JP2006269646A - Substrate processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processor for suppressing the generation of particles by preventing the adhesion of any sub-product to a holding part face. <P>SOLUTION: This substrate processor is provided with a treatment chamber 201 having a furnace port part (opening for conveying in/out a substrate) 210, a seal cap (sealing member) 219 constituted of metal air-tightly sealing the furnace port 210, a board (substrate supporting member) 217 for supporting a wafer or a heat insulating board 285 or the like in the treatment chamber 201, a boat receiver (holder) 216 constituted of metal mechanically connected through a rotary shaft 268 to the seal cap 219 for holding the boat 217, a gas feeding system for feeding treatment gas containing at least gas by which the raw materials of liquid are made to vaporize in room temperature to the treatment chamber 201, and a gas discharge pipe (discharge system) 231 for discharging atmosphere in the treatment chamber 201. Then, an upper face 211 and a side face 212 where the board 217 of a board receiving part 216a is held is covered by a quartz cover (quartz member) 280. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus, and more particularly to a substrate processing apparatus in which a metal member is exposed in a processing chamber.

  In a conventional substrate processing apparatus, for example, a substrate processing apparatus equipped with a vertical ALD (Atomic Layer Deposition) processing furnace, when a processing gas obtained by vaporizing a liquid raw material at room temperature is used, a low temperature portion of the furnace opening, particularly a metal surface By-products are likely to adhere to the surface, and the by-products attached to the metal surface tend to peel off and easily cause generation of particles.

This will be described with reference to FIG. FIG. 7 shows an example of the lower structure of a conventional vertical ALD processing furnace. In this processing furnace, for example, an HfO ₂ film is formed.

The quartz reaction tube 203 is supported on a metal furnace port flange 205. Unlike the CVD processing furnace, the reaction tube 203 of the ALD processing furnace is not a double tube but a single tube. The furnace port of the furnace port flange 205 is sealed with a metal seal cap 219. A metal boat receiving portion 216 is provided on a rotating shaft 268 that passes through the seal cap 219, and a quartz boat 217 is provided on the upper surface of the boat receiving portion 216 to place a large number of wafers and quartz heat insulating plates 285 in multiple stages. The A gas supply system (not shown) is connected to the reaction tube 203, and an exhaust pipe 231 is connected to the furnace port flange 205 at the bottom of the reaction tube 203, so that a processing gas containing at least a gas obtained by vaporizing a liquid raw material at room temperature is contained. An HfO ₂ film can be formed on the wafer 200 by exhausting while supplying it into the processing chamber 201.

  Further, in the illustrated example, a ring-shaped protrusion 206 protruding radially inward is provided on the inner peripheral wall of the furnace port flange 205, and this protrusion 206 is converted from a CVD processing furnace to an ALD processing furnace. It is a support part for supporting the inner tube of the double reaction tubes constituting the CVD processing furnace. Since the ALD processing furnace has much in common with the CVD processing furnace, the CVD processing furnace is often used as an ALD processing furnace.

  The boat receiving part 216 is inserted to the vicinity of the projecting part 206 in the furnace port flange 205, and passes through a passage extending from the processing chamber 201, which is a boat space where the boat 217 exists, to the boat lower space 204 formed at the lower part of the boat 217. The structure is made narrow to prevent gas from flowing into the boat lower space 204.

  By narrowing the space between the processing chamber 201 and the boat lower space 204 in this way, the processing gas flows into the boat lower space 204 from the processing chamber 201, and by-products are formed on the inner walls constituting the boat lower space 204. Prevents adhesion.

However, the by-product generated every time the HfO ₂ film is formed is not limited to the boat lower space 204, but also adheres to the boat receiving portion 216, the quartz bottom plate 215 constituting the boat 217, and the like. In particular, a circular hole is provided in the center of the quartz bottom plate 215 constituting the boat 217. When the upper surface of the boat receiving portion 216 exposed to the processing chamber 201 side from this circular hole is observed after processing, the attached by-product is observed. The product 302 is attached in a state where the film is peeled off. A similar product 302 is also attached to the protrusion 206 provided on the furnace port flange 205.

In the substrate processing apparatus as described above, the problem of the adhesion of the product 302 caused by the protruding portion in the processing chamber can be solved by eliminating the protruding portion from the processing chamber. However, it is difficult to prevent the by-product from adhering to the surface of the holding unit on the side where the substrate support member is held, and if the by-product adheres to the upper surface of the holding unit, it becomes a particle source. was there.
An object of the present invention is to solve the above-mentioned problems of the prior art, prevent adhesion of by-products to the holding part surface, and further suppress generation of particles due to peeling of the by-product film. Is to provide a simple substrate processing apparatus.

