JP3370030B2 - Cassette for storing wafers and X-ray fluorescence analyzer for analyzing wafers stored in the cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and certainly feed in and out the wafer in a cassette while preventing the trouble such as damage or the like of the wafer in the cassette in which the wafer is housed and a fluorescent X-ray analyzing apparatus for analyzing the wafer housed in the cassette. SOLUTION: In a cassette 22 having a front surface 22a opened in order to take in and out a wafer 1 and having many pairs of grooves 22c housing the wafer 1 one by one formed to the inner surfaces of left and right side walls 22b thereof up and down at a predetermined interval (p), obstacles 2d, 2e preventing the housing of the wafer 1 are provided to the grooves 22c of at least either one of the left and right side walls 22c at least every other groove to house the wafer 1 with a predetermined diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette for storing wafers such as semiconductor wafers and an X-ray fluorescence analyzer for analyzing wafers stored in such cassettes.

[0002]

2. Description of the Related Art Conventionally, a so-called fluorescent X-ray analyzer has been used for contamination analysis of semiconductor wafers.
Wafers are disk-shaped, 150 mm (6 inches), 200 mm
(8 inches), 300 mm (12 inches), and other types of diameters, each of which has a predetermined standard (SEMI; Semiconductor Equipment and Mate) according to the diameter of the wafer.
It is stored and handled in a ready-made (mass production) cassette having the dimensions and shape of rials International. An example of the ready-made cassette 22 is shown in FIG. 5 , which is a perspective view seen from the side 22a opposite to the side 22a for loading and unloading the wafer.

Here, as shown in the partial front view of FIG. 6 , the cassette 22 has one surface 22a for loading and unloading the wafer 1 (this surface may be used as an upper surface in some cases. The surface is used as a front surface, which will be referred to as the front surface hereinafter), and a plurality of pairs of grooves 22c for accommodating one wafer at a time are formed inside the left and right side walls 22b at predetermined intervals p. . For example, the cassette 22 for 150 mm has 25 pairs of grooves at 4.76 mm intervals and the wafer 1
Can store up to 25 wafers, and the 200 mm cassette 22 has 25 or 26 pairs of grooves at 6.35 mm intervals, and can store up to 25 or 26 wafers 1 and the 300 mm cassette 22 can have 10 mm intervals. There are 13 or 25 pairs of grooves, and up to 13 or 25 wafers 1 can be stored. As shown in FIG. 5 , a handle 22f for carrying is formed on the upper surface 22e with respect to the front surface 22a, the rear surface 22d, and the side wall 22b.

On the other hand, in the X-ray fluorescence analyzer for analyzing the wafers 1 housed in such a cassette 22, a robot hand, which is a transport means for transporting the wafers 1 in the cassettes 22 placed on the cassette table one by one. Carry in and out to perform analysis on the sample table. Here, since the wafer 1 having a larger diameter is heavier, the robot hand for transporting the wafer 1 also has a thicker hand portion or the like at the tip to enhance rigidity. Therefore, as described above, as the diameter of the wafer 1 increases, the interval p between the corresponding grooves of the cassette 22 in FIG. 6 also increases so that the hand portion of the robot hand can be inserted between the wafers 1 without interference. There is.

[0005]

However, in a fluorescent X-ray analysis apparatus in which the wafers 1 having three kinds of diameters are analyzed, that is, the cassettes 22 having three kinds of sizes are handled,
Due to its simple structure, the robot hand is the heaviest 300
equipped with a wafer of 1 mm, 150 mm, 20 mm
Also used for 0 mm wafer 1. Then, even if 200 mm wafers 1 stored at 6.35 mm intervals can be carried in and out, 150 mm wafers 1 stored at 4.76 mm intervals
On the other hand, since the gap between the wafers 1 is too narrow to insert the hand portion, and if the user tries to insert the hand portion by force, the wafer 1 may be interfered with and the wafer 1 may be damaged or damaged.

