JP2000195800A - Surface treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly feed gas to the surface of the objective such as a silicon wafer. SOLUTION: This surface treatment device is defined into the main body in which inside space is formed, the first space in which reaction gas is fed from outside, and the second space in which a reaction objective is housed, and shower plates, in which a path communicating to the first and the second spaces is provided, and the surface of the reaction objective in treated by a chemical reaction of the reactive gas. In this case, the first and the second members 31 and 32 have a plurality of through holes 31a..., 32a..., and a communicating paths 30a,..., are formed through the intermediate flow path 30a by connecting each through hole 31a of the first member 31 and the through holes 32a of the second member 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of oxidizing, nitriding, ashing, and oxidizing a surface of a target object by a chemical or physical reaction occurring at or near the surface of the desired object.
Also, the present invention relates to a surface treatment apparatus such as a CVD apparatus or an etching apparatus for performing an etching process or growing a film such as a metal film or a polysilicon oxide film on the surface of an object.

[0002]

2. Description of the Related Art An example of a conventional surface treatment apparatus will be described with reference to a plasma apparatus shown in FIG. The plasma device Y includes an apparatus main body 1 having an internal space 10 and an antenna 2 disposed above the internal space 10.
1, a susceptor 22 attached to the apparatus main body 1 via an insulator 23 to form a bottom of the internal space 10, a shower plate 3 arranged at a fixed distance from both the antenna 21 and the susceptor 22, It has. That is, the inner space 10 is divided into the first space 11 on the antenna 21 side and the second space 11 on the susceptor 22 side by the shower plate 3.
The space is divided into a space 12.

The shower plate 3 has a disk shape as shown in FIG. 7, and has a plurality of through holes 3 penetrating in the thickness direction.
are formed so as to be dispersed in a plane. A predetermined gas including a reactive gas and an inert gas is supplied to the first space 11, and the supplied gas passes through each through hole 3 a of the shower plate 3 and passes through the second space 11. It is made to flow to the 22 side. In addition, microwaves are emitted from the antenna 21, and the microwaves are supplied into the second space 12, and glow discharge occurs in the second space 12, whereby the reactive gas in the second space 12 is ionized. As a result, the reactive gas is brought into a plasma excited state.

In the plasma apparatus Y having such a configuration, a reaction target 4 such as a silicon wafer on which a large number of circuit elements are integrally formed is placed on the susceptor 22, and the surface thereof is processed. In the second space 12, the reactive gas is plasma-excited by the glow discharge caused by the supply of microwaves, and is in a state where the reactive gas easily reacts. The reactive gas in this state is generated on the surface of the reaction target 4 or in the vicinity thereof. Causes chemical or physical reaction. By this reaction, the surface of the reaction target 4 is modified, and an oxide film, a nitride film, a metal film, a polysilicon oxide film, or the like is formed on the surface.

[0005]

The present invention is not limited to the above-described plasma apparatus. In the surface treatment apparatus Y for treating the surface by causing a chemical or physical reaction on the surface of the reaction object 4 (including the vicinity thereof). It is necessary to supply the gas to the entire surface of the reaction object 4 as uniformly as possible. Otherwise, reactions such as oxidation may progress locally too much or, on the contrary, spots where the progress of the reaction may be slow, so that the surface may not be treated uniformly and the thickness of the formed film may be constant throughout. You can't do that.

In particular, in the case of a silicon wafer 4 on which a large number of semiconductor chips are simultaneously formed, it is necessary to integrally fabricate a large number of circuit elements over the entire surface thereof. In order to homogenize the chips, it is highly necessary to uniformly supply gas to the entire surface of the silicon wafer 4. Although the diameter of the silicon wafer 4 is usually 8 inches, in recent years, since semiconductor chips have been formed using the silicon wafer 4 having a diameter of 12 inches, the gas is uniformly spread over the entire surface of the silicon wafer 4. The demand for supply is ever increasing.

