JP2004319783A - Device for cleaning semiconductor substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for cleaning a semiconductor substrate that can prevent the substrate from being contaminated by a chemical liquid left as a reaction product in a groove for protecting the substrate, and can clean the substrate for a short time without blocking a liquid current. <P>SOLUTION: The device for cleaning a semiconductor substrate houses a plurality of semiconductor wafers 1 in position by a dedicated substrate holding tool 2, dips them successively in a plurality of treatment tanks 4 in a batch manner to clean them. A projection 6 is provided on the inner bottom of the treatment tank 4 housing the substrates 1 for dipping by the substrate holding tool 2 in a manner that the substrate 1 is slightly floated from the substrate holding tool 2. Thus, the projection 6 allows the lower end of the substrate 1 to be floated, and the substrate holding tool 2 supports the inclination of the substrate 1 by its both side ends. At least one or more projections 6 are provided to extend like a rib in the arrangement direction of the substrate 1, and a plurality of grooves are provided so that the substrate 1 is brought into contact with the rib-like tip end and it is held, and furthermore, the groove is made to have a V-shaped shape while it is inclined in contact with the front and rear lower ends of the substrate 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor substrate cleaning apparatus, and more particularly, to a semiconductor substrate cleaning apparatus that stores a plurality of substrates such as semiconductor wafers in a dedicated substrate holder and sequentially immerses them in a plurality of processing tanks in a batch manner for cleaning. About.
[0002]
[Prior art]
[Patent Document 1]
JP-A-6-333907
Conventionally, a semiconductor substrate cleaning apparatus stores a plurality of disk-shaped substrates such as semiconductor wafers arranged in a chemical-resistant substrate holder (wafer cassette) and batch-processes the substrate holder in a plurality of processing tanks. (See, for example, Patent Document 1), and in some cases, an ultrasonic wave is applied to improve the cleaning effect. FIG. 10 is a diagram showing a conventional semiconductor substrate cleaning apparatus for sequentially immersing a substrate in a plurality of processing tanks for cleaning. 11A and 11B are views showing an operation of loading the substrate 1 into the processing tank 10 shown in FIG. 10. FIG. 11A shows a state in which the substrate 1 is being loaded, and FIG. Are respectively shown. FIG. 12 is a diagram showing a state where the substrate 1 is cleaned in the processing bath 10 shown in FIG. FIG. 13 is a diagram showing details of the protrusion 12 shown in FIG.
[0004]
As shown in FIG. 10, the conventional semiconductor substrate cleaning apparatus is provided with a dedicated substrate holder 2 for arranging and storing a plurality of disk-shaped substrates 1 such as semiconductor wafers, holding the substrates 1 from both sides, and transporting them. A plurality of processing tanks 10 are provided for sequentially immersing and cleaning the substrates 1 stored in the substrate holder 2 in a batch manner. Further, the bottom of the processing tank 10 is provided with a projection 12 for completely transferring and holding a plurality of substrates 1 housed and immersed in the substrate holder 2 from the substrate holder 2. The protrusion 12 has a plurality of grooves 12a (see FIG. 13) extending at the bottom of the processing tank 10 in the arrangement direction of the substrates 1 and fitting and holding the lower end of the substrate 1 at the upper end thereof.
[0005]
When the substrate 1 is cleaned by the conventional semiconductor substrate cleaning apparatus having such a configuration, for example, as shown in FIG. 10, a first processing tank 10a in which water is mixed with sulfuric acid and hydrogen sulfate water and stored. , A second processing tank 10b storing pure water, and a third processing tank 10c storing water mixed with ammonia water and hydrogen peroxide water. The first processing tank 10a to the third processing tank A plurality of substrates 1 are stored in the substrate holder 2 until 10c, and the substrates 1 are sequentially immersed in a batch system to perform a cleaning process. In this processing tank 10, the first cleaning for removing contaminants attached to the surface of the substrate 1 is performed in the first processing tank 10a, and then the chemical in the first processing tank 10a is cleaned (rinsed) in the second processing tank 10b. At the same time, a second cleaning for removing contaminants attached to the substrate 1 is finally performed in the third processing tank 10c.