In order to avoid this, with respect to the cassette 22 for 150 mm, the operator must pay attention to, for example, the groove 22.
It is conceivable to store the wafers 1 every other c, that is, at intervals of 9.52 mm, but mistakes easily occur, and this is not sure. In addition, the cassette 22 has its purpose,
Although it is manufactured by resin molding from the shape, it is not realistic to manufacture a cassette 22 for 150 mm having a storage space p wider than that of the standard product by resin molding, which requires enormous cost.

The present invention has been made in view of the above-mentioned conventional problems, and it is an X-ray fluorescence analyzer for analyzing a wafer housed in a cassette or a wafer housed in the cassette.
It is an object of the present invention to provide a wafer in a cassette that can be carried in and out safely and reliably while preventing troubles such as damage.

[0008]

To achieve the above object, a cassette according to a first aspect of the present invention is a cassette that accommodates wafers of a predetermined diameter, the front surface of which is open for loading and unloading of wafers. For a cassette in which a large number of pairs of grooves for accommodating wafers one by one are formed inside a side wall of the cassette at predetermined intervals, at least one of the grooves is provided on at least one of the left and right side walls. There are obstacles to prevent storage.

According to the cassette of the first aspect, for example, the side wall of the conventional cassette, which is a standard product for 150 mm, which has been conventionally used, is provided with an obstacle for preventing the wafer from being stored in every other groove. With this simple configuration, it is possible to secure a storage interval of 9.52 mm for a 150 mm wafer,
Since a robot hand compatible with mm wafers can be easily inserted into the gap between the wafers, troubles such as damage can be prevented and the wafers can be carried in and out safely and reliably.

An X-ray fluorescence analyzer according to a second aspect of the present invention is an X-ray fluorescence analyzer for analyzing wafers housed in a cassette, wherein the cassette is a recess for discriminating outside the bottom of the cassette of the first aspect. It is a cassette that has formed. The fluorescent X-ray analysis apparatus includes a cassette base on which a convex portion that engages with the concave portion is formed and a cassette is placed.

According to the apparatus of claim 2, since the cassette having the features of claim 1 is usually used, as described above, for example, a wafer of 150 mm has a size of 9.52 mm.
The storage interval can be secured, and even if a robot hand compatible with 300 mm wafers is used, it can be easily inserted into the gap between the wafers, troubles such as damage can be prevented, and wafers can be loaded and unloaded safely and reliably.

In addition, a cassette that is normally used is one in which a discrimination concave portion, which is not present in a ready-made cassette, is formed on the outer side of the bottom portion, and this apparatus is provided with a cassette table in which a convex portion that engages with the concave portion is formed. Therefore, for example, even if the operator mistakenly tries to place a ready-made cassette for 150 mm in which wafers are stored at intervals of 4.76 mm on the cassette table, the convex portion of the cassette table does not engage and the cassette cannot be normally mounted. However, it will be a warning and you will notice that the operator should not place it, so that the robot hand corresponding to the 300 mm wafer is prevented from interfering with the wafer and damaging it, and the wafer can be carried out more safely and securely. You can enter.

An X-ray fluorescence analyzer according to a third aspect of the present invention is an X-ray fluorescence analyzer for analyzing wafers housed in a cassette, wherein the cassette is a protrusion for discriminating outside the bottom of the cassette of the first aspect. It is a cassette that forms a part. This X-ray fluorescence analyzer has a cassette table on which a cassette is mounted, which has a switch that is recessed corresponding to the convex portion, and a carrier for transferring a wafer from the cassette mounted on the cassette table. And a discriminating means for driving the conveying means in response to the depression of the switch.

According to the apparatus of claim 3, since the cassette having the features of claim 1 is usually used, as described above, for example, a wafer of 150 mm has a size of 9.52 mm.
The storage interval can be secured, and even if a robot hand (conveying means) compatible with 300 mm wafers is used, it can be easily inserted into the gap between the wafers, and troubles such as damage can be prevented and the wafers can be carried in and out safely and reliably.

