JP2007042890A - Substrate treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily assemble a shower head while uniformly supplying the inside of a treating chamber with a treating gas. <P>SOLUTION: A substrate treatment apparatus has a reaction chamber for treating a substrate, and the shower head 236 for supplying the inside of the reaction chamber with a raw material gas (the treating gas) G1 and radicals (the treating gas) G2 in a shower shape. The shower head 236 has a plurality of disks A1, A2 and A3 with a plurality of ports (through-holes) C1 and C2. Parts of a plurality of the ports C1 or C2 in at least the adjacent disks in a plurality of the disks A1, A2 and A3 are made mutually to communicate by at least one bolts (tubular members) B with communicating holes D. At least one end of the bolts B is formed in a screwable manner, and the bolts B are screwed to parts of a plurality of at least one ports C of the adjacent disks A1 and A2 or A2 and A3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus including a shower head that supplies a processing gas into a processing chamber in a shower shape.

  As a thin film deposition method used in one process of manufacturing a semiconductor device, there is chemical vapor deposition (CVD) using a chemical reaction. In the case of CVD using thermal energy, there are cases where the reaction in the gas phase becomes dominant and the reaction on the substrate surface becomes dominant. It can be said that the step coverage characteristic is better when the reaction on the substrate surface is more dominant.

In ordinary CVD, two or more kinds of processing gases, which are raw materials for forming a reaction-prone film, are mixed in the shower head and supplied to the substrate, so that the reaction in the gas phase becomes dominant. There are many. As a result, the characteristics of the step coverage may be deteriorated, or a product generated by the reaction in the gas phase may become a particle source and contaminate the thin film formed on the substrate.
In CVD using a cyclic method (cyclic CVD), a source gas for forming a film (usually a mixed source gas) and active oxygen for removing the contamination of the formed thin film are alternately supplied. Thus, a thin film with less contamination than ordinary CVD is formed.
In ALD, a plurality of source gases are alternately supplied one by one, the source is adsorbed on the substrate in units of one atomic layer, and film formation is performed using a surface reaction. For this reason, the step coverage characteristic is superior to CVD.

  As described above, in the normal CVD, it is necessary to prevent gas from being mixed in the shower head in order to improve the step coverage characteristics and form a thin film with little contamination. Further, even in cyclic CVD, since the source gas and the active oxygen are likely to react, mixing of these gases in the shower head should be avoided. Even in the case of ALD, it is necessary to avoid gas mixing in the shower head because the gas supplied in advance may remain in the shower head.

  For this reason, in a substrate processing apparatus for forming a film using a conventional shower head, the shower head is partitioned so that a plurality of types of gases are not mixed in the shower head, regardless of which thin film deposition method is used. I have to. The partitioning method here is to partition the shower head into a plurality of directions (for example, in the left-right direction) intersecting the gas introduction direction by the partition plate, thereby separating and flowing a plurality of types of gas in the shower head. I am doing so.

  However, when the shower head is partitioned by the partition plate in the direction intersecting with the gas introduction direction, each gas flows spatially and ubiquitously in the shower head. It was difficult to supply.

  Therefore, in order to solve the problem of uneven gas supply, a plurality of types of gases flow separately from each other in the shower head, but need to flow without being ubiquitous with each other. To that end, it is conceivable to configure the shower head as follows.

A plurality of chambers are provided by dividing the inside of the shower head into a plurality of directions in which the gas flows. For example, when two upper and lower chambers are provided, the shower head is partitioned by an upper plate into which gas is introduced, an intermediate plate through which gas passes, and a lower plate from which gas is led out, and the shower head is divided into an upper chamber and a lower chamber. Divide into Further, a plurality of through holes are provided in each of the upper plate, the middle plate, and the lower plate. The through holes of each plate communicate with each other through a cylindrical pipe as follows.
In the upper chamber, among a plurality of through holes of the upper plate and the middle plate, corresponding ones of the through holes are communicated with each other by one cylindrical pipe. In the lower chamber, the through holes that are not communicated by the cylindrical pipe in the middle plate of the upper chamber and the through holes of the lower plate corresponding to the through holes are communicated by a plurality of cylindrical pipes. Since there is no connecting means in the cylindrical pipe, adjacent plates are connected by welding via this cylindrical pipe.
Gas entering the upper chamber from the through hole of the upper plate that is not connected to the cylindrical pipe is dispersed in the upper chamber and is connected to the through holes of the middle plate and the lower plate through the plurality of cylindrical pipes. And is supplied into the processing chamber as a shower from a plurality of through holes in the lower plate connected to the cylindrical pipe. Gas entered from the cylindrical pipe connected to the through hole of the upper plate bypasses the upper chamber, enters the lower chamber, is dispersed in the lower chamber, and has a plurality of through holes in the lower plate to which the cylindrical pipe is not connected ( The remaining through-holes) are supplied into the processing chamber as a shower.
Therefore, the two kinds of processing gases are not mixed in the shower head, and each gas is not spatially ubiquitous in the shower head, and flows in a mixed manner while being separated. It is thought that it becomes possible to supply evenly into the processing chamber from the shower head.

  However, in the assumed technology described above, it is necessary to connect the respective plates constituting the shower head by welding with a cylindrical pipe, and there is a problem that it takes time to assemble the shower head.

  An object of the present invention is to provide a substrate processing apparatus that can easily assemble a shower head while eliminating the above-described problems of the prior art and supplying a processing gas evenly into a processing chamber.

  1st invention has the process chamber which processes a board | substrate, and the shower head which supplies process gas into the said process chamber in shower shape, The said shower head has several board | plates which have several through-holes A part of a plurality of through holes of at least adjacent plates among the plurality of plates are communicated with each other by at least one tubular member, and at least one end of the tubular member is formed so as to be screwed. A substrate processing apparatus, wherein the substrate processing apparatus is screwed into a part of at least one of the plurality of through holes.

