JP7458136B1 - Method for manufacturing a heating source used in semiconductor processing equipment - Google Patents

Abstract

The present invention provides a method for manufacturing a heat source used in a semiconductor processing apparatus that can prevent quality deterioration in heat treatment.
A method for manufacturing a heat source 22 used in a semiconductor processing apparatus 10, in which the heat source 22 includes a continuous annular portion 52 formed in a continuous annular shape in a plan view, and a continuous annular portion 52 connected to the continuous annular portion 52 in a vertical direction. The continuous annular part 52 is formed by combining a pair of semi-annular quartz tubes 56A, and the vertical fixing part 54 is formed by a T-shaped quartz tube 56B to which the semi-annular quartz tubes 56A are connected. A filament is formed by passing the tungsten wire 58 inside the semi-annular quartz tube 56A and the T-shaped quartz tube 56B.
[Selection diagram] Figure 12

Description

The present invention relates to a method for manufacturing a heat source used in semiconductor processing equipment.

In conventional semiconductor processing equipment, a heat treatment process is performed on a silicon substrate. In the heat treatment process, the silicon substrate is heated to 300 to 1200 degrees Celsius, and annealing treatment, oxidation treatment, impurity diffusion treatment, etc. are repeated several dozen times.

Here, in the heat treatment process, a batch processing device heat-treats multiple silicon substrates (for example, about 25 to 200 silicon substrates) at a time, or a single-wafer processing device heat-treats 1 to 4 silicon substrates at a time. be.

As the single wafer processing apparatus, an RTP (Rapid Thermal Processor) apparatus, an annealing apparatus, etc., which rapidly heat a silicon substrate using a quartz tube type heater to which argon gas or halogen gas is added and sealed, are used.

The heat source used in the heat treatment process is a so-called single-end structure heater, and a so-called double-end structure in which power is introduced from both ends of a quartz tube in which a heat generating section made of a single wire or a coil of tungsten wire is arranged continuously inside a rod-shaped quartz tube. A typical example is a structural heater.

Here, for example, in a double-end structure heater, since the silicon substrate is a disk, a circular and annular shape is preferable from the viewpoint of uniform heating. An O-ring made of an elastomer material (for example, bind rubber or fluororubber) is used as a method for holding the heater in an airtight state in the heat treatment chamber. By holding the heater with the O-ring, an airtight state inside the heat treatment chamber is maintained.

Japanese Patent Application Publication No. 2006-78019

However, in the conventional semiconductor processing apparatus, there is a problem that heating unevenness occurs on the silicon substrate during heat treatment of the silicon substrate, and the quality of the heat treatment deteriorates.

In view of the above circumstances, the present invention provides a method for manufacturing a heat source used in a semiconductor processing apparatus, which can prevent quality deterioration in heat treatment.

The present invention is a method for manufacturing a heat source used in a semiconductor processing apparatus through an airtight member , wherein the heat source includes a continuous annular portion formed in a continuous annular shape in a plan view, and a continuous annular portion connected to the continuous annular portion. a vertical fixing part that extends in the vertical direction and is provided with a radiant heat blocking part for blocking radiant heat at a contact portion with the airtight member, and the continuous annular part includes a pair of semi-annular quartz tubes. The vertical fixing part is formed by a T-shaped quartz tube connected to the semi-annular quartz tube, and a filament is formed by passing a tungsten wire through the semi-annular quartz tube and the T-shaped quartz tube. .

After inserting the tungsten wire into the semi-annular quartz tube, it is preferable to connect the pair of semi-annular quartz tubes together by flame processing and then anneal them at a predetermined temperature to remove processing distortion.

It is preferable to form a seal at the tip of the T-shaped quartz tube by flame processing.

According to the present invention, it is possible to prevent seal deterioration of a heat source holding mechanism used in a semiconductor processing apparatus.

