JP4885064B2 - Wafer carrier and wafer etching method using the same - Google Patents

Description

  The present invention accommodates a plurality of rectangular wafers such as solar cell substrates and liquid crystal display glass substrates (hereinafter simply referred to as wafers) so that the wafers are not in contact with each other, and are used for etching and cleaning. The present invention relates to a wafer carrier that can be used in a process.

The wafer carrier is generally used when a plurality of wafers are simultaneously transferred or processed in a semiconductor wafer manufacturing process or a device manufacturing process.
Such wafer carriers have been used for various purposes such as transfer and processing, and have various modes depending on the wafer shape, and have been developed to suit processes such as heat treatment, etching, cleaning, and drying. It was.

  For example, in Patent Document 1, in a wafer carrier that accommodates a plurality of circular wafers in a standing state in parallel, foreign matter adhesion to the entire wafer mirror surface is provided at the end of the wafer row in order to reduce foreign matter adhesion to the wafer. A wafer carrier is disclosed.

  In addition, Patent Document 2 can share a wafer for cleaning and transport, no transfer is required, no liquid residue is generated after cleaning, there is no drying failure, no water mark is generated, and the wafer is chipped or cracked during transport. In addition, a wafer carrier 21 as shown in FIG. 2 has been proposed for the purpose of preventing generation of cutting scraps and the like from the support surface of the wafer.

FIG. 2 is a schematic view showing an example of a conventional wafer carrier. The wafer carrier 21 has support members 28 formed by projecting a plurality of support protrusions 28a at predetermined intervals in the longitudinal direction on both sides of the frame body 29. By supporting both surfaces of the end portion of the wafer W, a plurality of rectangular wafers are arranged and accommodated at a predetermined interval.
With such a structure, even if the wafer carrier immersed in the cleaning liquid is lifted from the cleaning liquid after the wafer is cleaned, the cleaning liquid can be removed well.

  However, since the wafer carrier performs a texture forming process and a cleaning process while accommodating a rectangular wafer for solar cells or the like, the wafer carrier needs to be excellent in heat resistance and corrosion resistance. If a plurality of wafers are to be supported by the support member on which the protrusions are formed, it is necessary to manufacture the wafer carrier with an expensive material such as a PEEK material in order to ensure the strength of the wafer carrier. Therefore, if the rectangular wafer is supported by only a plurality of support members, there is a problem that the cost increases.

On the other hand, Patent Document 3 discloses a wafer carrier for cleaning and drying in a state where a plurality of wafers are accommodated.
3A and 3B are schematic views of a conventional wafer carrier that accommodates a wafer. FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along line XX in FIG.
The wafer carrier 31 is continuous to the left and right side walls 36c and 36d, which are parallel to each other and have a plurality of gripping grooves 37 formed in the inner wall at equal intervals in the longitudinal direction to hold the left and right edges of the wafer W, and the front ends of the left and right side walls. A front end wall 36a, a rear end wall 36b continuous to the rear ends of the left and right side walls and parallel to the front end wall, and a flange 35 provided between the front and rear end walls to support the lower edge of the wafer. The flank angle of the holding groove 37 is devised so that cleaning and drying can be performed satisfactorily.

In such a wafer carrier, since the lower end of the wafer is supported by the ridge, the drainage of the lower end of the wafer, where the cleaning liquid easily collects during drying, is good.
However, after the etching, the wafer carrier immersed in the etching tank is pulled up, washed with a cleaning solution, and the wafer is dried. During the drying process, especially between the groove formed inside the side wall of the wafer carrier and the rectangular wafer, At the bottom of the groove, there is a problem that the cleaning liquid is difficult to dry and it takes a long time to dry the hot air.