  The processing gas introduced into the through hole that is not communicated with the tubular member flows between the adjacent plates from one through hole of the adjacent plate, passes through the through hole of the other plate of the adjacent plate, and then enters the processing chamber. Supplied. Since the processing gas introduced into the through-hole communicated with the tubular member passes through the tubular member, it is separated from the processing gas flowing between the adjacent plates through the through-hole not communicated with the tubular member, After passing through the through-hole communicated with the tubular member of the other plate of the adjacent plates, it is supplied into the processing chamber. Therefore, between the adjacent plates, the processing gas passing through the tubular member and the processing gas not passing through the tubular member are not mixed in the shower head.

In addition, since a part of the plurality of through holes of the adjacent plates are communicated with each other by a tubular member, the processing gas is arranged in a space compared to the case where the processing gas is separated by ubiquitously dividing the shower head. Therefore, the gas can be supplied into the processing chamber while being separated, so that the processing gas can be evenly supplied from the shower head into the processing chamber.
Further, since at least one end of the tubular member is connected to the plate by screwing it into the through-hole, the assembling work of the shower head is easier as compared with the case where both ends of the tubular member are connected by welding.

  2nd invention has the process of carrying in a board | substrate in a process chamber, and the some board which has several through-holes, and at least some of the several through-holes of the board adjacent at least among these boards are at least. A processing gas is supplied into the processing chamber via a shower head that is communicated by one tubular member and one end of the tubular member is screwed into a part of at least one of the plurality of through holes of the adjacent plates. And a step of processing the substrate and a step of carrying out the processed substrate from the processing chamber.

In the carry-in process, the substrate is carried into the processing chamber. In the processing step, the processing gas introduced into the through hole that is not communicated with the tubular member flows between the adjacent plates from one through hole of the adjacent plate, and passes through the through hole of the other plate of the adjacent plate. It is supplied into the processing chamber later. Since the processing gas introduced into the through-hole communicated with the tubular member passes through the tubular member, it is separated from the processing gas flowing between the adjacent plates through the through-hole not communicated with the tubular member, After passing through the through-hole communicated with the tubular member of the other plate of the adjacent plates, it is supplied into the processing chamber. Therefore, between the adjacent plates, the processing gas that passes through the tubular member and the processing gas that does not pass through the tubular member are not mixed. Further, since the processing gas can be supplied into the processing chamber while being mixed while being spatially separated, the processing gas can be evenly supplied from the shower head into the processing chamber. It is mixed for the first time in the processing chamber supplied in a shower form. In the unloading process, the processed substrate is unloaded from the processing chamber.
When assembling the shower head, since at least one end of the tubular member is screwed into the through hole and connected to the plate, the work is easier than when both ends of the tubular member are connected by welding.

  According to the present invention, since the processing gas can be uniformly supplied into the processing chamber, the tubular member is connected to the plate by screwing it into the through hole, so that the shower head can be easily assembled as compared with the case of connecting by welding. Become.

  Embodiments of the present invention will be described below.

  5 and 6, the outline of the substrate processing apparatus to which the present invention is applied will be described.

  In the substrate processing apparatus to which the present invention is applied, a FOUP (front opening unified pod, hereinafter referred to as a pod) is used as a carrier for transporting a substrate such as a wafer. In the following description, front, rear, left and right are based on FIG. That is, with respect to the paper surface shown in FIG. 5, the front is below the paper surface, the back is above the paper surface, and the left and right are the left and right sides of the paper surface.

  As shown in FIGS. 5 and 6, the substrate processing apparatus includes a first transfer chamber 103 configured in a load lock chamber structure that can withstand a pressure (negative pressure) less than atmospheric pressure such as a vacuum state. The casing 101 of the first transfer chamber 103 is formed in a box shape having a hexagonal plan view and closed at both upper and lower ends. In the first transfer chamber 103, a first wafer transfer machine 112 for transferring the substrate 200 under a negative pressure is installed. The first wafer transfer device 112 is configured to be moved up and down by an elevator 115 while maintaining the airtightness of the first transfer chamber 103.

  The two side walls located on the front side of the six side walls of the housing 101 are connected to the carry-in spare chamber 122 and the carry-out spare chamber 123 via gate valves 244 and 127, respectively. Each has a load lock chamber structure that can withstand negative pressure. Further, a substrate placing table 140 for loading and unloading chambers is installed in the spare chamber 122, and a substrate placing table 141 for unloading chambers is installed in the spare chamber 123.

  A second transfer chamber 121 used at substantially atmospheric pressure is connected to the front side of the preliminary chamber 122 and the preliminary chamber 123 via gate valves 128 and 129. In the second transfer chamber 121, a second wafer transfer device 124 for transferring the substrate 200 is installed. The second wafer transfer device 124 is configured to be moved up and down by an elevator 126 installed in the second transfer chamber 121 and is configured to be reciprocated in the left-right direction by a linear actuator 132. .

  As shown in FIG. 5, an orientation flat aligning device 106 is installed on the left side of the second transfer chamber 121. Further, as shown in FIG. 6, a clean unit 118 for supplying clean air is installed in the upper part of the second transfer chamber 121.

  As shown in FIGS. 5 and 6, a wafer loading / unloading port 134 for loading and unloading the substrate 200 into and from the second transfer chamber 121 is provided in the housing 125 of the second transfer chamber 121. A lid 142 for closing the wafer carry-in / out opening and a pod opener 108 are installed. The pod opener 108 includes a cap of the pod 100 placed on the IO stage 105 and a cap opening / closing mechanism 136 that opens and closes a lid 142 that closes the wafer loading / unloading port 134, and the pod placed on the IO stage 105. The cap 142 opens and closes the lid 142 that closes the cap 100 and the wafer loading / unloading port 134 by the cap opening / closing mechanism 136, thereby enabling the wafer in and out of the pod 100. The pod 100 is supplied to and discharged from the IO stage 105 by an in-process transfer device (RGV) (not shown).

