JP5399771B2 - Deposition equipment - Google Patents

Description

The present invention relates to a film forming equipment, and more particularly, to a deposition apparatus for forming a film on a substrate while heating the substrate.

  In manufacturing an epitaxial wafer in which a single crystal film such as silicon is grown on a wafer as a substrate, a single wafer type film forming apparatus is often used.

  A conventional single wafer type film forming apparatus includes a film forming chamber, a base on which the film forming chamber is loaded, a gas supply means for supplying a reaction gas to the film forming chamber, a wafer heating means, and the like. A hollow cylindrical column extending upward into the film forming chamber is attached to the lower surface of the base.

  Wafer heating means is attached to the upper surface of the support column. On the other hand, the lower surface of the column is closed by the lower lid. Two wiring members that pass through the lower lid and are fixed to the column are provided inside the column. The two wiring members extend through the upper end portion of the support to the wafer heating means in the film forming chamber.

  The wafer heating means includes a heater and a conductive heater support. The heater is fixed to the heater support, and the heater support is fixed to the upper surface of the column. Thereby, the heater is structured to be fixed to the column. Further, the two wiring members are respectively connected to the heater support portion, and power can be supplied to the heater via the heater support portion.

  A susceptor for holding a wafer is provided in the film forming chamber, and this susceptor is rotatable. In other words, the cylindrical support column is provided with a hollow rotating shaft so as to surround the periphery thereof. The rotating shaft is attached to the base so as to be rotatable independently of the support by a bearing, and is rotated by a separate motor. A rotating cylinder is connected to the rotating shaft, and the susceptor rotates above the wafer heating means by attaching the susceptor to the upper surface of the rotating cylinder.

  Therefore, in such a film forming apparatus, the wafer is heated by a heater provided below the susceptor while rotating while being placed on the susceptor. Then, the reactive gas is supplied through the gas supply means, whereby an epitaxial film is formed on the wafer.

  Patent Document 1 discloses a film forming apparatus of a type in which a single wiring component passes through a lower lid of a hollow cylindrical column and is fixed at a lower portion and an upper portion of the column.

JP-A-5-152207

  In the film forming apparatus as described above, the temperature of the wafer may become a high temperature exceeding 1000 ° C. by the heating by the wafer heating means during the vapor phase growth. At this time, the wafer heating means also becomes hot and causes thermal expansion. Considering this, if the wafer heating means is made of a flexible metal, it is possible to prevent the wafer heating means from being cracked by heat. However, metal is not preferred because it may contaminate the wafer.

  Therefore, materials other than metal are used for the wafer heating means. Specifically, high-purity SiC or the like is used for the heater at the highest temperature, and SiC-coated carbon or the like is used for the conductive heater support that supports the heater. Moreover, molybdenum etc. are used for the wiring components arrange | positioned in the inside of the support | pillar whose temperature reached is a little lower than a heater.

  SiC or carbon coated with SiC is inferior in flexibility as compared with metal materials, although there is no risk of metal contamination of the wafer. On the other hand, as described above, the heater is fixed to the support via the rigid heater support. For this reason, there is no way to eliminate the stress generated in the heater due to thermal expansion at a high temperature, and a crack may occur in the heater or the heater support.

  The present invention has been made in view of these problems. That is, an object of the present invention is to provide a film forming apparatus provided with a mechanism for reducing stress generated in a heater and a heater support portion constituting a wafer heating unit during heating of a wafer.

  Other objects and advantages of the present invention will become apparent from the following description.

The present invention includes a film formation chamber,
Placed in a deposition chamber, a heater formed of a non-metallic heating the substrate,
A heater support portion formed of a nonmetal that supports the heater at its upper end and supplies power to the heater ;
Is characterized in Rukoto an elastic portion provided at a position separated from the upper end of the heater support.

  When the heater support portion includes a first support portion extending in the vertical direction and having an upper end in contact with the heater and a second support portion extending in the horizontal direction from the lower end of the first support portion, the elastic portion includes the second support portion. It is preferable that it is provided in the support part.

  The elastic portion may be a leaf spring portion provided with a cut in a direction perpendicular to the direction in which the stress due to heating of the heater acts on the heater support portion.

  The film forming apparatus of the present invention may further include a rotating cylinder in which the heater and the heater support portion are disposed, and a rotating mechanism unit that is provided at a lower portion of the film forming chamber and includes a rotating shaft that rotates the rotating cylinder. it can. In this case, an electrode for supplying power to the heater via the heater support portion can be provided inside the rotating shaft.