JP-A-9-64163 JP-A-11-180553 JP 2002-329702 A

  The present invention has been made in view of such problems, and has a structure that has corrosion resistance and heat resistance, and can maintain a sufficient strength to accommodate a plurality of rectangular wafers with an inexpensive material. However, for example, in the manufacture of solar cells, a wafer carrier that does not hinder the uniform formation of texture on the wafer, has good cleaning liquid drainage, and requires a shorter drying process is provided. An object of the present invention is to provide an etching method.

In order to achieve the above object, the present invention provides a guide rail for accommodating a plurality of rectangular wafers arranged in parallel at a predetermined interval in a state where at least the upper surface and the bottom surface are opened and inside the side walls facing each other. Is a wafer carrier comprising: a box-shaped container body formed in parallel with each other; and a support rod fixed to the bottom of the container body to support the wafer from falling off. Each of the opposing side walls has an opening through which liquid can enter and exit, and each of the guide rails has a slit formed so as to be intermittent in the vertical direction. Provide .

  As described above, in the present invention, the opposing side walls of the container body each have an opening through which liquid can enter and exit, and each guide rail is formed with a cut portion so as to be intermittent in the vertical direction. As a result, when the rectangular wafer is immersed in the cleaning solution or the etching solution, turbulence can be generated in the cleaning solution or the etching solution when performing the cleaning process or the etching process, and the gap between the guide rail and the rectangular wafer is cleaned. Etching can be performed, and etching or cleaning can be performed evenly within the surface of the rectangular wafer.

Also, when pulling up the wafer carrier immersed in the cleaning solution or the etching solution, the bottom surface of the container body is opened, the side wall has an opening, and the guide rail is formed with a cut portion. Injuries are good, and the amount of cleaning solution and etching solution taken out decreases.
Furthermore, in the drying process, since the cut portion is provided in the portion where the liquid can easily accumulate between the guide rail of the wafer carrier and the rectangular wafer, the time required for the hot air drying is shortened, and further, the outer periphery of the rectangular wafer is reached. Can be dried well.

  In addition, since the container body is not a box with several support members attached to the frame, but a box shape, a wafer carrier is manufactured using a relatively inexpensive material with excellent heat resistance and corrosion resistance. This can reduce the cost for manufacturing the wafer carrier.

The present invention also relates to a method for etching a rectangular wafer using the wafer carrier, wherein the wafer carrier contains a plurality of wafers in an etching tank filled with an etching solution for etching the wafer. A wafer etching method is provided in which the wafer is etched by immersing the wafer and further jetting an etching solution from the bottom of the etching tank toward the wafer carrier .

  As described above, when a rectangular wafer is etched using the wafer carrier, the wafer carrier containing a plurality of wafers is immersed in an etching tank filled with an etching solution for etching the wafer, By further jetting the etching solution from the bottom toward the wafer carrier, the etching solution jetted from the bottom of the etching tank wraps around the support rod of the wafer carrier, the opening of the side wall of the container body, and the cut portion of the guide rail, A turbulent flow is generated, and for example, a texture can be uniformly formed in a plane on a rectangular wafer for solar cells.

  As described above, the wafer carrier and the wafer etching method using the same according to the present invention have corrosion resistance and heat resistance, and maintain sufficient strength to accommodate a plurality of rectangular wafers with inexpensive materials. Although it is a structure that can be used, it can be used, for example, in an etching process for forming a texture in a solar cell manufacturing process, and the cleaning liquid can be easily removed, and the drying process can be further shortened.

  As described above, the wafer carrier used in the solar cell manufacturing process needs to be selected from a material that has a strength that can accommodate a plurality of rectangular wafers and that does not corrode even when used in the etching process. . In the conventional wafer carrier as shown in FIG. 2, since the structure of the wafer carrier itself is soft even if the liquid is good, the material constituting the wafer carrier is hard and a material having corrosion resistance to the etching solution is selected. Will be. As a result, the wafer carrier made of an expensive PEEK material is limited, and there is a problem that the cost is increased.