1 is a longitudinal cross-sectional view of a semiconductor processing apparatus according to an embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of a lid part that constitutes a semiconductor processing apparatus according to an embodiment of the present invention. 1 is a plan view of a quartz heater that is a heat source used in a semiconductor processing apparatus according to an embodiment of the present invention. 1 is a plan view of a configuration in which a plurality of quartz heaters, which are heat sources used in a semiconductor processing apparatus according to an embodiment of the present invention, are arranged in a ring shape. FIG. 2 is an enlarged vertical cross-sectional view showing a heating source holding mechanism in which a quartz heater used in a semiconductor processing apparatus according to an embodiment of the present invention is attached to a lid. FIG. 2 is a vertical cross-sectional view showing the thermal propagation of heating energy generated in a quartz heater used in a semiconductor processing device. FIG. 2 is a longitudinal cross-sectional view of a configuration in which a metal film is applied to a part of the quartz heater of the heat source holding mechanism according to an embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of a configuration in which a part of the quartz heater of the heating source holding mechanism according to an embodiment of the present invention is made of opaque quartz. It is a longitudinal cross-sectional view showing a holding mechanism for a continuous annular quartz heater of a heating source holding mechanism according to a modification of the present invention. It is a top view of one continuous annular quartz heater which constitutes the heating source holding mechanism concerning the modification of the present invention. FIG. 7 is a plan view of a configuration in which a plurality of continuous annular quartz heaters constituting a heating source holding mechanism according to a modification of the present invention are arranged concentrically. FIG. 7 is an exploded view of a continuous annular quartz heater of a heating source holding mechanism according to a modification of the present invention. It is a photograph when cutting the tungsten wire which constitutes the continuous annular quartz heater of the heat source holding mechanism based on the modification of this invention. It is a photograph of the state where the tungsten wire which constitutes the continuous annular quartz heater of the heating source holding mechanism concerning the modification of the present invention passes through the vertical fixing part, and extends outside. FIG. 7 is an explanatory diagram of a sealing method applied to a continuous annular quartz heater of a heating source holding mechanism according to a modification of the present invention.

The heat source holding mechanism, heat source holding method, and semiconductor processing apparatus used in one embodiment of the present invention will be described with reference to the drawings.

[Overall configuration of semiconductor processing equipment]
As shown in Fig. 1, the semiconductor processing apparatus 10 is an apparatus for accommodating a silicon substrate (e.g., a semiconductor wafer or a silicon wafer) in a space 12 formed inside the apparatus and for heating the silicon substrate to perform a heat treatment. The semiconductor processing apparatus 10 is composed of a base 14 on which the silicon substrate is placed, a lid 16 that covers the base 14 from above, and a peripheral wall 18 that surrounds the base 14 and the lid 16. The space 12 surrounded by the base 14, the lid 16, and the peripheral wall 18 becomes an airtight space that can isolate the silicon substrate from the atmosphere during heat treatment. In other words, the semiconductor processing apparatus 10 is also called a heat treatment chamber.

As shown in FIG. 2, the lid 16 includes a lid main body 20 and a heat source 22 disposed on the inner surface of the lid main body 20. As shown in FIG. The heat source 22 is composed of a light-transmissive member, such as a halogen heater, and specifically a quartz heater is used. In addition to quartz, the member may be made of a crystalline material such as glass-based ceramic material, sapphire ceramic material, acrylic resin, plastic resin, magnesium fluoride, calcium fluoride, etc., as long as it is a member that transmits light. The heat source 22 is composed of, for example, a halogen heater, and specifically a quartz heater is used. Hereinafter, a description will be given using a quartz heater 22H as the heat source 22. In this case, the semiconductor processing apparatus 10 is referred to as a halogen heater container.

As shown in FIGS. 3 and 4, since the silicon substrate is formed into a disk shape in plan view, it is preferable that the quartz heater 22H is formed in a circular and annular shape in plan view.

Here, in the quartz heater 22H, a gap 24 is formed that is partially discontinuous along the circumferential direction in a plan view. This void portion 24 is a non-light emitting portion 24N. For example, in the quartz heater shown in FIG. 4, four non-light emitting parts 24N are formed along the circumference, but the number is not limited to four.

Here, the quartz heater 22H includes a plurality of circular and annular quartz heaters having different diameters arranged along the radial direction. In the quartz heater 22H with this arrangement structure, a plurality of non-light emitting parts 24N exist on a straight line along the radial direction, but between the non-light emitting parts 24N adjacent to each other along the radial direction. The light emitting part 25B (see FIG. 4) of the quartz heater 22H is interposed. Note that the light emitting portion 25B refers to a portion where the quartz tube of the quartz heater 22H is present.