  By looking at the state of adhesion of by-products to the substrate loading / unloading opening (furnace port) during film formation, it appears that the attached film has been peeled off where the metal surface of the holding part is exposed. It was found that the product was adhered, and the product as described above was not adhered to the substrate support member. From this fact, the present inventor obtained the knowledge that the generation and adhesion of the aforementioned product to the holding portion can be reduced if exposure of the metal surface is prevented, and has come up with the present invention.

According to a first aspect of the present invention, there is provided a processing chamber having an opening for loading and unloading a substrate, a sealing member made of a metal for hermetically sealing the opening, a substrate supporting member for supporting a substrate in the processing chamber, A gas supply made of a metal that is mechanically connected to a sealing member, and that supplies a processing gas containing at least a gas obtained by vaporizing a liquid raw material at room temperature to the processing chamber. A substrate processing apparatus comprising: a system; and an exhaust system for exhausting an atmosphere in the processing chamber, wherein at least a surface of the holding portion on which the substrate support member is held is covered with a quartz member. is there.
Since at least the surface of the holding part on which the substrate support member is held is covered with a quartz member, generation and adhesion of products on the surface of the holding part on the side where the substrate support member is held can be prevented, and particles Can be suppressed.

According to a second aspect of the present invention, there is provided the substrate processing apparatus according to the first aspect, wherein the surface of the holding portion on the side where the substrate support member is held is covered with a quartz member not only on the upper surface but also on the side surface. .
Covering not only the upper surface but also the side of the surface of the holding part where the substrate support member is held with the quartz member, it is possible to prevent the generation and adhesion of products to the side of the holding part, further suppressing the generation of particles. it can.

A third invention is a substrate processing apparatus according to the first or second invention, wherein the quartz member is formed integrally with the substrate support member.
When the quartz member covers the surface of the holding unit on the side where the substrate support member is held, the quartz member may be configured separately from the substrate support member. With the configuration, it is possible to prevent the product from adhering to the surface of the holding unit on the side where the substrate support member is held, and to suppress the generation of particles.

A fourth invention is a substrate processing apparatus according to any one of the first to third inventions, wherein the holding portion is provided with a hole.
Since the hole is provided in the holding portion, the adhesion between the quartz member and the holding portion is improved, the processing gas is prevented from entering between the quartz member and the holding portion, and the substrate support member of the holding portion is The product can be further prevented from adhering to the surface to be held, and the generation of particles can be further suppressed. Further, it is possible to absorb a difference in thermal expansion between the quartz member and the holding portion.

  According to the present invention, it is possible to prevent the product from adhering to the surface of the holding unit that holds the substrate support member, and thus it is possible to suppress the generation of particles.

  The structure of the substrate processing apparatus of this invention is demonstrated using drawing.

  FIG. 3 is an external perspective view of a substrate processing apparatus applied to the present invention. This figure is drawn as a perspective view. FIG. 4 is a side view of the substrate processing apparatus shown in FIG.

The substrate processing apparatus of the present invention is configured to insert a pod (substrate storage container) 100 containing a wafer (substrate) 200 made of silicon or the like into the housing 101 from the outside, and vice versa. An I / O stage (holding member transfer member) 105 for paying out to the housing 101 is attached to the front surface of the housing 101, and a cassette shelf (mounting means) 109 for storing the inserted pod 100 in the housing 101. Is laid. In addition, an N ₂ purge (airtight chamber) 102 serving as a loading / unloading space for a boat 217 serving as a substrate support member, which will be described later, is provided as a transfer area for the wafer 200. Internal N ₂ purge chamber 102 when performing processing on the wafer 200, as inert gas such as N ₂ gas is filled in order to prevent the natural oxide film on the wafer 200, N ₂ purge chamber 102 is closed It is a container.

As the pod 100 described above, the FOUP type is currently mainly used, and the opening provided on one side surface of the pod 100 is closed with a lid (not shown) to isolate the wafer 200 from the atmosphere. The wafer 200 can be transferred into and out of the pod 100 by removing the lid. A pod opener (opening / closing means) 108 is provided on the front side of the N ₂ purge chamber 102 in order to remove the lid of the pod 100 and to communicate the atmosphere in the pod and the atmosphere of the N ₂ purge chamber 102. Yes. The pod 100 is transferred between the pod opener 108, the cassette shelf 109, and the I / O stage 105 by a cassette transfer machine 114. Air that has been cleaned by a clean unit (not shown) provided in the casing 101 is caused to flow in the transport space of the pod 100 by the cassette transfer device 114.

