JP2000124133A - Epitaxial growth furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epitaxial growth furnace equipped with a rotating means, which is capable of efficiently heating a semiconductor wafer and satisfactorily rotating the wafer without having an adverse effect on a drive system. SOLUTION: A cylindrical drum 2 is arranged rotatably in a non-reaction space separated by a partition from a reaction space in a reaction chamber 1, a semiconductor wafer 10 is held by the chuck of the cylindrical drum 2, so as to enable its surface where a film is epitaxially grown to be exposed to a reaction space blocking the one opening of the cylindrical drum 2, and the drum 2 is rotated as a rotor by a rotation drive device provided to the outer surface of the drum 2. With this setup, the semiconductor wafer 10 is rotated, and the backside of the semiconductor wafer 10 held at the opening of the drum 2 is irradiated with radiating heat by a heating means (heater 9).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epitaxial growth furnace for forming an epitaxial layer on a surface of a semiconductor wafer, and more particularly, to a rotating means for rotating a semiconductor wafer in the furnace.

[0002]

At present, the hydrogen carrier on a silicon substrate heated to a high _{temperature, SiCl 4, SiHCl 3, SiH} 2 Cl 2
Alternatively, a silicon source gas such as SiH ₄ is supplied to deposit and grow a silicon single crystal on the substrate through an H-Si-Cl-based reaction.
or deposition) method is most widely studied and applied as a silicon epitaxial growth method.

In such an epitaxial growth, a target semiconductor wafer is held on a susceptor in a shield chamber, and a material gas is fed into the chamber while being heated by a radiant heating method using, for example, a halogen lamp or an infrared lamp. Is used. The material gas is supplied to a growth target surface of the semiconductor wafer, and an epitaxial growth layer is formed on the surface.

Usually, in order to form a uniform epitaxial growth layer over the entire surface of the semiconductor wafer to be grown, during the epitaxial growth process, the semiconductor wafer is rotated while maintaining a uniform heating state and material gas supply. Performing a growth reaction.

[0005]

In a conventional epitaxial growth furnace, an electric motor is used to rotate a semiconductor wafer. As a method for mounting the motor, the motor is installed outside the reaction chamber, and rotation is transmitted to a susceptor or the like on which a wafer in the chamber is mounted via a transmission system through a seal portion provided on the chamber wall. Or a configuration in which an electric motor is installed in the chamber.

However, when the former electric motor is installed outside the chamber, it is necessary to make the seal through which the transmission system is as small as possible in order to strengthen the shield of the chamber. As a rotation axis. The heater installation position is further away from the chamber, that is, the wafer, by the rotation axis protruding out of the chamber, which lowers the heating efficiency for the wafer during the epitaxial growth reaction.

On the other hand, when the electric motor is installed in the chamber, the heater can be closer to the chamber than in the former case, but the motor itself is not only heated but also exposed to various gases supplied into the chamber. And may adversely affect the drive. In some cases, the reaction gas accumulates when the material gas touches the electric motor,
Peeled products can also cause wafer contamination.

In recent years, the chamber itself can be made compact due to the increase in the size of the chamber accompanying the increase in the diameter of the semiconductor wafer, and at the same time, the heating conditions, gas flow distribution, etc. can be easily designed, and the uniformity of the epitaxial film characteristics can be improved. A vertical type (where the surface is vertical) that can prevent warpage due to its own weight, which can cause crystal defects of the wafer, and can simultaneously perform epitaxial growth of one or more semiconductor wafers is adopted. It is considered that the method is suitable for a large-diameter wafer, but it is structurally difficult to install an electric motor in a vertical growth furnace by any method.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an epitaxial growth furnace having a rotating means capable of efficiently heating a semiconductor wafer without fear of particle contamination and simultaneously rotating the wafer without adversely affecting a driving system. The purpose is to provide. Another object of the present invention is to provide an epitaxial growth furnace provided with rotating means that can be easily arranged even in the case of a vertical installation type.

