JP3248192B2 - Jig and method for extracting wafer surface elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig and a method for extracting various contaminants (hereinafter referred to as "wafer surface elements") remaining or adsorbed on a wafer surface. More specifically, the present invention relates to a wafer surface element extraction jig for accurately and efficiently extracting a wafer surface element with a small amount of extract, and a method for extracting a wafer surface element using the extraction jig.

[0002]

2. Description of the Related Art Since the performance and reliability of semiconductor devices are greatly affected by the contamination of the wafer surface, it is important to reduce the occurrence of surface contamination and to remove the generated contamination by cleaning. Therefore, it is also important to accurately analyze surface contamination.

For example, at present, as a wiring material of VLSI, Ti / T using a barrier metal such as TiON or TiW is used.
A barrier metal structure such as iON / Al-Si has been used. In the lithography process, TiO 2 is used to prevent reflected light from the underlying Al surface.
Attempts have been made to employ an antireflection film made of a barrier metal such as N or α-Si. In such an element using a so-called Al multilayer film, since different kinds of metals are in contact with each other, after chlorine-based dry etching, Al corrosion called after-corrosion is likely to occur due to residual chlorine. For this reason, it has become an important issue to develop a method for detecting residual chlorine and to remove it, and various methods have been proposed.

[0004] Regarding the method of quantifying residual chlorine, ion chromatography has been used as a completed technique as a method of quantifying chlorine in a solution. Then, in order to obtain a sample solution for this ion chromatography, as a method of extracting residual chlorine from the wafer surface, a method of extracting the wafer by immersing it in pure water or a method of extracting pure water on the wafer with a surface tension. There is a method of holding and extracting.

[0005]

However, according to the method of immersing the wafer in pure water, the amount of the extraction solvent is increased, and the concentration of chlorine in the extract is reduced. There is a problem that the error tends to increase. According to the method of holding pure water on the wafer at surface tension, when the extraction time is extended to sufficiently extract, a considerable amount of pure water on the wafer evaporates, and the chlorine concentration in the extract changes. . Since this concentration change greatly depends on the extraction environment such as the temperature and humidity around the wafer holding pure water, the value of the residual chlorine obtained in this way depends on the extraction environment of the wafer. There is.

[0006] The present invention is to solve the above-mentioned problems of the prior art, and uses a small amount of extract, accurately and efficiently without affecting the surrounding extraction environment. The purpose is to be able to extract.

[0007] In order to achieve the above object, the present invention provides:
A extraction jig wafer surface elements ing from upper lid for covering the lower tray and lower tray thereof contain an extract of the wafer surface element,
In the lower plate, the extraction surface of the wafer surface element faces the bottom of the lower plate
A supporting means for supporting a wafer within the lower tray as upper lid is extracted under dish fitted into lower tray as the internal volume of the jig is reduced can be covered, the edge portion of the upper lid The lower plate
Between the end of the upper lid and the inner wall of the lower plate
Is cut in a tapered shape so that a void is formed
Of the upper lid and the lower plate
Provided is a jig for extracting an element on a wafer surface , wherein an angle formed between the inner wall and the inner wall is 10 degrees or more.

Further, as a method for extracting a surface element of a wafer using such a jig for extracting a surface element of a wafer,
Place the wafer in the lower plate so that the extraction surface of the wafer surface element faces the bottom surface of the lower plate, fill the extraction solution between the bottom surface of the lower plate and the extraction surface of the wafer surface element, cover the wafer, and place the wafer on top. A method for extracting a surface element is provided.

As described above, the jig for extracting elements on the wafer surface according to the present invention comprises the lower plate and the upper lid having characteristic shapes.

[0010] The supporting means provided for supporting the wafer in the lower plate is preferably one capable of supporting the wafer near the bottom surface of the lower plate. Can be configured. In this case, the projection or the like does not necessarily need to be fixed in the lower plate, and may be removable. Further, the projections and the like are preferably provided so that the number of supporting points of the wafer is three or more. When provided on the side surface, they may be provided on the entire circumference.

