JP5055044B2 - Multi-shower head for multi-layer CVD - Google Patents

Description

  The present invention relates to a CVD multi-shower head mainly used in a semiconductor manufacturing process, and more particularly to a method for manufacturing a multi-layer CVD multi-shower head.

  In the semiconductor manufacturing process, a CVD (Chemical Vapor Deposition) process is often used. Among the apparatuses used in these processes, there is an apparatus system named a shower head (see Patent Document 1). As shown in FIG. 5, the shower head shown in Patent Document 1 forms a pattern for a gas passage in the block body constituting each stage, and does not interfere with each other by stacking and integrating the blocks at each stage. A plurality of gas passages are formed. That is, the upper block 31 includes a first gas channel 34 and a second gas channel 35 each having a first gas (for example, source gas) inlet 32 and a second gas (for example, fuel gas) inlet 33 at the top. The middle block 36 is further provided with a first gas channel 34 'and a second gas channel 35' communicating with the first gas channel 34 and the second gas channel 35, respectively. 37, a first gas flow path 34 "and a second gas flow path 35" are formed, respectively, and the upper block 31, the middle block 36, and the lower block 37 are in close contact with each other to form a shower head 38.

Then, the first gas and the second gas are respectively ejected from the first gas ejection port 39 and the second gas ejection port 40 formed on the lower side of the lower block 37, where both gases are mixed and a chemical reaction occurs. At the same time, a film of a chemical reaction product is formed on the surface of a processing object (not shown) that is installed facing the gas outlet. Reference numeral 41 denotes a cooling water channel.
According to Patent Document 1, the “gas jets” 39 and 40 are “orderedly arranged at a predetermined pitch of, for example, about 10 to 20 mm”, and the “hole diameter” is set to “for example, about 5 to 6 mm. “The gas injection hole” and “the gas flow path” are “can be easily formed by drilling”.

There is also known an improved type in which a shower head is configured by combining a gas channel penetrating in the plate thickness direction and a block formed with a recess dug in the surface without forming a gas channel in the plate thickness. (See Patent Document 2).
According to Patent Document 2, as shown in FIG. 6, two kinds of process gases (for example, titanium tetrachloride and ammonia) are provided on a surface plate thickness through passage 43 provided on a faceplate 42, The process gas is supplied to the process region 46 through a lower gas distribution plate thickness through passage 45 provided in a lower gas distribution plate 44, mixed, and a chemical reaction occurs. A film of the chemical reaction product is formed on the surface of the processing object 47 installed facing the process gas jet port. In addition, 48 is a volt | bolt, The surface plate 42, the lower gas distribution plate 44, and the gas distribution assembly (a gas distribution manifold) 49 are mutually fixed with this volt | bolt 48.

An example of the process gas jet pattern in Patent Document 2 is shown in FIG.
According to Patent Document 2, the thickness of the surface plate is about 2.5 mm, the thickness penetration path has a length (depth) of about 1.21 mm, and the distance between adjacent centers is about 6.35 mm. The diameter is about 0.64 mm (0.025 inches).
In the showerhead devices shown in Patent Document 1 and Patent Document 2, since the density of the gas passages provided in the block and the plate is sparse, there is room for increasing the diameter of the opposed end, and the block And it is easy to assemble without much nerves to align the plates.

In this type of reaction system, the reaction of each gas is started by mixing after ejection, and it is preferable that a film is formed on the surface of the workpiece immediately after the reaction. It is generally preferable that the (diameter and the center distance between adjacent passages) is small in order to achieve uniformity of the film and the like.
When using a drill with a small diameter to increase the density of the gas passage, the strength of the drill itself is also reduced, and generally the drilling depth by the drill is limited to 6 to 10 times the drill diameter. There is a limit to producing a shower head having a high gas passage density only with through holes formed by a drill.
The applicant has attempted to increase the density of the gas passages by fitting a pipe having the required inner diameter into the through hole. The outline is shown in FIG.

