JP4570748B2 - Gas processing apparatus and collective valve used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas processing apparatus that performs gas processing such as CVD film formation and a collective valve used therefor.
[0002]
[Prior art]
In a semiconductor manufacturing process, W (tungsten) or WSi (tungsten silicide) is used to form a wiring pattern on a semiconductor wafer (hereinafter simply referred to as a wafer) as an object to be processed or to fill a hole between wirings. , Ti (titanium), TiN (titanium nitride), TiSi (titanium silicide) or the like is deposited to form a thin film.
[0003]
Among these, the WSi film has, for example, WF as a processing gas.₆(Tungsten hexafluoride) and SiH₄(Silane) or SiH₂Cl₂(Dichlorosilane).
[0004]
Then, when forming the WSi film, the processing gas is carried by a carrier gas and introduced into the chamber, and the processing gas is reacted by heating the wafer in the chamber. At this time, in the initial stage, WF₆The film quality is improved by strictly controlling the flow rate of the film to form a desired nucleation film. For this reason, the WF for a nucleation film capable of strictly controlling the flow rate₆Gas line and normal WF₆A gas line is provided.
[0005]
[Problems to be solved by the invention]
However, when these gas lines are switched, the WF is located on the downstream side of the valve of the conventional gas line.₆When the gas remains and the remaining amount is large, the residual gas is sucked out by the carrier gas, and the processing gas outside the control is supplied into the chamber, and the formed film has the required film quality. It may not be possible.
[0006]
The present invention has been made in view of such circumstances, and when the supply of the processing gas from the processing gas line is stopped, the gas processing apparatus capable of reducing the amount of the processing gas flowing out from the processing gas line, and the same An object is to provide a collective valve to be used.
[0007]
[Means for Solving the Problems]
As a result of repeated studies to solve the above problems, the present inventors have determined that the amount of the processing gas flowing out from the processing gas line when the supply of the processing gas is stopped is the confluence of the carrier gas line and the processing gas line. It has been found that the smaller the distance from the open / close valve to the processing gas line and the diameter of the processing gas line, that is, the smaller the volume of the portion from the open / close valve of the processing gas line to the junction, the smaller. Further, in order to reduce the volume of the portion from the open / close valve of the processing gas line to the junction point in this way, it is effective to use a collective valve having a structure capable of reducing the gas reservoir on the downstream side of the valve. I found out.
[0008]
  The present invention has been made based on such knowledge,A chamber in which a substrate to be processed is disposed, gas processing is performed on the substrate to be processed, a gas supply system that supplies a gas containing a processing gas into the chamber, and a vacuum pump that maintains the inside of the chamber in a vacuum state. DoA gas treatment device,
  The gas supply system includes:
  A processing gas supply source for supplying the processing gas into the chamber;
A processing gas line for introducing processing gas from the processing gas supply source into the chamber;
A collective valve in which a valve, a filter, and a mass flow controller are integrally arranged and have a part of a processing gas line;
Comprising
  The collective valve isOn the base block, a valve block for accommodating the valve, a filter, and a mass flow controller are arranged in a state of being connected by a joint block, and the processing gas line is arranged in the collective valve in the valve block, the filter, and the mass flow controller. The controller and the joint block are formed in a straight line so as to pass through,
The valve has a valve body accommodated in the valve block, and the valve body is switched between an open state in which the processing gas line passes linearly and a closed state in which the processing gas line is directly blocked. Is possibleThe gas processing apparatus characterized by the above is provided.
[0009]
  In the gas processing apparatus, the gas supply system further includes a carrier gas supply source for supplying a carrier gas for carrier of the processing gas, and a carrier gas line extending from the carrier gas supply source to the chamber, The collective valve may have a valve on the most downstream side, and a portion of the processing gas line that extends downstream from the most downstream valve may join the carrier gas line. The gas supply system further includes another gas line adjacent to the processing gas line for supplying another gas into the chamber, and the other gas line includes at least a valve. A collecting valve may be provided, and the valve of the collecting valve and the valve of the other collecting valve may be configured to allow gas flow. In this case, the valve of the collective valve and the valve of the other collective valve may be connected by a joint block.
[0010]
    AlsoThe present invention relates to a gas processing apparatus for introducing a predetermined processing gas into a chamber and performing a predetermined gas processing on a substrate to be processed in the chamber.Provided in the gas supply system, a valve, a filter, and a mass flow controller are integrally arranged, and has a part of a processing gas line that supplies a processing gas into the chamber.A collective valve,
  On the base block, a valve block for accommodating the valve, a filter, and a mass flow controller are arranged in a state of being connected by a joint block, and the processing gas line includes the valve block, the filter, the mass flow controller, and the joint block. It is formed in a straight line so as to penetrate inside,
The valve has a valve body accommodated in the valve block, and the valve body is switched between an open state in which the processing gas line passes linearly and a closed state in which the processing gas line is directly blocked. Is possibleA collective valve characterized by the above is provided.
[0012]
  In such a collective valve, the valve body of the valve has a gas flow path, and by rotating the valve body, the gas flow path is made to correspond to the processing gas line.The processing gas line is in an open state that penetrates linearly, and the gas flow path is the processingBy shifting from the gas lineClosed to directly shut off the process gas lineIt can be constituted as follows.