Inside the N ₂ purge chamber 102, a boat 217 for loading a plurality of wafers 200 in multiple stages, a substrate alignment device 106 for adjusting the position of a notch (or orientation flat) of the wafers 200 to an arbitrary position, and a pod opener 108 A wafer transfer machine (carrying means) 112 that carries the wafer 200 between the upper pod 100, the substrate alignment device 106, and the boat 217 is provided. A processing furnace 202 for processing the wafer 200 is provided in the upper part of the N ₂ purge chamber 102, and the boat 217 is loaded into the processing furnace 202 by the boat elevator (lifting means) 115 or unloaded from the processing furnace 202. Can be loaded.

  Next, the operation of the substrate processing apparatus of the present invention will be described.

First, the pod 100 that has been transported from the outside of the housing 101 by an AGV (self-propelled transport vehicle) or an OHT (ceiling suspended transport device) is placed on the I / O stage 105. The pod 100 placed on the I / O stage 105 is directly transported onto the pod opener 108 by the cassette transfer device 114, or once stocked on the cassette shelf 109 and then transported onto the pod opener 108. The The pod 100 transferred to the pod opener 108 is removed from the pod 100 by the pod opener 108, and the internal atmosphere of the pod 100 is communicated with the atmosphere of the N ₂ purge chamber 102.

Next, the wafer 200 is taken out from the pod 100 in communication with the atmosphere of the N ₂ purge chamber 102 by the wafer transfer device 112. The taken-out wafer 200 is aligned so that a notch is determined at an arbitrary position by the substrate alignment device 106, and is transferred to the boat 217 after alignment.

  When the transfer of the wafer 200 to the boat 217 is completed, the furnace port shutter 116 of the processing chamber 201 is opened, and the boat 217 loaded with the wafer 200 is loaded by the boat elevator 115.

  After loading, an arbitrary process is performed on the wafer 200 in the processing furnace 202. After the process, the wafer 200 and the pod 100 are discharged to the outside of the housing 101 in the reverse procedure described above.

  Next, a film forming process using the ALD method as an example of a process process for a substrate such as a wafer performed in the embodiment of the present invention will be briefly described.

  In the ALD method, under one film formation condition (temperature, time, etc.), two kinds (or more) of raw material gases used for film formation are alternately supplied onto the substrate one by one, and one atomic layer unit. In this method, the film is adsorbed by using a surface reaction to form a film.

That is, for example, in the case of forming an HfO ₂ film, the chemical reaction used is 180 to 250 ° C. using TEMAH (Hf [NCH ₃ C ₂ H ₅ ] ₄ , tetrakismethylethylaminohafnium) and O ₃ (ozone) in the ALD method. High-quality film formation is possible at low temperatures. Further, the process gas is supplied by alternately supplying a plurality of types of reactive gases one by one. The film thickness control is controlled by the number of cycles of the reactive gas supply (for example, assuming that the film forming speed is 1 kg / cycle, the process is performed 20 cycles when a 20 mm film is formed).

  Embodiments of the present invention will be described below.

FIG. 5 shows a schematic longitudinal sectional view of the processing furnace 202 described above, and FIG. The processing furnace 202 is provided with a heater 207 serving as a heating means, and a reaction tube 203 constituting a processing chamber 201 for processing the wafer 200 serving as a substrate is provided inside the heater 207. The lower end opening of the reaction tube 203 is blocked by a seal cap 219 via an O-ring 220.
The above-described heater 207, reaction tube 203, seal cap 219, and the like constitute the processing furnace 202.

  A boat 217 serving as a substrate holding unit is erected on the seal cap 219 via a quartz cap 218 for performing heat insulation and heat insulation in the processing chamber 201. Then, the boat 217 is inserted into the processing furnace 202. On the boat 217, a plurality of wafers 200 to be batch-processed are stacked in a multi-stage in the tube axis direction in a horizontal posture. The seal cap 219 is provided with a boat rotation mechanism 267 so as to rotate the boat 217. The heater 207 heats the wafer 200 inserted into the processing furnace 202 to a predetermined temperature. In place of the quartz cap 218, a quartz heat insulating plate may be loaded under the boat 217 on the seal cap 217 side in order to insulate the inside of the processing chamber 201.