[0007] The CV including the plasma device having the above-described configuration includes:
In the surface treatment apparatus Y such as the D apparatus, the diameter and depth of the through-hole 3a formed in the shower plate 3 and the number and arrangement thereof are adjusted, whereby the first space 11 and the second space 1 are adjusted.
The quantitative and qualitative uniformity of the reactive gas supplied to the silicon wafer 4 or the like is to be ensured by adjusting the pressure difference between the two. In order to uniformly supply gas to the surface of the reaction target 4 such as a silicon wafer, it is necessary to form a large number of through holes 3a in a dispersed manner and to set the diameter of each through hole 3a as small as possible. . This is because the diameter of the through hole 3a is large or the through hole 3a is small.
Is sparsely dispersed and formed, the gas supply state around the through-hole 3a and the gas supply state at a portion relatively far from the through-hole 3a greatly differ from each other. This is because the gas cannot be supplied uniformly.

However, since the shower plate 3 is required to have insulation, heat resistance and heat conductivity (heat dissipation), it is formed of a ceramic such as aluminum nitride (AlN). It is difficult to form many fine holes in the formed one. For example, in order to adjust the pressure difference between the first space 11 and the second space 12 as desired in order to uniformly supply gas to the entire surface of the silicon wafer 4 having a diameter of 12 inches, theoretically, The thickness of the shower plate 3 is relatively thick, 15 mm, whereas the diameter of the through hole 3 is 0.2 mm or less.
a must be dispersedly formed. However, with the current processing technology, a ceramic having a thickness of 15 mm has a diameter of 0.2 mm
The following through holes 3a cannot be formed. Therefore, it is difficult to uniformly supply gas over a wide area by measures such as reducing the diameter of the through hole 3a.

The present invention has been conceived in view of the above circumstances, and has as its object to provide a surface treatment apparatus capable of uniformly supplying a gas to the surface of a reaction target such as a silicon wafer. That is the subject.

[0010]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, in the surface treatment apparatus provided by the present invention, the apparatus main body in which the internal space is formed, the internal space, the first space to which a reactive gas is supplied from the outside, and the reaction target are accommodated. And a shower plate formed with a communication passage communicating the first space and the second space, wherein the reactive gas supplied to the first space is provided. A surface treatment that flows through the communication path to the second space side and that the surface of the reaction target is treated by a chemical or physical reaction of a reactive gas in the second space. In the apparatus, the shower plate has a first member and a second member which are joined to each other and in which a plurality of through holes are formed in a dispersed manner, and each through hole of the first member is Of the second member It is linked and Yichun of the through hole is characterized in that the communication passage is formed.

In this surface treatment apparatus, the reactive gas supplied to the first space flows toward the second space, and this reactive gas is directly oxidized or nitrided on the surface of the reaction object or in the vicinity thereof. The surface of the reaction target is treated by causing a chemical or physical reaction, or the compound generated by the chemical reaction of the reactive gas generated in the vicinity of the reaction target grows on the surface of the reaction target. The surface of the object is adapted to be treated.

In the above configuration, since the shower plate is constituted by at least two members, a through hole having a small diameter is formed in a relatively thick member like a conventional shower plate constituted by one member. Needless to say, uniformization of the gas to the reaction target can be reliably achieved. That is, a through hole is formed for each member having a relatively small thickness (less than half of one member), and a communication passage having a relatively large flow resistance is formed by connecting the through holes of the members. The pressure difference between the first space and the second section can be adjusted.

In the case of a shower plate having a large thickness, it is difficult to remove by-products that have clogged in the through holes due to the reaction of the reactive gas. On the other hand, in the present invention, since the depth of each through hole formed in each member as described above is small and the flow resistance as a whole as a whole communication path needs to be large, the diameter of the through hole formed in each member is sufficient. It is possible to increase. Therefore, even if a by-product is clogged in the through-hole of each member, removal of the by-product is significantly easier as compared with the case where the shower plate is constituted by one member.

The through-hole formed in the first member and the through-hole formed in the second member may be directly connected, and each through-hole of the first member may be connected to an intermediate flow passage. It may be configured to be connected to an appropriate through-hole of the second member via the.