[0014]
  Also, The collective valve isSaidBy lowering the disc,Close the process gas line directly.By raising the valve bodyIt is set as the open state which penetrates the said process gas line linearly.It can be constituted as follows.
[0015]
  Furthermore, the collective valve isOf the valveThe valve body has a gas flow path connected to another gas line, andSaidIn it from other linesSaid processingIt can be configured to have another gas flow path for flowing gas to the gas line.
[0016]
  Furthermore, the collective valve isIn addition to the processing gas line, a carrier gas line is formed in a straight line so as to penetrate the valve block, the filter, and the joint block,Of the valveSaidThe disc isThe processing gas line and the carrier gas lineA gas flow path that can be connected is provided, and the valve body can be rotated or moved up and down to switch the gas flow path.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view schematically showing a CVD apparatus according to an embodiment of the present invention, which is for forming a WSi film.
[0021]
As shown in FIG. 1, the CVD apparatus 1 has a chamber 11 formed in a cylindrical shape with aluminum or the like, for example, and a lid 12 is provided thereon. In the chamber 11, a mounting table 15 on which a wafer W is mounted via a holding member 14 is provided on a support member 13 erected from the bottom of the chamber 11. The inner side of the support member 13 in the radial direction is formed so as to reflect heat rays, and the mounting table 15 is made of, for example, a carbon material or ceramics having a thickness of about 2 mm.
[0022]
Below the mounting table 15, for example, three lift pins 16 for lifting the wafer W from the mounting table 15 are provided. The lift pins 16 are supported by a push-up rod 18 via a holding member 17. The push-up bar 18 is connected to the actuator 19. As a result, when the actuator 19 raises and lowers the push-up bar 18, the lift pins 16 move up and down via the push-up bar 18 and the holding member 17, and the wafer W moves up and down. The lift pins 16 are made of a material that transmits heat rays, for example, quartz. Further, a support member 20 is provided integrally with the lift pin 16, and a shield ring 21 is attached to the support member 20. The shield ring 21 has a function of preventing a heat ray of a halogen lamp 26, which will be described later, from being irradiated upward and securing a cleaning gas flow path during cleaning. Further, a thermocouple 22 for measuring the temperature of the wafer W when the wafer W is heated is embedded in the mounting table 15, and a holding member 23 for the thermocouple 22 is attached to the support member 13.
[0023]
A transmission window 24 made of a heat ray transmission material such as quartz is airtightly provided at the bottom of the chamber just below the mounting table 15, and a box-shaped heating chamber 25 is provided below the transmission window 24 so as to surround the transmission window 24. It has been. In the heating chamber 25, for example, four halogen lamps 26 are attached to a rotating table 27 that also serves as a reflecting mirror, and the rotating table 27 is provided at the bottom of the heating chamber 25 via a rotating shaft 28. It is rotated by a rotating motor 29. Therefore, the heat rays emitted from the halogen lamp 26 can pass through the transmission window 24 and irradiate the lower surface of the mounting table 15 to heat it. On the side wall of the heating chamber 25, a cooling air inlet 30 for introducing cooling air for cooling the room and the transmission window 24 and a cooling air outlet 31 for discharging the air are provided.
[0024]
On the outer peripheral side of the mounting table 15, a ring-shaped rectifying plate 32 having a large number of rectifying holes is placed on a water-cooled plate 34 provided at the upper end of a support column 33 formed in an annular shape. A ring-shaped quartz or aluminum attachment 35 is provided on the inner peripheral side of the water-cooling plate 34 to prevent the upper processing gas from flowing downward. An inert gas that does not react with the processing gas, such as nitrogen gas, is supplied as a backside gas to the lower side of the rectifying plate 32, the water cooling plate 34, and the attachment 35 so that the processing gas is placed on the mounting table. Thus, it is possible to prevent an unnecessary film forming action from being caused to wrap around the lower side of 15.
[0025]
In addition, exhaust ports 36 are provided at the four corners of the bottom of the chamber 11, and a vacuum pump (not shown) is connected to the exhaust ports 36. Thereby, the inside of the chamber 11 is, for example, 100 Torr to 10 Torr^-6The vacuum degree of Torr can be maintained.
[0026]
A shower head 40 for introducing a processing gas or the like is provided on the ceiling of the chamber 11. The shower head 40 has a shower base 41 that is formed by fitting to the lid 12, and an orifice plate 42 that allows processing gas or the like to pass therethrough is provided at the upper center of the shower base 41. . Further, two stages of diffusion plates 43 and 44 are provided below the orifice plate 42, and a shower plate 45 is provided below the diffusion plates 43 and 44. A gas introduction member 46 is disposed above the orifice plate 42, and a gas introduction port 47 is provided in the gas introduction member 46. A gas supply system 50 for supplying a processing gas or the like into the chamber 11 is connected to the gas introduction port 47.