  As shown in FIG. 5, two side walls located on the back side among the six side walls of the housing 101 are provided with a first processing furnace 202 that performs a desired process on the wafer, and a second processing furnace. A processing furnace 137 is connected adjacently. Both the first processing furnace 202 and the second processing furnace 137 are each constituted by a cold wall type processing furnace. In addition, a first cooling unit 138 and a second cooling unit 139 are connected to the remaining two opposite side walls of the six side walls of the housing 101, respectively. Reference numeral 139 is configured to cool the processed substrate 200.

  Hereinafter, a processing process using the substrate processing apparatus having the above-described configuration will be described.

  In a state where 25 unprocessed substrates 200 are stored in the pod 100, the substrate 200 is transferred to the substrate processing apparatus for performing the processing process by the in-process transfer apparatus. As shown in FIGS. 5 and 6, the pod 100 that has been transported is delivered and placed on the IO stage 105 from the in-process transport device. The cap 142 for opening and closing the cap of the pod 100 and the wafer loading / unloading port 134 is removed by the cap opening / closing mechanism 136, and the wafer loading / unloading port of the pod 100 is opened.

  When the pod 100 is opened by the pod opener 108, the second wafer transfer machine 124 installed in the second transfer chamber 121 picks up the substrate 200 from the pod 100, loads it into the spare chamber 122, and loads the substrate 200. Transfer to the substrate table 140. During this transfer operation, the gate valve 244 on the first transfer chamber 103 side is closed, and the negative pressure in the first transfer chamber 103 is maintained. When the transfer of the substrate 200 to the substrate table 140 is completed, the gate valve 128 is closed, and the preliminary chamber 122 is exhausted to a negative pressure by an exhaust device (not shown).

  When the preliminary chamber 122 is depressurized to a preset pressure value, the gate valves 244 and 130 are opened, and the preliminary chamber 122, the first transfer chamber 103, and the first processing furnace 202 are communicated. Subsequently, the first wafer transfer device 112 in the first transfer chamber 103 picks up the substrate 200 from the substrate placing table 140 and loads it into the first processing furnace 202. Then, a processing gas is supplied into the first processing furnace 202 and a desired processing is performed on the substrate 200.

  When the processing is completed in the first processing furnace 202, the processed substrate 200 is carried out to the first transfer chamber 103 by the first wafer transfer machine 112 in the first transfer chamber 103.

  Then, the first wafer transfer machine 112 carries the substrate 200 unloaded from the first processing furnace 202 into the first cooling unit 138, and cools the processed wafer.

  When the substrate 200 is transferred to the first cooling unit 138, the first wafer transfer machine 112 transfers the substrate 200 prepared in advance on the substrate mounting table 140 in the preliminary chamber 122 to the first processing furnace 202 by the operation described above. After the transfer, the processing gas is supplied into the first processing furnace 202, and a desired processing is performed on the substrate 200.

  When a preset cooling time elapses in the first cooling unit 138, the cooled substrate 200 is transferred from the first cooling unit 138 to the first transfer chamber 103 by the first wafer transfer device 112.

  After the cooled substrate 200 is carried out from the first cooling unit 138 to the first transfer chamber 103, the gate valve 127 is opened. Then, the first wafer transfer device 112 transports the substrate 200 unloaded from the first cooling unit 138 to the preliminary chamber 123 and transfers it to the substrate table 141, and then the preliminary chamber 123 is closed by the gate valve 127. .

  When the preliminary chamber 123 is closed by the gate valve 127, the inside of the discharge preliminary chamber 123 is returned to the atmospheric pressure by the inert gas. When the inside of the preliminary chamber 123 is returned to substantially atmospheric pressure, the gate valve 129 is opened, and the lid 142 for closing the wafer loading / unloading port 134 corresponding to the preliminary chamber 123 of the second transfer chamber 121 and the IO stage 105 are opened. The cap of the placed empty pod 100 is opened by the pod opener 108. Subsequently, the second wafer transfer device 124 in the second transfer chamber 121 picks up the substrate 200 from the substrate table 141 and carries it out to the second transfer chamber 121, and carries the wafer in and out of the second transfer chamber 121. It is stored in the pod 100 through the outlet 134. When the storage of the 25 processed substrates 200 into the pod 100 is completed, the pod opener 108 closes the lid 142 that closes the cap of the pod 100 and the wafer loading / unloading port 134. The closed pod 100 is transferred from the top of the IO stage 105 to the next process by the in-process transfer apparatus.

  By repeating the above operation, the wafers are sequentially processed. The above operation has been described by taking the case where the first processing furnace 202 and the first cooling unit 138 are used as an example, but also when the second processing furnace 137 and the second cooling unit 139 are used. Similar operations are performed.

  In the above-described substrate processing apparatus, the spare chamber 122 is used for carrying in and the spare chamber 123 is used for carrying out. However, the spare chamber 123 may be used for carrying in, and the spare chamber 122 may be used for carrying out. Moreover, the 1st processing furnace 202 and the 2nd processing furnace 137 may perform the same process, respectively, and may perform another process. When performing another process in the first process furnace 202 and the second process furnace 137, for example, after performing a process (for example, film formation such as a High-k film) on the substrate 200 in the first process furnace 202, Subsequently, another process (for example, nitriding process or the like) may be performed in the second processing furnace 137. In addition, when a second process furnace 137 performs another process after performing a process on the substrate 200 in the first process furnace 202, the first cooling unit 138 (or the second cooling unit 139) is installed. You may make it go through.

  FIG. 4 is a schematic view showing the first processing furnace 202 described above. The first processing furnace 202 is an example of a processing furnace of a single wafer MOCVD apparatus in which a remote plasma unit and a shower head are incorporated. is doing.