In the configuration in which the through holes of the respective members are connected via the intermediate flow path, the overall length of the communication path is increased by passing the intermediate flow path, thereby increasing the flow resistance as the communication path. It has been done. For this reason, since it is not necessary to increase the thickness of each member individually and to reduce the diameter of the through hole to be formed in each member to increase the flow resistance of the communication passage, the effect of the present invention described above is further enhanced. You can definitely enjoy it.

In a preferred embodiment, the joint surface of the first member or the second member further includes a through hole of one member and an appropriate through hole of the other member in a state where the members are joined. A plurality of grooves connecting the holes are formed.

That is, in the above configuration, by joining the members, the concave groove formed in one member forms an intermediate flow path connecting the through holes of the members.

In a preferred embodiment, the plurality of through-holes of the first member are arranged in a lattice, and the plurality of through-holes of the second member are formed of a plurality of through-holes of the first member. The through holes are arranged in the same lattice pattern as the holes, and in at least one member, the through holes arranged diagonally in the minimum unit cell defined by the four through holes are connected by two concave grooves, respectively. ,
Each member is joined to each other such that the intersection of these concave grooves faces the through hole formed in the other member.

Also in the above configuration, by joining the members, the concave groove formed in one member forms an intermediate flow path connecting the through holes of the members. Four grooves extend, and these grooves are connected to different through holes of the other member. Of course, in the through holes of the other member, each through hole is connected to four different through holes of one member.

In a preferred embodiment, a microwave generation source is further disposed in the first space so that the microwave is supplied to the second space through the shower plate. It has been done.

In the above configuration, the reactive gas in the second space is brought into a plasma-excited state by the microwave supplied to the second space, and a chemical or physical reaction occurs on or near the surface of the reaction object. Thus, the surface of the reaction target is modified, or a film is grown. In the method of exciting the reactive gas by plasma in this way, it is not necessary to raise the temperature of the reactive gas to high or high pressure.
There is an advantage that processing can be performed at a low temperature of about 400 ° C. and at a low pressure.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an example of the surface treatment apparatus according to the present invention, and FIG.
2 is an overall perspective view in which a part of a shower plate used in the surface treatment apparatus in FIG. 1 is cut away, FIG. 3 is a plan view in which a main part of the shower plate in FIG. 2 is enlarged, and FIG. FIG. 5 is a cross-sectional view taken along line VV of FIG. In these drawings, members and elements equivalent to those shown in the drawings referred to for explaining the conventional example are denoted by the same reference numerals.

The surface treatment apparatus X according to the present invention oxidizes, nitrides, and insulates the surface of the reaction object 4 by a chemical or physical reaction occurring on or near the surface of the reaction object 4 such as a silicon wafer. This is an apparatus for performing an etching process or growing a film such as a metal film or a polysilicon oxide film on the surface of a reaction target. In the present embodiment, a description will be given of a plasma apparatus as shown in FIG. 1 as an example.

As shown in FIG. 1, the surface treatment apparatus X has an apparatus main body 1 having an internal space 10 which is open at the top and bottom, and the antenna 21 is closed so that the upper opening of the apparatus main body 1 is closed. Are arranged, and the susceptor 22 is arranged so as to close the lower opening. In the internal space 10, the antenna 21 and the susceptor 2
2 at a fixed interval to both sides of the shower plate 30
Are arranged, and the interior space 10 is divided into a first space 11 and a second space 12 by the shower plate 30.

The apparatus main body 1 is formed entirely of aluminum or the like, and is not clearly shown in the drawings, but has a triangular or quadrangular shape in plan view. The first space 11 formed in the apparatus main body 1 communicates with the outside of the apparatus through a plurality of supply paths 11a,..., And reactant gas or the like enters the first space 11 from these supply paths 11a,. An inert gas is supplied. As described above, the susceptor 22 is disposed so as to close the lower opening of the apparatus main body 1.
Is attached to the apparatus main body 1 via an insulator 23 such as alumina (Al ₂ O ₃ ). And the susceptor 22
A silicon wafer or the like as the reaction target 4 is placed on the substrate, and the surface thereof is processed. Further, pumps 25,... Which depressurize the internal space 10 (in particular, the second space 12) are attached to the corners of the apparatus main body 1 so as to protrude downward.