[0027]
As shown in FIG. 2, the gas supply system 50 has a WF₆Purge gas (eg N₂Purge gas supply source 51 for supplying gas), WF₆Gas supply source 52, cleaning gas (eg ClF₃Cleaning gas supply source 53 for supplying gas), WF₆Carrier gas supply source 54 for supplying a carrier gas (for example, Ar gas) for carrier gas, SiH₂Cl₂Gas supply source 55, SiH₂Cl₂Purge gas (eg N₂Purge gas supply source 56 for supplying gas), SiH₂Cl₂A carrier gas supply source 57 that supplies a carrier gas (for example, Ar gas) for carrier gas is provided, and a purge gas line 58 is connected to the purge gas supply source 51 with a WF.₆The gas supply source 52 has WF₆The gas line 59 is connected to the cleaning gas supply source 53, the cleaning gas line 61 is connected to the carrier gas supply source 54, and the carrier gas line 62 is connected to the SiH.₂Cl₂The gas supply source 55 includes SiH₂Cl₂A purge gas line 64 is connected to the gas line 63, a purge gas supply source 56 is connected to a purge gas line 64, and a carrier gas supply source 57 is connected to a carrier gas line 65. WF₆A branch line 59 a is connected to the gas line 59. A branch line 65 a is connected to the carrier gas line 65.
[0028]
The purge gas line 58 is provided with two collective valves 66a and 66b, and WF₆The gas line 59 is provided with a collecting valve 67, and WF₆The branch line 59a branched from the gas line 59 is provided with a collecting valve 68, the cleaning gas line 61 is provided with a collecting valve 69, the carrier gas line 62 is provided with a collecting valve 70, and SiH₂Cl₂The gas line 63 is provided with a collecting valve 71, the purge gas line 64 is provided with two collecting valves 72 a and 72 b, the carrier gas line 65 is provided with a collecting valve 73, and a branch line branched from the carrier gas line 65 A collecting valve 74 is provided at 65a.
[0029]
Each collective valve is formed by integrating a plurality of valves and the like. And each collective valve is also comprised integrally, and has a space-saving structure.
[0030]
The collective valve 66a provided in the purge gas line 58 has a check valve 75, an opening / closing valve 76, and a branch block 77 having a branch portion arranged in order from the upstream side, and the collective valve 66b is arranged in order from the upstream side. An on-off valve 78, a branch block 79 having a branch portion, and an on-off valve 80 are arranged. There are joint blocks T between the check valve 75 and the open / close valve 76, between the open / close valve 76 and the branch block 77, between the open / close valve 78 and the branch block 79, and between the branch block 79 and the open / close valve 80, respectively. Is provided.
[0031]
WF₆In the collective valve 67 provided in the gas line 59, an opening / closing valve 81, a three-way valve 82, a filter 83, a mass flow controller 84, a three-way valve 85, and an opening / closing valve 86 are arranged in this order from the upstream side. Joint blocks T are provided between the three-way valve 82 and the filter 83, between the filter 83 and the mass flow controller 84, and between the mass flow controller 84 and the three-way valve 85, respectively.
[0032]
In the collective valve 68 provided in the branch line 59a, an opening / closing valve 87, a three-way valve 88, a filter 89, a mass flow controller 90, a three-way valve 91, and an opening / closing valve 92 are arranged in this order from the upstream side. Joint blocks T are provided between the three-way valve 88 and the filter 89, between the filter 89 and the mass flow controller 90, and between the mass flow controller 90 and the three-way valve 91, respectively.
[0033]
In the collective valve 69 provided in the cleaning gas line 61, an opening / closing valve 93, a three-way valve 94, a filter 95, a mass flow controller 96, a three-way valve 97, and an opening / closing valve 98 are arranged in this order from the upstream side. Joint blocks T are provided between the three-way valve 94 and the filter 95, between the filter 95 and the mass flow controller 96, and between the mass flow controller 96 and the three-way valve 97, respectively.
[0034]
In the collective valve 70 provided in the carrier gas line 62, an open / close valve 99, a filter 100, a mass flow controller 101, and an open / close valve 102 are arranged in this order from the upstream side. Joint blocks T are provided between the opening / closing valve 99 and the filter 100, between the filter 100 and the mass flow controller 101, and between the mass flow controller 101 and the opening / closing valve 102, respectively.
[0035]
SiH₂Cl₂In the collective valve 71 provided in the gas line 63, an opening / closing valve 103, a three-way valve 104, a filter 105, a mass flow controller 106, a three-way valve 107, and an opening / closing valve 108 are arranged in this order from the upstream side. Joint blocks T are provided between the three-way valve 104 and the filter 105, between the filter 105 and the mass flow controller 106, and between the mass flow controller 106 and the three-way valve 107, respectively.
[0036]
In the collective valve 72a provided in the purge gas line 64, a check valve 109, an opening / closing valve 110, and a branch block 111 having a branch portion are arranged in order from the upstream side, and the collective valve 72b is arranged in order from the upstream side. An on-off valve 112, a branch block 113 having a branch portion, and an on-off valve 114 are arranged. Joint blocks T are provided between the check valve 109 and the opening / closing valve 110, between the opening / closing valve 110 and the branch block 111, between the opening / closing block 112 and the branch block 113, and between the branch block 113 and the opening / closing valve 114, respectively. Is provided.
[0037]
In the collective valve 73 provided in the carrier gas line 65, an opening / closing valve 115, a filter 116, a mass flow controller 117, and an opening / closing valve 118 are arranged in this order from the upstream side. Joint blocks T are provided between the opening / closing valve 115 and the filter 116, between the filter 116 and the mass flow controller 117, and between the mass flow controller 117 and the opening / closing valve 118, respectively.