By providing such support means,
It becomes easy to place the wafer near the bottom of the lower plate. Also, at this time, the wafer is placed so that the extraction surface of the wafer surface element faces the bottom of the lower plate, and the extraction solution is filled between the bottom surface of the lower plate and the extraction surface of the wafer surface element. It becomes possible to extract the wafer surface element by the method.

The inner diameter of the lower plate can be appropriately determined according to the size of the wafer as a sample, and is generally preferably about 1 to 2 mm larger than the diameter of the wafer. By placing the wafer in a lower dish of such a size and filling the extract between the bottom surface of the lower dish and the extraction surface of the wafer surface element as described above, almost all of the interface of the extract is the wafer. Since the extract is covered by itself, it is possible to effectively prevent the extract from evaporating and causing a change in concentration of the element on the wafer surface in the extract.

FIG. 2 is a partial sectional view of the vicinity of a side wall of the extraction jig according to one embodiment of the present invention. As described above, the upper lid 1 of the present invention not only covers and covers the lower plate 2 but also fits into the lower plate 2 so as to reduce the internal volume of the extraction jig. As a result, the volume of the extracted liquid 3 that evaporates is reduced, so that the amount of evaporation until the vapor is saturated is also reduced, and it is possible to reduce the evaporation of water by the amount of the saturated water vapor of the extract.

The upper lid 1 has a tapered end 1a at a portion that fits into the lower plate 2 when the lower plate 2 is covered. Usually, the angle of the taper is such that the gap A formed by the end 1a of the upper lid with the inner wall 2a of the lower plate 2 is 10 degrees or more. If the upper lid 10 and the lower plate 20 are rubbed as shown in FIG. 3 without forming such a tapered space A, for example, the lower plate is made of quartz glass and the extract is put in the lower plate. When the extract 3 has wettability with respect to the lower plate and the interface of the extract is cut upward on the side wall of the lower plate, as in the case where is water, the internal volume of the extraction jig is reduced. The upper lid 10 to the lower plate 20
When the extract 3 is inserted deeply into the container, the extract 3 is rubbed between the upper lid 10 and the lower plate 20 by capillary action as shown by the arrow in the figure.
Will invade and escape. On the other hand, as shown in FIG. 2, when the end 1a of the upper lid 1 is tapered and the gap A is formed, the extract 3 is not lost by the capillary phenomenon.

[0015]

According to the present invention, since the lower plate of the jig for extracting the element on the surface of the wafer has the support means for supporting the wafer inside, the wafer can be easily set in the lower plate. At this time, if the extraction surface of the wafer surface element is placed facing the bottom of the lower plate and the extraction liquid is filled between the bottom surface of the lower plate and the extraction surface of the wafer surface element, the amount of extract used will be small. And a change in concentration due to evaporation of the extract can be prevented.

Further, since the upper lid is fitted into the lower plate to cover the lower plate, the internal volume of the extraction jig is reduced, so that the evaporation of water by the amount of water vapor due to the evaporation of the extract can be reduced. .

Furthermore, since the end of the upper lid fitted into the lower plate forms a space with an angle of 10 degrees or more with respect to the inner wall of the lower plate, an arbitrary extraction liquid is used, and the inner volume of the extraction jig is reduced. Even when the upper lid is inserted deeply into the lower plate to make it sufficiently small, the extract is prevented from escaping due to capillary action.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which a wafer is placed in a jig for extracting elements on a wafer surface according to one embodiment of the present invention, and an extraction solution is filled therein.

As shown in FIG. 1, the extraction jig of this embodiment comprises an upper lid 1 and a lower plate 2, and a plurality of projections 2b are provided at substantially equal intervals near the outer periphery of the bottom surface of the lower plate 2. ing. The end 1a of the upper lid 1 fitted in the lower plate 2 is tapered so that the angle A of the gap with respect to the inner wall 2a of the lower plate 2 is 10 degrees.

The wafer 4 is placed on the projection 2b of the lower plate 2 with the extraction surface facing downward. The gap C between the outer peripheral portion of the wafer 4 and the inner wall 2a of the lower plate 2 is 0.5 to
It is about 1 mm.