The antenna 21 is a microwave generation source, and a quartz or alumina ceramic or the like is provided between an antenna guide 21a made of aluminum or the like and a slot plate 21b made of copper or the like in which a plurality of through holes 21d,. The configuration is such that the dielectric plate 21c is sandwiched therebetween. The microwave from the antenna 21 is emitted into the first space 11, but since the plurality of through holes 21d,... Are dispersedly formed in the slot plate 21b as described above, the slot plate 21b (the antenna 21) is formed. Microwaves are uniformly emitted from the entirety of the above.

The shower plate 30 has a first member 31 and a second member 32 joined to each other as shown in FIG. 2, and has a disk shape, for example. Each member 3
A plurality of through holes 31a,... 32a,. As shown in FIGS. 3 and 4, the joining surface of the first member 31 has a minimum unit lattice defined by four through holes 31a (unit lattice surrounded by phantom lines in FIGS. 3 and 4). The diagonally arranged through holes 31a, 31a are connected by two concave grooves 31b, 31b, respectively. The members 31 and 32 are joined to each other such that the intersections of the concave grooves 31b and 31b face through the through holes 32a formed in the second member 32 as best seen in FIG. In such a joined state, the concave groove 31b of the first member 31 connects each through-hole 31a of the first member 31 and an appropriate through-hole 32a of the second member 32, as best seen in FIG. An intermediate channel 30a is formed. That is, the through hole 31 of the first member 31 is formed in the shower plate 30.
a, the intermediate passage 30a and the through hole 32a of the second member 32
Thereby, a communication path connecting the first space 11 and the second space 12 is formed.

In the surface treatment apparatus X configured as described above, in the internal space 10 in which the shower plate 30 is disposed, the pressure in the second space 12 is reduced by the pumps 25,. First space 1
A reactive gas or an inert gas flows from the first side to the second space 12 side. That is, the through hole 31a of the first member 31,
The gas flows from the first space 11 to the second space 12 through a communication path including the intermediate flow path 30a and the through hole 32a of the second member 32. On the other hand, the microwave from the antenna 21 is emitted into the first space 11, passes through the shower plate 30, and is supplied into the second space 12. A glow discharge occurs in the second space 12 by the supply of the microwave, and the reaction gas in the second space 12 is ionized by the glow discharge, so that the reaction gas is brought into a plasma excited state. Then, on the surface of the reaction target 4 such as a silicon wafer placed on the susceptor 22 or in the vicinity thereof, a chemical or physical reaction occurs due to the reactive gas in a plasma-excited state. 4 are treated.

In the surface treatment apparatus X having the above structure, the gas flows from the first space 11 to the second space 12 through the communication path of the shower plate 30, so that the first space 11 and the second space 1
2 is in the form of a communication path, ie, each member 3
It can be adjusted not only by the diameters and depths of the through holes 31a and 32a, but also by the form of the intermediate flow path 30a.

Since the intermediate flow path 30a is formed by a groove 31b formed on the joint surface of the first member 31 so as to be connected to the through hole 31a, the cross-sectional area and length of the groove can be reduced. If adjusted, the flow resistance in the intermediate flow path 30a can be adjusted. Such adjustment is performed by each member 3
This is extremely easy as compared with adjusting the thickness of the through holes 1 and 32 and reducing the diameters of the through holes 31a and 32a to be formed in the members 31 and 32.

If the flow resistance of the communication passage can be adjusted by the intermediate flow passage 30a, the thickness of each of the members 31, 32 is set to be relatively small, and such members 31, 3 are set.
2, the through holes 31a, 32a having a relatively large diameter
Is formed, and the reactive gas can be uniformly supplied to the reaction target 4 in a planar manner.

In such a configuration, the thickness of each of the members 31, 32 can be set relatively small, and the diameter of the through holes 31a, 32a can be made relatively large.
The following advantages are obtained. First, even when the flow resistance of the communication passage to be formed in the shower plate 30 has to be increased, the flow resistance of the through holes 31a and 32a itself is not greatly increased, and the intermediate flow passage 30a is mainly used. The adjustment of the flow resistance can surely respond. Secondly, even if by-products or the like due to the reaction of the reactive gas are clogged in the through holes 31a and 32a, they can be easily removed.