[0038]
On the branch line 65a branched from the carrier gas line 65, an opening / closing valve 119, a filter 120, a mass flow controller 121, and an opening / closing valve 122 are arranged in this order from the upstream side. Joint blocks T are provided between the opening / closing valve 119 and the filter 120, between the filter 120 and the mass flow controller 121, and between the mass flow controller 121 and the opening / closing valve 122, respectively.
[0039]
Further, between the branch block 77 of the collecting valve 66a and the three-way valve 82 of the collecting valve 67, between the three-way valve 82 of the collecting valve 67 and the three-way valve 88 of the collecting valve 68, and between the three-way valve 88 of the collecting valve 68 and the collecting valve. 69, the three-way valve 94 of the collective valve 71, the branch block 111 of the collective valve 72a, the branch block 79 of the collective valve 66b, and the three-way valve 85 of the collective valve 67, and the collective valve 67. Between the three-way valve 85 and the three-way valve 91 of the collecting valve 68, between the three-way valve 91 of the collecting valve 68 and the three-way valve 97 of the collecting valve 69, and the branch block 113 of the three-way valve 107 of the collecting valve 71 and the collecting valve 72b. Joint blocks T are also provided between the two. In FIG. 2, CV is a check valve, V1 is an on-off valve, V2 is a three-way valve, F is a filter, and MFC is a mass flow controller.
[0040]
The purge gas passed through the purge gas line 58 branches from the branch block 77 and branches through the three-way valves 82, 88 and 94, respectively, or from the branch block 79, and passes through the three-way valves 85, 91 and 97, respectively. WF₆The gas line 59, the branch line 59a, and the cleaning gas line 61 can be passed. Further, the purge gas passed through the purge gas line 64 branches from the branch block 111 and branches from the three-way valve 104 or from the branch block 113 and passes through the three-way valve 107 to form SiH.₂Cl₂It is possible to flow to the gas line 63.
[0041]
WF₆The gas line 59 and the branch line 59a merge with the carrier gas line 62 at the downstream portion of the collecting valve. SiH₂Cl₂The gas line 63 joins the carrier gas line 65 at the downstream portion of the collecting valve. The carrier gas lines 62 and 65 and the cleaning gas line 61 are connected to the gas inlet 47 of the chamber 11.
[0042]
Next, of the collective valves provided in each gas line, WF₆The structure of the collective valve 67 provided in the gas line 59 will be described as an example. The collective valves 68, 69, 70, 71, 73, 74 are substantially the same, although there are some differences. FIG. 3 is a cross-sectional view showing the collective valve 67. As described above, the collective valve 67 has the WF₆From the upstream side of the gas line 59, an open / close valve 81, a three-way valve 82, a filter 83, a mass flow controller 84, a three-way valve 85, and an open / close valve 86 are integrally arranged. It is attached. The valve element 133 of the opening / closing valve 81 and the valve element 134 of the three-way valve 82 are accommodated in a common block 131, and the valve element 135 of the three-way valve 85 and the valve element 136 of the opening / closing valve 86 are accommodated in a common block 132. Yes. WF₆The gas line 59 extends through the block 131 and the block 132. The valve element 133 of the on-off valve 81, the valve element 134 of the three-way valve 82, the valve element 135 of the three-way valve 85, and the valve element 136 of the on-off valve 86 are rotated by actuators 138, 139, 140, 141, respectively, to perform the valve operation. It has come to be. At this time, the valve bodies 133, 134, 135, and 136 of each valve directly act on the gas line 59.
[0043]
That is, as shown in FIG. 4, the valve body 133 of the on-off valve 81 has a through hole 133a at a position corresponding to the gas line 59, and the through hole 133a is formed as shown in FIG. By continuing the gas line 59, the valve 81 is opened, and by rotating the valve body 133, the through hole 133a is moved away from the gas line 59 as shown in FIG. As a result, the valve 81 is closed. The on-off valve 86 is similarly configured.
[0044]
Further, as shown in FIG. 5, the valve body 134 of the three-way valve 82 has a through hole 134a at a position corresponding to the gas line 59, and a circumferential groove into which the purge gas from the purge gas line 58 can be introduced. 134b is formed along the outer periphery of the upper portion thereof, and a vertical groove 134c extending downward from the circumferential groove 134b to the position of the gas line 59 is formed. Then, as shown in FIG. 5A, the through-hole 134a is made continuous with the gas line 59, whereby the gas line 59 is connected and the purge gas flow path is closed. When the valve body 134 is rotated from this state, as shown in FIG. 5B, the through hole 134 a is moved away from the gas line 59 and the vertical groove 134 c is connected to the gas line 59. 59 enters a closed state, and the purge gas flows to the gas line 59 through the circumferential groove 134b and the vertical groove 134c. The three-way valve 85 is similarly configured.
[0045]
As described above, the joint blocks T are provided between the three-way valve 82 and the filter 83, between the filter 83 and the mass flow controller 84, and between the mass flow controller 84 and the three-way valve 85, respectively. As shown in FIG. 3, the joint block T is connected to the three-way valve 82, the filter 83, and the like by a bolt B.
