JP2000133699A - Wafer carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce contamination on the surface of a semiconductor wafer due to the generation of dusts, the elimination of a gaseous organic matter and the like in a wafer carrier, by a method wherein the wafer carrier is formed using a synthetic resin as its material and an amorphous carbon film is coated on the surface which is contacted with the wafer, of the carrier. SOLUTION: A wafer carrier 1 is provided with a rectangular bottom plate and four side plates which are respectively provided vertically from the four sides of this bottom plate, comb teeth-shaped grooves 8 are respectively formed in one pair of the side plates, and the fellow grooves are made to oppose to each other. Moreover, an amorphous carbon film 4 is formed by coating the whole surfaces of the inner wall surfaces 2 (the crest parts, the valley parts and the slant parts of the comb teeth) of the grooves. As a method of coating this film 4, there are various methods, such as a method (a technique of growing the film 4 on the surface, which is contacted with a semiconductor wafer, of the carrier 1) of coating by a vacuum deposition and a method of pasting a film which is previously kept formed independently, but any method of those methods is preferable. Moreover, it is preferable that the thickness of the film 4 is formed in a thickness of several tens μm or thicker in consideration of strength and durability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer carrier used for transporting and storing semiconductor wafers.
The present invention relates to a wafer carrier capable of reducing contamination on the surface of a semiconductor wafer due to generation of dust and emission of gaseous organic substances.

[0002]

2. Description of the Related Art A wafer carrier is generally used as a jig for transporting and storing a single crystal silicon wafer which is an intermediate form thereof in a semiconductor device manufacturing process. 2 and 3 are perspective views showing a conventional wafer carrier, and FIG. 4 is an enlarged view of a portion B shown in FIG. FIG.
FIG. 4 is a schematic diagram showing dust attached to a wafer surface.

As shown in FIGS. 2 to 4, the wafer carrier 21 is provided with a rectangular bottom plate and four side plates standing upright from four sides of the bottom plate. Are formed, and the grooves 8 are opposed to each other. The upper part of the wafer carrier 21 has an open structure so that the semiconductor wafer 3 can be set on the wafer carrier 21. Further, a handle is provided on the side plate on which the groove 8 is not formed.

In the conventional wafer carrier 21 configured as described above, when the semiconductor wafer 3 is transported and stored, the outer peripheral portion 5 can be held by the pair of grooves 8, so that the wafer can be processed in the process. 3 to prevent damage and fouling,
Easy handling.

The semiconductor wafer 3 has a very fine electric circuit densely formed on its surface and a large number of logic circuits are integrated. Therefore, in the processing step, as shown in FIG. Even if (.1 μm or more) 7 adheres to the surface of the wafer 3, a short circuit or disconnection of the circuit occurs, and the semiconductor device becomes defective. For this reason, the manufacturing yield of the semiconductor device is reduced, the characteristics are deteriorated, and the reliability is further reduced.

Further, when forming the circuit, it is necessary to use only extremely high-purity materials (gas, chemical solution, silicon substrate, etc.) and to prevent impurities from deteriorating the electrical characteristics of the circuit. For example, if a trace amount of impurity atoms
This is because, when the gate oxide film of the S-type transistor is penetrated, an increase in current leakage and a decrease in breakdown voltage occur.

As described above, the wafer carrier used in the manufacturing process of the semiconductor device comes into direct contact with the semiconductor wafer which is sensitive to impurities and the like, and is associated with the semiconductor wafer for the longest time in the process. This is extremely important for maintaining and improving the product quality of the apparatus, and it is necessary to prevent the wafer carrier itself from becoming a contamination source.

As a main material constituting the wafer carrier, a synthetic resin has conventionally been generally used, for example, polypropylene (PP), polycarbonate (P)
C), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polybutylene terephthalate (PBT), and polyether ether ketone (PEEK). These synthetic resins are advantageous in that they are lighter and easier to handle than metals and ceramics, and that carriers having a complicated structure can be easily and inexpensively manufactured by injection molding technology or the like. In addition, it has many advantages as a material constituting a wafer carrier, such as having elasticity with respect to a single-crystal silicon wafer which is easily brittle and having a soft impact (low impact).

