JP2006083406A - Substrate treatment device, substrate placing stand, and substrate treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate treatment device and a substrate treatment method capable of ensuring uniformity of the in-plane temperature of a susceptor to prevent the susceptor from being damaged, and preventing a wafer from temperature-lowering and being contaminated with metals. <P>SOLUTION: A film deposition apparatus 100 comprises a treatment container 1 to treat a wafer W, a susceptor 2 to place the wafer in the treatment container 1, a heater 5 to heat the susceptor 2, a wafer supporting pin 39 which is provided on a wafer placing face in a projecting/retracting manner to displace the wafer W in the placing state in which the wafer is abutted on the wafer placing face and a separate state in which the wafer is separated from the wafer placing face, and a cover ring which is provided displaceably between a state abutted on the wafer placing face and a state separate from the wafer placing face to cover the periphery of a wafer placing area on the wafer placing face in the abutted state. During the precoat, since a precoat film 50 is deposited on the surface of a dummy wafer Wd and the surface of the cover ring 4, no precoat film 50 is deposited on the wafer placing surface, the radiation rate is unified to prevent the susceptor 2 from being damaged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substrate processing apparatus, a substrate mounting table, and a substrate processing method, and more particularly, to a substrate processing apparatus, a substrate mounting table, and a substrate processing method for performing processing such as film formation on a target substrate such as a semiconductor wafer. .

  In a film forming apparatus that forms a film on a semiconductor wafer (hereinafter, simply referred to as “wafer”) as a substrate to be processed by a method such as CVD, the susceptor as a substrate mounting table on which the wafer is mounted is heated. Means are provided, and various film-forming reactions are advanced while the wafer is indirectly heated by heating the susceptor.

Since a ceramic material such as AlN with excellent thermal conductivity is used for the susceptor, a precoat film is formed on the susceptor in advance before the film formation process in order to avoid contamination of the wafer with the constituent metal elements. To be done. Regarding this pre-coating process, for example, in the process of manufacturing a semiconductor integrated circuit in which film formation and pattern etching are repeated, a pre-coating layer made of a TiN film is deposited before forming a TiN film as a barrier metal, and heating is continued for a predetermined time. However, a technique for stabilizing the precoat film by acting ammonia has been proposed (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2001-1444033 (FIG. 1 and the like)

  By the way, there are roughly two methods for forming the precoat film. One of them is a method of performing pre-coating without placing a wafer on a susceptor, and Patent Document 1 also forms a pre-coating film by this method. In this case, the precoat film is formed on the entire surface including the wafer mounting area of the susceptor. For this reason, there is a concern that the heat radiation rate from the susceptor decreases and the wafer temperature does not rise sufficiently compared with the heating setting temperature of the susceptor. Further, since the precoat film is also formed on the wafer mounting region, the back surface of the wafer comes into contact with the precoat film, and depending on the type of the precoat film, the constituent metal element adheres to the wafer, or the wafer itself, or It may cause metal contamination of the transport route.

  Another method is a method of forming a precoat film in a state where a dummy wafer is placed on a susceptor. This method will be described with reference to FIG. FIG. 3A shows a state in which a pre-coating process using titanium nitride or ruthenium oxide is performed with the dummy wafer Wd placed on the susceptor 201 prior to the processing of the wafer W. By the precoat process, the precoat film 50 is formed on the surface of the susceptor 201 and the exposed surface of the dummy wafer Wd, but the precoat film 50 is not formed in the wafer placement region 201a on which the dummy wafer Wd is placed. The heat emissivity from the susceptor 201 after the pre-coating process is uniform as shown by an arrow in FIG. 3A when the dummy wafer Wd is placed.

  Next, the wafer W is placed on the susceptor 201 instead of the dummy wafer Wd, and a film forming process such as a titanium nitride film is performed. The film forming process is repeated while changing the wafer W. In this film forming process, the susceptor 201 is heated to a temperature of, for example, 500 ° C. or higher by the heater 204. In this case, since the precoat film 50 is not interposed between the wafer W and the susceptor 201, the wafer W can directly receive heat transfer from the susceptor 201, and contact between the wafer W and the precoat film 50 is also possible. Since it does not occur, the problems of temperature drop and metal contamination hardly occur.