[0046]
Further, as shown in FIG. 6, the connection of the three-way valves 82 and 85 between the adjacent collecting valves 67 and 68 is also made by using a bolt by the joint block T having the same structure. The other connecting portions of the adjacent collecting valves are similarly made by the joint block T.
[0047]
As shown in the side view of FIG. 7 (a) and the perspective view of FIG. 7 (b), such a joint block T has notches for inserting bolts into two corner portions on both connection surfaces. The bolt insertion hole 172 is horizontally formed as a through hole from the notch 171. A gas flow hole 173 constituting the gas line 59 is horizontally formed as a through hole.
[0048]
In this embodiment, since the collective valve is designed to directly act on the gas line as described above, the structure is simple. When connecting the elements, for example, the valve and the filter, In addition, it is only necessary to interpose a joint block T having a simple structure only having a gas flow hole constituting the gas line, and the elements can be connected to each other very easily.
[0049]
For the on-off valve, as shown in FIG. 8, the valve body 133 ′ is lowered by the actuator 138 ′, so that the upper opening 145 a of the portion extending vertically upward from the valve body action portion upstream side of the gas line 59. In addition, the upper opening 145b of the portion extending vertically upward from the downstream side of the valve body action portion of the gas line 59 can be directly closed by the valve body 133 ′.
[0050]
Further, as shown in FIG. 9, a recess 146 extending downward from the gas line is formed in the middle of the gas line 59, and the valve body 133 '' is lowered by the actuator 138 '', so that the valve body 133 '' It is also possible to close the gas line 59 by fitting the tip portion into the recess 146.
[0051]
When the WSi film is formed on the surface of the wafer W by the CVD apparatus 1 configured as described above, first, a gate valve (not shown) provided on the side wall of the chamber 11 is opened, and the inside of the chamber 11 is formed by the transfer arm. Then, the wafer W is transferred to the lift pin 16 by pushing up the lift pin 16, and the lift pin 16 is pushed down by lowering the push-up bar 18 to place the wafer W on the mounting table 15.
[0052]
Next, the inside atmosphere is sucked and exhausted from the exhaust port 36 to set the inside of the chamber 11 to a value within a predetermined vacuum level, for example, 13.3 to 10640 Pa (0.1 to 80 Torr). WF, which is a processing gas, enters the chamber 11 from the supply system 50 through the shower head 40.₆Gas and SiH₂Cl₂Gas is introduced, and simultaneously, the halogen lamp 26 in the heating chamber 25 is turned on while rotating, and the mounting table 15 is irradiated with heat rays from the halogen lamp 26. Thereby, a predetermined reaction occurs and a WSi film is formed on the wafer W.
[0053]
Next, supply of the processing gas by the gas supply system 50 will be described in detail.
As described above, when the processing gas is supplied from the gas supply system 50, the carrier gas, for example, Ar gas is supplied from the carrier gas supply source 54 to the carrier gas line 62, and then the WF is first supplied.₆WF for new creation while strictly controlling the flow rate from the gas supply source 52 with the high-precision mass flow controller 90 of the collecting valve 68₆Gas WF₆While flowing from the gas line 59 to the branch line 59a, a carrier gas such as Ar gas is allowed to flow from the carrier gas supply source 57 to the carrier gas line 65, while SiH₂Cl₂SiH which is the other processing gas from the gas supply source 55₂Cl₂Gas is SiH₂Cl₂Flow in gas line 63. WF from branch line 59a₆The gas joins the carrier gas line 62 and is carriered by the carrier gas.₂Cl₂SiH from gas line 63₂Cl₂The gas joins the carrier gas line 65 and is carriered by the carrier gas, and both are supplied into the chamber 11 through the shower head 40.
[0054]
After a predetermined time has elapsed, each valve of the collecting valve 68 of the branch line 59a is closed, and the WF to the branch line 59a is closed.₆Gas supply is stopped, WF instead₆Each valve of the collective valve 67 of the gas line 59 is opened, and the WF has a higher flow rate than at the time of new creation₆Gas is WF₆The gas line 59 merges with the carrier gas line 62.
[0055]
After the film forming gas is supplied into the chamber 11 and the film forming process is completed in this way, the purge gas sources 51 and 56 supply N as a purge gas.₂Gas, WF₆Gas line 59, branch line 59a, SiH₂Cl₂These gases are purged by flowing to the gas line 63, and then ClF as a cleaning gas is passed from the cleaning gas supply source 53 through the cleaning gas line 61.₃Is supplied into the chamber 11 for cleaning, and then the purge gas is supplied from the purge gas supply source 51 to the cleaning gas line 61 to purge the cleaning gas and prepare for the next processing.
[0056]
In such a film forming process, as described above, WF₆Gas WF from branch line 59a for new creation₆When switching to the gas line 59, the downstream side of the collecting valve 68 of the branch line 59a has a WF₆Gas remains, and the residual gas is sucked out by the carrier gas. The amount of the sucked-out gas is determined from the junction of the carrier gas line 62 and the branch line 59a to the most downstream valve (of the collecting valve 68). The smaller the distance to the valve 92) and the diameter of the branch line 59a that is the processing gas line, that is, the smaller the volume of the portion from the valve 92 on-off valve on the most downstream side of the branch line 59a that is the processing gas line to the junction point. Few. Therefore, the distance from the junction of the carrier gas line 62 and the branch line 59a, which is the processing gas line, to the valve of the branch line 59a and the diameter of the processing gas line are made as short and narrow as possible, and the processing gas is closed when the valve is closed. The amount of processing gas remaining in the line is set to be equal to or less than a predetermined value that does not affect the film formation.