In addition, a cassette that is normally used is one in which a distinguishing convex portion, which is not present in a ready-made cassette, is formed on the outside of the bottom portion, and a cassette base having a switch corresponding to the convex portion and a switch for the switch. Since this apparatus is provided with a discrimination means that can drive the robot hand in response to the depression, for example, an operator mistakenly stores a ready-made cassette for 150 mm storing wafers at 4.76 mm intervals as a cassette table. The robot hand cannot be driven by the discrimination means because the switch is not recessed even if it is placed on the wafer. Therefore, it is possible to prevent the robot hand corresponding to the 300 mm wafer from interfering with the wafer and damaging it. Wafers can be loaded and unloaded.

[0016]

[0017]

[0018]

[0019]

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The apparatus according to the first embodiment of the present invention will be described below. This device is 150mm, 200m
As shown in the side view of FIG. 1, a wafer 1 having three kinds of diameters of m and 300 mm is analyzed, and as shown in the side view of FIG. The intensity of the fluorescent X-rays 8 generated by irradiating the primary X-rays 7 is detected by the detecting means 1
It is a fluorescent X-ray analyzer for measuring and analyzing in 2. The detection means 12 disperses the fluorescent X-rays 8 generated from the wafer 1, and the fluorescent X-rays 1 dispersed by the dispersive element 9.
A detector 11 or the like for measuring the intensity of 0, but a detector with high energy resolution without using the spectroscopic element 9 such as SS
You may comprise by D etc.

Further, in this apparatus, the cassette table 3 on which the cassettes 2 and 22 containing the wafers 1 are placed, and the cassettes 2 and 22 placed on the cassette table 3 to the sample table 5 are used.
The wafer 1 is unloaded to the cassettes 2 and 2 from the sample table 5 on the contrary.
2 and a robot hand 4 which is a transfer means for loading the wafer 1 into the wafer 2. In this robot hand 4, the hand portion 4a at the tip is formed in an appropriate size and shape so that the heaviest 300 mm wafer 1 can be supported with sufficient rigidity, and the hand portion 4a is a horizontal surface of an arbitrary height. It can point in any direction and in any direction. The sample table 5 is formed with a cutout portion 5a through which the hand portion 4a can pass so as not to interfere with the loading and unloading of the wafer 1.

With this configuration, the wafers 1 are unloaded one by one from the cassettes 2, 22 placed on the cassette table 3 by the robot hand 4 and placed on the sample table 5, and the primary radiation from the X-ray source 6 is transferred. After irradiating the X-rays 7 and measuring the intensity of the generated fluorescent X-rays 8 by the detection means 12, the robot hand 4 repeatedly carries the cassettes 2 and 22 to the original positions (grooves 22c), and the cassettes The analysis can be performed on all the wafers 1 stored in 2, 22. In addition, since the sample table 5 is actually inside the vacuum container, a transfer device which is a second transfer means is provided therein, and the robot hand 4 is provided outside the transfer device.
And a cassette table 3 are provided, the wafer 1 is transferred between the cassettes 2 and 22 and the transfer device by the robot hand 4, and the wafer 1 is transferred between the robot hand 4 and the sample table 5 by the transfer device. Good.

The hand portion 4 of the robot hand 4 of this apparatus
a is 3 stored in a ready-made cassette 22 at intervals of 10 mm
Can be easily inserted between 00 mm wafers 1 and 200 mm wafers 1 stored in a ready-made cassette 22 at 6.35 mm intervals, but ready-made cassettes 2 at 4.76 mm intervals.
With respect to the 150 mm wafer 1 housed in 2, the gap between the wafers 1 is too narrow to be inserted. Therefore, in this apparatus, 300 mm and 200 mm wafers 1 are stored in ready-made cassettes 22 for analysis, but 150 mm wafers 1 are stored in the following cassette 2 for analysis.