  The exchange between the processed wafer W and the unprocessed wafer W is performed in a state where the wafer W is separated from the susceptor 201. As shown in FIG. 3B, the susceptor 201 is provided with a plurality of wafer support pins 203 so as to be able to project and retract, and by raising the wafer support pins 203, the tip portion thereof is the lower surface of the wafer W. The wafer W is pushed up while being in contact with.

  Here, on the wafer mounting surface of the susceptor 201, there are an area where the precoat film 50 is formed and an area where the precoat film 50 is not formed because the dummy wafer Wd is mounted (wafer mounting area 201a). To do. Therefore, in the susceptor 201 in a heated state, a significant difference occurs in the heat radiation rate between these two regions. That is, as indicated by an arrow in FIG. 3B, the thermal radiation rate of the susceptor surface on which the precoat film 50 is formed is as small as εt, while the wafer mounting region 201a exposed by separating the wafer W is separated. The thermal emissivity increases to εs.

  As a result, there is a problem that the uniformity of the in-plane temperature of the susceptor 201 is impaired, distortion is caused by thermal stress, and the susceptor 201 is damaged in the worst case. In particular, as the wafer size increases from 200 mm to 300 mm, the ratio of the diameter to the thickness of the disc-shaped susceptor 201 tends to increase, and therefore the susceptor 201 is more easily damaged. .

  In view of the above, the present invention provides a substrate processing apparatus, a substrate mounting table, and a substrate processing method that ensure uniformity of the in-plane temperature of the susceptor and prevent its breakage, and that does not cause a decrease in wafer temperature or metal contamination. The purpose is to provide.

In order to solve the above problems, according to a first aspect of the present invention,
A processing container that divides a processing chamber for processing a substrate to be processed;
A substrate mounting table for mounting the substrate to be processed on the substrate mounting surface in the processing container;
Heating means for heating the substrate mounting table;
A substrate support that displaces the substrate to be processed into a placement state in contact with the substrate placement surface and a separated state separated from the substrate placement surface;
A cover member is provided so as to be displaceable between a state in contact with the substrate placement surface and a state in which the substrate placement surface is separated from the substrate placement surface.
A substrate processing apparatus is provided.

  In the above substrate processing apparatus, by providing a cover member, it is possible to prevent the formation of a precoat film on the substrate mounting surface, so that even when the substrate is separated after the precoat processing, the thermal radiation rate of the substrate mounting table is uniform. Can be.

  Further, the cover member is in contact with the substrate mounting table in a mounting state in which the substrate to be processed is in contact with the substrate mounting surface, and in a separated state in which the processing substrate is separated from the substrate mounting table, It is preferable to separate from the substrate mounting table. Thus, by contacting and separating the cover member in accordance with the substrate to be processed, the thermal uniformity of the substrate mounting table can be maintained even after the pre-coating process.

  Further, it is preferable that the cover member is displaced in conjunction with the substrate to be processed by a common displacement mechanism. Thus, the apparatus configuration can be simplified by interlocking the substrate to be processed and the cover member with a single displacement mechanism.

  Further, the cover member is preferably a ring-shaped member having an opening having a size corresponding to the substrate to be processed. By adopting the ring shape, the substrate placement surface other than the substrate placement area can be covered with a single cover member.

  The outer diameter of the cover member is preferably larger than the outer diameter of the substrate mounting table. Thereby, the substrate mounting surface of the substrate to be processed can be reliably covered.

According to the second aspect of the present invention, there is provided a substrate mounting table for mounting a substrate to be processed on a substrate mounting surface in a processing container and heating the substrate by a heating means.
A substrate support that displaces the substrate to be processed into a placement state in contact with the substrate placement surface and a separated state separated from the substrate placement surface;
A cover member that is provided so as to be displaceable between a state in contact with the substrate placement surface and a state in which the substrate placement surface is separated from the substrate placement surface.
A substrate mounting table is provided.

  Moreover, according to the 3rd viewpoint of this invention, the to-be-processed substrate is processed using the said substrate processing apparatus, The substrate processing method characterized by the above-mentioned is provided.

  In the substrate processing method, it is preferable that the pre-coating process is performed in a state where the dummy substrate is mounted on the substrate mounting table, and then the substrate to be processed is mounted instead of the dummy substrate. Moreover, it is preferable that the process with respect to a to-be-processed substrate is a film-forming process.