  The processing furnace 202 is provided with two gas supply pipes 232a and 232b as supply pipes for supplying a plurality of types, here two types of gases. When the raw material supplied from the first gas supply pipe 232a is liquid, the first gas supply pipe 232a includes a liquid mass flow controller 240 that is a flow control means, a vaporizer 241 and a first valve 243a that is an on-off valve. Then, the reaction gas is supplied to the processing furnace 202 through the first nozzle 233a after joining with the first carrier gas supply pipe 234a. When the raw material supplied from the first gas supply pipe 232a is gas, the liquid mass flow controller 240 is exchanged for gas, and the vaporizer 241 becomes unnecessary. The first carrier gas supply pipe 234a is provided with a second mass flow controller 241b and a third valve 243c.

Further, the second gas supply pipe 232b merges with the second carrier gas supply pipe 234b via the first mass flow controller 241a which is a flow rate control means and the second valve 243b which is an on-off valve, and further the second gas supply pipe 232b. The reaction gas is supplied to the processing furnace 202 through the nozzle 233b. The second carrier gas supply pipe 234b is provided with a third mass flow controller 241c and a fourth valve 243d.
A gas supply system is constituted by the gas supply pipes 232a and 232b and the nozzles 233a and 233b described above.

  The processing furnace 202 is connected to a vacuum pump 246 which is an exhaust means through a fifth valve 243e by a gas exhaust pipe 231 for exhausting gas, and is evacuated. The fifth valve 243e is an open / close valve that can open and close the valve to stop evacuation / evacuation of the processing furnace 202, and can adjust the pressure by adjusting the valve opening. The gas exhaust pipe 231 and the vacuum pump 246 constitute an exhaust system.

  In a space formed between the inner wall of the reaction tube 203 constituting the processing furnace 202 and the boat 217 inserted into the reaction tube 203, a first nozzle 233a is formed along the loading direction of the wafers 200. And the second nozzle 233b is extended, and the first gas supply hole 248a and the second gas supply hole which are supply holes for supplying gas are provided on the side surfaces of the first nozzle 233a and the second nozzle 233b. 248b is provided. The first gas supply hole 248 a and the second gas supply hole 248 b open toward the center of the reaction tube 203, that is, toward the wafer 200. The first gas supply hole 248a and the second gas supply hole 248b have the same opening area from the lower part to the upper part, and are further provided at the same opening pitch.

  The controller 121 serving as a control means includes a liquid mass flow controller 240, first to third mass flow controllers 241a, 241b, 241c, first to fifth valves 243a, 243b, 243c, 243d, 243e, a heater 207, and a vacuum pump 246. , A boat rotation mechanism 267, connected to a boat lifting mechanism not shown in the figure, liquid mass flow controller 240, flow rate adjustment of first to third mass flow controllers 241a, 241b, 241c, first to fourth valves 243a, 243b, 243c, 243d open / close operation, fifth valve 243e open / close and pressure adjustment operation, heater 207 temperature adjustment, vacuum pump 246 start / stop, boat rotation mechanism 267 rotation speed adjustment, boat elevator 115 lift operation Control is performed.

FIG. 1 shows a detailed sectional view of the lower structure of the processing furnace 202 described above.
The reaction tube 203 is supported on the furnace port flange 205a. The furnace port portion 210 that is an opening for loading and unloading the substrate of the furnace port flange 205a is sealed by a seal cap 219 that is a sealing member made of metal through an O-ring 220 that is an airtight member. Note that the furnace port portion 210 means the furnace port of the furnace port flange 205a, as well as the boat receiving unit 216, the lower part of the furnace port flange 205, the seal cap 219, etc. constituting the vicinity of the furnace port. There is also.

  On the seal cap 219, a boat 217 as a substrate holding means is erected via a disc-shaped boat receiving portion 216a as a holding portion made of metal, for example, SUS. The boat receiving portion 216 a is attached to a rotating shaft 268 that passes through the seal cap 219 and is inserted into the reaction tube 203. The boat 217 is inserted into the reaction tube 203. On the boat 217, a plurality of wafers 200 to be batch-processed are stacked in a multi-stage in the tube axis direction in a horizontal posture.

  The boat 217 can enter and exit the reaction tube 203 by a boat elevator 115 (see FIG. 3). Further, in order to improve the uniformity of processing, a boat rotation mechanism 267 that is a rotation means for rotating the boat 217 is provided at the lower part of the boat 217. By rotating the boat rotation mechanism 267, a boat receiving portion is provided. A boat 217 held by 216a is rotated.