[0010]

In order to achieve the above object, in the epitaxial growth furnace according to the first aspect of the present invention, a reaction space in which the material gas flows exclusively and a reference gas containing no material gas flow. A reaction chamber partitioned into two independent spaces, a non-reaction space, a cylindrical drum portion rotatably disposed in the non-reaction space of the chamber, and a growth target surface of a semiconductor wafer exposed in the reaction space. A chuck that holds the semiconductor wafer detachably in the opening so as to close one opening end of the drum portion in the mounted state, and a drum in the chamber with the drum portion as a rotor. The semiconductor device includes a rotation driving device configured on an outer peripheral surface portion, and heating means for irradiating radiant heat to the back surface of the semiconductor wafer held in the opening of the drum portion.

According to a second aspect of the present invention, in the epitaxial growth furnace according to the first aspect, the cylindrical drum portion rotates around a substantially horizontal axis, and the semiconductor wafer is substantially rotated. Are held in a vertical plane.

According to a third aspect of the present invention, there is provided the epitaxial growth furnace according to the first or second aspect, further comprising a flow path for flowing a cooling gas through the outer peripheral surface of the drum portion. Things.

The epitaxial growth furnace according to the invention described in claim 4 is the first, second or third aspect of the present invention.
In the epitaxial growth furnace described in (1), the rotary drive device comprises a gas fluid pressure motor formed on an outer peripheral surface of the drum portion.

According to a fifth aspect of the present invention, in the epitaxial growth furnace according to the fourth aspect, at least a part of a driving gas of the gas fluid pressure motor also serves as a cooling gas. .

Further, in the epitaxial growth furnace according to the invention of claim 6, in the epitaxial growth furnace according to claim 5, the gas fluid pressure motor includes a plurality of vanes on an outer peripheral surface of the drum portion, and the plurality of vanes. A rotor housing provided on the outer peripheral surface of the drum portion,
A stator-side nozzle for flowing a gas as a driving fluid and a cooling fluid into the rotor housing.

According to a seventh aspect of the present invention, in the epitaxial growth furnace according to the second aspect, a pair of cylindrical drum portions for holding a pair of semiconductor wafers such that respective surfaces to be grown face each other. And an annular housing that forms a reaction space independent from the surroundings between the growth target surfaces of the pair of semiconductor wafers.

According to the present invention, a semiconductor wafer is held in a cylindrical drum portion arranged in a non-reaction space in a reaction chamber, and the cylindrical drum portion is rotated and driven. Is doing the rotation. Since the semiconductor wafer is held on the cylindrical drum portion via the chuck so that the growth target surface is exposed to the reaction space and the back surface closes the opening at one end of the cylindrical drum, the wafer back surface is at the other end of the cylindrical drum. From the opening, it is exposed to a non-reaction space in which only a reference gas (or an inert gas) containing no material gas flows.

Therefore, only the non-reaction space including the space inside the cylindrical drum closed by the wafer exists on the back surface side of the wafer, so that the rotation from the conventional electric motor is transmitted to the wafer mounting susceptor. The rotation shaft does not protrude from the center of the wafer back side to the outside of the chamber via the seal part,
Accordingly, the heater can be arranged near the chamber wall closer to the back surface of the wafer. As a result, the semiconductor wafer can be efficiently heated.

The axial length of the cylindrical drum portion is sufficient if the outer peripheral surface portion has a width capable of forming a rotary driving device. Therefore, the distance from the back surface of the wafer to the chamber wall is limited when the rotary shaft of the electric motor protrudes. It does not become so large as the length of the cylindrical portion of the drum portion.

If the cylindrical drum portion of the present invention is rotated about a substantially horizontal axis to hold the semiconductor wafer in a substantially vertical plane, it is particularly useful for a large-diameter semiconductor wafer. The vertical growth furnace can be easily configured.

Further, as the heater is brought closer to the back surface of the wafer, the cylindrical drum portion is also heated and the temperature of the drum rises during the reaction step. Since it is possible to suppress an excessive rise in the temperature of the drum portion, for example, a heater can be arranged at a position very close to the back surface of the wafer, that is, in the drum portion, so that the heating efficiency can be further improved and the apparatus of the entire growth furnace The structure can be made compact.

