer step of opening the gate valve to transfer the substrate from the substrate preparation chamber to the film formation chamber and closing the gate valve;
A film forming process step of introducing the film forming gas into the film forming chamber and forming a film on the substrate;
In the transfer process from the opening of the gate valve to the closing of the gate valve, a pressure adjusting process for introducing a pressure adjusting gas into the film forming chamber and increasing the pressure in the film forming chamber to a film forming pressure. A film forming method characterized by being performed.

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