JPH0626194B2 - Wafer heat treatment equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wafer heat treatment apparatus having a vertical structure, and in particular, it oxidizes and diffuses on a surface of a wafer housed in a container while flowing a predetermined gas. The present invention relates to a wafer heat treatment apparatus that performs various heat treatments such as vapor deposition or etching.

“Prior Art” Conventionally, as shown in FIG. 6, for example, in a furnace core tube 61 extending in a horizontal direction, a wafer 62 is arranged upright and aligned along an axial direction of the furnace core tube 61. After that, the processing gas introduced from the side of the tail tube 611 is flowed to the side of the discharge tube 612 while being in contact with the surface of the wafer 62, and various heat treatments such as oxidation, diffusion, vapor phase growth, or etching are performed on the surface of the wafer 62. The horizontal type heat treatment apparatus is known.

In this type of heat treatment apparatus, the processing gas is not sufficiently circulated in order to flow the processing gas along the axial direction of the core between the furnaces substantially orthogonal to the wafer alignment direction, and the front side of the wafer 62a located on the gas introduction side is further reduced. Is always in contact with raw gas, and the rear row side 62b
Since the gas used for wafer processing on the front row side 62a comes into contact with the front row side 62a, the gas concentration in contact with the wafer 62 on the front row side and the rear row side is different, making it difficult to perform uniform wafer processing. become.

Therefore, in the so-called vertical structure heat treatment apparatus,
As shown in the figure, on the side wall surface of the cylindrical furnace tube 71 facing the wafer 72 group arranged in the vertical direction, a plurality of gas introduction holes perforated along the axial direction of the furnace tube 71 so as to face the peripheral edge of the wafer 72. There is also an apparatus in which a heat treatment is performed while a processing gas is made to flow substantially parallel to the surface of the wafer 62 by providing 73 and a discharge port 74. In the figure, 75 is a boat and 76 is a heater.

However, even in such an apparatus, since the gas flow direction is constant, the gas concentration distributions of the starting side and the ending side of the wafer 72 in contact with the raw gas also change, and it is difficult to perform uniform wafer processing.

Therefore, the inventors of the present invention filed a patent application (Japanese Patent Application No. 61-296)
No. 636), by rotating the wafer group arranged in the vertical direction together with the boat on the axis of rotation or revolving around the axis of the furnace tube 71, raw gas is allowed to flow sequentially along the circumferential direction of the wafer peripheral edge. We have proposed a device that eliminates the drawbacks.

[Problems to be Solved by the Invention] When the prior invention is applied to a processing furnace having a vertical structure, wafers arranged substantially horizontally are arranged vertically to form a wafer group, Even if the wafer is rotated about the vertical axis, the wafer will not fall off and no problem will occur. However, in a horizontal type heat treatment furnace, the wafers are arranged upright in a substantially vertical direction, and since the upper space of the wafer is open in order to improve the gas circulation, the wafer is placed in the horizontal axis in this state. When it is rotated around the center, the wafer naturally falls off from the boat, the invention of the prior application cannot be applied at all, and as a result, it is impossible to make the concentration distribution of the gas in contact with the wafer uniform. .

Further, even in the vertical heat treatment furnace, the wafer itself rotates, but it is difficult to make the atmospheric gas concentration in the furnace tube 71 uniform because the direction of the gas introduced into the container from the gas outlet is constant. In particular, the treatment gas concentration in the vicinity of the gas inlet is still non-uniform, so that the above-mentioned drawbacks are not always completely eliminated.

In addition, rotating the boat on which the large number of wafers are mounted inevitably causes the drive system to be large in size and consumes a large amount of power. Particles are likely to be generated from a portion or the like.

Therefore, in order to eliminate such drawbacks, it is necessary to manufacture the rotating boat, the pedestal, and the like with good accuracy, preferably with a good weight balance around the rotation axis. It is extremely difficult to manufacture in a well-balanced manner from the viewpoint of design and manufacturing. Therefore, due to the shake at the time of rotation due to the lack of accuracy, not only particles are more likely to be generated, but also the risk of wafer falling off is increased, and in the worst case, the rotating wafer or boat is There is also a case where the gas introducing pipe or the inner surface of the furnace pipe 71 is accidentally struck.

