JPH10311315A - Silicon-made screws - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high accurate screws of long life difficult to be attached by etching gas and plasma, so as to attain stabilization in operation and improvement in quality, in a semiconductor manufacturing device. SOLUTION: In screws used in a semiconductor manufacturing device, the screws are silicon-made screws with material thereof as polycrystal or monocrystal silicon, and a kind thereof is a bolt, nut, hexagonal bolt, round screw, flat countersunk head screw, round countersunk head screw, or wood screw. In the case of material of the screw in monocrystal silicon, its resistance value is 0.001 to 20 Ω.cm, an impurity content except B, N, C, O 0.01 ppb to 1000 ppm, and an oxygen content thereof 15±5 ppm is suited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to screws, and more particularly to screws used in semiconductor manufacturing equipment.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing apparatus such as a semiconductor manufacturing process typified by a dry etching process, various parts are mounted inside and outside a reaction apparatus. In a conventional semiconductor manufacturing apparatus, screws such as screws, bolts, nuts, and the like made of an aluminum alloy that have been subjected to an alumite treatment have been used in such a mounting portion in order to prevent corrosion.

However, in a reaction chamber under severe conditions such as plasma dry etching and reactive ion etching, screws are exposed to an etching gas or plasma, and therefore, even in a place not originally intended for reaction processing. Etching occurred gradually, and this was the cause of generation of particles and contamination, and there was a high risk of lowering the wafer yield.

[0004] In recent years, aluminum alloy screws that have been subjected to alumite treatment have been used to prevent this. In the alumite treatment, when exposed to plasma,
The aluminum alloy was also corroded, causing particles to be generated, and became a contamination in the wafer to be processed and the reaction chamber, thereby lowering the yield, resulting in incomplete corrosion resistance. Outside the reactor, screws made of alumite-treated aluminum alloy have been used mainly for common use of parts.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and is hardly affected by an etching gas or plasma, does not generate particles and contamination, and has a long life. Is long,
It aims to provide high-precision screws at low cost.

[0006]

In order to solve such a problem, the invention described in claim 1 of the present invention relates to a screw used in a semiconductor manufacturing apparatus, wherein the material of the screw is polycrystalline silicon or single crystal. Silicon screws which are made of crystalline silicon.

[0007] As described above, the screws used in the semiconductor manufacturing apparatus are made of the same material as the silicon wafer, which is the main processing object of the apparatus, so that particles are generated even when exposed to an etching gas or plasma. In addition, there is almost no contamination, and the yield of silicon wafers can be improved.

In the second aspect, the silicon screws are bolts and nuts, hexagon bolts, round screws, flathead screws, roundhead screws, or wood screws. The screws mentioned here are a combination of male and female screws and bolts and nuts, hexagonal bolts, and the screws include round screws, flathead screws, roundhead screws, etc. There is a tapered part with a sharp tip (there is a round head, a plate, and a round plate).

When the resistance value of the single crystal silicon is in the range of 0.001 to 20 Ω · cm, it is easy to obtain as a material for manufacturing screws, which is economically advantageous. It is. Further, when the material is single crystal silicon, it is superior to polycrystalline silicon in quality control in terms of impurity content and mechanical strength, and is advantageously used as a material for manufacturing screws.

According to a fourth aspect of the present invention, the content of impurities other than B, N, C and O in the single crystal silicon is set to 0.01 pp.
The range of b to 1000 ppm is set, and in claim 5, the oxygen content is set to 15 ± 5 ppm.

When the content of heavy metals, which are impurities other than B, N, C, and O, mainly exceeds 1000 ppm, the influence of contamination increases. Therefore, it is preferable to suppress the content to 1000 ppm or less. 5pp
Control within the range of m is preferable because heavy metals can be trapped by the so-called gettering effect to reduce impurity contamination and ensure mechanical strength.

According to a sixth aspect of the present invention, the pitch of the silicon screws is set to 0.25.
In the present invention, the ratio between the outer diameter of the screw and the outer diameter of the fastening portion is set to be in a range of 1 / 1.2 to 1/3.

When the pitch of the screws is within this range, a highly accurate screw can be manufactured at low cost, and when the pitch exceeds 6 mm, the screw portion must be lengthened to obtain a tightening force. If the ratio of the outer diameter of the screw portion to the outer diameter of the tightening portion is within this range, the tightening force will be sufficiently transmitted to the fixed component.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings, but the present invention is not limited thereto. Here, FIG. 1 is an explanatory view of bolts and nuts showing an example of the silicon screws of the present invention.
FIG. 3 is a plan view of an electrode plate showing an example of use of the silicon screws of the present invention, and FIG. 3 is a schematic diagram of a plasma dry etching apparatus provided with this electrode plate.