As shown in FIG. 1, a reflective treatment plate 26 is provided on the inner surface of the lid body 20. The reflective treatment plate 26 reflects the radiant heat emitted from the quartz heater 22H, preventing the heat from being transferred to the inside of the lid body 20. This prevents thermal damage to the lid body 20 due to fixed conduction heat. This is not limited to the reflective treatment plate 26, and a reflective treatment film may be applied to the inner surface of the lid body 20.

A coolant flow path 28 for flowing a coolant is formed inside the lid main body 20. By circulating the coolant through the coolant flow path 28, the entire lid portion 16 is cooled.

[Heating source holding mechanism]
Next, a heat source holding mechanism used in a semiconductor processing apparatus will be explained.

As shown in FIGS. 1 and 2, the quartz heater 22H is held by the lid 16. A mounting flange 30 extending in the vertical direction (direction of gravity) is formed on the lid portion 16 . For this reason, a recess 32 surrounded by the inner surface of the lid 16 and the mounting flange 30 is formed in the lid 16 . The quartz heater 22H is located in this recess 32. Note that the reflective treatment plate 26 is provided from the inner surface of the lid portion 16 to the mounting flange 30, and reflects radiant heat.

As shown in FIG. 5, the quartz heater 22H includes a first heater section 23A that extends in the horizontal direction, and a second heater section 23B that is connected to the first heater section 23A and extends in the vertical direction (direction of gravity). ing. A through hole 34 is formed in the lid main body 20 in the thickness direction, and the second heater portion 23B of the quartz heater 22H is inserted into the through hole 34. Note that, for example, the second heater section 23B is formed by being bent perpendicularly to the first heater section 23A, but both may be formed from separate members and connected to each other.

Therefore, as shown in FIGS. 3 and 4, the circumferentially adjacent quartz heaters 22H become discontinuous at the second heater section 23B, forming a non-light-emitting section 24N. Further, the distance between the first heater parts 23A of the quartz heaters 22H adjacent to each other in the circumferential direction can be set to the minimum distance T (see FIG. 5), and the non-light emitting part 24N can be minimized to improve the performance of the semiconductor processing apparatus 10. Avoids increasing size.

The second heater portion 23B of the quartz heater 22H is formed as a non-heat generating portion, for example.

As shown in FIG. 5, an airtight member 36 is disposed on the inner circumferential surface of a through hole 34 that penetrates the lid main body 20 in the thickness direction. The airtight member 36 holds the quartz heater 22H by pressing against the second heater portion 23B of the quartz heater 22H. The airtight member 36 is, for example, an elastic member and is composed of an O-ring. The O-ring is made of an elastomeric material. As the elastomer material, for example, bind rubber or fluororubber is used.

A compression ring 38 for pressing against the airtight member 36 and a restraining flange 40 for fixing the compression ring 38 to the lid main body 20 are provided on the inner peripheral surface of the through hole 34 . Thereby, the airtight member 36 is fixed to the inner peripheral surface of the through hole 34.

A current introduction part 42 that connects to the second heater part 23B of the quartz heater 22H protrudes from the upper side (atmosphere side) of the lid part 16. When a voltage is applied to the current introduction part 42, the first heater part 23A of the quartz heater 22H generates heat, and the silicon substrate is heated. Because the current introduction part 42 is exposed to the atmosphere side, there is no heat transfer to the current introduction part 42, and no technical problems due to heat generation occur.

[Radiant heat blocking treatment of heating source holding mechanism]
Next, a radiant heat cutoff process for the heat source holding mechanism used in the semiconductor processing apparatus 10 will be described.

As shown in FIG. 7, a radiant heat cutoff portion for blocking radiant heat is provided near the quartz heater 22H, that is, at a position on the optical path where the light from the quartz heater 22H can irradiate the airtight member 36. For example, a radiant heat cutoff portion for blocking radiant heat is provided on the outer surface of the quartz heater 22H at a contact portion with the airtight member 36. In other words, the outer surface of the second heater section 23B of the quartz heater 22H is coated with a metal film (metal reflective film) X1 as a radiant heat blocking section. The metal film X1 is made of aluminum, aluminum alloy, silver, gold, nickel, etc., which have a high heat reflectance and are difficult to absorb heat, either singly or by mixing arbitrary materials. The metal film X1 reflects the radiant heat from the first heater section 23A of the quartz heater 22H, thereby preventing heat transfer into the second heater section 23B. Therefore, the second heater section 23B maintains its function as a non-heat generating section.