[0006]
Here, the substrate 1 is sequentially transported into each of the processing tanks 10 and is completely transferred from the substrate holder 2 to the protrusion 12 provided at the bottom for processing. At this time, as shown in FIG. 11A, the substrate 1 is transported while being stored in a plurality of substrate holders 2, and is directly lowered into the processing bath 10 together with the substrate holder 2 to be immersed. Then, in the processing tank 10, as shown in FIG. 11 (b), the substrate 1 stored in the substrate holder 2 descending is held and transferred by the groove 12a of the projection 12 provided on the bottom. As a result, the outer peripheral holding surface of the substrate 1 held in the substrate holder 2 shown in FIG. 11A can be reduced to the holding surface of only the groove 12a of the projection 12 shown in FIG. The surface of the substrate 1 can be effectively exposed by maximally exposing the surface of the substrate 1 in the processing tank 10. At this time, the processing tank 10 circulates a processing liquid such as a chemical solution or pure water stored in the processing tank, and injects the processing liquid from the bottom again to generate a liquid flow inside the tank to process the substrate 1 as shown in FIG. It is formed so that.
[0007]
However, in such a conventional semiconductor substrate cleaning apparatus, as shown in FIG. 13, the processing is performed while the lower end of the substrate 1 is completely held in the groove 12a of the projection 12 in each processing tank 10, so that the groove 12a Cleaning (rinsing) of the portion held in the case may be insufficient. As described above, for example, when the cleaning processing of the portion held in the groove 12a by moving from the first processing tank 10a to the second processing tank 10b (see FIG. 1) is insufficient, the chemical solution remaining in the groove 12a Adheres to the surface of the substrate 1 and moves to the third treatment tank 10c in this state, whereby the adhered chemical solution reacts with the reaction product (for example, the reaction between sulfuric acid in the first treatment tank 10a and ammonia in the third treatment tank 10c). , Etc.) to contaminate the substrate 1.
Further, in the conventional semiconductor substrate cleaning apparatus, as shown in FIG. 12, the projections 12 for holding the substrate 1 are provided at the bottom of the processing bath 10, so that the processing liquid can be sprayed uniformly from below. Also, turbulence may occur on the surface of the substrate 1 because the projection 12 blocks the flow of the processing liquid.
[0008]
[Problems to be solved by the invention]
As described above, in the conventional semiconductor substrate cleaning apparatus, the chemical liquid remains in the groove 12a of the protrusion 12 for holding the substrate 1 in the processing tank 10 and is not washed and adheres to the substrate 1. However, there is a problem in that, as a reaction product, contamination is generated, and in order to avoid the generation of contamination, a cleaning (rinsing) time is lengthened and production efficiency is reduced.
Further, in the conventional semiconductor substrate cleaning apparatus, since the projections 12 obstruct the flow of the processing liquid by providing the projections 12 at the bottom of the processing bath 10, the processing liquid of the substrate 1 is sprayed no matter how uniformly the processing liquid is sprayed from below. There was a problem that a turbulence was generated on the surface and the cleaning process could not be performed well.
The present invention solves such a problem, and provides a semiconductor substrate cleaning apparatus capable of preventing a chemical solution remaining in a groove holding a substrate from becoming a reaction product and contaminating the same, and performing a cleaning process in a short time without obstructing a liquid flow. The purpose is to:
[0009]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a semiconductor substrate cleaning apparatus that arranges a plurality of substrates such as semiconductor wafers in a dedicated substrate holder, stores the substrates, and sequentially immerses the substrates in a plurality of processing tanks for cleaning. A projection is provided at the bottom of the processing tank in which a plurality of substrates are stored and immersed in the substrate holder, and the substrate is slightly lifted from the substrate holder. While supporting the fall of the substrate at both side ends, the protrusion extends in a rib shape in the arrangement direction of the substrate, and at least one protrusion is arranged. A plurality of grooves supported by the substrate in contact with the rib-shaped tip are provided. The groove is provided in a V-shape in which the groove is inclined and in contact with the front and back lower ends of the substrate.
Here, it is preferable that the projection is provided with a notched auxiliary groove below the V-shaped groove, and the auxiliary groove improves the liquid flow during cleaning in the processing tank. In addition, it is preferable that a plurality of grooves are formed in the protrusion by cutting out a V-shaped groove having a width of 2 to 6 mm and a depth of 2 to 5 mm at a rib-like tip. Further, it is preferable that the projections be floated by 10 mm to 40 mm from a state in which the substrate is stored in the substrate holder. Further, the protrusion is preferably formed of any material of PEEK, PTFE, and PVDF.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a semiconductor substrate cleaning apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a view showing an embodiment of a semiconductor substrate cleaning apparatus according to the present invention. FIG. 2 is a diagram showing details of the protrusion 6 shown in FIG. FIG. 3 is a diagram showing a state in which the substrate 1 is cleaned in the processing tank 4 shown in FIG. FIG. 4 is a diagram showing details of the groove 6a shown in FIG. FIG. 5 is a diagram showing a state viewed from the arrow A direction shown in FIG. 6A and 6B are views showing an operation of loading the substrate 1 into the processing tank 4 shown in FIG. 1, wherein FIG. 6A shows a state in which the substrate 1 is being loaded, and FIG. Are respectively shown. FIG. 7 is a view showing another embodiment of the protrusion 6 shown in FIG. FIG. 8 is a diagram showing a state viewed from the direction of arrow B shown in FIG. FIG. 9 is a view showing another embodiment of the auxiliary groove shown in FIG.