  The film forming apparatus of the present invention can further include a susceptor on which the substrate is placed. In this case, the susceptor can be disposed on the top of the rotating cylinder, and the heater can heat the substrate through the susceptor.

  According to the present invention, since the heater support part has the elastic part in a part of its structure, the stress generated in the heater and the heater support part can be reduced.

It is typical sectional drawing of the film-forming apparatus of this Embodiment. It is an example of the leaf | plate spring part in this Embodiment, (a) is a perspective view of a leaf | plate spring part, (b) is sectional drawing which follows the AA line of (a).

  FIG. 1 is a schematic cross-sectional view of a single wafer deposition apparatus 100 according to the present embodiment. In this embodiment, a silicon wafer 101 is used as a substrate. However, the present invention is not limited to this, and a wafer made of another material may be used depending on the case.

  The film forming apparatus 100 includes a chamber 102 as a film forming chamber and a base 104 on which the chamber 102 is loaded. On the lower surface side of the base 104, a column 105 having a non-conductive and hollow cylindrical shape that extends upward into the chamber 102 is attached.

  Connected to the upper portion of the chamber 102 is a reaction gas supply path 103 for supplying a reaction gas for forming a crystal film on the surface of the heated silicon wafer 101. In this embodiment mode, trichlorosilane can be used as a reaction gas, and is introduced into the chamber 102 from the reaction gas supply path 103 in a state of being mixed with hydrogen gas as a carrier gas.

  The reaction gas supplied from the reaction gas supply path 103 flows down toward the silicon wafer 101. The chamber 102 may be provided with a current plate having an appropriate number of through holes through which the reaction gas passes on the upstream side in the direction in which the reaction gas flows with respect to the silicon wafer 101 (arrow direction).

  Inside the chamber 102, a susceptor 110 on which the silicon wafer 101 is placed is provided on a hollow rotating cylinder 111. The rotating cylinder 111 is supported by the rotating shaft 112 and is provided so as to surround the periphery of the hollow cylindrical column 105 extending into the chamber 102 from the lower surface of the base 104.

  The rotating shaft 112 is attached to the base 104 so as to be rotatable independently of the support column 105 by a bearing (not shown), and is rotated by a separate motor 113. That is, when the rotating shaft 112 rotates through the motor 113, the rotating cylinder 111 attached to the rotating shaft 112 rotates, and the susceptor 110 provided on the rotating cylinder 111 also rotates.

  Wafer heating means 120 is attached to an upper portion of a hollow cylindrical column 105 extending into the chamber 102. The column 105 and the wafer heating means 120 are closed with an upper lid 106 in order to prevent contaminants from flowing into the chamber 102.

  The surface temperature of the silicon wafer 101 that changes due to heating is measured by a radiation thermometer (not shown) provided at the top of the chamber 102. For this reason, it is preferable that the chamber 102 is made of quartz so that the temperature measurement by the radiation thermometer is not hindered by the chamber 102. The same applies when a current plate is provided.

  Next, the structure of the main part of the film forming apparatus of this embodiment will be specifically described.

  As shown in FIG. 1, the shape of the upper surface of the support column 105 may be a flange shape, that is, a shape having a portion protruding so as to protrude from the cylindrical member. In this case, it is preferable that an edge rising upward is provided around the protruding portion. Since the upper end portion of the support column 105 has such a shape, the attachment of the wafer heating means described below can be made more reliable. Note that this embodiment is not limited to this, and the shape of the upper surface of the support column 105 may be a donut shape.

  Two electrodes 107 a and 107 b are provided inside the hollow cylindrical column 105. All of these electrodes have electrode bars 108a and 108b and booth bar support portions 124a and 124b that support booth bars 123a and 123b, which will be described later, while being fixed to the upper end portions of the electrode bars 108a and 108b.

  The booth bar support portions 124 a and 124 b have shapes extending from the upper end portions of the electrode bars 108 a and 108 b in the circumferential direction of the support column 105. Therefore, the upper portions of the electrodes 107a and 107b are L-shaped with the electrode rods 108a and 108b and the booth bar support portions 124a and 124b. The electrode rods 108a and 108b and the booth bar support portions 124a and 124b are both made of molybdenum (Mo).

  An electrode fixing portion 109 is disposed below the rotating shaft 112. The two electrode rods 108 a and 108 b are fixed to the electrode fixing portion 109 and extend to the upper end side of the support column 105. The electrode fixing portion 109 also functions as a lower cover of the hollow cylindrical rotating shaft 112.