  The furnace port flange 205a communicating with the reaction tube 203 is connected to a vacuum pump 246 (see FIG. 5) by a gas exhaust tube 231 for exhausting gas, and the inside of the reaction tube 203 is evacuated. A heater 222 is provided in close contact with the outer periphery of the furnace port flange 205a and the exhaust pipe 231 to heat the furnace port flange 205a and the exhaust pipe 231 so that no by-product adheres to the inner walls of the furnace port flange 205a and the exhaust pipe 231. It is like that. The heating temperature is, for example, 170 ° C. ± 10 ° C.

  The inner peripheral wall surface of the furnace port flange 205a of the embodiment is smooth without having a protruding portion as in the prior art. This is because the furnace port flange 205a is configured as a furnace port flange that supports the reaction tube 203 for an ALD processing furnace formed of a single tube.

The rotating mechanism 267 is configured to rotate the rotating shaft 268 by rotating a worm gear / worm wheel (not shown) by the motor 271, for example.
The rotary shaft 268 passes through the center of the seal cap 219 via the bearing 270 and is inserted into the furnace port flange 205a. The disc-shaped boat receiving portion 216a made of SUS described above is attached to the inserted rotating shaft 268.
From the rotating mechanism 267, N ₂ gas is allowed to flow into the reaction tube 203 as a purge gas. For example, the N ₂ gas is introduced from the gap between the rotating shaft 268 and the bearing 270.

  The boat lower space 204 is defined by a seal cap 219, a boat receiving portion 216a, and a furnace port flange 205a. A quartz plate 221 is provided on the upper surface of the seal cap 219 (the inner surface of the furnace port flange) in order to prevent the adhesion of reaction byproducts and the adhesion of products generated by peeling off the byproducts. Yes.

  The diameter of the boat receiving portion 216a is set so that a slight gap is formed between the boat receiving portion 216a and the inner diameter of the furnace port flange 205a. The gap allows insertion of the boat 217 into the reaction tube 203 and rotation of the boat 217, and restricts gas intrusion from the processing chamber 201 into the boat lower space 204. On the outer periphery of the upper surface (the surface on the side where the substrate support member is held) of the boat receiving portion 216a, a step for covering the side surface covering the side surface of the boat receiving portion (the surface on the side where the substrate support member is held) is provided.

  The boat 217 is composed entirely of quartz and has a substantially cylindrical shape as a whole. The boat 217 has a plurality of quartz columns 281 extending vertically, a quartz bottom plate 280 and a quartz top plate (see FIG. (Not shown) as a component. Each quartz column 281 is provided with a large number of grooves 283 for horizontally holding a large number of wafers 200 and a quartz heat insulating plate 285. A plurality of quartz heat insulating plates 285 are held in the groove 283 below each quartz column 281 to insulate the outside and inside of the processing furnace 202 from each other.

  The circular quartz bottom plate 280 also serves as a quartz member 282 that covers the surface of the boat receiving portion 216a on the side where the boat 217 is held. For this reason, the quartz bottom plate 282 does not have a hole, and the diameter thereof is substantially the same as that of the boat receiving portion 216a so as to cover at least the upper surface 211 of the boat receiving portion 216a. In the embodiment, the diameter of the quartz bottom plate 280 is slightly larger than the diameter of the boat receiving portion 216a in order to cover the side surface 212 of the boat receiving portion 216a. On the lower outer periphery of the quartz bottom plate 280, engagement protrusions that fit into the steps of the boat receiving portion 216a are provided. By engaging the quartz bottom plate 280 with the boat receiving portion 216a, the quartz bottom plate 280 covers the surface on the side where the boat 217 is held, that is, the upper surface 211 of the boat receiving portion 216a and the side surface 212 of the boat receiving portion 216a. It has become. As for the side surface 212 of the boat receiving portion 216a, the illustrated example shows a case where a part of the side surface 212 is covered, but it is preferable to cover the entire side surface if possible.

Further, the boat lower space 204 below the boat receiving portion 216a is constantly purged with N ₂ so that the processing gas (reactive gas) does not enter the boat lower space 204 from the processing chamber 201. Further, the boat receiving portion 216a has a plurality of holes 225 extending from the upper surface 211 to the lower surface. The hole 225 is provided to prevent gas from entering between the quartz bottom plate 280 and the boat receiving portion 216a and to absorb a difference in thermal expansion between the quartz bottom plate 280 and the boat receiving portion 216a.