That is, as shown in the partial front view of FIG. 2, the cassette 2 accommodates a wafer 1 having a predetermined diameter, here 150 mm, and the front surface 22a is opened for loading and unloading the wafer 1 and the left and right sides are opened. In contrast to the ready-made cassette 22 (FIG. 6 ) in which a plurality of pairs of grooves 22c for accommodating the wafers 1 one by one are formed in the upper and lower sides at predetermined intervals p inside the side walls 22b of the left and right side walls 22b. An obstacle 2d (hatched in FIG. 2) that blocks the storage of the wafer 1 is provided in every other 22c, and further, as shown in the local cross section of FIG. 1, there is no ready-made cassette 22 on the outside of the bottom. It is the cassette 2 in which a discrimination recess 2f is formed. The recess 2f can be formed by cutting or the like.

As shown in FIG. 2, the obstacle 2d for preventing the wafer 1 from being stored in every other groove 22c is specifically a front portion of a pair of left and right grooves 22c at the same height ( 2) in the vertical direction, the groove 22c
2d of resin pieces that are attached so as to be filled in every other pair
The attachment is by adhesion, screwing from the outside of the side wall 22b, or the like.

Further, instead of such a resin piece 2d,
As shown in the front partial view of FIG. 3, front and rear ends of a pair of left and right grooves 22c at the same height are attached to the front end faces (front side in the direction perpendicular to the paper surface of FIG. 3) of the left and right side walls 22b. The resin plates 2e that close every other pair of the grooves 22c in the direction may be attached by adhesion or the like. As shown in FIG. 5 , the ready-made cassette 22
Since the side wall 22b of the front side (front side 22a side) spreads to the left and right and the end face is wide, it is easy to attach the resin plate 2e as shown in FIG. Note that the resin piece 2d in FIG. 2 and the resin plate 2e in FIG. 3 may be attached to only one of the left and right side walls 22b of the cassette 2 as long as the storage of the wafer 1 can be sufficiently prevented. Further, the apparatus of the first embodiment is provided with a cassette table 3 on which the cassette 2 is placed by forming a convex portion 3f which engages with the concave portion 2f of the cassette 2 of FIG. It should be noted that such a convex portion 3f can be formed by adhering a resin piece or the like, screwing or the like.

According to the apparatus of the first embodiment, first, 15
For 0 mm, since the cassette 2 as described above is usually used, a storage interval of 9.52 mm can be secured for a 150 mm wafer 1, and even if a robot hand 4 corresponding to a 300 mm wafer 1 is used, the space between the 150 mm wafers 1 can be increased. The hand portion 4a can be easily inserted into the gap, and troubles such as damage can be prevented and the wafer 1 can be carried in and out safely and reliably. As shown in FIGS. 2 and 3, such a cassette 2 has a side wall 22b of a conventional ready-made cassette 22 (FIG. 6 ), which is a standard product for 150 mm, in which the wafer 1 is stored. By providing obstacles 2d and 2e for blocking every other groove 22c, it is possible to easily configure.

Moreover, as shown in FIG. 1, the cassette 2 normally used for 150 mm is a ready-made cassette 2 on the outside of the bottom.
2 (FIG. 5 ), a concave portion 2f for discrimination which is not present is formed, and since this apparatus is equipped with the cassette base 3 having the convex portion 3f that engages with the concave portion 2f, for example, an operator Even if the 150 mm ready-made cassette 22 accommodating the wafers 1 at 4.76 mm intervals is erroneously attempted to be mounted on the cassette table 3, it cannot be normally mounted because the convex portion 3f of the cassette table 3 is not engaged. Is a warning and the operator does not actually place it, so that the hand portion 4a of the robot hand 4 corresponding to the wafer 1 of 300 mm is prevented from interfering with and damaging the wafer 1 and the wafer can be more safely and securely provided. 1 can be carried in and out.