  Here, the first processing furnace 202 includes a heater unit 207a in which a reaction chamber 201 as a processing chamber has a susceptor 217 for holding a substrate and a heater 207 for heating the susceptor 217, and the heater unit 207a. And an elevator (not shown), a shower head 236, a rectifying plate 11 for adjusting the gas flow, and an exhaust port 231a. Details will be described below.

  As shown in the figure, a hollow heater unit 207a whose upper opening is covered with a susceptor 217 as a substrate holding means is provided in a reaction chamber 201 as a processing chamber. A heater 207 serving as a heating unit is provided inside the heater unit 207a, and the substrate 200 placed on the susceptor 217 is heated by the heater 207. The heater 207 is controlled by the temperature control means 253 so that the temperature of the substrate 200 becomes a predetermined temperature. The substrate 200 placed on the susceptor 217 is, for example, a semiconductor silicon wafer, a glass substrate, or the like.

  A substrate rotating unit 267 as a rotating means is provided outside the reaction chamber 201, and the substrate unit 200 on the susceptor 217 can be rotated by rotating the heater unit 207 a in the reaction chamber 201 by the substrate rotating unit 267. The reason why the substrate 200 is rotated is to perform processing on the substrate in a film forming process and an RPO process, which will be described later, quickly and uniformly within the substrate surface.

  Further, a shower head 236 having a large number of holes 240 is provided above the susceptor 217 in the reaction chamber 201. The shower head 236 is vertically divided into a film forming shower head unit 236a and a radical shower head unit 236b. From the divided film forming shower head unit 236a and radical shower head unit 236b, as described later, source gas, oxygen Radicals (hereinafter referred to as radicals) can be separated separately and ejected in the form of a shower.

A deposition source supply unit 250b for supplying an organic liquid source as a deposition source to the outside of the reaction chamber 201, a liquid flow rate control device 241b as a flow rate control means for controlling a liquid supply flow rate of the deposition source, and a deposition source And a vaporizer 255 for vaporizing. Further, an inert gas supply unit 250a for supplying an inert gas as a non-reactive gas and a flow rate control device 241a for controlling the supply flow rate of the inert gas are provided. The organic liquid source MO is used as the film forming source. Further, Ar, He, N ₂ or the like is used as the inert gas. A raw material gas supply pipe 232b provided in the film forming raw material supply unit 250b and an inert gas supply pipe 232a provided in the inert gas supply unit 250a are unified and connected to the film formation shower head 236a. A raw material supply pipe 232e is provided. The raw material supply pipe 232e is configured to supply a mixed gas of a film forming gas and an inert gas as a processing gas to the film forming shower head portion 236a of the shower head 236 in the film forming process. The source gas supply pipe 232b and the inert gas supply pipe 232a are provided with valves 243b and 243a, respectively, and the supply of the mixed gas of the deposition gas and the inert gas is controlled by opening and closing these valves 243b and 243a. It is possible.

Further, outside the reaction chamber 201, a remote plasma unit 222 is provided as an activating means for activating the gas with plasma. A gas supply pipe 232 g is provided on the upstream side of the remote plasma unit 222. The gas supply pipe 232g includes an oxygen supply unit 250d for supplying oxygen (O ₂ ) and an Ar supply unit 250c for supplying Ar, which is a gas for generating plasma (plasma ignition gas). And O ₂ and Ar used in the RPO process are supplied to the remote plasma unit 222. The oxygen supply unit 250d and the Ar supply unit 250c are provided with flow rate control devices 241d and 241c as flow rate control means for controlling the supply flow rates of the respective gases. The supply pipes 232d and 232c are provided with valves 243d and 243c, respectively, and the supply of O ₂ gas and Ar gas can be controlled by opening and closing these valves 243d and 243c.

  A radical supply pipe 232f connected to the radical shower head unit 236b is provided on the downstream side of the remote plasma unit 222, and oxygen radicals are supplied to the radical shower head unit 236b of the shower head 236 in an RPO (remote plasma oxidation) process. It is supposed to be. The radical supply pipe 232f is provided with a valve 243e, and the supply of radicals can be controlled by opening and closing the valve 243e.

  The film forming gas supplied to the substrate 200 in the film forming process by the film forming shower head 236a and the radical shower head 236b including the raw material supply pipe 232e and the radical supply pipe 232f provided in the reaction chamber 201 described above, and the RPO Separate supply ports for supplying radicals to be supplied to the substrate 200 in the process are configured.

  An exhaust port 231a is provided in the reaction chamber 201, and the exhaust port 231a is connected to a vacuum pump 246 as an exhaust device and an exhaust pipe 231 communicating with a detoxifying device (not shown). The exhaust pipe 231 is provided with a pressure control means 254 for controlling the pressure in the reaction chamber 201 and a raw material recovery trap 251 for recovering the film forming gas raw material. This raw material recovery trap 251 is used in common for the film forming process and the RPO process. The exhaust port 231a and the exhaust pipe 231 constitute an exhaust system.

The source gas supply pipe 232b and the radical supply pipe 232f include a source gas bypass pipe 252a and a radical bypass pipe 252b (these are simply referred to as a bypass pipe 252) connected to a source recovery trap 251 provided in the exhaust pipe 231. Each is provided. Valves 243f and 243g are provided in the source gas bypass pipe 252a and the radical bypass pipe 252b, respectively. Thus, when supplying the film forming gas to the substrate 200 in the reaction chamber 201 in the film forming process, the radical bypass pipe 252b and the raw material are bypassed so as to bypass the reaction chamber 201 without stopping the supply of radicals used in the RPO process. It becomes possible to exhaust air through the recovery trap 251. In addition, when supplying radicals to the substrate 200 in the RPO process, the supply of the film forming gas used in the film forming process is not stopped, and the reaction chamber 201 is bypassed without being stopped via the source gas bypass pipe 252a and the source recovery trap 251. It becomes possible to exhaust.