The present inventors have conducted various studies on the prevention of corrosion of screws used particularly in semiconductor device manufacturing equipment, and found that the materials of the screws are the same as those of the silicon wafer which is the main workpiece. The present invention has been completed by assuming that a material may be used.

Here, an example of an electrode plate of a semiconductor device in which the silicon screws of the present invention are used will be described with reference to FIG. 2. The material of the disk-shaped electrode plate 10 is silicon. Hundreds to thousands of small-diameter holes 11 are formed. An electrode plate mounting hole 12 is formed in the outer periphery of the electrode plate, and the electrode plate is mounted on the plasma dry etching apparatus shown in FIG. 3 using the silicon screws of the present invention. The size of the electrode plate is usually 200 to 400 mm in diameter and several mm in thickness, corresponding to the size of the workpiece.
The small diameter hole has a diameter of several tens μm to several hundred μm in diameter.

An example of an apparatus to which this electrode plate is applied is a dry etching apparatus for applying a high frequency as shown in FIG. Here, the electrode plate 21 is a dry etching apparatus 20 for applying a high frequency.
2 shows a state of being set using the screws 28 of the present invention, and a semiconductor wafer 23 and a plane electrode 22 which are objects to be processed are provided at positions facing the electrode plate 21, and between the two electrodes. High frequency is applied. On the other hand, the etching gas enters the internal gas container 25 from the gas supply system 26, is rectified by the small-diameter hole of the electrode plate 21, and jets out toward the wafer 23, where plasma is generated to etch the wafer surface. It has become.

According to the present invention, in the screws used in the above-described semiconductor manufacturing apparatus, the material is polycrystalline silicon or single crystal silicon. This is because the screws and the like are made of the same material as the silicon wafer which is the main object to be processed of the apparatus, so that particles and contamination hardly occur even when exposed to an etching gas or plasma. The yield can be improved, and the stable operation of the process can be ensured.

The silicon screws used here were bolts and nuts, hexagon bolts, round screws, flathead screws, roundhead screws, or wood screws. Here,
The screws include a combination of male and female bolts and nuts, hexagonal bolts, and the screws include round head screws, flat head screws, round head screws, etc. There are tapered ones (there are round heads, plates, and round plates). For these, screws are selected and used in consideration of the position in the device for mounting the components of the semiconductor manufacturing device, the type of mounting tool, the material, thickness, bonding strength, etc. of the body to be bonded.

When single-crystal silicon is used as a material for the screws, the resistance value is set to 0.001 to 20 Ω ·
cm, so that it is easy to obtain as a material for manufacturing screws, which is economically advantageous. Further, single crystal silicon is superior to polycrystalline silicon in quality control in terms of the amount of impurities and mechanical strength, and is advantageously used as a material for manufacturing screws.

Then, B, N,
The content of impurities other than C and O is 0.01 ppb to 100
It is preferably in the range of 0 ppm, and the oxygen content is preferably 15 ± 5 ppm.

If the content of heavy metals, which are impurities other than B, N, C and O, mainly exceeds 1000 ppm, the influence of contamination on the workpiece in the apparatus becomes large, so that it is preferable to suppress the content to 1000 ppm or less. ,
It is preferable to use a material whose oxygen content is controlled in the range of 15 ± 5 ppm, because a so-called gettering effect can capture heavy metals to reduce impurities and also ensure mechanical strength.

As an important design element of the screws, FIG.
As shown in FIG.
, And the ratio d / D between the outer diameter of the threaded portion of the screws and the outer diameter of the tightening portion is set to be in the range of 1 / 1.2 to 1/3.

In view of the scale of a semiconductor manufacturing apparatus in which the silicon screws are mainly used, the screw pitch P
By preparing a screw having a size within the above range, the screw becomes suitable for use of screws such as mounting of a component and mounting and dismounting of a sample, and a highly accurate screw can be manufactured at low cost. Also, the ratio d / D of the outer diameter of the screw portion to the outer diameter of the fastening portion.
Is within this range, the tightening force is sufficiently transmitted to the part to be fixed.

If the pitch of the screws is less than 0.25 mm, a special tool must be prepared for machining.
On the other hand, if the pitch exceeds 6 mm, the thread must be lengthened to obtain a tightening force. If the pitch of the screw is in the range of 0.25 to 6 mm, such a problem is eliminated, and a highly accurate screw can be manufactured at low cost.