Further, even if it is possible to manufacture with good weight balance at the beginning of manufacturing, since the boat has a heavy weight burden, thermal deformation is apt to occur due to the rotation under high heat, and therefore the above drawbacks are solved. It is difficult. In addition, since the boat has a complicated structure, once it is thermally deformed, it is difficult to repair it, so it will be replaced, but the boat is relatively expensive, which increases maintenance and maintenance costs. It has drawbacks.

In view of the above-mentioned drawbacks of the prior art, the present invention provides a wafer capable of smoothly supplying a predetermined gas into a furnace core tube or other container while achieving a uniform concentration of the processing gas in the atmosphere inside the furnace tube, particularly near the gas inlet. The object is to provide a heat treatment apparatus.

Another object of the present invention is to provide a wafer heat treatment apparatus capable of eliminating the non-uniformity of the gas concentration distribution in contact with the wafer surface aligned on the boat even when the boat is stationary. For the purpose, it is possible to eliminate the above-mentioned various drawbacks caused by rotating the boat.

Another object of the present invention is to provide a wafer heat treatment apparatus which can be easily applied to both a vertical structure heat treatment apparatus and a horizontal structure heat treatment apparatus.

[Means for Solving the Problems] In order to achieve the technical object, the present invention is one or more in which a plurality of gas outlets are bored in a vertical container that houses a wafer and extends in the vertical axis direction. The wafer heat treatment apparatus that extends the gas introduction pipe along the axial direction of the container so that it can face a predetermined portion of the wafer arranged in the container, and heat-treats the wafer surface while flowing a predetermined gas from the outlet. In the above-mentioned introduction pipe, at least a portion where the gas blowing port is perforated is configured to be rotatable, and a plurality of gas blowing ports are perforated around the introduction pipe along a virtual spiral line, and the gas of the blowing port is The outlet is tilted by a predetermined angle so that the blowing direction substantially coincides with the inclination angle of the projection line located on the one circumferential surface side of the introducing pipe when the virtual spiral is projected horizontally. And characterized in that the hole.

That is, to more specifically describe the gas outlet direction of the outlet, the horizontal projection plane corresponding to the front view of the inlet pipe on one side when the inlet pipe is vertically divided into two along the axis, One side of the spiral stripe is formed as an inclined projection line that is substantially parallel, but it is necessary to incline the blow-out port by a predetermined angle so that it substantially matches the inclination angle of the projection line of the spiral spiral on one side. It is a feature.

Further, in the invention according to claim 2, one or a plurality of gas introduction pipes having a plurality of gas outlets are provided in a vertical container which houses the wafer and extends in the vertical axis direction. In a wafer heat treatment apparatus that extends along the axis of a container so as to face a predetermined portion of a wafer and heats the surface of the wafer while flowing a predetermined gas from the blow-out port, a plurality of wafers are formed substantially symmetrically around the axis of the container. Along with arranging the wafer group, a gas introduction pipe having a plurality of gas outlets formed along the container axial direction is provided along the container axis and in the annular space sandwiched between the wafer group and the inner wall of the container. At least, the gas outlet direction of the gas inlet pipe located on the axis of the container has an inclination angle of a projection line located on one circumferential surface side of the inlet pipe when the virtual spiral line is horizontally projected. The blow-out opening is inclined at a predetermined angle so as to substantially match with, and each gas introduction pipe located on the container axis and in the annular space is connected to a rotary shaft portion arranged on the container axis. By being integrally rotated, one of the introducing pipes arranged on the axis of the container is rotated along the axis of the container, while the other introducing pipe is revolvable along the annular space. .

[Operation] According to the technical means, since the gas outlet is perforated so that the gas outlet direction of the outlet substantially matches the inclination angle of the virtual spiral, the gas discharged from the outlet is radially and While swirling, it moves over the entire furnace tube to further homogenize the gas atmosphere temperature in the furnace tube.