  In FIG. 8, a gas 1 (for example, source gas) passage hole 58 and a gas 2 (for example, fuel gas) passage hole 52 are formed in the lower plate 51. A concave portion 54 is formed in the lower surface of the upper plate 53 over a wide range, and a gas 2 passage hole 55 is formed at a position corresponding to the gas 2 passage hole 52 of the lower plate 51. The lower plate 51 and the upper plate 53 are in contact with each other, and a long gas passage pipe 56 is embedded across the gas 2 passage hole 52 and the gas 2 passage hole 55. A short gas passage pipe may be embedded in the gas 1 passage hole 58.

The contact portion between the lower plate 51 and the upper plate 53, the gas 2-passage holes 52 and 55 and the long gas passage pipe 56 formed in the lower plate 51 and the upper plate 53, and the short gas passage when used. The pipe and the periphery of the gas 2 passage hole 52 of the lower plate 51 are joined in an airtight (gastight) manner, for example, by brazing.
In the case of a general metal material, if the clearance is about 50 μm, it is joined in an airtight (gas tight) manner, for example, by brazing.
Reference numeral 57 denotes an object to be processed.

In the insertion of the gas passage pipe into the gas passage hole, since the short gas passage pipe is related only to the lower plate 51, there is no particular problem.
In the case of the long gas passage pipe 56, since it relates to both the lower plate 51 and the upper plate 53, it tends to be problematic.
There can be two ways. First, in the case of use, after setting a short gas passage pipe on the lower plate 51, the lower plate 51 and the upper plate 53 correspond to the gas 2 passage hole 52 and the gas 2 passage hole 55. And the long gas passage pipe 56 is inserted in common there. In this method, as the hole having a relatively small clearance becomes longer, the processing accuracy and the strength of the pipe itself become problems, and the difficulty increases.

  Second, when used, a short gas passage pipe is set on the lower plate 51, and then a long gas passage pipe 56 is also set (At this time, most of the long gas passage pipe 56 is placed on the upper plate 51. This is a method of inserting the gas 2 passage hole 55 of the upper plate 53 into the projecting long gas passage pipe 56 group while fitting it. This method makes it difficult to insert the upper plate 53 as the number of pipes increases or the density of the pipes increases.

The problem of improving the performance of the shower head is firstly the addition of a cooling function corresponding to the higher temperature of the reaction system, and secondly the diversification of gases (substances) involved in the reaction.
As an approach of thinking experiment to realize such high performance, “increase in blocks or boards” can be assumed. However, as described above, simultaneous insertion of several hundred pipes with a clearance of about 50 μm capable of airtight joining is almost impossible.

JP-A-8-291385 US Pat. No. 6,086,677

  In view of the above circumstances, an object of the present invention is to establish a policy for practically realizing a multi-stage shower head.

CVD multi shower head having a multilayer structure of the present invention, the reaction gas to a shower head to form a coating film on the surface of the object to be treated by mixing the CVD method in the vicinity of the object, the cover plate, the upper plate, medium In a multi-layer CVD multi-shower head formed by laminating a plate and a lower plate , a first fluid distribution space for supplying a first fluid is formed between the cover plate and the upper plate, and the upper plate and the middle plate A second fluid distribution space to be supplied with a second fluid is formed between the plate and a third fluid distribution space to be supplied with a third fluid between the middle plate and the lower plate. A first fluid passage pipe for ejecting the first fluid in the distribution space to the reaction space is inserted through the upper plate, the middle plate, and the lower plate, and the second fluid in the second fluid distribution space is passed through the reaction space. A second fluid passage pipe for injecting into the first through the middle plate and the lower plate, In the through hole of the second fluid passage pipe inserted through the top and middle plate, it is characterized in that gap pipe guide between the through hole and the fluid passage pipe is inserted installed. In the through hole, it is preferable that a space between the fluid passage pipe and the pipe guide is made of a brazing material.

  By inserting thousands of fluid passage pipes into a plate having through holes formed in a forested state, as in the present invention, the fluid passage pipes have a small outer diameter, and between the through holes and the fluid passage pipes. By inserting the pipe guide into the wall, the great effect that it becomes possible in the manufacturing industry is obtained, and as a result, the formation of a uniform and precise CVD film is made efficient.