  On the other hand, in the case of a box-type wafer carrier, the number of types of materials that can maintain a strength sufficient to accommodate a plurality of rectangular wafers can be increased without using an expensive material such as a PEEK material. The range of material selection for the wafer carrier is widened, and as a result, the manufacturing cost of the wafer carrier is reduced.

  However, even with a box-shaped wafer carrier such as that shown in FIG. 3, when texture is formed on the wafer, there is a portion where no texture is formed between the gripping grooves of the rectangular wafer, and the vicinity of the gripping grooves when dried. However, it was difficult to dry, and the drying process took time.

Therefore, the present inventors have conducted intensive research in order to solve such problems.
For example, when a wafer carrier as shown in FIG. 3 is used in an etching process for forming minute pyramidal irregularities (textures) on a rectangular wafer for solar cells, the etching solution filled in the etching tank and the rectangular silicon wafer Reacts to generate bubbles (H ₂ ). This bubble may accumulate between the holding groove of the wafer carrier and the wafer accommodated therein, and the etching solution may not reach the corner of the wafer. As a result, a portion where no texture is formed is formed on the outer peripheral portion of the wafer.

  Therefore, for example, an etching process for texture formation in a solar cell manufacturing process while having a structure that has corrosion resistance and heat resistance and can maintain a sufficient strength to accommodate a plurality of rectangular wafers with an inexpensive material. In order to provide a wafer carrier that can reduce unevenness in the texture formation of the wafer by the wafer carrier and that the cleaning liquid can be easily removed and the drying process can be performed in a shorter time, the opposing side walls of the container body are each made of liquid. It is conceived that any wafer carrier may be used as long as it has a slit portion that is intermittent in the vertical direction in the guide rail that divides and aligns the individual wafers in parallel. Was completed.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 4, 5, and 6, but the present invention is not limited thereto.
FIG. 1 is a schematic view showing an example of a wafer carrier according to the present invention. FIG. 4 is a top view of the wafer carrier shown in FIG. FIG. 5 is a left side view of the wafer carrier shown in FIG. 6A and 6B are explanatory views of the turbulent flow of the etching solution when the wafer carrier shown in FIG. 1 is immersed in an etching tank and performing the etching process, FIG. 6A is a sectional view, and FIG. FIG.

  The wafer carrier 1 of the present invention includes a box-shaped container body 2 and two support bars 5 that support the plurality of rectangular wafers W so as not to fall off. The container main body 2 has a box shape with an open top and bottom surface, and a guide for accommodating a plurality of rectangular wafers W in parallel with a predetermined interval in a state of standing inside the side walls 2a and 2b facing each other. A plurality of rails 3 are formed in parallel in the vertical direction. The opposing side walls 2a and 2b of the container body 2 have openings 10 through which liquid can enter and exit, respectively. Each guide rail 3 is formed with a cut portion 4 so as to be intermittent in the vertical direction.

  As described above, since the container body 2 of the wafer carrier 1 is box-shaped, the structure of the wafer carrier 1 is more than that of the wafer carrier constituted by a plurality of support members and frames having support protrusions as shown in FIG. , The strength can be increased. Therefore, among the materials having the corrosion resistance and heat resistance necessary for the wafer carrier used in the etching process, cleaning process, and drying process of solar cell manufacturing, the hardness of the material itself is not so limited. The range of material selection for manufacturing is expanded. As a result, a relatively inexpensive material can be selected, leading to a reduction in wafer carrier manufacturing costs.

In particular, in the conventional wafer carrier structure as shown in FIG. 2, the material of the wafer carrier suitable for manufacturing the solar cell is a PEEK material. In order to manufacture such a wafer carrier, it has to be manufactured by a solid material shaving method, and thus processing costs have been added.
However, in the wafer carrier of the present invention, hydrophilic material such as carbon-added PPS can be used as a material, and the wafer carrier can be manufactured by a die-cutting method. Therefore, the production cost can be reduced for both materials and processing.