[0009]

However, as described above, these synthetic resins are softer than single-crystal silicon wafers, and are abraded due to contact with the wafer and friction, and are liable to generate dust. Part of the generated dust adheres to the wafer and hinders the formation of microcircuits on the wafer surface, or becomes harmful impurities due to thermal decomposition and chemical decomposition in the subsequent processing and deteriorates circuit characteristics. And other disadvantages that lower the production yield and reliability of the semiconductor device. For this reason, it has been required to modify the surface of the carrier so that it is hardly worn, and to reduce the amount of abraded dust.

These synthetic resins, unlike metals and ceramics, emit gaseous organic substances from the surface. As shown in FIG. 4, a part of the gaseous organic substance 6 released from the inner wall surface 2 of the groove of the wafer carrier 1 is reattached to the surface of the wafer 3, and harmful impurities are generated as they are or by thermal decomposition or chemical decomposition. , Which hinders circuit formation of the semiconductor device and deteriorates circuit characteristics. Therefore, it has been required to reduce the emission of gaseous organic substances from the surface of the wafer carrier and reduce the contamination of the wafer surface.

Further, these synthetic resins generally have electrical insulation properties. That is, since the wafer carrier has an insulating property, the wafer carrier or the wafer is easily charged, and the wafer has a drawback that adsorption and contamination of floating dust by a clone force and burning and destruction of a fine circuit due to electric discharge are increased. . For this reason, measures have been taken to make the synthetic resin conductive. Specifically, a conductive powder (filler) is mixed into the resin, a surfactant is mixed into the resin, and the base resin is mixed. The synthetic resin is made conductive by taking measures such as alloying the conductive polymer.

[0012] However, the countermeasure for mixing the filler has a drawback that dust is increased due to the falling off of the filler, and the countermeasure for mixing the surfactant has a disadvantage that contamination by the surfactant increases. As a countermeasure for alloying a conductive polymer, there is a problem of an increase in outgassing due to a conductive polymer, and improvement of these is also required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a wafer carrier used for transporting and storing semiconductor wafers, contamination of a semiconductor wafer surface due to generation of dust and emission of gaseous organic substances. It is an object of the present invention to provide a wafer carrier capable of reducing the number of wafers.

[0014]

A wafer carrier according to the present invention is characterized in that a synthetic resin is used as a raw material and an amorphous carbon film is deposited on a surface in contact with a semiconductor wafer.

In the present invention, since the amorphous carbon film is deposited on the surface in contact with the wafer carrier, the coefficient of friction of the surface of the wafer carrier in contact with the semiconductor wafer can be reduced. Surface hardness and wear resistance can be improved. Therefore, it is possible to reduce abrasion dust generated at a contact portion between the wafer carrier and the wafer.

Further, since the amorphous carbon film acts as a gas barrier to prevent the gaseous organic matter from being released from the inside of the synthetic resin as the material of the wafer carrier, the gaseous organic matter adheres to the wafer. Pollution can be reduced.

Furthermore, since the amorphous carbon film has an appropriate conductivity, static electricity is less likely to be generated on the wafer carrier and the wafer. Therefore, it is possible to reduce obstacles due to dust adsorption and discharge breakdown due to static electricity on the wafer. .

[0018] The amorphous carbon film may be applied to the entire inner wall surface of the groove for accommodating the semiconductor wafer.

Further, in the present invention, it is preferable that the semiconductor device has a pressure fixing mechanism for pressing and fixing the semiconductor wafer, and the amorphous carbon film is adhered to a contact pressing surface which contacts and presses the semiconductor wafer. Thereby, the wear resistance of the contact pressing surface can be improved.

Further, it is preferable that a film made of a material different from the material of the pressing surface and the amorphous carbon film is provided between the contact pressing surface of the pressing and fixing mechanism and the amorphous carbon film. Thus, a film made of a different substance becomes an adhesive, and the amorphous carbon film can be hardly peeled off from the contact pressing surface.

Further, the amorphous carbon film may be applied by vacuum evaporation, and the amorphous carbon film is formed in a film shape in advance, and the film is attached to a coating surface. It may be attached.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wafer carrier according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. 1A and 1B are views showing a wafer carrier according to an embodiment of the present invention, wherein FIG. 1A is a perspective view, and FIG. 1B is an enlarged view of a portion A shown in FIG.