The present invention provides a sufficiently large gap between the inner diameter of the through hole and the outer diameter of the gas passage pipe so as not to hinder the insertion, and the gap between the inner diameter of the through hole and the outer diameter of the gas passage pipe The basic concept is to fill the gap to about 50 μm that can be joined in an airtight (gas tight) manner by inserting and adding a guide to the gap.
Hereinafter, the present invention will be described in detail with reference to the drawings.
First, FIG. 1 is an explanatory view showing the flow of the fluid and the cooling water in the embodiment of the shower head of the present invention separately.
In FIG. 1, reference numeral 1 denotes a shower head according to the present invention, which basically comprises a lid plate 2, an upper plate 3, an intermediate plate 4, and a lower plate 5.

The first fluid (for example, source gas) is supplied from the first fluid supply port 6 to the first fluid passage pipe 8 (see also FIG. 4) through the first fluid distribution space 7 formed in the lower part of the lid plate 2. And ejected into the reaction space 9.
As shown in the middle stage of FIG. 1, the second fluid (for example, fuel gas) is supplied from the second fluid supply tool 10 to the second fluid passage pipe 12 (see also FIG. 4) through the second fluid distribution space 11, It is ejected into the reaction space 9.
As shown in the lower part of FIG. 1, the third fluid (for example, cooling water) passes through the third fluid distribution space 14 from the third fluid supply passage 13 and is discharged out of the system from the third fluid discharge passage 15. The

In FIG. 2, the whole structure in embodiment of the shower head of this invention is shown as explanatory drawing.
FIG. 2 shows the cover plate 2, the upper plate 3, the middle plate 4, the lower plate 5 described in FIG. 1, the first fluid distribution space 7, the second fluid distribution space 11, the third fluid distribution space 14, and the like. The first fluid supply port 6, the first fluid passage pipe 8, the second fluid supply tool 10, the second fluid passage pipe 12, the third fluid supply passage 13, A three-fluid discharge passage 15 is shown. Reference numeral 16 denotes a measurement terminal site for inserting a temperature sensor or other parameter measurement terminal during operation. In the illustrated example, one site has 5 sites per radius, but the number of sites in one row and the set number of radii. May be appropriate, and may be distributed in-plane without forming a row.

The ends of the first fluid passage pipe 8 and the second fluid passage pipe 12 on the reaction space side are fluid ejection ports 17, and an example of the arrangement is shown in FIG. Figure In the example shown in 2 (b), in 4mm is the length of one side of the unit of square fluid ejection ports are arranged, 1589 or spout of the first fluid in the illustrated example, the ejection port of the second fluid There are 1,588, a total of 3,177.
As shown in an enlarged view in FIG. 3, the fluid ejection ports 17 are alternately arranged at the apexes of a square, such as the first fluid ejection port 18 and the second fluid ejection port 19. The squares can be arranged in a regular hexagonal arrangement, or various arrangements as long as the intervals between the ejection ports are approximated. However, in the case where there is a difference in the activity of each gas component depending on the type of the gas reaction system, it is not always indispensable to evenly arrange the outlets of the first fluid and the second fluid. .

Next, the manufacturing method of the multi shower head of this invention is demonstrated using FIG. Here, the main part of the present invention, which is a part that realizes the reactive gas injection ports at a high density, which has been considered extremely difficult in the past, will be mainly described.
A through-hole 20 through which the first fluid passage pipe 8 and the second fluid passage pipe 12 are inserted is drilled in the lower plate 5 which is a flat plate. The clearance between the inner diameter of the through hole 20 and the outer diameter of the fluid passage pipe (the first fluid passage pipe 8 and the second fluid passage pipe 12) is about 50 μm.
The middle plate 4 is formed with a recess that becomes the third fluid distribution space 14, and the third fluid supply passage 13 and the through holes 22, 24 for inserting the pipe guides 21, 23 are drilled.