Since the prefabricated cassette 22 has an uneven shape on the outer side of the bottom portion depending on the size, that is, the diameter of the wafer 1 to be housed, it can be used for 20
As for the ready-made cassettes 22 for 0 mm and 300 mm, the positions for mounting the cassettes 22 of each size on the cassette table 3, the positions of the convex portions 3f, and the convex portions 3f are set so that they can be normally mounted on the cassette table 3 as they are. The size and shape can be defined. Further, it is not necessary to share one cassette table 3 for all the cassettes 2 and 22 of all sizes, and for example, one cassette table 3 is provided for the cassettes 2 and 22 for 150 mm and 200 mm, and the cassettes 2 and 22 for 300 mm are provided. Another cassette table 3 may be provided.

Next, an apparatus according to the second embodiment of the present invention will be described. Similar to the device of the first embodiment, this device also targets the wafers 1 having three kinds of diameters of 150 mm, 200 mm, and 300 mm, as shown in the side view of FIG.
This is a fluorescent X-ray analysis apparatus that measures and analyzes the intensity of fluorescent X-rays 8 generated by irradiating the wafer 1 mounted on the sample table 5 with the primary X-rays 7. The cassette table 3 and the robot hand 4 are I have it. For the 150 mm wafers 1 which are stored in the ready-made cassette 22 at intervals of 4.76 mm, the hand part 4 a of the robot hand 4 cannot be inserted because the gap between the wafers 1 is too narrow. The apparatus is also similar to the apparatus of the first embodiment in that it is housed in the cassette 2 provided with the obstacles 2d and 2e (FIGS. 2 and 3) and used for analysis.

However, the cassette 2 normally used for 150 mm in the apparatus of the second embodiment has a protrusion 2g for discrimination, which is not present in the ready-made cassette 22, on the outside of the bottom, as shown in the local cross section of FIG. The cassette base 3 of the apparatus according to the second embodiment has a switch 3g that is recessed corresponding to the convex portion 2g. In addition, the convex portion 2g of the cassette 2
Can be formed by adhering or screwing a resin piece or the like, and the recess 3h in which the switch 3g is embedded in the cassette base 3 can be formed by cutting or the like. Further, this apparatus is provided with a discriminating means 13 which can drive the robot hand 4 in response to the depression of the switch 3g.

According to the apparatus of the second embodiment, firstly, the first
Similar to the apparatus of the embodiment, since the cassette 2 as described above is normally used for 150 mm, a storage interval of 9.52 mm can be secured in the wafer 1 of 150 mm.
Even if the robot hand 4 corresponding to the 0 mm wafer 1 is used, the hand portion 4a can be easily inserted into the gap between the 150 mm wafers 1, and troubles such as damage can be prevented and the wafer 1 can be safely carried in and out.

Moreover, the cassette 2 normally used for 150 mm has a convex projection 2g formed on the outside of the bottom, which is not present in the ready-made cassette 22, and a switch 3g which is depressed corresponding to the convex projection 2g. Since the present apparatus is provided with the cassette table 3 that it has and the determination means 13 that can drive the robot hand 4 in response to the depression of the switch 3g, for example, the operator mistakenly sets the wafer 1 at intervals of 4.76 mm. Even if the ready-made cassette 22 for 150 mm that stores therein is placed on the cassette table 3, the switch 3g does not recess, so the determination means 13
Due to this, the robot hand 4 cannot be driven.
The robot hand 4 corresponding to the 00 mm wafer 1 is prevented from interfering with and damaging the wafer 1 and the wafer 1 can be carried in and out more safely and securely.

Since the ready-made cassette 22 has different concave and convex shapes on the outer side of the bottom portion depending on the size, that is, the diameter of the wafer 1 to be housed, it can be used for 20
For the 0 mm and 300 mm ready-made cassettes 22, the robot hand 4 can be mounted on the cassette table 3 as it is.
In order to be able to drive the
It is possible to provide a size discriminating means for discriminating the size of 22 for 200 mm and 300 mm so that the discriminating means 13 does not function. Further, as described above, a plurality of cassette bases 3 can be provided depending on the size of the cassette 1.