In addition, as a configuration other than applying the metal film (metal reflective film) X1 to the outer surface of the second heater portion 23B of the quartz heater 22H, for example, the metal film It is also possible to cover or wind the outer surface of the heater section 23B.

As another embodiment, the outer surface of the second heater section 23B of the quartz heater 22H is coated with an optical film (an optical filter film, an infrared filter film, not shown) as a radiant heat blocking section. The optical film reflects the radiant heat from the quartz heater 22H, thereby preventing heat transfer into the second heater section 23B. Therefore, the second heater section 23B maintains its function as a non-heat generating section. As the optical film, for example, frosted glass, a material that diffusely reflects quartz, a metal that is foamed to scatter light, or a metal that changes the refractive index so that no light is transmitted may be used.

In addition to the structure in which an infrared filter film (optical filter film) is applied to the surface of the second heater part 23B of the quartz heater 22H, for example, an infrared filter film is formed as a separate member, and the surface of the second heater part 23B of the quartz heater 22H is It is also possible to cover or wind the surface of the second heater section 23B.

As another embodiment, as shown in FIG. 8, the material of the second heater part 23B of the quartz heater 22H is made of opaque quartz X2, the material of the first heater part 23A is made of transparent quartz, and the material of the first heater part 23A is made of transparent quartz. The end portion and the end portion of the transparent quartz may be fused and connected. Although the connecting portion between the end of the opaque quartz X2 and the end of the transparent quartz is made of transparent quartz, a radiant heat blocking portion can be formed in the second heater portion 23B. Thereby, the second heater section 23B maintains its function as a non-heat generating section.

In addition, as a material other than opaque quartz X2 for the second heater part 23B of the quartz heater 22H, for example, a radiant heat reflecting member made of opaque quartz X2 is made as a separate member, and the second heater part 23B of the quartz heater 22H is made of a material other than the opaque quartz X2. It is also possible to cover or wrap a radiant heat reflecting member on the outer surface of 23B.

Next, the operation of this embodiment will be explained.

As shown in FIGS. 5 to 8, in the configuration in which the second heater part 23B of the quartz heater 22H is inserted into the through hole 34 of the lid main body 20, and the airtight member 36 is held in contact with the second heater part 23B, The heating energy generated in the first heater section 23A of the quartz heater 22H (see the arrow in FIG. 6) is thermally propagated toward the second heater section 23B, and the temperature of the second heater section 23B becomes high. At this time, the heating energy also propagates to the airtight member 36 that is in contact with the second heater section 23B, and the temperature of the airtight member 36 becomes high.

In detail, in general, quartz can transmit thermal energy in the range of visible light 400 nm to infrared light 2700 nm, but it is transmitted in the radial direction of the quartz tube (cross-sectional direction of the pipe) centered on the heat source, and the quartz It also has the property of being transparent in the axial direction of the tube. Therefore, in a configuration in which the quartz heater 22H is supported in the vertical direction (in the direction of gravity) by the airtight member 36, the airtight member 36 is affected by visible light to infrared heat transmitted through the wall of the quartz tube. For this reason, the heating energy also propagates to the airtight member 36 that is in contact with the second heater section 23B, resulting in a high temperature. If this temperature reaches the upper limit temperature of the airtight member 36 or higher, the airtight member 36 It melts or burns out.

For these reasons, the heat treatment in the semiconductor processing apparatus 10 brings the airtight member 36 into an abnormally high temperature state, causing the airtight member 36 to melt or carbonize, and further deteriorate its elasticity. Therefore, a gap is formed between the quartz heater 22H and the through hole 34 of the lid main body 20, which may cause a technical problem in which heat escapes to the outside through the gap. If heat leaks to the outside, the heat treatment of the silicon substrate will be insufficient, leading to defects. Further, if the airtight member 36 melts, the holding force for holding the quartz heater 22H becomes weak, and there is also a risk that the quartz heater 22H may fall.