Next, in the configuration as described above, an example of film formation by the ALD method will be described using an example in which an HfO ₂ film is formed using TEMAH and O ₃ .

  First, a batch of wafers 200 to be deposited is loaded into a boat 217 and loaded into a processing furnace 202. After carrying in, the following four steps are sequentially executed.

[Step 1]
In step 1, TEMAH and carrier gas (N ₂ ) are flowed. First, the first valve 243a provided in the first gas supply pipe 232a, the third valve 243c provided in the first carrier gas supply pipe 234a, and the fifth valve 243e provided in the gas exhaust pipe 231 are all opened. The flow rate was adjusted by the liquid mass flow controller 240 from the first gas supply pipe 232a and the flow rate was adjusted by the second mass flow controller 241b from the first carrier gas supply pipe 234a and the TEMAH gas vaporized by the vaporizer 242. Carrier gas (N ₂ gas) is mixed, and the mixed gas is exhausted from the gas exhaust pipe 231 while being supplied into the reaction tube 203 from the first gas supply hole 248a of the first nozzle 233a. The supply flow rate of the TEMAH gas controlled by the liquid mass flow controller 240 is 0.1 to 0.3 g / min. The time for exposing the wafer 200 to the TEMAH gas is 30 to 180 seconds. The temperature of the heater 207 at this time is set so that the wafer becomes 180 to 250 ° C. The pressure in the processing chamber 201 is 50 to 100 Pa. As a result, the TEMAH raw material is adsorbed on the underlying film of the wafer 200.

[Step 2]
In step 2, the first valve 243a of the first gas supply pipe 232a and the third valve 243c of the first carrier supply pipe 234a are closed to stop the supply of TEMAH gas and carrier gas. The fifth valve 243e of the gas exhaust pipe 231 is kept open, and the processing furnace 202 is exhausted to 20 Pa or less by the vacuum pump 246, and residual TEMAH gas is removed from the reaction pipe 203. At this time, if an inert gas, for example, N ₂ gas used as a carrier gas is supplied to the processing furnace 202, the effect of eliminating residual TEMAH is further enhanced.

[Step 3]
In step 3, O ₃ gas and carrier gas (N ₂ ) are flowed. First, the second valve 243b provided in the second gas supply pipe 232b and the fourth valve 243d provided in the second carrier gas supply pipe 234b are both opened, and the first mass flow is started from the second gas supply pipe 232b. The O ₃ gas whose flow rate has been adjusted by the controller 241a and the carrier gas (N ₂ gas) whose flow rate has been adjusted by the third mass flow controller 241c from the second carrier gas supply pipe 234b are mixed, and the second nozzle 233b The gas is exhausted from the gas exhaust pipe 231 while being supplied into the reaction pipe 203 from the second gas supply hole 248b. The time for exposing the wafer 200 to O ₃ gas is 10 to 120 seconds. The wafer temperature at this time is 180 to 250 ° C., as in the case of supplying the TEMAH gas. Further, the pressure in the processing chamber 201 is also 50 to 100 Pa as in the case of supplying the TEMAH gas. By supplying the O ₃ gas, the TEMAH gas and the O ₃ gas on the base film of the wafer 200 react with each other to form a HfO ₂ film on the wafer 200.

[Step 4]
After the film formation, the second valve 243b and the fourth valve 243d are closed, and the processing furnace 202 is evacuated by the vacuum pump 246 to eliminate the remaining O ₃ gas after contributing to the film formation. At this time, if an inert gas, for example, N ₂ gas used as a carrier gas is supplied to the processing furnace 202, the effect of further removing the remaining O ₃ gas from the processing furnace 202 is enhanced.

The above steps 1 to 4 are defined as one cycle, and a HfO ₂ film having a predetermined thickness is formed on the wafer 200 by repeating this cycle a plurality of times.
Here, the cycle consisting of the four steps of TEMAH gas introduction, purge, O ₃ gas introduction, and purge is defined as one cycle, and this is repeatedly formed. In this case, if the time for each step is 10 to 180 seconds, the film thickness per cycle is about 1 to 2 mm depending on the wafer temperature. For example, when HfO ₂ or Al ₂ O ₃ (alumina) is used as a gate insulating film or a capacitor insulating film, the film is formed in a thickness of 15 to 50 mm by repeating several to several tens of cycles.

  After film formation, the boat 217 is unloaded from the processing furnace 202, the wafer 200 is cooled, and then discharged to the outside of the substrate processing apparatus.