As a rotary driving device for the drum unit, a configuration in which a gas fluid pressure motor driven by a gas fluid is provided on the outer peripheral surface of the drum unit is simple. This is because there is no danger that the drive system will not be adversely affected by exposure to various gases as in the case of a conventional electric motor unless it is a material gas for depositing reaction products. Further, if the driving gas flow is also used as the cooling gas for cooling the drum section, the piping system can be simplified.

If the gas fluid pressure motor has a configuration in which a plurality of vanes as rotating blades are provided on the outer peripheral surface of the drum, the stator side nozzle is provided in a rotor housing including the vanes and provided on the outer peripheral surface of the drum. The drum can be rotated simply by flowing the driving gas flow to the vane. The driving gas at this time can also serve as a cooling gas for cooling the outer peripheral surface of the drum unit.

Further, by arranging a pair of vertical drums which rotate the semiconductor wafer around a horizontal axis while holding the semiconductor wafer in a vertical plane, a relatively compact reaction chamber is provided at a time, even though the reaction chamber is relatively compact. An epitaxially grown layer can be formed on the semiconductor wafer. That is, a configuration may be adopted in which a pair of semiconductor wafers are held by a pair of drums such that the respective growth target surfaces face each other, and a material gas is passed between the two semiconductor wafer growth target surfaces. At this time, by providing the annular housing that covers the outer periphery of both semiconductor wafers, a reaction space independent from the surroundings can be formed between the respective growth target surfaces of the pair of semiconductor wafers.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, FIGS. 1 and 2 show an epitaxial growth furnace provided with a pair of substantially cylindrical drum susceptors for holding a pair of semiconductor wafers such that the surfaces to be grown face each other. FIG. FIG.
FIG. 2 is a central vertical cross-sectional view as viewed from a side surface in the reaction chamber. FIG.

In the epitaxial growth furnace of the present embodiment,
As shown in FIGS. 1 and 2, a pair of substantially cylindrical drum-shaped susceptors 2 are rotatably supported in the reaction chamber 1. Opposite ends of each of the susceptors 2 are fixed to the pair of semiconductor wafers 10 in a vertical direction via a wafer holder 11 with the respective growth target surfaces facing each other so as to close the openings. There, each opening edge matches the outer peripheral shape of the wafer holder 11, the peripheral portion of the wafer holder 11 is releasably clamped by the lock mechanism R ₂ of the susceptor opening edge.

On the other hand, on the outer peripheral surface of the susceptor 2, a rotating fin 3 having a plurality of vanes arranged in a rotor housing h is attached. The fins 3 are rotated by the gas supply blown from the rotation gas supply pipe 4 to the vanes, and the semiconductor wafer held in a vertical plane together with the wafer holder 11 by the rotation of the susceptor 2 about the horizontal axis accompanying the rotation of the fins 3. 10 is also rotated about a horizontal axis.

As described above, in the present embodiment, since the rotating mechanism is formed on the outer peripheral surface of the susceptor 2, the protrusion from the chamber 1 such as a rotating shaft connected to a conventional electric motor is provided on the back surface of the wafer. Does not exist, and the heater 9 can be arranged close to the chamber wall on the back surface side of the wafer.

Here, by using the rotating gas from the rotating gas supply pipe 4 to cool the outer peripheral surface of the susceptor 2, even if the heater 9 provided near the susceptor 2 heats the susceptor 2, the temperature rises. Can be suppressed. Therefore, in the present embodiment, the cooling by the cooling gas is performed, and the heater 9 is arranged at a position in the cylindrical portion of the susceptor 2 very close to the back surface of the wafer. Thereby, the heating efficiency can be further improved and the entire apparatus can be made compact.