  The wafer heating means 120 includes a heater 121 that heats the substrate, and two arm-shaped booth bars 123a and 123b that fix and support the heater 121 as a heater support portion. The booth bars 123a and 123b are supported by the above-described booth bar support portions 124a and 124b at the end opposite to the side supporting the heater 121. The booth bar 123a is fixed and integrated with the booth bar support portion 124a by bolting or the like, and similarly, the booth bar 123b is fixed and integrated with the booth bar support portion 124b.

  Specifically, the electrodes 107a and 107b are both L-shaped at the top, and the booth bars 123a and 123b and the top of the support column 105 have shapes that engage with the L-shaped portions, respectively. Yes. And the L-shaped part of electrode 107a, 107b is being fixed to booth bar 123a, 123b with the volt | bolt 131 inserted in the hole provided in the said shape part of the booth bar 123a, 123b.

  The heater 121 is configured using SiC. The two arm-shaped booth bars 123a and 123b that support the heater 121 are made of a conductive high heat resistant member, for example, a carbon material coated with SiC. Furthermore, the booth bar support portions 124a and 124b are made of molybdenum in the same manner as the electrode rods 108a and 108b. Thus, power can be supplied from the electrodes 107a and 107b to the heater 121 via the booth bars 123a and 123b which are heater support portions.

  As shown in FIG. 1, in the fixed and integrated booth bar 123a and the booth bar support portion 124a, the lower surface of the booth bar support portion 124a protrudes so as to protrude from the upper end of the support column 105, that is, the cylindrical member of the support column 105. It is in contact with at least a part of the upper surface of the part. In addition, at least one of the booth bar 123 a and the booth bar support portion 124 a is in contact with the edge of the upper surface of the support column 105. The booth bar 123a and the booth bar support portion 124a are fixed to the support column 105 by such support of at least two points.

  Further, the other booth bar 123b and the booth bar support portion 124b which are fixed and integrated are also fixed to the support column 105 by the same method as described above. With this structure, the heater can be supported by the heater support portion.

  As described above, the interior of the chamber 102 has a temperature exceeding 1000 ° C. during the vapor phase growth. For this reason, high-purity SiC is used for the heater 121 having the highest temperature, and SiC-coated carbon is used for the conductive booth bars 123a and 123b that support the heater. However, SiC or SiC-coated carbon does not have the flexibility that metal materials have. Therefore, under the high temperature when heating the silicon wafer 101, the heater 121 is thermally expanded by its own temperature rise, and as a result, stress is generated inside. Here, if the heater 121 is configured to be supported on the upper surface of the support column 105 via the booth bars 123a and 123b and the booth bar support portions 124a and 124b having high rigidity, the stress generated in the heated heater 121 There is no way to solve the problem. As a result, the heater 121 and the booth bars 123a and 123b are cracked.

  Therefore, in the present embodiment, as shown in FIG. 1, a leaf spring portion 125 is provided on the booth bar 123b. Stress due to heating of the heater 121 is generated from the heater 121 along the booth bar 123a and the booth bar 123b. Therefore, by making the leaf spring portion 125 a structure in which a cut 125a is provided in a direction perpendicular to the direction in which the stress acts, the leaf spring portion 125 absorbs the stress and causes the heater 121 and the booth bars 123a and 123b to absorb the stress. Generation of cracks can be prevented.

  That is, if the booth bar 123b is provided with the leaf spring portion 125, even if stress is generated in the heated heater 121, the heater 121 and the booth bar 123b can extend and change their own dimensions. Can be eliminated. In other words, even if the heater 121 generates an internal stress due to an increase in temperature, the heater 121 and the booth bar 123b can change their positions using the deformation of the leaf spring portion 125. Deformation that relieves stress can be brought to the heater 121 and the booth bar 123b.

  As shown in FIG. 1, the booth bar 123b that supports one end of the heater 121 is fixed to the booth bar support part 124b, and the electrode bar 108b is fixed to the booth bar support part 124b. The electrode rod 108b is fixed to the electrode fixing portion 109 at the lower end thereof. According to the configuration of the present embodiment, the influence of the stress generated in the heater 121 reaches the booth bar 123b, but the stress is absorbed by the leaf spring portion 125, so the booth bar support portion 124b, the electrode rod 108b, and the electrode fixing It hardly reaches the part 109. In addition, since the stress is absorbed by the leaf spring portion 125, the influence of the stress on the booth bar 123a becomes small.