  According to the present invention, a pre-coating is provided by covering the periphery of the substrate placement area on the substrate placement surface of the substrate placement table and contacting or separating the substrate placement table in conjunction with the substrate. Even when the substrates are separated after the processing, the heat radiation rate of the substrate mounting table can be made uniform. Therefore, even when the substrate is carried in and out repeatedly, the substrate mounting table is not distorted or damaged by the thermal stress, and a highly durable substrate processing apparatus can be provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a CVD film forming apparatus suitable for TiN film formation according to an embodiment of the present invention, and FIG. 2 is an enlarged schematic view showing a susceptor 2 as a substrate mounting table. is there. The film forming apparatus 100 includes a chamber 1 that is a substantially cylindrical processing container configured to be airtight. In the chamber 1, a susceptor 2 for horizontally supporting a wafer W, which is an object to be processed, is arranged in a state of being supported by a cylindrical support member 3 provided at the center lower part thereof. A cover ring 4 is provided on the wafer placement surface of the susceptor 2 so as to cover the periphery of the wafer placement area 2a (see FIG. 2) on which the wafer W is placed. The cover ring 4 will be described later.

  In addition, a heater 5 as a heating unit is embedded in the susceptor 2, and the heater 5 is heated by a heater power supply 6 to heat the wafer W as a substrate to be processed to a predetermined temperature. The susceptor 2 is made of ceramics such as AlN. Moreover, as a heating means, not only the heater 5 by a resistor but a heating lamp can also be used, for example.

  A shower head 10 is provided on the top wall 1 a of the chamber 1 via an insulating member 9. The shower head 10 includes an upper block body 10a, a middle block body 10b, and a lower block body 10c. Discharge holes 17 and 18 for discharging gas are alternately formed in the lower block body 10c. A first gas inlet 11 and a second gas inlet 12 are formed on the upper surface of the upper block body 10a. In the upper block body 10a, a large number of gas passages 13 are branched from the first gas introduction port 11. Gas passages 15 are formed in the middle block body 10b, and the gas passages 13 communicate with the gas passages 15 through communication passages 13a extending horizontally. Further, the gas passage 15 communicates with the discharge hole 17 of the lower block body 10c.

  In the upper block body 10a, a large number of gas passages 14 branch from the second gas introduction port 12. Gas passages 16 are formed in the middle block body 10 b, and the gas passage 14 communicates with these gas passages 16. Further, the gas passage 16 is connected to a communication passage 16a extending horizontally into the middle block body 10b, and the communication passage 16a communicates with a number of discharge holes 18 of the lower block body 10c. The first and second gas inlets 11 and 12 are connected to a gas line from the gas supply mechanism 20.

The gas supply mechanism 20 is connected to a first gas supply source 21 and a second gas supply source 22, and the first gas supply source 21 is, for example, ClF ₃ that supplies ClF ₃ gas as a cleaning gas. ₃ gas supply source, Ti-containing TiCl TiCl ₄ gas supply source for supplying a ₄ gas is a gas, _{N 2} gas has _{N 2} gas supply source for supplying, while the second gas supply source 22, for example, , Another N ₂ gas supply source, and an NH ₃ gas supply source for supplying NH ₃ gas.

  A high frequency power supply 34 is connected to the shower head 10 via a matching unit 33, and high frequency power is supplied from the high frequency power supply 34 to the shower head 10 as necessary. Normally, the high-frequency power source 34 is not necessary, but in order to increase the reactivity of the film forming reaction, the high-frequency power supplied from the high-frequency power source 34 allows the gas supplied into the chamber 1 through the shower head 10. It is also possible to form a film by converting into a plasma.

  A circular hole 35 is formed at the center of the bottom wall 1 b of the chamber 1, and an exhaust chamber 36 protruding downward is provided on the bottom wall 1 b so as to cover the hole 35. An exhaust pipe 37 is connected to a side surface of the exhaust chamber 36, and an exhaust device 38 is connected to the exhaust pipe 37. By operating the exhaust device 38, the inside of the chamber 1 can be depressurized to a predetermined degree of vacuum.

  The susceptor 2 is provided with wafer support pins 39 as three (not shown) substrate support members so as to protrude and retract with respect to the surface of the susceptor 2 in order to support and lift the wafer W. The support pin 39 is fixed to the connecting plate 40. The wafer support pins 39 are lifted and lowered via the connecting plate 40 by a drive mechanism 41 such as an air cylinder.