Further, according to the invention described in claim 2, one of the introduction pipes arranged on the axis of the container is allowed to rotate along the axis of the container, while the other introduction pipe can be revolved or revolved around the annular cavity. Due to the above configuration, the gas outlet side is not rotated on the wafer side but is revolved around the axis of rotation and / or the container axis. For example, when revolving along the circumference of the wafer, gas always intrudes from the 36 ° direction of the wafer. In addition, the direction of gas intrusion into the wafer becomes indefinite even when it is rotated,
Furthermore, since the gas outlet is rotated by rotation and moves while changing the outlet angle due to revolution, the predetermined gas is evenly dispersed and mixed in the atmosphere in the container, and it is possible to prevent nonuniform treatment gas concentration. .

In particular, ensuring the uniformity of the processing gas concentration of the atmosphere itself in the container is effective in each process of diffusion and CVD (vapor phase growth).
For example, in the diffusion process, the penetration rate of the doping source (BP, etc.) to the wafer surface depends on the concentration gradient of the doping source on the surface, so that this can be made constant and the control of the processing layer thickness becomes easy. Also, in CVD, it becomes easy to control the thickness and density of the grown film.

Further, the gas introduction pipe itself has a simpler structure than a boat because it is simply formed by forming a quartz pipe into a linear shape, a U shape, a vertical U shape, etc., and then forming a gas blowing hole at a desired portion. In addition, it can be easily and accurately machined with good weight balance, and even if it is damaged or thermally deformed, it can be repaired and replaced at low cost, which leads to reduction in maintenance and maintenance costs.

Further, since the gas introduction pipe has a simple structure and does not burden the weight, there is no room for vibration or particles even if a slight misalignment or a straightness shortage occurs, which is also preferable.

Incidentally, when rotating a conventional wafer group, especially when the material of the boat for mounting the wafer is made of quartz glass,
The accuracy degradation due to the thermal deformation of the boat occurred more often, and the boat had to be replaced for a short period of time, but according to the present invention, the boat can be in a stationary state, so that it is not necessary to request high precision, and as a result, In addition, the life of the boat can be extended, and further, the accident of dropping the wafer does not occur.

Further, even when the gas introduction pipe is a rotary structure as in the present invention, the weight burden is small, so that the drive system can be made compact and the power consumption can be reduced.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be exemplarily described in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but merely illustrative examples. Nothing more than.

FIG. 1 shows a heat treatment apparatus having a vertical structure according to an embodiment of the present invention in which the revolution and rotation of a gas introduction pipe are combined. The heat treatment device has a cylindrical shape with a flange between bases 11 and 12 arranged in parallel vertically. In addition to supporting and fixing the furnace tube (1), a vertically movable support base (13) for sealing the lower opening of the furnace tube (1) is provided.

A plurality of boat mounting bases 14 are mounted on the supporting base 13 at symmetrical positions on both sides of the center line, and a heat insulating cylinder 15 is mounted on the mounting base 14.
The boats 3 are installed vertically via the.

Wafers 2 tilted slightly upward are mounted on the boat 3 aligned vertically. In addition, a gas exhaust pipe 4 opening on a mounting base 14 is penetrated through an elevating shaft 131 for advancing and retracting the supporting base 13, and a predetermined gas after the wafer 2 processing is exhausted from a gap between the heat insulating cylinder 15 and the mounting base 14. Led to tube 4,
It is configured so that it can be discharged to the outside.

On the other hand, the upper base 12 is rotatably supported by a gas introduction pipe 5 that penetrates into the furnace pipe 1 along the central axis of the furnace pipe. The introduction pipe 5 is located outside the furnace pipe 1 above the base 12. Is connected to a gear train 17 for transmitting the rotation of the motor 16, is configured to be rotatable at a predetermined rotation speed by receiving the rotation of the motor 16, and is branched into three forks immediately after entering the furnace tube 1, It consists of one gas blowout hole perforation site 5A that hangs along the central axis, and a pair of perforation sites 5B and 5C that hang at symmetrical positions between the boat 3 and the inner peripheral wall of the furnace tube 1.

Each of the blowout hole perforation sites 5A is formed of a quartz tube with a sealed tip, and one perforation site 5A is hung along the central axis of the furnace tube 1 sandwiched between the boats 3 on the left and right sides. A plurality of gas blowout ports 6A are bored along the tube axis direction on both sides of the periphery of the site 5A facing the wafer 2 group.