[0011]
As shown in FIG. 1, an embodiment of a semiconductor substrate cleaning apparatus according to the present invention, similar to the prior art shown in FIG. 10, arranges and stores a plurality of disk-shaped substrates 1 such as semiconductor wafers from both sides. A dedicated substrate holder 2 for holding and transporting is provided, and a plurality of processing tanks 4 are provided for sequentially immersing and cleaning the substrates 1 stored in the substrate holder 2 in a batch manner. Also, in the present embodiment, unlike the prior art shown in FIG. 10, when a plurality of substrates 1 are stored and immersed in the substrate holder 2, the substrate 1 is not held at the bottom in the processing tank 4. A projection 6 is provided to slightly float from the substrate holder 2. Therefore, in the present embodiment, when the substrate 1 is held during cleaning, the projections 6 support the lower end of the substrate 1 by floating, and the substrate holder 2 supports the fall of the substrate 1 at both ends (FIG. 6B). See).
[0012]
Here, as shown in FIG. 2, the protrusions 6 are formed on the bottom of the processing tank 4, extend in a rib shape in the arrangement direction of the substrates 1, and are arranged in parallel. The projections 6 are made of a material that is not easily contaminated, such as PEEK, PTFE (ethylene tetrafluoride), and PVDF (ethylene trifluoride). Further, the processing tank 4 circulates the processing liquid (chemical solution or pure water or the like) stored therein and injects it again from the bottom to generate a liquid flow inside the tank as shown in FIG. 3 for processing. Has formed. Therefore, in the present embodiment, unlike the prior art shown in FIG. 12, by forming the protrusion 6 in a rib shape, the processing liquid can be removed without obstructing the liquid flow from the lower part as shown in FIG. It becomes possible to flow uniformly on the surface of the substrate 1. At this time, the projections 6 are arranged in a pair in parallel with the bottom of the processing tank 4. If two or more projections 6 are provided, the stability of the substrate 1 during processing is improved. However, if the protrusions 6 are provided too much at the bottom of the processing tank 4, the flow of the processing liquid is obstructed. Therefore, it is preferable that the protrusions 6 be provided in parallel as shown in FIG. 2.
[0013]
Further, as shown in FIG. 2, the projection 6 is provided with a plurality of grooves 6a at the rib-like tip, which are supported by the substrate 1 being in contact therewith. The groove 6a is provided in a V-shape extending so as to be inclined and in contact with the front and back lower ends of the substrate 1. As shown in FIG. 4, the groove 6a has a width C at the tip of the rib-shaped projection 6 of 2 to 6 mm and a depth D of 2 to 5 mm, and is formed in a V-shape. . Thus, during processing or lifting of the substrate 1, the substrate 1 can be stably held by engaging with the groove 6a so as not to move unnecessarily. The grooves 6a are formed so as to be substantially the same as the intervals between the substrates 1 arranged and housed in the substrate holder 2, and are designed so that the adjacent substrates 1 are stabilized with a certain interval. I have. Here, the interval E between the adjacent substrates 1 is preferably set to 4 to 6 mm. As described above, in the present embodiment, as shown in FIG. 5, the substrate 1 is not held, and the lower ends on the front and back sides are point-contacted to the V-shaped slope to support the substrate 1. It is possible to prevent the chemical solution from remaining during the cleaning, and to wash the chemical solution attached to the substrate 1 in a short time.