Therefore, in this embodiment, as shown in FIG. 7, the outer surface of the second heater section 23B of the quartz heater 22H is coated with a metal film (metal reflective film) X1 as a radiant heat blocking section. Therefore, the heating energy generated in the first heater section 23A of the quartz heater 22H is blocked by the metal film X1, so that heat is not conducted to the second heater section 23B. Thereby, the temperature of the second heater section 23B can be prevented from becoming high. As a result, the temperature of the airtight member 36 in contact with the second heater portion 23B can be prevented from becoming too high, and deterioration of the airtight member 36 can be prevented.

Since deterioration of the airtight member 36 can be prevented, the holding power of the second heater section 23B by the airtight member 36 can be ensured. Therefore, heat leakage to the outside and falling of the quartz heater 22H can be prevented.

Furthermore, the same effect can be achieved even in a configuration in which an infrared filter film (optical filter film) is applied as a radiant heat blocking part using metal, dielectric material, etc. on the outer surface of the second heater part 23B of the quartz heater 22H. is obtained.

As shown in FIG. 8, the same effect can be obtained even if the second heater portion 23B of the quartz heater 22H is made of opaque quartz X2.

[Improved invention]
Next, a heat source holding mechanism, a heat source holding method, and an improved invention for a semiconductor processing apparatus used in a semiconductor processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. Note that the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[Technical issues of the above embodiment]
According to the above embodiment, the non-light-emitting portion 24N is formed in the quartz heater 22H, but as the temperature locally decreases in the non-light-emitting portion 24N, the portion of the silicon substrate onto which the non-light-emitting portion 24N projects is subjected to heat treatment. There is a technical problem in that the temperature locally decreases (heating non-uniformity). Additionally, there is a technical problem in that it is difficult to produce a quartz heater with an annular structure (difficulty in producing a heating source).

Therefore, in the improved invention, the quartz heater 22H, which is the heat source 22, is formed into a complete annular structure without forming a non-light-emitting portion. Therefore, in the modified example, the continuous annular quartz heater 50 is completed, and no non-heat generating portion is formed.

As shown in FIGS. 9 to 11, the continuous annular quartz heater 50 of the improved invention includes a continuous annular portion 52 extending in the horizontal direction, and a vertical fixing portion 54 connected to the continuous annular portion 52 and extending in the vertical direction (direction of gravity). It consists of and.

The heating source 22 is configured by a plurality of continuous annular portions 52 having different diameters arranged concentrically in a plan view. Therefore, there is no non-light emitting part in the circumferential direction of the continuous annular quartz heater 50, and the quartz tubes of the continuous annular part 52 are continuously connected.

The vertical fixing part 54 is provided with a radiant heat blocking part that blocks radiant heat, as in the above embodiment. In other words, the outer surface of the vertical fixing part 54 is coated with a metal film (metal reflective film) X1 (not shown in FIGS. 9 to 11) serving as a radiant heat shielding part. Further, as another embodiment, an infrared filter film (optical filter film, not shown) is applied to the outer surface of the vertical fixing part 54 as a radiant heat blocking part. Furthermore, the material of the vertical fixing part 54 is made of opaque quartz X2 (not shown in FIGS. 9 to 11), the material of the continuous annular part 52 is made of transparent quartz, and the end of the opaque quartz X2 and the end of the transparent quartz It may also be connected by fusion bonding. Thereby, seal deterioration of the airtight member 36 that contacts and elastically supports the vertical fixing portion 54 can be prevented.

Similar to the above embodiment, a through hole 34 is formed in the lid main body 20 in the thickness direction, and the vertical fixing portion 54 of the continuous annular quartz heater 50 is inserted into the through hole 34. Note that a method for manufacturing the continuous annular quartz heater 50 will be described later.

Note that the other configurations are the same as those in the above embodiment.

As described above, according to the improved invention of the present embodiment, since the continuous annular quartz heater 50 generates light emission in a continuous annular structure, no non-heat generating portion is formed in the continuous annular quartz heater 50. It is possible to prevent uneven heating from occurring on the silicon substrate. The silicon substrate is formed into a disk shape in plan view, and the continuous annular quartz heater 50 is similarly formed into a disk shape in plan view, so that it is possible to uniformly heat the surface of the silicon substrate. , it is possible to eliminate uneven heating on the silicon substrate. This makes it possible to suppress the occurrence of defects during heat treatment of silicon substrates.