  The electrode fixing portion 109 is disposed below the rotating shaft 112, but is not exposed to such a high temperature because it is outside the chamber 102. Therefore, it is possible to select materials from a relatively wide temperature range from the viewpoint of heat resistance. Specifically, it is preferable to use a relatively flexible member that has appropriate heat resistance and can absorb even stress applied from the heater 121. A resin material is suitable as the member having such characteristics. In the present embodiment, it is preferable to configure the electrode fixing portion 109 using a fluororesin that can be used without deterioration even under the temperature environment of the above conditions.

  Thus, in the film-forming apparatus 100 of this Embodiment, the leaf | plate spring part 125 is provided in the booth bar 123b. Thus, the film forming apparatus 100 includes a mechanism for eliminating stress generated in the heater 121 that constitutes the wafer heating unit 120. As a result, when the silicon wafer 101 is heated, it is possible to sufficiently suppress the occurrence of cracks and breakage in the heater 121 and the booth bars 123a and 123b.

  A leaf | plate spring part should just be provided in any one of the booth bar 123a and the booth bar 123b, and may be provided in the booth bar 123a. Even if the leaf spring portion is provided on one of the booth bars, the fixing of the heater 121 can be realized sufficiently firmly by the other booth bar.

Further, the leaf spring portion may be provided in a part of the booth bar, but it is preferable to provide the leaf spring portion in a portion extending in the horizontal direction rather than a portion extending in the vertical direction of the booth bar. For example, as shown in FIG. 1, the booth bar 123 b includes a first support portion 123 b ₁ that extends in the vertical direction and has an upper end that contacts the heater 121, and a second support portion that extends in the horizontal direction from the lower end of the first support portion 123 b ₁ . and a support portion 123b _2. Like this example, it is preferable that the leaf | plate spring part 125 is provided in the _2nd support part 123b2. This is because the load by the heater 121 is applied to the first support portion 123b _1, and therefore, it is possible to effectively absorb the stress by providing the leaf spring portion 125 on the second support portion 123b ₂ . The same applies to the booth bar 123a.

  Moreover, it can replace with a leaf | plate spring part and the effect of this invention can be acquired also by comprising a part of booth bar with the material from which an elasticity modulus differs. That is, most of the booth bar is made of a carbon material coated with SiC, and a part of the booth bar serving as an elastic portion is made of a material having a larger elastic modulus. Thereby, the stress which generate | occur | produces by the thermal expansion at the time of the temperature rising of the heater 121 can be absorbed by an elastic part.

  In the present embodiment, the leaf spring portion may be structured as shown in FIG. FIG. 2A is a perspective view of the leaf spring portion, and FIG. 2B is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 2A and 2B, the leaf spring portion 200 includes a leaf spring portion main body 201 and a rod-like member 202. A concave portion 203 is provided in the leaf spring portion main body 201 along the longitudinal direction thereof, and the rod-like member 202 is fitted into the concave portion 203 and fixed to a predetermined position of the concave portion 203 with a screw 204. The leaf spring portion main body 201 is provided with a cut 205. The leaf spring portion 200 is arranged so that its longitudinal direction is parallel to the portion of the booth bar extending in the horizontal direction. In this case, since the stress generated by heating the heater acts along the longitudinal direction, the notch 205 is provided in a direction perpendicular to the longitudinal direction, as shown in FIG.

  In the example of FIGS. 2A and 2B, the concave portion 203 is provided on one side surface of the leaf spring portion main body 201, but the concave portion is provided on both side surfaces, and each of the two rod-like members has these concave portions. You may make it fit in.

A material having heat resistance and conductivity such as molybdenum (Mo) or tungsten (W) is used for the leaf spring body 201. On the other hand, the rod-shaped member 202 is made of a material having heat resistance and insulating properties such as silicon dioxide (SiO ₂ ), alumina (Al ₂ O ₃ ), and aluminum nitride (AlN). In particular, when used at a high temperature of 700 ° C. or higher, aluminum nitride is preferably used.

  By setting the leaf spring portion to the configuration shown in FIGS. 2A and 2B, the following effects can be obtained. First, since the notch 205 is provided in the leaf spring portion main body 201, the stress generated by the heating of the heater can be absorbed by the leaf spring portion 200, thereby preventing the heater and the booth bar from cracking. Secondly, since the recessed portion 203 is provided in the leaf spring main body 201 and the rod-like member 202 is fitted and fixed to the recessed portion 203, the movement of the booth bar is restricted, and the booth bar is greatly displaced from a predetermined position. Can be prevented. Note that if the rod-like member 202 is firmly fixed to the leaf spring main body 201, the stress generated by the heating of the heater may be difficult to be eliminated. Therefore, it is preferable that the screw 204 has a certain amount of play by making the screw hole 206 fitted to the screw 204 into a long hole.