  And as for the container main body 2 of this invention, the upper surface and the bottom face are open | released. In particular, since the bottom surface is open, when the wafer carrier immersed in the cleaning tank or the etching tank is pulled up, the liquid drainage is improved. In the etching or cleaning process, ultrasonic vibration can be applied to the cleaning liquid or the etching liquid from the lower part of the wafer carrier, or the liquid can be jetted from below.

  In addition, a plurality of guide rails 3 for receiving a plurality of rectangular wafers W in parallel at a predetermined interval in a state where the plurality of rectangular wafers W are set up are arranged in parallel inside the side walls 2a, 2b facing each other of the container body 2. Is formed. In particular, the opposing side walls 2a and 2b of the container body 2 have openings 10 through which liquid can enter and exit, and the individual guide rails 3 are formed with cuts 4 so as to be intermittent in the vertical direction. When the wafer carrier 1 is immersed in a cleaning tank or an etching tank and subjected to etching or cleaning treatment on a plurality of rectangular wafers, ultrasonic vibration is applied to the cleaning liquid or etching liquid, or these liquids are applied to the wafer carrier. If it is sprayed toward the side wall or the lower part, a turbulent flow of liquid can be generated by the cut portion 4 or the opening 10.

In particular, due to the occurrence of turbulent flow at the wafer edge near the guide rail, the etching solution filled in the etching tank reacts with the rectangular silicon wafer, and even if bubbles (H ₂ ) are generated, there is a break 4. Air bubbles do not accumulate between the guide rail 3 and the wafer W accommodated therein. Therefore, the texture can be uniformly formed in the wafer surface without unevenness.

  Further, when the wafer texture forming step is completed and the wafer carrier of the present invention shown in FIG. 1 is pulled up from the etching tank, the bottom surface of the container body 2 is opened, and the side wall opening 10 and Since the guide rail cut portion 4 is formed, the liquid drains well and the amount of liquid taken out from the tank is reduced. Therefore, the consumption of the chemical solution is reduced, which leads to reduction of the solar cell manufacturing cost.

  And also in the drying of the wafer after the cleaning process, as described above, by using the wafer carrier of the present invention, the liquid can be drained particularly by the opening 10 of the side wall and the cut portion 4 of the guide rail. The drying time by hot air drying can be made shorter than before, and the outer peripheral portion of the rectangular wafer can be surely dried, and the appearance of the wafer surface is maintained because there is no stain or unevenness.

  In the present invention, if the cut portion 4 of the guide rail 3 is formed more in the lower half of the side walls 2a, 2b, the liquid drainage is better. Further, the cut portions 4 may be formed at equal intervals with respect to the guide rail 3, but if they are formed at irregular intervals as shown in FIG. 1, liquid turbulence is generated. It becomes an easy wafer carrier.

Hereinafter, a method of etching a rectangular wafer using the wafer carrier shown in FIG. 1 will be described in detail with reference to FIG.
The wafer carrier 1 containing a plurality of wafers W is immersed in an etching tank 12 filled with an etching solution 11 for etching the wafers W. Then, the etching solution 11 is further jetted from the bottom of the etching tank 12 toward the wafer carrier 1.

As described above, by using the wafer carrier 1 and jetting the etching solution 11 from the bottom of the etching tank 12, turbulent flow as shown in FIG. 6 is generated.
That is, the etching solution 11 jetted from the bottom of the etching tank 12 enters the wafer carrier 1 from the support rod 5 of the wafer W of the wafer carrier 1, the opening 10 of the side wall, and the cut portion 4 of the guide rail ( Further, a turbulent flow of the etching solution is generated. As a result, the etching solution flows to the portion where the bubbles are likely to accumulate between the guide rail 3 and the wafer W, and the wafer W is in a state of swimming, so that the bubbles can be driven out. Therefore, the texture can be formed evenly on the outer periphery of the rectangular wafer.