The wafer holder 11 has a ring shape having an opening at the center corresponding to the outer peripheral shape of the wafer 10, and the opening edge has a surface including a chamfered tapered surface of the peripheral edge of the growth target surface of the wafer 10. The outer periphery of the holder 11 itself is engaged with the opening edge of the susceptor 2 without any gap in the entire periphery contact state, as described above.

Therefore, when a material gas is circulated on the surface of the wafer 10, the gap between the susceptor 2 and the wafer holder 11
In addition, the material gas does not flow from between the wafer holder 11 and the wafer 10 toward the back surface of the wafer.

The wafer holder 11 holds the wafer 1 at the periphery of the opening.
And a releasable locking mechanism R ₁ for holding a 0. The locking mechanism R ₂ as wafer holder 11 holding mechanism at the opening of the lock mechanism R ₁ and the susceptor 2, for example, such structures can be locked releasably pinching state by the biasing of the pawl member using spring, respectively What is necessary is just to be able to easily hold the wafer 10 and the holder 11 detachably. However, these movable parts
It is desirable to be located on the back side of the wafer where the material gas does not touch. As a result, it is possible to prevent the reaction products deposited on the movable part and the dust generated by the movement from dropping onto the wafer surface and causing particle contamination.

As described above, the two holders 11 holding the respective wafers 10 are respectively attached to the susceptors 2 in the chamber 1 so that the two wafers 10
Can be positioned and arranged in the chamber 1 with the surfaces to be grown facing each other.

Further, in this embodiment, the chamber 1
A material gas supply nozzle 6 for supplying a material gas in a direction along the wafer surface over the diameter width of the wafer from above the wafer between the two growth target surfaces of the pair of semiconductor wafers 10, and the material gas supply nozzle 6 is opposed to the material gas supply nozzle 6. The entire outer periphery of both wafers 10 is annularly covered with a material gas suction nozzle 7 that sucks a material gas on the downstream side to form a reaction space substantially independent from the surroundings between both wafer growth target surfaces. .

Material gas is supplied into the reaction space from the upper portion of the chamber 1 through a nozzle 6 from a material gas supply pipe 5 penetrating into the chamber 1, and the material gas downstream from the nozzle 7 is sucked from the nozzle 7. Chamber 1 from gas discharge pipe 8
It is discharged outside. The gas supply nozzle 6 is connected to the wafer 1
0 has an arc-shaped slit hole along the substantially upper half circumference,
The gas suction nozzle 7 has an arc-shaped slit hole along the substantially remaining lower half circumference of the wafer 10.

In the independent reaction space between the pair of wafers 10 as described above, the material gas is supplied from the upper side to the lower side, so that the material gas laminar flow along the surfaces only on the front sides of the two wafers 10. Thus, the material gas does not flow toward the back side of the wafer. In addition, a pair of semiconductor wafers 10
Around the reaction space formed between the growth target surfaces, a non-reaction space in which only a reference gas or an inert gas containing no material gas flows (a piping system is not shown) is provided. The rotating gas supplied from the rotating gas supply pipe 4 to the rotating fin 3 for cooling also serves as a rotating gas.
A reference gas or an inert gas containing no material gas may be used.

As described above, in the epitaxial growth furnace according to the present embodiment, the rotating mechanism of the semiconductor wafer is disposed in the reaction chamber. Since there is no electric motor for transmitting the rotation, a heater can be arranged closer to the back surface of the wafer. Also,
The susceptor (cylindrical drum part) can be used if the driving gas sent to the rotating fins, which is the rotating mechanism, is also used as the cooling gas.
Can be cooled and the temperature rise can be suppressed, so that it is possible to arrange the heater at a position very close to the back surface of the wafer in the susceptor drum.

[0038]

As described above, according to the present invention, since the rotating mechanism of the semiconductor wafer is in the non-reaction space in the reaction chamber and the member of the rotating mechanism does not exist on the back side of the wafer, the heating means is located near the wafer. Can be disposed, so that the wafer can be efficiently heated during the epitaxial reaction.