[0014]
When the substrate 1 is cleaned using the semiconductor substrate cleaning apparatus according to the embodiment of the present invention thus formed, for example, sulfuric acid and sulfated water are added to the water shown in FIG. A first processing tank 4a in which hydrogen water is mixed and stored, a second processing tank 4b in which pure water is stored, and a third processing tank 4c in which ammonia water and hydrogen peroxide are mixed and stored in water are provided. Then, a plurality of substrates 1 are stored in the substrate holder 2 from the first processing tank 4a to the third processing tank 4c, and are sequentially immersed in a batch manner to perform a cleaning process. In the processing tank 4, a first cleaning for removing contaminants adhered to the surface of the substrate 1 is performed in a first processing tank 4a, and then a chemical solution in the first processing tank 4a is cleaned (rinsed) in a second processing tank 4b. At the same time, a second cleaning for removing contaminants attached to the substrate 1 is finally performed in the third processing tank 4c. The substrate holder 2 is transported by a transport robot (not shown), and is loaded into each processing tank 4 at predetermined time intervals for processing.
[0015]
Here, unlike the prior art, the substrate 1 is processed by being sequentially transported into each processing tank 4 and slightly lifted while being held on the substrate holder 2 by the protrusion 6 provided at the bottom. More specifically, as shown in FIG. 6A, a plurality of substrates 1 are conveyed while being stored in a plurality of substrate holders 2, and are directly lowered and immersed in the processing tank 4 together with the substrate holders 2. . Then, in the processing tank 4, as shown in FIG. 6B, the substrate 1 accommodated in the descending substrate holder 2 is held in a slightly floating state in contact with the groove 6a of the projection 6 provided on the bottom. Is done. At this time, it is desirable that the projection 6 is preferably floated by 10 mm to 40 mm from a state in which the substrate 1 is stored in the substrate holder 2. As a result, the substrate 1 is held in the substrate holder 2 shown in FIG. 6A and the outer periphery thereof is held, and the protrusion for supporting and lowering the two lower ends of the substrate 1 shown in FIG. 6 and the substrate holder 2 supporting the falling of the substrate 1 at two points on both side ends, so that the substrate 1 is held at a total of four points. Therefore, in this embodiment, since the lower end of the substrate 1 is held in point contact with the groove 6a of the projection 6 (see FIG. 4), the contact surface for holding the substrate 1 is reduced, and the surface in the processing bath 4 is reduced. The cleaning treatment can be performed effectively by exposing the substrate 1 to the maximum, and the inside of the substrate holder 2 can be cleaned at the same time by the protrusion 6 slightly lifting the substrate 1.
[0016]
As described above, according to the embodiment of the semiconductor substrate cleaning apparatus according to the present invention, the projection 6 supports the substrate 1 being processed in the processing tank 4 by floating slightly in the substrate holder 2 by point contact (see FIG. 5). Due to the structure, the residual chemical solution in the pretreatment stage can be effectively washed away, whereby reduction in treatment time and improvement in quality can be expected.
Further, according to the embodiment of the semiconductor substrate cleaning apparatus of the present invention, since the projection 6 is formed in a rib shape on the bottom of the processing tank 4 and installed (see FIG. 3), the jet is injected into the processing tank 4. It is possible to uniformly flow the surface of the substrate 1 without obstructing the flow of the processing liquid, and it is possible to more effectively execute the cleaning processing.
[0017]
By the way, as shown in FIG. 5, when the lower end of the substrate 1 is supported in the V-shaped groove 6a, a small triangular gap is formed between the substrate 1 and the groove 6a. It may not be sufficiently washed. Therefore, it is also possible to provide a further notch in the V-shaped groove to form a Y-shaped groove. As shown in FIG. 7, another embodiment of the projection in which the Y-shaped groove is formed is formed in a rib shape at the bottom of the processing tank, and the V-shaped groove 7a is formed at the tip of the rib shape. And a notched auxiliary groove 7b is provided below the V-shaped groove 7a.
As shown in FIG. 8, the protrusion 7 thus formed supports the lower end of the substrate 1 in point contact with the V-shaped groove 7a, so that the same effect as the protrusion shown in FIG. 5 is obtained. In addition, by providing the auxiliary groove 7b further below in the V-shaped groove 7a shown in FIG. 8, the liquid flow passes through the lower part of the substrate 1 supported by the V-shaped groove 7a. A large space is provided, and the cleaning process can be performed by generating a liquid flow more effectively than the projection shown in FIG.
[0018]
On the other hand, unlike the auxiliary groove notched vertically downward in the V-shaped groove, for example, an auxiliary groove notched in an arc shape can be provided. As shown in FIG. 9, another embodiment of the arc-shaped auxiliary groove is provided with a rib-shaped protrusion 8 at the bottom of the processing tank, and a V-shaped groove is formed at the tip of the protrusion 8. An auxiliary groove 8b is formed below the V-shaped groove 8a.