The cover ring 4 is a flat plate having an outer shape formed in a ring shape, and is arranged so as to contact and cover the surface of the susceptor around the wafer. The cover ring 4 has an opening having a size substantially corresponding to the wafer W and has a diameter larger than that of the susceptor 2. It is configured to cover. Thereby, it is possible to reliably prevent the susceptor 2 from covering the wafer mounting surface during the pre-coating process and to push up the lower surface of the cover ring 4 protruding around the susceptor 2 by the push-up pins 7. That is, the displacement of the cover ring 4 by the push-up pins 7 can be easily synchronized with the displacement of the wafer support pins 39, and the mechanism itself can be simplified. The cover ring 4 may be made of any material as long as it has heat resistance. For example, Al ₂ O ₃ or SiO ₂ can be suitably used. However, similarly to the susceptor 2, the cover ring 4 has excellent thermal conductivity such as AlN. It can also be formed of a material.

  Three push-up pins 7 (only two are shown) are fixed to the connecting plate 40 in parallel with the wafer support pins 39. Each push-up pin 7 is arranged to be movable up and down so as to surround the susceptor 2 by the drive mechanism 41. In a state where the wafer W is placed on the susceptor 2, the tip of the push-up pin 7 is lower than the wafer placement surface of the susceptor 2, but the support pin 39 is lifted by the drive mechanism 41 to move the wafer W to the wafer of the susceptor 2. In a state of being separated from the mounting surface, the tip of the push-up pin 7 is higher than the wafer mounting surface and pushes up the cover ring 4. In this way, by connecting the wafer support pins 39 and the push-up pins 7 with the connecting plate 40, the single drive mechanism 41 can be moved up and down. In addition, since the displacement of the wafer W and the displacement of the cover ring 4 can be interlocked without requiring a control means, the apparatus configuration can be simplified as compared with the case where separate drive mechanisms are provided.

  On the side wall of the chamber 1, a loading / unloading port 42 for loading / unloading the wafer W to / from a transfer chamber (not shown) and a gate valve 43 for opening / closing the loading / unloading port 42 are provided.

Next, a film forming method when forming a TiN film with such a film forming apparatus 100 will be described. Note that the chamber 1 is cleaned, and the susceptor 2 is in a state where all unnecessary films are removed.
In film formation, first, pre-coating treatment of the susceptor 2 is performed. The inside of the chamber 1 is evacuated by the exhaust device 38, the gate valve 43 is opened, and the dummy wafer Wd is carried into the chamber 1 from a vacuum wafer transfer chamber (not shown). Next, the wafer support pins 39 are projected from the surface of the susceptor 2, and the dummy wafer Wd is placed on the wafer support pins 39. Next, the wafer support pins 39 are lowered to place the dummy wafer Wd on the susceptor 2.

In this state, the chamber 1 is sealed, and TiCl ₄ , NH ₃ , for example, and N ₂ as a carrier gas are introduced into the chamber 1 from the shower head 10 at a predetermined flow rate. At this time, the susceptor 2 is heated and maintained at, for example, about 500 to 700 ° C. by the heater 5. By this thermal CVD operation, a TiN film is deposited on the surface of the susceptor 2 to form a thin precoat film 50 as shown in FIG. When the wafer size is 8 inches, for example, the flow rate of TiCl ₄ gas is approximately 30 to 50 mL / min, the flow rate of NH ₃ gas is approximately 400 mL / min, and the N ₂ gas is approximately 500 mL / min. The pressure is about 40 Pa (300 mTorr), and the temperature is about 680 ° C.

  As described above, the precoat process is completed by forming the precoat film 50 having a thickness of, for example, about 1 μm. In the case of the substrate processing apparatus 100 of the present invention having the cover ring 4, since the precoat film 50 is formed on the surface of the dummy wafer Wd and the surface of the cover ring 4, the precoat film 50 is directly deposited on the wafer mounting surface of the susceptor 2. Not done. In this state, the heat radiation rate from the susceptor 2 is εt, which is substantially uniform as shown by an arrow in FIG.

After forming the precoat film 50, the dummy wafer Wd in the chamber 1 is replaced with the wafer W, and a normal film forming process is performed. For example, when a plurality of wafers W are continuously processed, the wafers may be sequentially loaded into the chamber 1 one by one and a TiN film may be formed using TiCl ₄ gas and NH ₃ gas.