Even when the heating means is disposed outside the reaction chamber, the reaction product accumulates on the chamber wall located between the heating means and the radiant heat, since the back side of the semiconductor wafer is a non-reaction space. , And stable heating can always be performed, so that a high quality epitaxial layer formation wafer can be obtained.

Further, the rotary driving device formed on the outer peripheral surface of the cylindrical drum portion holding the semiconductor wafer is a gas fluid motor, and the outer peripheral portion of the drum portion is cooled by using the driving rotation gas as a cooling gas. So you can
Since the heating means can be arranged at a position very close to the back surface of the semiconductor wafer in the drum portion, the wafer can be heated more efficiently.

Further, in the present invention, the rotary drive device can be easily configured even in a vertical type growth furnace that holds a wafer in a vertical plane, so that the entire growth furnace can be made compact and the efficiency of the epitaxial growth process such as two-wafer processing can be improved. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a reaction chamber of an epitaxial growth furnace as an embodiment of the present invention, as viewed from a side.

FIG. 2 is a schematic front view of the inside of the chamber of FIG. 1 as viewed from the back side of the wafer.

[Explanation of symbols]

1: Reaction chamber 2: Susceptor 3: Rotation fin 4: Rotation gas supply pipe 5: Material gas supply pipe 6: Nozzle (for material gas supply) 7: Nozzle (for gas suction) 8: Gas exhaust pipe 9: Heater 10: semiconductor wafer 11: holder 12: opening peripheral R _{1, R 2:} locking mechanism h: a rotor housing

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masanori Mayuzumi 555-1, Nakanoya, Annaka-shi, Gunma Inside the Super Silicon Research Laboratories Co., Ltd. (72) Inventor Kazutoshi Inoue 555-1, Nakanoya, Annaka-shi, Gunma Inside the Super Silicon Laboratories, Inc. (72) Inventor Masatoshi Gima 555-1, Nakanoya, Annaka-shi, Gunma F-term in the Super Silicon Laboratories Co., Ltd. 5F045 AA06 AB02 AF03 BB15 DP11 EE02 EE20 EF02 EF13 EF20 EG06 EM02 EM03 EM10

Claims (7)

[Claims] 1. A reaction chamber partitioned into two independent spaces, a reaction space in which a material gas flows exclusively and a non-reaction space in which a reference gas containing no material gas flows, and a non-reaction space of the chamber. A cylindrical drum portion rotatably disposed in the reaction space, while holding the growth target surface of the semiconductor wafer exposed in the reaction space, and closing the one opening end of the drum portion in the mounted state. A chuck that detachably holds the semiconductor wafer in a unit, a rotation driving device that is configured on the outer peripheral surface of the drum using the drum as a rotor in the chamber, and a semiconductor wafer that is held in an opening of the drum. A heating means for irradiating the back surface with radiant heat. 2. The epitaxial growth furnace according to claim 1, wherein said cylindrical drum portion rotates around a substantially horizontal axis, and said semiconductor wafer is held in a substantially vertical plane. 3. The fuel cell system according to claim 1, further comprising a flow path through which the cooling gas flows through the outer peripheral surface of the drum portion.
Or the epitaxial growth furnace according to claim 2. 4. The epitaxial growth furnace according to claim 1, wherein said rotary drive device comprises a gas fluid pressure motor formed on an outer peripheral surface portion of said drum portion. 5. The epitaxial growth furnace according to claim 4, wherein at least a part of a driving gas of the gas fluid pressure motor also serves as a cooling gas. 6. The gas fluid pressure motor comprises: a plurality of vanes on an outer peripheral surface of the drum portion; a rotor housing including the vanes and provided on an outer peripheral surface of the drum portion; 6. The epitaxial growth furnace according to claim 5, further comprising: a stator side nozzle for flowing gas as a driving fluid and a cooling fluid. 7. A pair of cylindrical drum portions for holding a pair of semiconductor wafers such that their respective growth target surfaces face each other, and a reaction space independent from surroundings is formed between the respective growth target surfaces of the pair of semiconductor wafers. The epitaxial growth furnace according to claim 2, further comprising an annular housing.