The other pair of perforated parts 5B and 5C are respectively the boat 3 and the furnace tube.
1 Hanging at symmetrical positions between the inner peripheral walls, the perforated parts 5B, 5
A plurality of gas outlets 6B, 6C are bored along the tube axial direction on the circumference of one side of the wafer C facing the second group of wafers. In the figure, 20 is a heater.

According to such an embodiment, by rotating the motor 16, the one perforated portion 5A hung along the central axis line rotates and the other pair of pierced portion 5B hangs in a symmetrical position with respect to the central axis line. , 5C while revolving, the processing gas supplied from the rotating shaft passes through the perforated parts 5A, 5B, 5C and blows out 6A, 6B,
The gas is discharged from 6C into the furnace tube 1, and the gas flows in parallel along the surface of the wafer 2 while swirling in the furnace tube 1 by the rotation and the revolution, respectively, so that the operation of the present invention is smoothly achieved.

It should be noted that in the above-described embodiment, the wafer base 2 itself can be revolved by arranging the support base 13 to rotate, and such a structure is preferable in terms of achieving uniform gas concentration.

FIG. 2 shows a heat treatment apparatus having a vertical structure according to an embodiment of the present invention in which a plurality of gas introduction pipes are configured to be rotatable. The furnace tube 21 has a cylindrical dome shape in order to focus on the differences between the embodiments. And is hermetically supported on the base 22.

The base 22 is provided with a boat mount 33 on the central axis, and the heat insulating cylinder 15
The boat 3 is installed via the, and the gas discharge pipe 23 is hung from the mounting table 33 toward the outside of the furnace and bent at an intermediate position.

The gas introduction pipes 24 and 25 are vertically arranged at symmetrical positions between the boat 3 in the furnace pipe 21 and the inner peripheral wall of the furnace pipe 21, and the lower end side of the gas introduction pipes 24 and 25 is a vertical rising portion 26A of the base 22 and the gas supply pipe 26. , 26B are rotatably supported by a pair of bearings 27, and the lower end side of the gas supply pipe 26 has a vertical rising portion 26A,
Open inside 26B.

Further, the gas introduction pipes 24 and 25 are provided outside the furnace pipe 21 by rotating gears 28A and 28B.
Motor fitted through the drive gear 30 fitted to the one gas introduction pipe 24 side, meshed with the relay gear 29 rotatably supported in the discharge pipe 23 in a free state. The gas introduction pipes 24 and 25 are configured to rotate together at the same peripheral speed while rotating the rotational force of 31 in the order of the rotary gear 28A, the relay gear 29, and the rotary gear 28B.

Further, the gas introduction pipe 5 penetrating into the furnace pipe 1 along the central axis of the furnace pipe shown in FIG. 1 is an axial circumference of the gas introduction pipes 24, 25 shown in FIGS. 2 and 3 facing the wafer 2 group. As shown in FIG. 4, a large number of gas outlets 32 are formed in a spiral shape (32A) along the tube axis direction.

That is, a large number of gas outlets 32 are bored around the introduction pipes 5, 24, 25 along the virtual spiral 32A, and the gas outlet direction 32B of the outlet 32 projects the virtual spiral 32A horizontally. At this time, the blowout port 32 is inclined at a predetermined angle so as to be perforated so that the inclination angle of the projection line located on the one circumferential surface side of the introduction pipe substantially matches.

In other words, in other words, the gas blowing direction of the blowing port 32 corresponds to a front view of the introduction pipe on one side when the introduction pipes 5, 24 and 25 are vertically divided into two along the axis. On the horizontal projection plane, one side of the spiral strip 32A is formed as an inclined projection line that is substantially parallel, but the outlet 32 is formed so as to substantially match the inclination angle of the projection line of the one side spiral strip 32A. Punch by inclining at a predetermined angle.

According to this embodiment, the rotation of the motor 31 causes the relay gears to rotate.
Both gas introduction pipes 24 and 25 rotate at the same speed via 29, and since the blowout port 32 is perforated in a spiral shape, the gas discharged from the blowout port 32 is radiated and swirled in the furnace. It moves over the entire area of the tube 21 to make the gas atmosphere temperature in the furnace tube 21 more uniform.