  Next, the film forming method of the present invention will be described.

  In this embodiment, a silicon epitaxial film is formed using the film formation apparatus 100.

  First, the silicon wafer 101 is carried into the chamber 102. Next, the silicon wafer 101 is placed on the susceptor 110 and attached to the rotating cylinder 111, and the silicon wafer 101 is rotated at about 50 rpm.

  Next, the heater 121 is operated to heat the silicon wafer 101. For example, the film is gradually heated to a film forming temperature of 1150 ° C. After confirming that the temperature of the silicon wafer 101 has reached 1150 ° C. by measurement with a radiation thermometer (not shown), the rotational speed of the silicon wafer 101 is gradually increased. Then, the reaction gas is caused to flow onto the silicon wafer 101 from the reaction gas supply path 103.

  In the film forming apparatus 100, a heater 121 is disposed inside the rotating cylinder 111. Booth bars 123a and 123b that support the heater 121 are fixed to the rotating mechanism unit 130 via two electrodes 107a and 107b. Since the leaf spring portion 125 is provided in the booth bar 123b, it is possible to sufficiently suppress the occurrence of cracks and breakage in the heater 121 and the booth bars 123a and 123b when the silicon wafer 101 is heated.

  After the epitaxial film having a predetermined thickness is formed on the silicon wafer 101, the supply of the reaction gas is terminated. Thereafter, after confirming that the silicon wafer 101 has been cooled to a predetermined temperature, the silicon wafer 101 is carried out of the chamber 102.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the film is formed while rotating the silicon wafer, but the film may be formed without rotating the silicon wafer. In the above embodiment, the silicon wafer is placed on the susceptor and the silicon wafer is heated through the susceptor. However, the silicon wafer may be directly heated without passing through the susceptor. However, if it is configured to heat through the susceptor, the rotating cylinder is covered with the susceptor, so that inflow of contaminants from the rotating cylinder can be prevented. Furthermore, in the above-described embodiment, an epitaxial growth apparatus is described as an example of a film forming apparatus, but the present invention is not limited to this. Any other film forming apparatus may be used as long as it supplies a reactive gas into the film forming chamber and heats the substrate placed in the film forming chamber to form a film on the surface of the substrate.

DESCRIPTION OF SYMBOLS 100 Film-forming apparatus 101 Silicon wafer 102 Chamber 103 Reaction gas supply path 104 Base 105 Support column 106 Upper lid 107a, 107b Electrode 108a, 108b Electrode rod 109 Electrode fixing part 110 Susceptor 111 Rotating cylinder 112 Rotating shaft 113 Motor 120 Wafer heating means 121 Heater 123a , 123b Booth bar 124a, 124b Booth bar support part 125, 200 Leaf spring part 125a Notch 130 Rotating mechanism 131 Bolt 201 Leaf spring part body 202 Bar-shaped member 203 Recessed part 204 Screw 205 Notch 206 Screw hole

Claims (5)

A deposition chamber;
Is installed in the deposition chamber, a heater formed of a non-metallic heating the substrate,
A heater support portion formed of a non-metal that supports the heater at its upper end and supplies power to the heater;
A film forming apparatus, comprising: an elastic portion provided at a position separated from an upper end of the heater support portion . The heater support portion includes a first support portion that extends in a vertical direction and has an upper end in contact with the heater, and a second support portion that extends in a horizontal direction from a lower end of the first support portion,
The film forming apparatus according to claim 1, wherein the elastic portion is provided in the second support portion.   The said elastic part is a leaf | plate spring part by which the notch was provided in the direction orthogonal to the direction where the stress by the heating of the said heater acts with respect to the said heater support part, The Claim 1 or 2 characterized by the above-mentioned. Deposition device. A rotating cylinder in which the heater and the heater support are disposed;
A rotation mechanism provided at a lower portion of the film formation chamber and provided with a rotation shaft for rotating the rotating cylinder;
The film forming apparatus according to claim 1, wherein an electrode that supplies power to the heater via the heater support portion is provided inside the rotation shaft. A susceptor on which the substrate is placed;
5. The film forming apparatus according to claim 1, wherein the susceptor is disposed on an upper portion of the rotating cylinder, and the heater heats the substrate via the susceptor.

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