The upper plate 3 is formed with a recess that becomes the second fluid distribution space 11, a third fluid supply passage 13, a through hole (not shown) for the second fluid supply tool, and a through hole 24 for installing the pipe guide 23. Perforate. The clearance between the size (inner diameter) of the through holes (22, 24) for inserting and installing the pipe guide (21, 23) and the outer size (outer diameter) of the pipe guide (21, 23) is about 50 μm. .
In the example of illustration, although the example which has a profile in the hole shape of the through-hole 22 and the through-hole 24 was shown, a straight through-hole may be sufficient.
The lid plate 2 is formed with a third fluid supply passage 13, a through hole for the second fluid supply tool (not shown), and a first fluid supply port 6 (FIG. 1, etc., not shown in FIG. 4).

The assembly is as follows.
The fluid passage pipe is inserted and erected in the through hole 20 for the fluid passage pipe provided in the lower plate 5 so as to have a predetermined arrangement.
If the clearance is about 50 μm, since it is performed one by one, there is no particular problem in the operation of inserting and standing the fluid passage pipe.
The middle plate 4 is overlapped on the lower plate 5 where the fluid passage pipes (the first fluid passage pipe 8 and the second fluid passage pipe 12) stand. A number of fluid passage pipes are erected on the lower plate 5, but the clearance between the fluid passage pipe and the through holes 22 and 24 for inserting and installing the pipe guides 21 and 23 can be inserted into the pipe guides 21 and 23. Because there are only minutes, there is no particular obstacle to the stacking operation.

After the lower plate 5 and the middle plate 4 are overlapped, the gap between the fluid passage pipe (the first fluid passage pipe 8 and the second fluid passage pipe 12) and the through holes 22 and 24 for installing the pipe guides 21 and 23 is provided. The pipe guides 21 and 23 are inserted and installed.
Here, the distal end of the second fluid passage pipe 12 opens into the second fluid distribution space, and the first fluid passage pipe 8 protrudes greatly from the intermediate plate 4.
A brazing material is applied to and placed on the joint between the lower plate 5 and the middle plate 4, the joint between the fluid passage pipe and the pipe guide (pipe guides 21, 23), and the joint between the pipe guide and the middle plate 4. To do.

The upper plate 3 is overlapped while the protruding first fluid passage pipe 8 is inserted into the through hole 24 for installing the pipe guide 23 from above the middle plate 4. Since the clearance between the through hole 24 and the first fluid passage pipe 8 is as long as the pipe guide 23 can be inserted, there is no particular obstacle to the overlapping operation. Then, the pipe guide 23 is inserted and installed.
Here, the tip of the first fluid passage pipe 8 opens into the first fluid distribution space.
A brazing material is applied to and placed on the contact portion between the middle plate 4 and the upper plate 3 and the junction between the fluid passage pipe and the pipe guide 23.

The cover plate 2 is placed on the upper plate 3, and a brazing material is applied and placed on the contact portion.
The entire assembly is inserted into a vacuum furnace and heated to a predetermined temperature, thereby producing a multi-shower head having a multilayer structure that does not leak at a place where a brazing material is applied and placed.
As the material constituting the multi shower head of the present invention, a conventionally used stainless material such as SUS316L having high heat resistance and corrosion resistance, pure Ni material, Inconel material, and the like can be used.
Further, when the process temperature is low, all members may be made of an aluminum material or the like.

  The multi (3) shower head that secures the two-gas reaction system and the cooling system has been described above. However, if the low-temperature reaction system is a three-gas (or more) reaction system, for example, the reaction starts from the third fluid distribution space. Needless to say, it is possible to perform corresponding deformation by forming a passage to the system space. Furthermore, it is possible to construct a further multi-shower head by stacking similar plates. However, it goes without saying that it is necessary to pay due consideration to the arrangement pattern of the fluid ejection ports.