FIG. 3 shows another embodiment in which the group of wafers 2 is rotated along with a plurality of gas introducing pipes 24 and 25. The mounting base 33 of the second embodiment is not fixed to the base 22 and is used as a base. The relay gear 29 is fixedly mounted via a cylindrical pipe 34 that is rotatably supported by the base 22.

According to this embodiment, rotation of the motor 31 causes rotation of the rotary gear.
28A-Relay gear 29-Rotating gear 28B co-rotatably rotates both gas introduction pipes 24 and 25 at the same speed, and the boat 3 and wafer 2 group also rotate via the mounting base 33 to rotate the outer wafer. 2 A more uniform gas concentration distribution in contact with the surface can be achieved.

"Effects of the Invention" As described above, according to the present invention, the atmosphere in the furnace tube,
In particular, it is possible to smoothly supply the predetermined gas into the container while achieving the uniformization of the concentration of the processing gas near the gas introduction port.

Further, in particular, the present invention can eliminate the non-uniformity of the gas concentration distribution in contact with the wafer surface aligned on the boat even when the boat is stationary, which results in the case where the boat is rotated. It is possible to eliminate the various drawbacks described above that occur.

It has various remarkable effects.

[Brief description of drawings]

FIG. 1 is a heat treatment apparatus having a vertical structure according to an embodiment of the present invention in which the revolution and rotation of a gas inlet pipe are combined, and FIG. 2 is another embodiment of the present invention in which a plurality of gas inlet pipes are rotatable. FIG. 3 shows another embodiment of the present invention in which a wafer group is rotated along with a plurality of gas introducing pipes, and FIG. 4 is shown in FIGS. 2 and 3. FIG. 3 is an enlarged cross-sectional view of a main part of the gas introduction pipe, showing a state in which a large number of gas outlets are spirally formed. FIG. 5 and FIG. 6 are cross-sectional views showing a vertical structure heat treatment apparatus and a horizontal structure heat treatment apparatus according to the prior art, respectively.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 21/31 E (56) References JP-A-48-41670 (JP, A) JP-A-60-200521 ( JP, A) JP 60-21538 (JP, A) JP 58-146436 (JP, A)

Claims (2)

[Claims] 1. A vertical part of a wafer in which a wafer is housed and one or more gas introducing pipes having a plurality of gas outlets are provided in a vertical container extending in the vertical axis direction. In a wafer heat treatment apparatus that extends along the container axial direction so as to be able to face the wafer and heat-treats the wafer surface while flowing a predetermined gas from the blowout port, at least the gas blowout port of the introduction pipe is perforated And a plurality of gas outlets are formed around the introduction pipe along a virtual spiral line, and the gas outlet direction of the outlet port is the same when the virtual spiral line is projected horizontally. A wafer heat treatment apparatus, characterized in that the blow-out opening is inclined at a predetermined angle so as to substantially match the inclination angle of a projection line located on one side peripheral surface side of the introduction tube. 2. A vertical container for accommodating wafers and extending in the vertical axis direction, wherein one or a plurality of gas introducing pipes having a plurality of gas outlets are provided in a predetermined portion of the wafer. In a wafer heat treatment apparatus that extends along the axis of the container so as to face each other and heat-treats the wafer surface while flowing a predetermined gas from the outlet, a plurality of wafer groups are arranged substantially symmetrically around the axis of the container. On the axis of the container, and in the annular space sandwiched between the wafer group and the inner wall of the container, extending gas introduction pipes having a plurality of gas outlets along the axial direction of the container, respectively, and at least the container The gas blowing direction of the blowing port of the gas introducing pipe located on the axis line is substantially the same as the inclination angle of the projection line located on the one side peripheral surface side of the introducing pipe when the virtual spiral line is projected horizontally. As described above, the blow-out port is inclined at a predetermined angle and perforated, and further, the respective gas introduction pipes located on the container axis and in the annular space are connected to a rotary shaft portion arranged on the container axis to be integrally formed. A wafer heat treatment apparatus characterized in that one of the introduction pipes arranged on the axis of the container is made to rotate along the axis of the container by rotating, while the other introduction pipe is configured to be able to revolve along the annular space. .