  A main controller 256 is provided for controlling the film forming process and the RPO process to be repeated a plurality of times in succession by controlling the opening and closing of the valves 243a to 243g. The main controller 256 also controls the flow control devices 241a to 241d, the temperature control means 253, and the pressure control means 254.

  Next, a procedure for depositing a thin film using the processing furnace of the substrate processing apparatus configured as shown in FIG. 4 will be described. Here, a case where a thin film such as a metal film or a metal oxide film is formed on a substrate by cyclic CVD using an organometallic material will be described.

First, the substrate 200 is placed on the susceptor 217 in the reaction chamber 201 shown in FIG. 4, and electric power is supplied to the heater 207 while rotating the substrate 200 by the substrate rotation unit 267, thereby setting the temperature of the substrate 200 to, for example, 300. It heats uniformly so that it may become predetermined | prescribed temperature between -500 degreeC (temperature raising process). When the substrate 200 is transported or heated, if a valve 243a provided on the inert gas supply pipe 232a is opened and an inert gas such as Ar, He, or N _{2 is} allowed to flow constantly, particles or metal contaminants Can be prevented from adhering to the substrate 200.

After the temperature raising process, the film forming process is started. In the film forming process, the flow rate of the organic liquid source MO supplied from the film forming source supply unit 250b is controlled by the liquid flow rate controller 241b and supplied to the vaporizer 255 to be vaporized. By opening a valve 243b provided in the source gas supply pipe 232b, the evaporated source gas is supplied onto the substrate 200 via the film forming shower head 236a. At this time, the valve 243a is kept open, and an inert gas (N ₂ or the like) is always supplied from the inert gas supply unit 250a to stir the film forming gas. When the film forming gas is diluted with an inert gas, it becomes easy to stir. The film forming gas supplied from the raw material gas supply pipe 232b and the inert gas supplied from the inert gas supply pipe 232a are mixed in the raw material supply pipe 232e and led to the film forming shower head 236a as a mixed gas. The liquid is supplied as a shower onto the substrate 200 on the susceptor 217 via a large number of holes 240.

  By supplying the mixed gas for a predetermined time, first, a thin film of about several to several tens of angstroms (several to several tens of atomic layers) is formed on the substrate 200. During this time, since the substrate 200 is kept at a predetermined temperature (film formation temperature) by the heater 207 while rotating, a uniform film can be formed over the substrate surface. Next, the valve 243b provided in the source gas supply pipe 232b is closed, and supply of the source gas to the substrate 200 is stopped. At this time, the valve 243f provided in the source gas bypass pipe 252a is opened, the supply of the film forming gas is exhausted by bypassing the reaction chamber 201 with the source gas bypass pipe 252a, and the supply of the film forming gas is not stopped. It is preferable to do this. Since it takes time to vaporize the liquid raw material and stably supply the vaporized raw material gas, if the reaction chamber 201 is allowed to flow without stopping the supply of the film forming gas, the next formation is performed. In the film process, the film forming gas can be immediately supplied to the substrate 200 only by switching the flow.

After the film formation process is completed, the purge process is started. In the purge step, the inside of the reaction chamber 201 is purged with an inert gas to remove residual gas. Note that the valve 243a is kept open in the film forming process, and an inert gas (N ₂ or the like) always flows from the inert gas supply unit 250a into the reaction chamber 201. The purge is performed at the same time as the supply of the gas to the substrate 200 is stopped.

After the purge process is completed, the RPO process is started. Here, the RPO process is a remote plasma oxidation process in which a film is oxidized using oxygen radicals generated by activating an oxygen-containing gas (O ₂ , N ₂ O, NO, etc.) with plasma. In the RPO process, the valve 243c provided in the supply pipe 232c is opened, the flow rate of the Ar supplied from the Ar supply unit 250c is controlled by the liquid flow rate control device 241c and supplied to the remote plasma unit 222, and Ar plasma is generated. After generating the Ar plasma, by opening the valve 243d provided in the supply pipe 232 d, a remote plasma unit is generating Ar plasma by flow rate is controlled by the O ₂ was supplied from the O ₂ supply unit 250d liquid flow controller 241d 222 is supplied to activate O ₂ . Thereby, oxygen radicals are generated. A valve 243e provided in the radical supply pipe 232f is opened, and a gas containing oxygen radicals is supplied from the remote plasma unit 222 onto the substrate 200 via the radical shower head unit 236b. During this time, the substrate 200 is kept at a predetermined temperature (the same temperature as the film forming temperature) by the heater 207 while rotating, and therefore, several to several tens of angstroms (several to several tens of atoms) formed on the substrate 200 in the film forming process. Impurities such as C and H can be quickly and uniformly removed from a thin film of about (layer).

  Thereafter, the valve 243e provided in the radical supply pipe 232f is closed, and the supply of oxygen radicals to the substrate 200 is stopped. At this time, by opening the valve 243g provided in the radical bypass pipe 252b, the supply of the gas containing oxygen radicals is exhausted by bypassing the reaction chamber 201 with the radical bypass pipe 252b, and the supply of oxygen radicals is not stopped. It is preferable to do so. Since it takes time until oxygen radicals are stably supplied after generation, if the reaction chamber 201 is allowed to flow without stopping the supply of oxygen radicals, the flow can be switched in the next RPO process. Immediately, radicals can be supplied to the substrate 200.

  Note that the RPO process and the film forming process are preferably performed at substantially the same temperature (the set temperature of the heater 207 is preferably kept constant without being changed). This is because, by not causing temperature fluctuation, particles due to thermal expansion of peripheral members such as the shower head 236 and the susceptor 217 are less likely to be generated, and metal jumping out (metal contamination) from metal parts can be suppressed. is there.