Fluid passage pipe inner diameter 0.4 ± 0.01mm, outer diameter 1.2mm, pipe guide inner diameter 1.2mm, outer diameter 2.4mm, pipe guide insertion hole diameter 2.4mm, upper plate / middle plate -The plate thickness of the lower plate was 9 mm, 11.5 mm, 4 mm in order, and a fluid jet outlet arrangement surface was prototyped with a regular square shape with a side of 4 mm.
As the material of the multi shower head manufactured this time, all members are made of SUS316L material that can be used in semiconductor processes, has excellent heat resistance and corrosion resistance, and is relatively inexpensive.
There were no places where airtightness was impaired in each part.

  According to the present invention, a multi-shower head with a fine distribution of fluid jets can be manufactured with high performance and high efficiency, and by using this, it becomes possible to form a precise film as intended. This is a big contribution to the industrial field such as semiconductor manufacturing.

It is explanatory drawing which divides and shows the flow of the fluid and cooling water in embodiment of the shower head of this invention, respectively. It is explanatory drawing which shows the whole structure in embodiment of the shower head of this invention, Comprising: (a) is elevation sectional drawing, (b) is explanatory drawing of the bottom face which faces the reaction space of a lower board. It is a partial expanded explanatory view which shows an example of the fluid jet nozzle arrangement | sequence formed in the lower board. It is a figure explaining the manufacturing method of the multi shower head of this invention. Exploded view showing a conventional shower head. Explanatory drawing which shows the other example of the conventional shower head. It is explanatory drawing which shows an example of the jet pattern of each process gas opened to the working space in a double shower head. Explanatory drawing which shows the further another example of the conventional shower head.

Explanation of symbols

1: shower head 2: lid plate 3: upper plate 4: middle plate 5: lower plate 6: first fluid (for example, source gas) supply port 7: first fluid distribution space 8: first fluid passage pipe 9: reaction space 10: Second fluid (for example, fuel gas) supply tool 11: Second fluid distribution space 12: Second fluid passage pipe 13: Third fluid supply passage 14: Third fluid distribution space 15: Third fluid discharge passage 16: Measurement Terminal site 17: Fluid outlet 18: First fluid outlet 19: Second fluid outlet 20: (For fluid passage pipe) Through hole 21: Pipe guide 22: (For pipe guide) Through hole 23: Pipe guide 24: (For pipe guide) Through hole 31: Upper block 32: First gas inlet 33: Second gas inlet 34, 34 ', 34': First gas flow path 35, 35 ', 35 ": Second gas flow Road 36: Middle block 37: Lower block 38: Shower Head 39: first gas ejection port 40: second gas ejection port 41: cooling water passage 42: surface plate (a the Faceplate)
43: Surface plate thickness through passage 44: Lower gas distribution plate 45: Lower gas distribution plate thickness through passage 46: Process region 47: Process object 48: Bolt 49: Gas distribution assembly 51: Lower plate 58: Gas 1 (For example, source gas) passage hole 52: gas 2 (for example, fuel gas) passage hole 53: upper plate 54: recess (of upper plate) 55: gas 2 passage hole 56: long gas passage pipe 57: object to be treated

Claims (2)

A shower head in which a reaction gas is mixed in the vicinity of an object to be processed and a film is formed on the surface of the object to be processed by a CVD method, and a multilayer structure formed by laminating a cover plate, an upper plate, an intermediate plate, and a lower plate In the CVD multi-shower head, a first fluid distribution space in which a first fluid is supplied is formed between the lid plate and the upper plate, and a second fluid is supplied between the upper plate and the middle plate. A second fluid distribution space is formed, a third fluid distribution space is formed between the middle plate and the lower plate, and a third fluid is supplied, and the first fluid in the first fluid distribution space is ejected into the reaction space. A first fluid passage pipe is inserted through the upper plate, the middle plate, and the lower plate, and the second fluid passage pipe for ejecting the second fluid in the second fluid distribution space to the reaction space is the middle plate The upper plate and the middle plate are inserted through the lower plate and the first and second fluid passage pipes are inserted therethrough. In the hole, multi shower head, characterized in that gap pipe guide between the through hole and the fluid passage pipe is inserted installed. The multi shower head according to claim 1, wherein a space between the fluid passage pipe and the pipe guide is made of a brazing material in the through hole.

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