  When the wafer W is placed on the susceptor 2 instead of the dummy wafer Wd, or when the wafer W is processed and replaced with the next wafer W, as shown in FIG. The pins 39 are raised so that the wafer W is separated from the susceptor 2.

  In this embodiment, the susceptor 2 is heated to a temperature of, for example, 500 ° C. or more by the heater 5, but the cover ring 4 prevents the formation of the precoat film 50 directly on the wafer mounting surface of the susceptor 2. The difference in emissivity does not occur as in the prior art shown in FIG. That is, as shown in FIG. 2B, the thermal emissivity of the susceptor 2 when the wafer W and the cover ring 4 are separated is εs, which is substantially uniform, so that the thermal stress on the susceptor 2 is a limit value. It will not increase beyond the limit and damage will be prevented.

  The present invention is not limited to the above embodiment and can be variously modified. For example, in the above-described embodiment, the film forming apparatus that performs the pre-coating process is described as an example. Can be applied.

  Further, in FIG. 1, the wafer support pins 39 and the push-up pins 7 are provided on the connecting plate 40 so as to be moved up and down in conjunction with the drive mechanism 41, but the push-up pins 7 are different from the wafer support pins 39. You may make it drive by a drive mechanism. In this case, the displacement of the cover ring 4 is not limited to the vertical movement similar to the wafer W, but may be a drive mechanism in which the cover ring is divided and slid in the horizontal direction, for example.

  Furthermore, the substrate to be processed is not limited to a semiconductor wafer, and may be another substrate such as a liquid crystal display (LCD) substrate, or may be one in which another layer is formed on the substrate. .

Sectional drawing which shows the CVD film-forming apparatus which concerns on one Embodiment of this invention. It is drawing explaining the effect | action of a cover plate, (a) The state which applied the precoat to the susceptor which mounted the dummy wafer is shown, (b) is a schematic diagram which shows the state which raised the wafer and separated from the susceptor. It is drawing which shows the conventional susceptor, (a) The state which applied the precoat to the susceptor which mounted the dummy wafer, (b) is a schematic diagram which shows the state which raised the wafer and separated from the susceptor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Chamber 2; Susceptor 4; Covering 5; Heater 7; Push-up pin 10; Shower head 20; Gas supply mechanism 39; Wafer support pin 40;

Claims (9)

A processing container that divides a processing chamber for processing a substrate to be processed;
A substrate mounting table for mounting the substrate to be processed on the substrate mounting surface in the processing container;
Heating means for heating the substrate mounting table;
A substrate support that displaces the substrate to be processed into a placement state in contact with the substrate placement surface and a separated state separated from the substrate placement surface;
A cover member that is provided so as to be displaceable between a state in contact with the substrate placement surface and a state in which the substrate placement surface is separated from the substrate placement surface.
A substrate processing apparatus comprising:   The cover member is in contact with the substrate mounting table in a mounting state in which the substrate to be processed is in contact with the substrate mounting surface, and in the separated state in which the processing substrate is separated from the substrate mounting table. The substrate processing apparatus according to claim 1, wherein the substrate processing apparatus is separated from the mounting table.   The substrate processing apparatus according to claim 2, wherein the cover member is displaced in conjunction with the substrate to be processed by a common displacement mechanism.   4. The substrate processing apparatus according to claim 1, wherein the cover member is a ring-shaped member having an opening having a size corresponding to the substrate to be processed.   The substrate processing apparatus according to claim 4, wherein an outer diameter of the cover member is larger than an outer diameter of the substrate mounting table. A substrate mounting table in which a substrate to be processed is mounted on a substrate mounting surface in a processing container and heated by a heating means,
A substrate support that displaces the substrate to be processed into a placement state in contact with the substrate placement surface and a separated state separated from the substrate placement surface;
A cover member that is provided so as to be displaceable between a state in contact with the substrate placement surface and a state in which the substrate placement surface is separated from the substrate placement surface.
A substrate mounting table characterized by comprising:   A substrate processing method, comprising: processing a substrate to be processed using the substrate processing apparatus according to claim 1.   8. The substrate according to claim 7, wherein a pre-coating process is performed in a state where a dummy substrate is mounted on the substrate mounting table, and then a substrate to be processed is mounted instead of the dummy substrate. Processing method.   The substrate processing method according to claim 7, wherein the process for the substrate to be processed is a film forming process.

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