By the way, during the formation of the HfO ₂ film, the by-product tends to adhere to the low-temperature part of the furnace opening 210, particularly the metal surface, and the by-product attached to the metal surface tends to peel off. As described above, the generation of particles is caused. The detected by-product is such that the TEMAH gas is liquefied at the low temperature portion and adheres to the furnace port portion 210 and reacts with the next flowing O ₃ gas, or the furnace port portion 210 comes into contact with the atmosphere after processing. It is thought that it is produced by reacting when it occurs.

The cause of the film peeling of the by-product is considered to be that the film was peeled off due to the stress generated by thermal contraction in the by-product (HfO ₂ film) generated on the metal (SUS) surface of the boat receiving portion 216.
Here, about the linear expansion coefficient of SUS and quartz,
The linear expansion coefficient of SUS is 16.2 × 10 ⁻⁶ / ° C.
The linear expansion coefficient of quartz is 0.4 × 10 ⁻⁶ / ° C.
Since quartz has a smaller linear expansion coefficient than SUS, even if a film (by-product) is generated, it is less affected by thermal stress, so that it is considered that film peeling hardly occurs.

Again, the cause of the by-product is due to the liquefaction of the gas, and a large amount of product adheres to the low temperature part, so that the liquefied gas adheres to the furnace port part 210, which is then flowed. By-products are considered to be generated by reacting with O ₃ gas or the atmosphere. FIG. 2 shows the temperature characteristics of the vapor pressure of TEMAH which is the Hf raw material. From the figure, it can be seen that when the processing pressure is about 50 Pa (about 0.37 Torr), the liquid is liquefied at 80 ° C. or lower.

Normally, after the boat 217 loaded with the processed wafers 200 is unloaded from the processing chamber 201, the furnace port shutter 116 of the processing furnace 202 is closed immediately so that the atmosphere does not flow into the processing chamber 201. At the time of carrying out 217, inflow of the atmosphere into the processing chamber 201 is inevitable. For this reason, the liquefied TEMAH gas adhering to the furnace opening 210 reacts with the atmosphere to generate a by-product, and adheres to the metal surface of the furnace opening 210.
Although there is a risk that by-products may adhere to the quartz member, even if the by-product adheres to the quartz member, since the linear expansion coefficient of quartz is small as described above, by-product is formed on the surface of the quartz member. Generation and adherence of products due to peeling of objects can be suppressed. Further, while metals such as SUS are easily cooled, the quartz member has a large heat capacity and is difficult to cool, and thus has a large heat retaining effect. Therefore, an effect of suppressing liquefaction of gas and adhesion of by-products can be expected.

  According to the above embodiment, since the entire upper surface 211 of the SUS boat receiver 216a is covered with the quartz bottom plate 280, which is the quartz member 282, in the processing chamber 201, the by-product is formed in the boat receiver 216a. It is possible to prevent generation and adhesion of a product generated by peeling off. Further, since the side surface 212 of the boat receiving portion 216a is covered with the quartz bottom plate 280, it is possible to further prevent the product from adhering to the boat receiving portion 216a in the same manner.

  Further, the inner peripheral wall of the furnace port flange 205a of the embodiment is smooth without having a conventional protruding portion, and convection may occur along the inner peripheral wall of the furnace port flange 205a due to the protruding portion. Further, since the wall is heated by the heater 222, liquefaction of the TEMAH gas can be suppressed, and adhesion of by-products to the inner wall surface of the furnace port flange 205 can be suppressed.

Further, by narrowing the gap between the smooth inner wall of the furnace port flange 205a and the boat receiving portion 216a or the quartz bottom plate 280, the inflow from the processing chamber 201 side to the boat lower space 204 can be reliably suppressed. .
Moreover, since an inert gas such as N ₂ gas is introduced from the rotating shaft 268 side into the boat lower space 204 and flows to the processing chamber 201 side, the inflow from the processing chamber 201 side to the boat lower space 204 is more reliably suppressed. can do. At this time, since the gap between the inner wall of the furnace port flange 205a and the boat receiving portion 216a or the quartz bottom plate 280 is narrow, it is possible to suppress the processing gas from flowing into the boat lower space 204 with a small amount of N ₂ gas. N ₂ purge efficiency can be increased.

  Further, when the quartz member 282 covers the surface of the boat receiving portion 216a on the side where the boat 217 is held, the quartz member 282 may be configured separately from the boat 217, but as in the present embodiment, When the quartz member 282 is configured integrally with the boat 217, it is possible to effectively prevent by-products from adhering to the surface of the boat receiving portion 216a on the side where the boat 217 is held with a simple configuration. Generation of particles due to peeling of by-products can be effectively suppressed. Furthermore, since the quartz member 282 covering the boat receiving portion 216a is integrated with the boat 217, maintenance is easy.