After completion of the RPO process, the purge process is started again. In the purge step, the inside of the reaction chamber 201 is purged with an inert gas to remove residual gas. Note that the valve 243a is kept open even in the RPO process, and an inert gas (such as N ₂ ) always flows from the inert gas supply unit 250a into the reaction chamber 201. The purge is performed at the same time as the supply is stopped.

  After the purge process is completed, the film forming process is started again, and the valve 243b provided in the source gas supply pipe 232b is opened to supply the film forming gas onto the substrate 200 via the film forming shower head 236a. A thin film of about 10 angstroms (several to several tens of atomic layers) is deposited on the thin film formed in the previous film formation step.

  As described above, a thin film having a predetermined film thickness with very little CH and OH mixing can be formed by the cycle process in which the film forming process → the purge process → the RPO process → the purge process is repeated a plurality of times.

  After the formation of the thin film with the predetermined film thickness, the rotation of the substrate 200 by the substrate rotating unit 267 is stopped, and the substrate 200 on which the thin film with the predetermined film thickness is formed is taken out from the reaction chamber 201.

When forming a thin film such as the above-described metal film or metal oxide film, in the shower head 236 having two paths for separately supplying a plurality of types of gases, a process gas that does not proceed reaction is mixedly supplied from one path. However, a processing gas that easily reacts with the mixed processing gas is supplied from the other path.
For example, when an HfSiO film that is an Hf silicate film is formed, a processing gas obtained by vaporizing an Hf raw material and an Si raw material is mixedly supplied from one path. A gas containing oxygen atoms or a radical excited by plasma is supplied from the other path.

There are various combinations of raw materials for forming the HfSiO film. For example, as the Hf raw material, Hf [OC (CH ₃ ) ₂ CH ₂ OCH ₃ ] ₄ (abbreviated as Hf-MMP), Hf [OC (CH ₃ ) ₃ ] ₄ (abbreviated as Hf-OtBu), Hf [O— Si— (CH ₃ )] ₄ (abbreviated as Hf—OSi) and the like. As Si raw materials, Si [OC (CH ₃ ) ₂ CH ₂ OCH ₃ ] ₄ (abbreviated as Si-MMP), Si [OCH (CH ₃ ) CH ₂ N (CH ₃ ) ₂ ] ₄ (abbreviated as Si-DMAP) ), H—Si [N (CH ₃ ) ₂ ] ₃ (abbreviated as TDMAS), and the like. Examples of the radical include an oxygen radical obtained by exciting oxygen O ₂ with plasma.
Note that CVD using Hf-MMP is disclosed in Japanese Patent Application Laid-Open No. 2004-6699.

  FIG. 1 is a schematic view of the configuration of the shower head 236 for supplying the processing gas as described above, wherein (a) is a perspective view and (b) is a longitudinal sectional view.

  The shower head 236 having two paths is not a side-by-side structure having a plurality of chambers (film formation shower head unit 236a, radical shower head unit 236b) in parallel in a direction (horizontal direction) intersecting the flow direction of the processing gas. Are stacked in series in the flow direction (vertical direction) of the processing gas.

The shower head 236 will be specifically described below.
The shower head 236 of the embodiment shown in FIG. 1 has a port C (a source gas port C1, a radical gas port C1) as two through holes into which a source gas G1 indicated by a dotted line and a radical G2 indicated by a solid line are respectively introduced. An example in which the port C2) has an off-axis structure in order to dispose the port C2) near the center of the shower head 236 is shown. The source gas G1 and the radical G2 constitute a processing gas.

  The shower head 236 includes a cylinder E that constitutes a main body of the shower head 236 and a plurality of sheets as upper and lower partition plates for forming a plurality of chambers in the axial direction (gas flow direction) in the cylinder E. Disk A. Here, the disk A is composed of three disks A1, A2, A3 having the same diameter as the inner diameter of the cylinder E. The first disc A1 constitutes a cover plate that closes the upper opening of the cylinder E, the second disc A2 constitutes a partition that divides the upper and lower chambers, and the third disc A3 is the lower portion of the cylinder E A bottom plate that closes the opening is formed. Accordingly, the shower head 236 has a two-stage stacked structure in which the chamber is divided into a film forming shower head portion 236a through which source gas flows and a radical shower head portion 236b through which radicals flow.

  Each of the disks A1, A2, A3 has a plurality of ports C (raw material gas port C1, radical port C2) as a plurality of through holes. The disc A1 has one port C1 for introducing the raw material gas G1 and one port C2 for introducing the radical G2. The port C2 is disposed in the center of the disc A1, and the port C1 is disposed in the vicinity of the port C2. The raw material supply pipes 232e and 232f are connected to the ports C1 and C2 of the disc A1, respectively. The disc A2 has a plurality of ports C1 and C2 through which the source gas G1 and the radical G2 pass, respectively. The disc A3 has a plurality of ports C1 and C2 through which the source gas G1 and the radical G2 are derived.

One port C2 provided in the second disk A2 is provided at a position corresponding to the center position of the port C2 provided in the first disk A1. The plurality of ports C1 provided in the second disc A2 are provided in a distributed manner so as not to overlap the port C2. The plurality of ports C1 provided in the third disk A3 are provided at positions corresponding to the plurality of ports C1 provided in the second disk A2. The plurality of ports C2 provided in the third disc A3 are provided in a distributed manner with respect to the port C1 so as not to overlap with the plurality of ports C1 provided in the third disc A3. That is, the third disk A3 is provided with a plurality of ports C1 and C2 mixedly.
The third disk A3 described above constitutes a shower plate having a large number of holes 240 (see FIG. 4), and supplies the source gas G1 and the radical G2 into the reaction chamber 201 in a shower shape. A large number of ports C1 and C2 provided in the disk A3 correspond to a large number of holes 240.