In the auxiliary groove 8b formed as described above, since the auxiliary groove is further formed below the V-shaped groove 8a, the same effect as that of the auxiliary groove shown in FIG. By providing the auxiliary groove 8b by cutting it out in an arc shape, the concave corners on the inner surfaces of the groove 8a and the auxiliary groove 8b are eliminated, so that the chemical liquid does not easily remain and the liquid can easily flow.
[0019]
As described above, the embodiment of the semiconductor substrate cleaning apparatus according to the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and can be modified without departing from the gist thereof.
For example, although an embodiment has been described in which a pair or more projections are provided in parallel at the bottom of the processing tank, the present invention is not limited to this, and only one projection may be provided at the bottom of the processing tank.
[0020]
【The invention's effect】
As described above, according to the semiconductor substrate cleaning apparatus of the present invention, the projections in the processing tank support the substrate being processed by being slightly floated in the substrate holder by point contact, so that the residual chemical solution in the pretreatment stage is removed. The washing can be effectively carried out, thereby reducing the washing processing time and improving the washing quality.
Further, according to the embodiment of the semiconductor substrate cleaning apparatus of the present invention, since the protrusion is formed in a rib shape at the bottom in the processing tank and installed, the flow of the processing liquid jetted at the bottom in the processing tank is reduced. Without being obstructed, it is possible to uniformly flow on the surface of the substrate, and it is possible to more effectively execute the cleaning process.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a semiconductor substrate cleaning apparatus according to the present invention.
FIG. 2 is a diagram showing details of a projection shown in FIG. 1;
FIG. 3 is a diagram showing a state where a substrate is cleaned in the processing bath shown in FIG. 1;
FIG. 4 is a view showing details of a groove shown in FIG. 2;
FIG. 5 is a view showing a state viewed from the direction of arrow A shown in FIG. 4;
FIG. 6 is a view showing an operation of loading a substrate into the processing tank shown in FIG. 1;
FIG. 7 is a view showing another embodiment of the projection shown in FIG. 4;
FIG. 8 is a diagram showing a state viewed from the direction of arrow B shown in FIG. 7;
FIG. 9 is a view showing another embodiment of the auxiliary groove shown in FIG. 8;
FIG. 10 is a view showing a conventional semiconductor substrate cleaning apparatus.
FIG. 11 is a view showing an operation of carrying a substrate into the processing tank shown in FIG. 10;
FIG. 12 is a diagram showing a state where a substrate is cleaned in the processing bath shown in FIG. 10;
FIG. 13 is a view showing details of a protrusion shown in FIG. 10;
[Explanation of symbols]
Reference Signs List 1 substrate 2 substrate holder 4 processing tank 6 protrusion 6a groove

Claims (5)

In a semiconductor substrate cleaning apparatus, a plurality of substrates such as semiconductor wafers are arranged and stored in a dedicated substrate holder, and sequentially immersed and cleaned in a plurality of processing tanks in a batch manner.
A projection is provided at the bottom of the processing tank for accommodating and immersing a plurality of the substrates in the substrate holder, and the projection is provided to slightly float the substrate from the substrate holder, and the projections support and support the lower end of the substrate. The holder supports the fall of the substrate at both ends, and the protrusions extend in a rib shape in the arrangement direction of the substrate and are arranged at least one or more, and the substrate abuts on the rib-shaped tip. A semiconductor substrate cleaning apparatus, wherein a plurality of grooves to be supported are provided, and the grooves are provided in a V-shape in which the grooves are inclined and contact the front and back lower ends of the substrate. The apparatus for cleaning a semiconductor substrate according to claim 1,
The semiconductor substrate cleaning apparatus according to claim 1, wherein the protrusion further includes a notched auxiliary groove below the V-shaped groove, and the auxiliary groove improves the liquid flow during cleaning in the processing bath. The semiconductor substrate cleaning apparatus according to claim 1 or 2,
The semiconductor substrate cleaning apparatus according to claim 1, wherein the plurality of protrusions are formed by cutting out a plurality of the V-shaped grooves at the rib-shaped tip at a width of 2 to 6 mm and a depth of 2 to 5 mm. The semiconductor substrate cleaning apparatus according to any one of claims 1 to 3,
The semiconductor substrate cleaning apparatus according to claim 1, wherein the protrusions float from the state where the substrate is stored in the substrate holder by 10 mm to 40 mm. The semiconductor substrate cleaning apparatus according to any one of claims 1 to 4,
The semiconductor substrate cleaning apparatus, wherein the protrusion is formed of any one of PEEK, PTFE (tetrafluoroethylene), and PVDF (trifluoroethylene).

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