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

In the above-described first and second embodiments , the hand unit 4a of the robot hand 4 shown in FIG.
Between the 300 mm wafers 1 stored in the ready-made cassette 22 at an interval of mm, and the ready-made cassette 2 at an interval of 6.35 mm
Although it can be easily inserted between the 200 mm wafers 1 accommodated in the No. 2 wafer, the broken pieces of the standard sample wafer are attached to another wafer 1 and continue to be used as the standard sample. When a thicker wafer 1 is stored in the cassettes 2 and 22 for analysis, even when the ready-made cassette 22 for 300 mm or 200 mm is used,
Since the gap between the wafers 1 is too narrow to insert the hand portion 4a, the wafer 1 may be damaged.

[0042] In such a case, first, with respect to apparatus of the second embodiment, obstacles 2d also for 300mm for and 200 mm, 2e (2, 3) the use of a cassette 2 provided with The distance between the obstacles 2d and 2e (FIGS. 2 and 3) can be set appropriately. Also, such 300
Ready-made cassette 22 for cassette 2 for mm and 200 mm
It is possible to form a concave portion 2f or a convex portion 2g (FIG. 4) for discrimination which is not present, and the apparatus can be provided with the cassette table 3 or the like corresponding to the concave portion or the convex portion (FIG. 4) .

[0043]

As described above in detail, according to the present invention, in a cassette storing a wafer or an X-ray fluorescence analyzer for analyzing the wafer stored in the cassette, the wafer in the cassette is damaged. You can carry in and out safely and securely by preventing troubles such as.

[Brief description of drawings]

FIG. 1 is a side view of an X-ray fluorescence analyzer according to a first embodiment of the present invention.

FIG. 2 is a partial front view of an example of a cassette that stores wafers to be analyzed by the apparatus.

FIG. 3 is a partial front view of another example of a cassette that stores wafers to be analyzed by the apparatus.

FIG. 4 is a side view of an X-ray fluorescence analyzer according to a second embodiment of the present invention.

FIG. 5 is a perspective view of an example of a ready-made cassette viewed from the rear.
is there.

FIG. 6 is a partial front view of the cassette.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Cassette of the present invention, 2d, 2e ... Obstacle, 2f ... Recess of cassette, 2g ... Convex part of cassette, 3
... cassette tables, 3f ... cassette stand protrusions, 3 g ... switch, 4 ... transporting means (robot hand), 13 ... judging means, 2 2 ... ready-made cassette, 22a ... front face of the cassette,
22b ... sidewall of cassette, 22c ... groove, p ... predetermined time
Every second.

Claims (3)

(57) [Claims] 1. A cassette for storing wafers of a predetermined diameter, the front surface of which is opened for loading and unloading of wafers, and a pair of grooves for storing the wafers one by one inside the left and right sidewalls. A cassette in which a plurality of pairs are formed vertically at intervals, and at least one of the left and right sidewalls is provided with an obstacle that blocks the storage of wafers at every other groove. 2. An X-ray fluorescence analyzer for analyzing wafers housed in a cassette, wherein the cassette is a cassette having a recess for determination on the outside of the bottom of the cassette according to claim 1. An X-ray fluorescence analyzer provided with a cassette base on which a cassette is placed, on which a convex portion that engages with is formed. 3. An X-ray fluorescence analyzer for analyzing wafers stored in a cassette, wherein the cassette is a cassette having a discriminating convex portion formed outside the bottom of the cassette according to claim 1. A cassette table on which a cassette is placed, which has a switch that is recessed corresponding to the convex portion, a transfer unit that transfers a wafer from the cassette that is mounted on the cassette table, and a switch that corresponds to the depression of the switch. And a discriminating means capable of driving the carrying means.