[0057]
Hereinafter, simulation results that have led to such a conclusion will be described.
A simulation was performed using the structure of the joining portion of the processing gas line and the carrier gas line as shown in FIG. The length of the processing gas line 200 downstream of the valve 202 was set to 10 cm and 20 cm, and the tube diameters of the processing gas line 200 and the carrier gas line 201 were set to φ6 mm and φ12 mm. The supply of the processing gas was interrupted by the valve 202, and the processing gas remained in the portion of the processing gas line 200 on the downstream side of the valve 202. In the structure of FIG. 10, when the valve 83 on the processing gas line side is closed and only the carrier gas is allowed to flow, the portion immediately below the valve of the processing gas line (point B in the figure) and the merging point of the two lines (point A in the figure) The residual concentration of the processing gas after elapse of a certain period of time was determined by simulation with carrier gas flow rates of 0.005, 0.05, 0.25, 0.5 L / min. For simulation, FULLENT, a general-purpose analysis program, was used.
[0058]
Examples of analysis charts used at that time are shown in FIGS. FIG. 11 shows a case where the length (hereinafter referred to as line length) from the valve 202 of the processing gas line 200 to the merging point is changed. (A) is when the line length is 10 cm, and (b) is when the length is 20 cm. is there. FIG. 12 shows the case where the tube diameter of the processing gas line 200 is changed. FIG. 12A shows the case where the tube diameter is 6 mm, and FIG. 12B shows the case where the tube diameter is 12 mm. In the actual chart, the gas concentration is indicated by color, so that the concentration distribution can be clearly understood.
[0059]
A summary of the simulation results is shown in FIGS. FIG. 13 and FIG. 14 show the remaining amount of the processing gas when the carrier gas flow rate is changed by comparing the line lengths of 10 cm and 20 cm. FIG. 13 shows the processing gas remaining concentration at the point A. FIG. Indicates the residual concentration of the processing gas at point B. 15 and 16 show the processing gas residual concentration when the carrier gas flow rate is changed in comparison with the tube diameters φ6 mm and φ12 mm, and FIG. 15 shows the processing gas residual concentration at point A. FIG. 16 shows the process gas residual concentration at point B. FIG.
[0060]
From FIG. 13 and FIG. 14, it can be seen that the remaining amount of the processing gas increases in proportion to the increase in the line length regardless of the flow rate of the carrier gas.
[0061]
On the other hand, FIG. 15 and FIG. 16 show that the remaining concentration of the processing gas is higher when the pipe diameter is larger, regardless of the flow rate of the carrier gas. Further, when the tube diameter is φ6 mm, the residual concentration of the processing gas is less dependent on the carrier gas flow rate. In particular, when the carrier gas is 0.1 L / min or more, there is almost no dependency on the carrier gas flow rate. It can be seen that the dependency of the residual concentration of the processing gas on the carrier gas flow rate is high at the portion where the carrier gas is small.
[0062]
From the above, (1) the processing gas residual concentration after closing the valve of the processing gas line can be kept low as the line length is shortened, and (2) the thinner the tube diameter, The processing gas residual concentration can be kept low, and (3) when the tube diameter is φ6 mm or less, the carrier gas has a flow rate dependency of 0.1 L / min or more, and therefore the carrier gas flow rate can be optimized. Can guide you.
[0063]
From the above (1) and (2), the processing gas residual concentration of the processing gas line is smaller as the distance from the confluence of the carrier gas line and the processing gas line to the valve of the processing gas line and the diameter of the processing gas line are smaller. In other words, it can be said that the smaller the volume of the portion from the valve of the processing gas line to the above-mentioned confluence, the smaller the volume.
The amount of processing gas that is sucked out of the processing gas line into the carrier gas and flows out increases when the processing gas residual concentration in the processing gas line is high, that is, as the processing gas residual amount is large. It is derived that the outflow amount of the processing gas can be reduced as the distance from the confluence of the gas and the processing gas line to the valve of the processing gas line and the diameter of the processing gas line are shortened and made narrower. Therefore, it is derived that the processing gas line may be set to be short and narrow until the amount of the processing gas flowing out from the processing gas line when the valve is closed becomes equal to or less than a predetermined value that does not cause a problem for processing. Further, from the above (3), it can be seen that the diameter of the processing gas line may be set to φ6 mm or less in order to eliminate the dependency of the processing gas outflow amount on the carrier gas.
[0064]
Further, in order to reduce the amount of the processing gas flowing out from the processing gas line as described above, it is necessary to reduce the volume of the portion from the opening / closing valve of the processing gas line to the junction point. As described above, a collective valve in which a plurality of valves are gathered is provided in the process gas line, and the collective valve is configured such that the valve body of each valve directly acts on the process gas line.