The extraction liquid 3 is filled so as to fill the space between the bottom surface of the lower plate 2 and the extraction surface of the wafer 4. As a method for putting the extract 3 in this way, for example, the wafer 4
Is placed on the lower plate 2 and the extract 3 may be dropped from an opening of an orientation flat (not shown) generally provided on the wafer 4. In addition, the method of collecting the extract 3 after the completion of the extraction can be easily performed by using the opening of the orientation flat.

In order to determine the amount of the extract 3 dropped onto the lower plate 2, the amount to be dropped can be easily calculated from the product of the area of the bottom surface of the lower plate 2 and the height of the projection 2b. The liquid volume may be measured. Alternatively, the weight may be measured before and after the space between the bottom surface of the lower plate 2 and the extraction surface of the wafer 4 is filled with the extract 3, and the amount of the extract 3 may be calculated from the weight difference. .

The extraction of the wafer surface elements is performed by leaving the wafer in the state shown in the figure for a predetermined time. In this case, various operations for improving the extraction efficiency of the surface elements can be added as long as the illustrated state is maintained. For example, the extraction jig can be heated and kept warm so that the temperature of the wafer 4 is about 40 ° C., and ultrasonic waves may be applied. Even if such an operation is added, the extract 3 does not escape from the portion where the upper lid 1 and the lower plate 2 are rubbed by capillary action, and the amount of extract decrease due to evaporation is extremely small. It is possible to extract the element on the wafer surface with high reproducibility and high accuracy by using the extraction liquid 3 described above.

The material for forming the jig for extracting elements on the wafer surface according to the present invention may be any material which does not contain the element to be extracted and which is not affected by the extract. Various ones can be used according to. For example, transparent quartz or Teflon can be used. In addition, the type of the extract to be used can also be appropriately determined from pure water, an acid, an alkali, an organic solvent, etc., depending on the type of the element to be extracted.
Pure water can be used to extract halogen-based ions, and organic solvents can be used to extract fats and the like due to hand soiling.

[0026]

According to the present invention, it is possible to accurately and efficiently extract a wafer surface element from a wafer by using a small amount of extract without being affected by the surrounding extraction environment.

[Brief description of the drawings]

FIG. 1 is a sectional view of a jig for extracting elements on a wafer surface according to the present invention.

FIG. 2 is a partial cross-sectional view of the vicinity of a side wall of the jig for extracting a wafer surface element according to the present invention.

FIG. 3 is a partial cross-sectional view of the vicinity of a side wall of an extraction jig composed of a combination of an upper lid and a lower plate that are not tapered.

[Explanation of symbols]

 Reference Signs List 1 upper lid 1a end of upper lid fitted into lower plate 2 lower plate 2a inner wall of lower plate 2b projection 3 extract 4 wafer A gap between end 1a of upper lid and inner wall 2a of lower plate C wafer 4 Gap between outer periphery and inner wall 2a of lower plate

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/66 G01N 1/28

Claims (2)

(57) [Claims] 1. A jig for extracting a wafer surface element comprising a lower plate for holding an extract of a wafer surface element and an upper lid for covering the lower plate, wherein the lower plate has a lower surface for extracting the wafer surface element. The upper cover has a support means for supporting the wafer inside the lower plate so as to face the lower plate, and the upper cover can be fitted into the lower plate so as to reduce the internal volume of the extraction jig, and cover the lower plate. The portion is tapered so that a gap is formed between the end of the upper lid and the inner wall of the lower plate when fitted into the lower plate, and the end of the upper lid cut in a tapered shape. A jig for extracting an element on a wafer surface, wherein an angle formed between the portion and an inner wall of the lower plate is 10 degrees or more. 2. Extraction of elements on the wafer surface according to claim 1.
In the method of extracting a wafer surface element using a jig,
Place the wafer in the lower dish with the extraction surface of the wafer surface element down.
Place it so that it faces the bottom of the plate,
Fill the extraction liquid between the surface element extraction surface and cover
A method for extracting surface elements.