  The adjacent disc A1 and disc A2 in the upper chamber are connected by a bolt B as one tubular member having a communication hole D that communicates the ports C with each other in the center. This one bolt B connects the port C2 of the disk A1 and the port C2 of the disk A2 through the communication hole D, and the radical G2 introduced from the port C2 of the disk A1 is connected to the disk A1 and the disk A2. Without being introduced into the film forming shower head 236a formed between A2 and A2, it is separated from the source gas G1 and introduced into the port C2 of the disk A2.

  The adjacent disks A2 and A3 in the lower chamber are connected by a plurality of bolts B having a communication hole D at the center. The plurality of bolts B are introduced from the plurality of ports C1 of the disk A2 by connecting the plurality of ports C1 of the disk A2 and the plurality of ports C1 of the corresponding disk A3 through the communication holes D, respectively. The raw material gas G1 indicated by the dotted line is not supplied into the radical shower head 236b formed between the disc A2 and the disc A3, but is separated from the radical G2 to be separated from the plurality of ports C1 of the disc A3. To introduce.

The raw material gas G1 and the radical G2 are respectively introduced into two ports C1 and C2 provided in the disc A1 of the shower head 236 through a raw material supply pipe 232e and 232f, respectively, from a supply source (not shown).
The source gas G1 is introduced from the port C1 of the disk A1 and flows into the film forming shower head 236a. In the film forming shower head 236a, as shown by a dotted line, the source gas G1 is dispersed from the center to the periphery, and the bolts connecting the disks A2 and A3 from the plurality of ports C1 of the second disk A2 in the process. It flows into the communication hole D provided at the center of B. The source gas flowing into the communication hole D of the bolt B is introduced into the plurality of ports C1 of the disk A3 without mixing with the radical G2 in the radical shower head 236b in the radical shower head 236b. C1 is uniformly supplied into the processing chamber as a shower.

  The radical G2 is introduced from the port C2 of the disk A1, flows into the communication hole D of the bolt B connecting between the disks A1 and A2, and does not mix with the source gas G1 in the film formation shower head 236a. It is introduced into the port C2 of the disc A2. The radical G2 introduced from the port C2 of the disk A2 flows into the radical shower head portion 236b. In the radical shower head portion 236b, the radical G2 is dispersed from the center to the periphery without being mixed with the raw material gas G1, and is introduced into the plurality of ports C2 of the third disk A3 in the process, and from these ports C2 to the processing chamber. It is supplied uniformly in the form of a shower.

  Therefore, by using the shower head 236 having such a configuration, the source gas G1 and the radical G2 introduced into the ports C1 and C2 of the disk A3 are mixed in the shower head 236 in the film forming process described above. Without being sprayed into the reaction chamber 201 separately, and can be supplied evenly to the substrate 200.

Next, the connection structure of the disks A by the bolts B will be specifically described with reference to FIG. 3A and 3B are explanatory views showing the configuration of the shower head, wherein FIG. 3A is an explanatory view of bolt installation, FIG. 3B is a sectional view of the main part of the disk, FIG. 3C is a perspective view of the bolt, and FIG. It is sectional drawing of a volt | bolt.
As shown in FIG. 3 (a), the connection means between the discs A (A1 and A2, A2 and A3) is not using nuts, but the ends of the bolt B provided with the communication hole D in the center are discs. Screws directly into A1, A2, and A3. For this reason, as shown in FIG. 3 (b), a thread I corresponding to the bolt B is cut in the port C of the disk A into which the bolt B is screwed. Further, as shown in FIG. 3 (c), the bolt B is formed of a stud bolt-like member having the same overall length, and both ends of the bolt B when the bolt B is screwed into the disk A are It is set to be the same as or buried in the front or back surface. The bolt B has a driver groove H at its upper end in order to screw it. Further, as shown in FIG. 3 (d), in the bolt B of the present embodiment, the thread F is cut all around, but the both ends of the bolt B are screwed into the ports C1 and C2 of the disk A. The thread F may be cut at both ends at least.

In order to assemble the shower head 236 composed of a plurality of parts as described above, the disk A3 and the disk A3 are arranged so as to overlap each other with a space below the disk A2, and the disk A2 and the disk A3 are connected to a plurality of bolts. Both ends of B are connected to each other by screwing into port C. In addition, the disc A1 is disposed so as to overlap the disc A2 with an interval therebetween, and the disc A2 and the disc A1 are connected to each other by screwing both ends of one bolt B into the port C. The three discs A1 to A3 thus opposed to each other are covered with a cylinder E serving as a common outer wall, and the three discs A1 to A3 are respectively inscribed and fixed at predetermined positions of the cylinder E. . This fixing is performed by welding, for example. Thus, the shower head 236 is configured.
Although not shown, an outer cylinder is placed on the outer side of the illustrated shower head 236 so as to be coaxial with the cylinder E, in order to ensure vacuum sealing.

As described above, the chambers for forming the film forming shower head portion 236a and the radical shower head portion 236b are formed by simply connecting the disc A1 and disc A2 and the disc A2 and disc A3 to each other at both ends of the bolt B. Since only screw connection is required, the connection work is simpler than that in which both ends of the cylindrical pipe are welded to the plate, and the assembly of the shower head 236 is facilitated.
Further, the basic shapes of the disks A1 to A3 are the same, and the disks A1 to A3 can be easily manufactured only by changing the number of ports C provided on the disk A. Moreover, the bolt B which connects the discs A can be easily manufactured only by making a communicating hole in the center of the existing bolt. Therefore, the workability of the members in making these parts is also good.

  In the embodiment described above, both ends of the bolt B are screw-connected to the two adjacent discs A, but only one end of the bolt B may be screw-connected. That is, the bolt B has a thread at least at one end. Only one end of the bolt B is screwed into the port C of either one of the two discs A and the other end is inserted into the port C of the other disc A. The bolt B may be cantilevered.