[0065]
In a conventional collective valve, the gas pipe extends into the valve body, and the valve is turned on and off in the valve body. Therefore, the pipe length in the collective valve is long, and the carrier gas is supplied from the valve. The distance from the line to the process gas line to the junction is also increased, and as a result, the volume of the portion from the open / close valve of the process gas line to the junction is increased. On the other hand, if the collective valve is configured such that the valve body of each valve acts directly on the processing gas line as described above, the distance from the valve to the junction of the carrier gas line and the processing gas line is minimized. Thus, the volume of the portion from the open / close valve of the processing gas line to the junction can be reduced.
[0066]
In the gas supply system 50, it is necessary to switch the gas in order to cause the purge gas to flow into the processing gas line. However, it is also possible to open / close and switch the two lines of the purge gas and the processing gas using the collective valve. it can. The example of the valve | bulb integrated in the collective valve in that case is demonstrated based on FIG. 17 and FIG.
[0067]
The valve 150 shown in FIG. 17 is configured such that the valve body 151 is rotatable by an actuator 154, and two lines of gas lines 152 and 153 are formed in the block 131 '. A through hole 151 a is formed in the valve body 151 at a position corresponding to the gas line 152, and a through hole 151 b is formed at a position corresponding to the gas line 153. Further, a groove 151 c through which gas can flow from the gas line 152 to the gas line 153 is formed on the surface of the valve body 151.
When the gas line 152 is used as the purge gas and the gas line 153 is used as the processing gas line, the through holes 151a and 151b correspond to the gas lines 152 and 153, respectively, in the state of FIG. The purge gas flows through the gas line 152 and the processing gas flows through the gas line 153. As shown in FIG. 17B, when the groove 151c is positioned to connect the gas line 152 and the gas line 153, Purge gas can flow through gas line 153. The supply of both gases can also be stopped by setting the valve body to the intermediate position. In addition, when it is necessary to flow gas from the gas line 153 to the gas line 152, the valve body 151 may be further rotated so that the groove 151c is connected in reverse.
[0068]
A valve 160 shown in FIG. 18 is configured such that a valve body 161 can be moved up and down by an actuator 164, and two lines of gas lines 162 and 163 are formed in a block 131 ″. A through hole 161 a is formed in the valve body 161 at a position corresponding to the gas line 162, and a through hole 161 b is formed at a position corresponding to the gas line 163. Further, a groove 161 c through which gas can flow from the gas line 162 to the gas line 163 is formed on the surface of the valve body 161. When the gas line 162 is used as the purge gas and the gas line 163 is used as the processing gas line, the through holes 161a and 161b correspond to the gas lines 162 and 163, respectively, in the state of FIG. The purge gas flows through the gas line 162 and the processing gas flows through the processing gas line 163. However, as shown in FIG. 18B, when the groove 161c is positioned to connect the gas line 162 and the gas line 163, , Purge gas can be flowed into the process gas line 163. The supply of both gases can also be stopped by setting the valve body to the intermediate position. Further, when it is necessary to flow gas from the gas line 163 to the gas line 162, a groove extending from the gas line 163 to the gas line 162 may be further formed at a position having a different height.
[0069]
The present invention can be variously modified without being limited to the above embodiment. For example, in the above-described embodiment, the present invention is defined as the WSi CVD film formation. However, the present invention is not limited to this, and the present invention can be applied to CVD film formation of other materials such as W, Ti, TiN, and the like. It can also be applied to other gas treatments. Further, the substrate to be processed is not limited to a wafer, and may be another substrate. Furthermore, although Ar gas is exemplified as the carrier gas, the present invention is not limited to this, and other inert gas may be used.₃, N₂It may function as a part of the processing gas, such as an inorganic gas such as O or NO, or an organic gas such as a vaporized or evaporated organic solvent.
[0070]
【The invention's effect】
As described above, according to the present invention, the amount of the processing gas flowing out from the processing gas line depends on the distance from the junction of the carrier gas line and the processing gas line to the opening / closing valve of the processing gas line and the processing gas line. Based on the result that the smaller the diameter, that is, the smaller the volume of the portion from the open / close valve of the processing gas line to the confluence, the smaller the diameter of the processing gas line from the confluence of the carrier gas line and the processing gas line. Since the distance to the on-off valve and the diameter of the processing gas line are set so as to be short and narrow so that the processing gas flowing out from the processing gas line when the on-off valve is closed is less than or equal to a predetermined value, processing from the processing gas line When the gas supply is stopped, the outflow amount of the processing gas from the processing gas line can be surely reduced. In addition, a collective valve in which a plurality of valves are gathered is provided in the process gas line, and the collective valve is configured so that the valve body of each valve directly acts on the process gas line, so that the process gas from the process gas line is configured. The amount of outflow can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a CVD apparatus according to an embodiment of the present invention.
2 is a schematic configuration diagram showing a gas supply system used in the CVD apparatus of FIG.
FIG. 3 is a cross-sectional view showing the structure of a collective valve used in a gas supply system.
FIG. 4 is a cross-sectional view for explaining the structure and operation of an on-off valve applied to the collective valve.
FIG. 5 is a cross-sectional view for explaining the structure and operation of a three-way valve applied to the collective valve.
FIG. 6 is a cross-sectional view for explaining a state where three-way valves are connected by joint blocks between adjacent collecting valves.
7A and 7B are a side view and a perspective view for explaining the structure of the joint block.