The present invention will be described in more detail below with reference to examples of the present invention, but these examples do not limit the present invention.
(Example)
Using a wafer carrier 1 as shown in FIG. 1, a texture was formed on 20 rectangular wafers for solar cells, washed and dried.
In particular, the wafer carrier 1 to be used was one produced by a carbon + PPS material die-cutting method so that the cut portions 4 of the guide rail have an irregular pattern.
When the texture was formed on the 20 wafers W, the etching solution was jetted from the bottom of the etching tank toward the wafer carrier 1.

  As a result, no unevenness was observed on the wafer surface of all the 20 wafers W on which the texture was formed. Further, the amount of the etching solution taken out from the etching tank before and after the etching process was about 18 g with respect to 20 wafers. Moreover, the drying time was about 15 minutes and it was able to dry completely.

(Comparative example)
For comparison, a texture was formed on 20 rectangular wafers for solar cells, washed, and dried using a wafer carrier in which the opening of the side wall and the guide rail were not formed.
In particular, the wafer carrier to be used was one having no cut portion in the guide rail, and one produced by a carbon + PPS material die cutting method.
When the texture was formed on the 20 wafers W, the etching solution was jetted from the bottom of the etching tank toward the wafer carrier.

  As a result, unevenness was confirmed in the vicinity of the 20 wafers W on which the texture was formed, sandwiched between the guide rails. Further, the amount of the etching solution taken out from the etching tank before and after the etching process was 20 g with respect to 20 wafers, which was larger than in the example. Although the drying time was 20 minutes, the end portion of the wafer sandwiched between the guide rails of the wafer carrier could not be completely dried.

  The present invention is not limited to the above embodiment. The above-described 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 any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  In particular, the above describes the case where the wafer carrier of the present invention is used in the etching, cleaning, and drying processes in the manufacture of solar cells. However, even if it is used for manufacturing other semiconductor substrates, glass substrates, etc., it is a rectangular wafer. The same effect is obtained.

It is the schematic which shows an example of the wafer carrier which concerns on this invention. It is the schematic which shows an example of the conventional wafer carrier. 3A and 3B are schematic views of a conventional wafer carrier that accommodates wafers, FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along line XX in FIG. It is a top view of the wafer carrier shown in FIG. It is a left view of the wafer carrier shown in FIG. FIGS. 6A and 6B are explanatory views of a turbulent flow of an etching solution when the wafer carrier shown in FIG. 1 is immersed in an etching tank and an etching process is performed, FIG. 6A is a cross-sectional view, and FIG. FIG.

Explanation of symbols

1, 21, 31 ... wafer carrier, 2 ... container body, 2a, 2b ... side wall,
3 ... Guide rails, 4 ... Cuts, 5 ... Support bars, 10 ... Openings,
11 ... Etching solution, 12 ... Etching tank,
28 ... a support member, 28a ... a projection for support, 29 ... a frame,
36a, 36b, 36c, 36d ... wall, 37 ... grip groove,
W: Rectangular wafer.

Claims (2)

A box in which at least the top and bottom surfaces are open, and a plurality of guide rails are formed in parallel in the vertical direction so as to accommodate a plurality of rectangular wafers in parallel with each other at a predetermined interval in a state of standing a plurality of rectangular wafers. A wafer carrier comprising: a container body of a mold; and a support bar fixed to the bottom of the container body to support the wafer from falling off,
The opposing side walls of the container body each have an opening through which liquid can enter and exit,
Each of the guide rails is formed with a cut portion so as to be intermittent in the vertical direction , and the cut portion does not match the height position between the adjacent guide rails, and is below the side wall. A wafer carrier characterized in that it is formed in half more than the upper half .   A method of etching a rectangular wafer using the wafer carrier according to claim 1, wherein the wafer carrier containing a plurality of wafers in an etching tank filled with an etching solution for etching the wafer. A wafer etching method, wherein the wafer is etched by dipping and further jetting an etching solution from the bottom of the etching tank toward the wafer carrier.

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