Furthermore, in the heat treatment of the silicon substrate, since non-uniformity in heating is eliminated, there is no need to rotate the silicon substrate, and there is no need to use a substrate rotation mechanism. Therefore, the number of parts can be reduced, downsizing and cost can be reduced, and highly accurate rotation control of the substrate rotation mechanism is no longer required.

[Method of manufacturing a continuous annular quartz heater]
Next, a method for producing the continuous annular quartz heater 50 will be described.

As shown in FIG. 12, in order to fabricate a continuous annular quartz heater 50 with no non-heat generating portions, a quartz part 56 and a tungsten wire 58 are prepared. The quartz part 56 is composed of two bisected semi-annular quartz tubes 56A, two T-shaped quartz tubes 56B, and four quartz tube support parts 56C that support various quartz tubes.

As shown in FIGS. 13 and 14, a T-shaped quartz tube 56B is connected to the semicircular quartz tube 56A, and a tungsten wire 58 is passed inside to form a filament.

Specifically, as shown in FIG. 15, a tungsten wire 58 serving as a heating element is cut to a length with a heat density of 6-10 W/mm and a resistance value within ±5%, and the inside of a semicircular quartz tube 56A is cut. Insert into. Next, after inserting the tungsten wire 58 into the semi-annular quartz tube 56A, the semi-annular quartz tubes 56A are connected to each other by flame processing, and annealing is performed at about 1000 degrees to remove processing distortion.

A sealing process is performed on the tip of the T-shaped quartz tube 56B. The sealing process is achieved by flame processing the tip of the T-shaped quartz tube 56B. As a result, a sealing portion is formed at the tip of the T-shaped quartz tube 56B, and since the sealing portion remains smaller than the diameter of the quartz tube, it can be inserted into the through hole 34 formed in the lid main body 20. In this manner, the continuous annular quartz heater 50 is held on the lid 16.

Note that the above-described embodiment is merely an example that embodies the technical idea of the present invention. Naturally, the present invention is not limited to this embodiment, but includes all aspects that utilize the technical idea of the present invention.

10 Semiconductor processing equipment 12 Space section 14 Base section 16 Lid section (support section)
18 Peripheral wall portion 20 Lid body 22 Heat source 22H Quartz heater 23A First heater portion 23B Second heater portion 24 Gap portion 24N Non-light emitting portion 25B Light emitting portion 26 Reflection treatment plate 28 Coolant flow path 30 Mounting flange 32 Recess 34 Through hole 36 Airtight member 38 Compression ring 40 Holding flange 42 Current introduction part 50 Continuous annular quartz heater 52 Continuous annular part 54 Vertical fixing part 56 Quartz component 56A Semi-annular quartz tube 56B T-shaped quartz tube 56C Quartz tube support part 58 Tungsten wire X1 Metal film X2 Opaque quartz

Claims (3)

A method for manufacturing a heat source used in a semiconductor processing device through an airtight member , comprising the steps of:
The heating source includes a continuous annular portion formed in a continuous annular shape in a plan view, and a vertical fixing portion connected to the continuous annular portion, extending in a vertical direction, and having a radiant heat blocking portion for blocking radiant heat at a contact portion with the airtight member ,
The continuous annular portion is formed by combining a pair of semi-annular quartz tubes,
The vertical fixing portion is formed of a T-shaped quartz tube to which the semi-annular quartz tube is connected,
A method for manufacturing a heat source for use in a semiconductor processing apparatus, comprising passing a tungsten wire through the inside of the semi-annular quartz tube and the T-shaped quartz tube to form a filament. According to claim 1, after the tungsten wire is inserted into the semi-circular quartz tube, the pair of semi-circular quartz tubes are connected by flame processing and annealed at a predetermined temperature to remove processing distortion. A method for manufacturing a heating source used in semiconductor processing equipment. 3. The method of manufacturing a heat source used in a semiconductor processing apparatus according to claim 1, wherein a sealing portion is formed at the tip of the T-shaped quartz tube by flame processing.

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