FIG. 8 is a cross-sectional view showing another example of an open / close valve applied to the collective valve.
FIG. 9 is a cross-sectional view showing still another example of an on-off valve applied to the collective valve.
FIG. 10 is a schematic diagram showing the conditions of simulation leading to the present invention.
FIG. 11 is a chart showing simulation results.
FIG. 12 is a chart showing simulation results.
FIG. 13 is a graph showing the processing gas residual concentration at point A when the carrier gas flow rate is changed based on the simulation results in comparison with line lengths of 10 cm and 20 cm.
FIG. 14 is a graph showing the processing gas residual concentration at point B when the carrier gas flow rate is changed based on the simulation results in comparison with line lengths of 10 cm and 20 cm.
FIG. 15 is a graph showing the treatment gas residual concentration at point A when the carrier gas flow rate is changed based on the simulation results in comparison with the tube diameters φ6 mm and φ12 mm.
FIG. 16 is a graph showing the treatment gas residual concentration at point B when the carrier gas flow rate is changed based on the simulation results in comparison with the tube diameters φ6 mm and φ12 mm.
FIG. 17 is a cross-sectional view for explaining the structure and operation of a valve incorporated in a collective valve capable of opening / closing and switching two lines.
FIG. 18 is a cross-sectional view for explaining the structure and operation of another example of a valve incorporated in a collective valve capable of opening / closing and switching two lines.
[Explanation of symbols]
11; chamber
15: Mounting table
40; shower head
50; gas supply system
59; WF₆Gas line (processing gas line)
59a; branch line (processing gas line)
62,65; Carrier gas line
66a, 66b, 67, 68, 69, 70, 71, 72a, 72b, 73, 74; collective valve
133, 133 ', 133' ', 134, 151, 161; valve body
T: Joint block
W: Semiconductor wafer

Claims (9)

A chamber in which a substrate to be processed is disposed, gas processing is performed on the substrate to be processed, a gas supply system that supplies a gas containing a processing gas into the chamber, and a vacuum pump that maintains the inside of the chamber in a vacuum state. A gas processing device that performs
The gas supply system includes:
A processing gas supply source for supplying the processing gas into the chamber;
A processing gas line for introducing processing gas from the processing gas supply source into the chamber;
A collective valve in which a valve, a filter, and a mass flow controller are integrally arranged and have a part of a processing gas line;
Comprising
The collective valve is arranged on a base block in a state in which a valve block that accommodates the valve, a filter, and a mass flow controller are connected by a joint block, and the processing gas line is arranged in the collective valve in the valve block, It is formed in a straight line so as to penetrate the filter, the mass flow controller, and the joint block,
The valve has a valve body accommodated in the valve block, and the valve body is switched between an open state in which the processing gas line passes linearly and a closed state in which the processing gas line is directly blocked. A gas processing apparatus capable of being used. The gas supply system further includes a carrier gas supply source for supplying a carrier gas for carrier of the processing gas, and a carrier gas line extending from the carrier gas supply source to the chamber,
  2. The collecting valve has a valve on the most downstream side, and a portion extending downstream from the most downstream valve of the processing gas line joins the carrier gas line. The gas processing apparatus as described in. The gas supply system further includes another gas line adjacent to the processing gas line for supplying another gas into the chamber, and the other gas line has at least another valve. The gas processing apparatus according to claim 1, wherein the valve of the collective valve and the valve of the other collective valve are configured to allow gas flow. The gas processing device according to claim 3, wherein the valve of the collective valve and the valve of the other collective valve are connected by a joint block. Provided in a gas supply system in a gas processing apparatus that introduces a predetermined processing gas into the chamber and performs predetermined gas processing on the substrate to be processed in the chamber, and a valve, a filter, and a mass flow controller are integrally arranged, and the chamber A collecting valve having a part of a processing gas line for supplying a processing gas therein ,
On the base block, a valve block for accommodating the valve, a filter, and a mass flow controller are arranged in a state of being connected by a joint block, and the processing gas line includes the valve block, the filter, the mass flow controller, and the joint block. It is formed in a straight line so as to penetrate inside,
The valve has a valve body accommodated in the valve block, and the valve body is switched between an open state in which the processing gas line passes linearly and a closed state in which the processing gas line is directly blocked. A collective valve characterized by being possible . Said valve body of said valve has a gas flow path by rotating the valve body, and an open state for passing said processing gas line linearly by matching the gas flow passage into the processing gas line, wherein 6. The collective valve according to claim 5 , wherein a closed state in which the processing gas line is directly shut off by shifting a gas flow path from the processing gas line. By lowering the valve body of the valve, and a closed state for blocking the processing gas line directly, characterized by an open state for passing said processing gas line linearly by increasing the valve element The collective valve according to claim 5 . Said valve body of said valve claims characterized by having another has a gas flow path leading from the gas line, and the processing other gas flow path for flowing a gas into the gas line therein from the other lines Item 7. The collective valve according to Item 6 . In addition to the processing gas line, a carrier gas line is formed in a straight line so as to penetrate the valve block, the filter, and the joint block,
Wherein the valve body of the valve has a gas passage capable of connecting the said carrier gas line and the process gas line, the rotation or by lifting the valve body, and characterized in that for switching the gas flow path The collective valve according to claim 5 .

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