FIG. 2 is a schematic view showing a modified example of the shower head including a modified connection example (hereinafter referred to as a cantilever connection example) in which only one end of such a bolt is screw-connected. ) Is a perspective view, and FIG. 2B is a longitudinal sectional view.
The shower head 236 of this modification is coaxial with the two ports C3 and C4 for introducing the raw material gas G1 indicated by the dotted line and the radical G2 indicated by the solid line, respectively, so as to overlap each other at the substantially center of the shower head 236. It has a double tube structure. The shower head 236 has the same basic configuration as that of FIG. 1 except that the arrangement configuration of the ports C provided in the first disc A1 is different.

Specifically, a port C3 for source gas is formed in the center of the disc A1. The diameter of the port C3 is set larger than that in FIG. In the port C3, one end of the bolt B having the communication hole D constituting the radical port C4 is disposed, and the outer port C3 and the inner port C4 are coaxially configured. The other end of the bolt B is cantilevered only by being screwed to the disk A2.
In this modification, the gas introduction point of the source gas and radical can be provided in the center of the disc A1 to the shower head 236, so that more uniform gas distribution can be realized.

Note that, according to the above-described embodiment, the source gas G1 and the radical G2 can be more reliably separated in the shower head 236. The cantilever connection method applied to the film forming shower head 236a shown in FIG. 2 can also be applied to the bolt B in the radical shower head 236b shown in FIG. That is, one end of the bolt B is screwed into one of the ports C3 of the disc A2 or A3, but the other end of the bolt B is only inserted into the other port C3 of the disc A3 or A2. . In this case, the diameter of the port C3 into which the other end of the bolt B is inserted is not set large as in the film forming shower head portion 236a, but is set according to the diameter of the bolt B.
According to the application example of the cantilever connection example to the bolt B in the radical shower head portion 236b, it is inevitable that some clearance is generated between the bolt B and the port C on the other end side. Also in the application example, the source gas G1 and the radical G2 can be effectively separated. Moreover, according to this application example, the connection of the bolt B to the disk A can be performed only at one end, so that the connection work becomes easier.

  Further, in the above-described cantilever connection example, the other end of the bolt is inserted into the port, but the other end of the bolt may be simply brought into contact with the outer peripheral portion of the port without being inserted into the port. In this case, even if a gap is formed between the other end of the bolt and the disk, the gap can be filled during the film forming process due to thermal expansion at the time of temperature increase in the temperature increase process.

  In the above-described embodiment, the three disks A1 to A3 are connected to the cylinder E by welding, but may be connected by sliding connection. This is because the vacuum sealing that becomes a problem in the case of the sliding connection is already secured by the outer cylinder that covers the outer periphery of the shower head 236 as described above. According to this, connection work becomes easier.

  Further, according to the above-described embodiment, two adjacent discs A1 and A2, A2 and A3 are connected by one bolt B, but three or more discs are connected to each other by one long bolt. Through-connection may be performed. For example, when three kinds of processing gases are supplied to the processing chamber from the shower head without mixing them in the middle, four disks are arranged one above the other to form the upper, middle and lower three chambers. The three discs are connected through with long bolts, and one of the three processing gases is allowed to pass through the communication holes in the bolts without being mixed in the upper and middle chambers. It is also possible to disperse in the lower chamber formed between the third and fourth sheets from the top and then supply them into the processing chamber from a plurality of ports provided in the fourth disk It is.

  The introduction ports C1 and C2 for the source gas G1 and the radical G2 may be interchanged.

  Moreover, although the case where the main body of the shower head 236 was comprised with the cylinder was demonstrated, it is not limited to a cylinder, A shape is arbitrary if it is a cylindrical body. By the way, in the case of a square tube, the partition plate is not a disc but a rectangular plate.

In the embodiments, cyclic CVD has been described. However, the substrate processing apparatus of the present invention can also be applied to ALD.
Furthermore, the present invention can also be applied to ordinary CVD in which two or more kinds of processing gases that are raw materials that easily cause a reaction to form a film are supplied simultaneously. When applied to normal CVD, two or more kinds of processing gases are not mixed in the shower head, but are mixed for the first time when they are supplied from the shower head into the processing chamber. Accordingly, since the reaction on the substrate surface becomes dominant, the step coverage characteristic can be improved.

It is description of the shower head which comprises a part of substrate processing apparatus in embodiment of this invention, Comprising: (a) is a perspective view, (b) is a longitudinal cross-sectional view. It is explanatory drawing of the shower head which shows the modification in embodiment, Comprising: (a) is a perspective view, (b) is a longitudinal cross-sectional view. It is explanatory drawing which shows the structure of the shower head in embodiment, Comprising: (a) is attachment explanatory drawing of a volt | bolt, (b) is principal part sectional drawing of a disc, (c) is a perspective view, (d) is sectional drawing. FIG. It is the schematic which shows an example of the processing furnace of the single wafer type MOCVD apparatus incorporating the remote plasma unit which comprises the substrate processing apparatus concerning embodiment of this invention. 1 is a plan view of a substrate processing apparatus according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the substrate processing apparatus concerning embodiment of this invention.

Explanation of symbols

236 Shower head 236a Deposition film shower head portion 236b Radical shower head portion A, A1, A2, A3 Disc (plate)
B Bolt C, C1, C2 port (through hole)
D Communication hole E Cylindrical G1 Source gas (processing gas)
G2 radical (processing gas)

Claims (1)

A processing chamber for processing a substrate; and a shower head for supplying a processing gas into the processing chamber in a shower shape,
The shower head has a plurality of plates having a plurality of through holes, and a part of the plurality of through holes of at least adjacent plates among the plurality of plates is communicated with at least one tubular member,
The tubular processing apparatus is characterized in that at least one end of the tubular member is formed so as to be capable of being screwed, and is screwed into a part of at least one of a plurality of through holes of the adjacent plates.

Images