  In addition, when the quartz is overlapped, the accuracy (verticality) of the boat is difficult to be obtained. However, in the embodiment, the quartz bottom plate 280 is overlapped on the boat receiving portion 216a made of SUS. Accuracy can be easily achieved.

  Further, since the hole 225 is provided in the boat receiving portion 216a, the adhesion between the quartz bottom plate 280 and the boat receiving portion 216a is improved, and the processing gas enters between the quartz bottom plate 280 and the boat receiving portion 216a, and By restricting the occurrence of gas accumulation, it is possible to further prevent adhesion of by-products to the surface of the boat receiving portion 216a on the side where the boat 217 is held, and to further suppress the generation of particles.

  Further, it is impossible to avoid the boat receiving portion 216a from being cooled when the wafer 200 is transferred to the boat 217. The simplest method for avoiding this is to put the boat 217 into the reaction tube 203 and preheat the wafer before transferring the wafer and during processing standby of the substrate processing apparatus. Conventionally, even if the boat 217 is placed in the reaction tube 203 and preheated, the metal SUS (boat receiving portion 216a) has a large heat release and quickly cools down, thereby suppressing gas liquefaction and thermal contraction. It was difficult to do. In this respect, in the embodiment, it is possible to put the boat 217 into the reaction tube 203 and preheat it during the processing standby of the substrate processing apparatus, and when the wafer 200 is transferred to the boat 217. It is possible to suppress the cooling of the boat receiving portion 216a.

In the present embodiment, an example is described in which the film type is applied to HfO _{2 formed} by ALD using a liquid raw material at room temperature. However, the present invention can also be applied to alumina film formation. In the case of alumina film formation, TMA (Al (CH ₃ ) ₃ : trimethylaluminum) is used as the “raw material”, O ₃ (ozone) is used as the “reaction gas”, and an Al ₂ O ₃ (alumina) film is used. Form a film. Here, the processing chamber pressure is 100 to 1 Pa. The temperature of the Si wafer is in the range of 150 to 500 ° C. depending on the difference in self-decomposition temperature of the source gas. For example, in TMA and TEMAH, 180-300 degreeC is used.

It is sectional drawing which shows the lower structure of the processing furnace which comprises the substrate processing apparatus in embodiment. FIG. 6 is a temperature characteristic diagram of TEMAH that is a film forming raw material when an HfO ₂ film is formed using an ALD method. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the vertical type substrate processing apparatus concerning embodiment, and is the figure which showed the substrate processing apparatus by the external appearance perspective view. FIG. 4 is a side view of the substrate processing apparatus shown in FIG. 3. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the vertical type | mold substrate processing furnace concerning embodiment of this invention, and is the figure which showed the processing furnace part with the longitudinal cross-sectional view. It is the figure which showed the processing furnace part of the substrate processing furnace shown in FIG. 5 in the cross section. It is sectional drawing which shows the lower structure of the processing furnace which comprises the substrate processing apparatus in a prior art example.

Explanation of symbols

201 Processing chamber 210 Furnace port (opening for substrate loading / unloading)
219 Seal cap (sealing member)
200 wafer (substrate)
217 boat (substrate support member)
232a, 232b Gas supply pipe (gas supply system)
233a, 233b Nozzle (gas supply system)
231 Gas exhaust pipe (exhaust system)
246 Vacuum pump (exhaust system)
216 Boat receiving part (holding part)
268 Rotating shaft (Means for mechanically connecting the holding part to the sealing member)
211 Boat receiver upper surface (surface on the side where the substrate support member is held)
212 Side surface of the boat receiving portion (surface on which the substrate support member is held)
280 Quartz bottom plate (quartz member)
282 Quartz material

Claims (1)

A processing chamber having an opening for loading and unloading a substrate;
A sealing member made of a metal that hermetically seals the opening;
A substrate support member for supporting the substrate in the processing chamber;
A holding portion for holding the substrate support member, which is made of metal mechanically connected to the sealing member;
A gas supply system for supplying a processing gas containing at least a gas obtained by vaporizing a liquid raw material at room temperature to the processing chamber;
An exhaust system for exhausting the atmosphere in the processing chamber;
With
A substrate processing apparatus, wherein at least a surface of the holding unit on a side where the substrate support member is held is covered with a quartz member.

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