The ratio of the outer diameter of the screw portion to the outer diameter of the fastening portion d /
When D is smaller than 1 / 1.2, when fixing parts,
Tightening force is not sufficiently transmitted to the parts. Also, 1/3
If it exceeds, for example, it is necessary to increase the diameter of this counterbore part when counterbore processing is performed on the screw hole part of the part and the screw tightening part is to be set at a position lower than the surface of the part. Although extra time and cost are required for the processing, the processing can be performed with a small load in terms of time and cost within the above range.

Further, since silicon is a hard and brittle material, it is preferable that the pitch and the like of the screws to be produced are such that cracks and chips are less likely to occur.

As a method for producing the silicon screws of the present invention from a material, electric discharge machining, cutting with a diamond tool, and the like are suitable. However, in the case of electric discharge machining,
In the case where silicon having a high resistance value exceeding 1 Ω · cm is used as a base material, electric discharge does not occur and machining is not possible, so cutting with a diamond tool is mainly performed.

[0029]

EXAMPLES The present invention will now be described specifically with reference to examples of the present invention, but the present invention is not limited to these examples. (Example 1) An M3 × 8.8 × 8 × 8 mm × 8 mm × 8 × 8 mm square electric discharge machine was used as a base material and copper was used as an electrode.
5mm (outer diameter of screw part: 3mm, outer diameter of tightening part:
Ten silicon screws (8.5 mm, pitch: 1.0 mm, total length: 12 mm) were produced.

Using this screw, a silicon electrode plate used in a plasma dry etching apparatus was attached and fixed to the apparatus, and etching was performed on a single crystal silicon wafer. 3 for anodized aluminum alloy screws
While the number was as large as one, the number was significantly reduced to eight in the silicon screw of the present invention.

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and has the same effect. Within the technical scope of

For example, while the embodiment of the present invention has been described above as an example in which the silicon bolt of the present invention is used for mounting an electrode plate of a plasma dry etching apparatus, the present invention is not limited to such an example. Not for reactive ion etching equipment, for plasma ashing equipment,
Needless to say, it can be used in various semiconductor manufacturing apparatuses such as a sputtering apparatus or a plasma CVD apparatus.

As the screws, bolts and nuts, hexagon bolts, round screws, countersunk screws, round countersunk screws or wood screws have been specifically mentioned, but are not restricted by such names, and screws and other screws are used. An attachment device using a screw is also included.

[0034]

According to the present invention, silicon screws are
It does not generate particles or contamination even when exposed to an etching gas or plasma, and the damage to the silicon wafer to be processed is much smaller than when using screws made of other materials. can do. Further, since the screws are made of silicon, they can be used stably for a long period of time in a semiconductor manufacturing process, thereby enabling a stable operation of the process and preventing a decrease in the yield of a wafer during the reaction treatment.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing bolts and nuts as an example of screws of the present invention.

FIG. 2 is an explanatory diagram showing an example of an electrode plate using the screws of the present invention.

FIG. 3 is an explanatory view showing an example of a semiconductor manufacturing apparatus using the screws of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bolt, 2 ... Nut, 10 ... Electrode plate, 11 ... Small diameter hole, 12 ... Mounting hole, 20 ... Plasma dry etching apparatus, 21 ... Electrode plate, 22 ... Flat electrode plate, 23 ... Semiconductor wafer, 24 ... Chamber, 25: Internal gas container, 26: Gas supply system, 27: Gas discharge system, 28: Silicon bolt. D: outer diameter of tightening part, d: outer diameter of screw part, P: pitch.

Claims (7)

[Claims] 1. A screw used in a semiconductor manufacturing apparatus, wherein the screw is made of polycrystalline silicon or single crystal silicon. 2. The silicon screws according to claim 1, wherein the screws are bolts and nuts, hexagon bolts, round screws, flathead screws, roundhead screws, or wood screws. 3. The resistance of the single crystal silicon is 0.0
The silicon screw according to claim 1, wherein the screw is in a range of 01 to 20 Ω · cm. 4. The single crystal silicon has an impurity content other than B, N, C, and O of 0.01 ppb to 1000 ppm.
The silicon screws according to any one of claims 1 to 3, wherein: 5. An oxygen content of said single crystal silicon is 15
The amount is ± 5 ppm.
The silicon screws described in any one of the above. 6. The screw pitch of the screws is 0.25 to 0.25.
The screw made of silicon according to any one of claims 1 to 5, wherein the screw is 6 mm. 7. The screw according to claim 1, wherein a ratio of an outer diameter of the screw portion to an outer diameter of the fastening portion is 1 / 1.2 to 1/3. Or the silicon screws according to item 1.