Of course, the technical scope of the present invention is not limited to those described in the above embodiments, and various design changes can be made. For example, in this embodiment,
Although the surface reaction apparatus X in which the reactive gas is plasma-excited has been described, the surface reaction apparatus X having no antenna 21 or susceptor 22 is also applicable to the present invention.

In the shower plate 30,
Each through-hole 31a of the first member 31 is connected to an appropriate through-hole 32a of the second member 32 via the intermediate flow path 30a. However, the through-holes 31a, 32a of each of the members 31, 32 are directly connected. May be adopted.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating an example of a surface treatment apparatus according to the present invention.

FIG. 2 is an overall perspective view in which a part of a shower plate used in the surface treatment apparatus of FIG. 1 is broken.

FIG. 3 is an enlarged plan view of a main part of the shower plate of FIG. 2;

FIG. 4 is a partially cutaway bottom view in which main parts of the shower plate of FIG. 2 are enlarged.

FIG. 5 is a sectional view taken along the line VV in FIG. 3;

FIG. 6 is a longitudinal sectional view illustrating a plasma apparatus which is an example of a conventional surface treatment apparatus.

7 is an overall perspective view in which a part of a shower plate used in the surface treatment apparatus of FIG. 6 is cut away.

[Explanation of symbols]

 X Surface treatment device 1 Device main body 4 Reaction object 10 Internal space 11 First space (of internal space) 12 Second space (of internal space) 21 Antenna (as electrode unit) 22 Electrode unit 30 Shower plate 30a Intermediate flow path 31 first member (of the shower plate) 31a through hole (of the first member) 31b concave groove (of the first member) 32 second member (of the shower plate) 32a through hole (of the second member)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05H 1/46 H01L 21/302 B (72) Inventor Eisuke Murakawa 21 Ryozaki-cho, Niinin, Ukyo-ku, Kyoto ROHM Co., Ltd. Company F term (reference) 4K030 BA44 EA05 FA02 KA12 4K057 DA20 DB01 DD01 DM29 DM37 5F004 AA01 BA20 BB14 BB28 BB32 BD01 BD04 5F045 AA08 AA09 DP03 EB02 EF05 EH03

Claims (5)

[Claims] 1. An apparatus main body having an internal space formed therein, and the internal space is partitioned into a first space to which a reactive gas is supplied from the outside and a second space to accommodate a reaction target, and A shower plate formed with a communication passage communicating the first space and the second space, wherein the reactive gas supplied to the first space passes through the communication passage and is connected to the second space. A surface treatment device configured to treat the surface of the reaction target by a chemical or physical reaction of the reactive gas in the second space, wherein the shower plates are joined to each other. As well as
A first member and a second member in which a plurality of through-holes are dispersedly formed, and each through-hole of the first member is connected to an appropriate through-hole of the second member to form the communication passage; A surface treatment device characterized by being formed. 2. The surface treatment apparatus according to claim 1, wherein each through hole of the first member is connected to an appropriate through hole of the second member via an intermediate flow path. 3. A joint groove that connects each through hole of one member and an appropriate through hole of the other member in a state where the above members are joined, on a joint surface of the first member or the second member. The surface treatment device according to claim 2, wherein a plurality of the surface treatment devices are formed. 4. The plurality of through-holes of the first member are arranged in a grid, and the plurality of through-holes of the second member are formed in a grid similar to the plurality of through-holes of the first member. And, in at least one member, through holes arranged diagonally in a minimum unit cell defined by four through holes are connected by two concave grooves, respectively. The surface treatment apparatus according to claim 2, wherein the members are joined to each other such that the intersection portion faces from a through hole formed in the other member. 5. The microwave generating source is disposed in the first space, and the microwave is supplied to the second space through the shower plate. 5. The surface treatment apparatus according to any one of 1 to 4.