As shown in FIGS. 1 (a) and 1 (b), the wafer carrier 1 is provided with a rectangular bottom plate and four side plates standing upright from four sides of the bottom plate. Are formed with comb-shaped grooves 8, and the grooves 8 are opposed to each other. The upper part of the wafer carrier 1 has an open structure.
It can be set to. Further, a handle is provided on the side plate on which the groove 8 is not formed.

An amorphous carbon film 4 is formed on the entire inner wall surface 2 of the groove (peaks, valleys, and slopes of the comb teeth). There are various methods for applying the amorphous carbon film 4 such as a method of applying a film by vacuum evaporation (a technique for growing a film on the surface) and a method of attaching a film that has been separately formed in advance. It may be a method. The thickness of the amorphous carbon film 4 is preferably several tens μm or more in consideration of strength and durability.

The wafer carrier 1 of the present embodiment thus configured holds the outer peripheral portion 5 of the semiconductor wafer 3 with a pair of grooves 8 when transporting and storing the semiconductor wafer 3. Therefore, when the wafer 3 is held and when the wafer 3
The wafer 3 always comes into contact with only the amorphous carbon film 4 when the wafer is taken in and out of the wafer carrier 1. The amorphous carbon film 4 has a property similar to diamond while being amorphous, and has a friction coefficient of fluorine resin such as Teflon (registered trademark) which is said to have the lowest friction coefficient among substances on the earth. The amorphous carbon film 4 has a high surface hardness and its abrasion resistance is 50% less than that of ceramics alumina used for electronic parts and the like as a material which is hard to wear.
More than double.

Since the amorphous carbon film 4 can uniformly and densely cover carbon atoms, the wafer carrier 1
Even if the amount of gaseous organic matter generated from the material resin is very small, it has almost perfect gas barrier properties even when used in a semiconductor device manufacturing process that causes wafer contamination.

Further, since the amorphous carbon film 4 has an appropriate conductivity, static electricity is hardly generated on the wafer carrier 1 and the wafer 3.

As described above, in this embodiment, since the amorphous carbon film 4 is deposited on the inner wall surface 2 of the groove of the wafer carrier 1, the friction coefficient of the contact surface of the wafer carrier 1 with the wafer 3 is reduced. It is small and has high surface hardness and abrasion resistance, so that it is possible to reduce abrasion dust due to repeated friction and collision between the wafer carrier 1 and the wafer 3.

Further, since the gaseous organic matter released from the inside of the material resin of the carrier 1 is almost completely sealed, the contamination by the gaseous organic matter adhering to the surface of the wafer 3 can be prevented.

Further, since the amorphous carbon film 4 has an appropriate conductivity, static electricity is hardly generated on the wafer carrier 1 and the wafer 3, and therefore, troubles due to dust adsorption and discharge breakdown due to static electricity on the wafer 3 are reduced. can do.

The amorphous carbon film 4 is formed at least on the surface in contact with the wafer 3.
It is desired that the wafer 3 is formed on all surfaces that may come into contact with the wafer 3.

By the way, a particularly high abrasion resistance is required for a contact pressing surface with a wafer in a mechanism portion (not shown) for pressing and fixing a semiconductor wafer provided in a wafer carrier. Since the amorphous carbon film has high abrasion resistance, it is preferable that the amorphous carbon film is applied to the contact pressing surface.

In particular, when the pressing mechanism has elasticity (such as a leaf spring), the adhesion between the amorphous carbon film and the surface covered with the amorphous carbon film becomes insufficient, and the amorphous carbon Since the film is easily peeled off from the coated surface, the thickness of the amorphous carbon film is set to an appropriate thickness, and a film made of another material is used as an adhesive between the amorphous carbon film and the coated surface. It may be interposed. This makes it difficult for the amorphous carbon film to peel off from the coated surface.

[0034]

As described in detail above, according to the present invention,
Since the coefficient of friction of the contact surface of the wafer carrier with the semiconductor wafer can be reduced and the surface hardness and wear resistance thereof can be improved, abrasion dust generated at the contact portion between the wafer carrier and the wafer can be reduced. Can be reduced.

Further, since the amorphous carbon film acts as a gas barrier to prevent gaseous organic substances from being released from inside the synthetic resin of the material of the wafer carrier, gaseous organic substances adhere to the wafer. Pollution can be reduced.

Further, since the amorphous carbon film has an appropriate conductivity, static electricity is hardly generated on the wafer carrier and the wafer. Therefore, it is possible to reduce obstacles due to dust adsorption and discharge breakdown due to static electricity on the wafer. .

[Brief description of the drawings]

1A and 1B are views showing a wafer carrier according to an embodiment of the present invention, wherein FIG. 1A is a perspective view, and FIG. 1B is an enlarged view of a portion A shown in FIG.

FIG. 2 is a perspective view showing a conventional wafer carrier.

FIG. 3 is a perspective view showing a conventional wafer carrier.

FIG. 4 is an enlarged view of a portion B shown in FIG.

FIG. 5 is a schematic diagram illustrating dust adhering to a wafer surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Wafer carrier 2; Groove inner wall surface 3; Semiconductor wafer 4; Amorphous carbon film 5; Outer perimeter 6; Gaseous organic matter 7;

[Procedure amendment]

[Submission date] September 20, 1999 (1999.9.2)
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014]

SUMMARY OF THE INVENTION A wafer carrier according to the present invention comprises a carrier body made of synthetic resin and a semiconductor body.
Wafer cap having a pressure fixing mechanism for pressing and fixing a wafer
Rear, wherein the carrier body is the semiconductor wafer
An amorphous carbon film is applied to the entire inner wall surface of the groove for accommodating the semiconductor wafer, and the pressing and fixing mechanism contacts the semiconductor wafer.
The amorphous carbon film is deposited on the contact pressing surface to press
And the contact pressing surface of the pressing and fixing mechanism and the amorphous carbon film
Characterized in that an adhesive is interposed therebetween .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

[0018] The amorphous carbon film that is deposited on the entire surface of the inner wall surface of the groove for accommodating the semiconductor wafer.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

[0019] In the present invention, it has a pressing and fixing mechanism for pressing and fixing the semiconductor wafer, wherein the amorphous carbon layer to contact the pressing surface in contact with the pressing the semiconductor wafer that has been deposited. Thereby, the wear resistance of the contact pressing surface can be improved.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

Further, a film made of a material different from the material of the pressing surface and the amorphous carbon film is provided as an adhesive between the contact pressing surface of the pressing and fixing mechanism and the amorphous carbon film . Thus, the amorphous carbon film is not easily peeled off from the contact pressing surface.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E068 AA33 AB04 AC06 BB06 BB11 BB17 CC02 CD02 CE03 CE20 DD06 DD19 DE18 EE01 3E096 AA06 BA16 BB04 CA02 CB03 DA01 DB01 DC01 EA02X EA20Y FA09 FA10 GA03 5F031 CA02 DA01 EA04 FA

Claims (6)

[Claims] 1. A wafer carrier comprising a synthetic resin as a raw material and an amorphous carbon film adhered to a surface in contact with a semiconductor wafer. 2. The wafer carrier according to claim 1, wherein the amorphous carbon film is applied to the entire inner wall surface of the groove for accommodating the semiconductor wafer. 3. The semiconductor device according to claim 1, further comprising a pressing and fixing mechanism for pressing and fixing the semiconductor wafer, wherein the amorphous carbon film is applied to a contact pressing surface that contacts and presses the semiconductor wafer. Or the wafer carrier according to 2. 4. A film made of a material different from the material of the pressing surface and the amorphous carbon film is provided between the contact pressing surface of the pressing and fixing mechanism and the amorphous carbon film. The wafer carrier according to claim 3, wherein 5. The method according to claim 1, wherein the amorphous carbon film is applied by vacuum evaporation.
Item 9. The wafer carrier according to item 1. 6. The amorphous carbon film according to claim 1, wherein the amorphous carbon film is formed into a film in advance, and the film is adhered by attaching the film to a covering surface. The described wafer carrier.