JPS6118337B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a wafer inspection apparatus.

In the semiconductor industry, circuit elements are arranged and formed on a semiconductor wafer made of silicon, and each circuit element is divided into pellets, and various semiconductor devices and integrated circuit devices are manufactured from these pellets.

Incidentally, there is a task of inspecting the state of circuit elements formed on the semiconductor wafer during or after manufacturing. Conventionally, this inspection equipment (for example, visual inspection equipment, resistivity measuring machine, probe inspection machine, etc.)
As such, the apparatus shown in FIG. 1 is used.
The arrangement of each part of this device is as follows.
That is, a loader section 2 that supplies the wafer 1;
A first unloader section 3 stores defective wafers after inspection, and a second unloader section 3 stores non-defective wafers after inspection.
It is arranged in parallel with the unloader section 4. Furthermore, a supply conveyor 5 and a first unloading conveyor 6 are arranged parallel to each other from the front surfaces of the loader section 2 and the second unloader section 4. Further, a transfer conveyor 7 is provided between the leading ends of the supply conveyor 5 and the first discharge conveyor 6. An inspection section (inspection position) 8 for inspecting wafers is provided at the center of the transfer conveyor 7. In addition, it is parallel to the transfer conveyor 7,
A second unloading conveyor 9 is provided that connects the supply conveyor 5 and the first unloading conveyor 6, and a third unloading conveyor that connects the second unloading conveyor 9 and the first unloader section 3. 10 are provided. Furthermore, the tips of the conveyors facing the loader section 2 and the first and second unloader sections 3 and 4 extend into the loader section 2 and the first and second unloader sections 3 and 4, respectively. In addition, the loader section 2, the first and second
A wafer storage jig 11 having the structure shown in FIG. 2 is placed on the unloader sections 3 and 4, and is adapted to be raised or lowered in sequence for loading and unloading.

Next, the usage of such a device will be simply explained. First, the wafer storage jig 11 containing the wafer 1 is placed on the loader section 2, and the empty wafer storage jig 11 is placed on the first and second unloader sections 3 and 4. At this time, the wafer storage jig 11 on the loader section 2 is set at the highest position, and is lowered one step each time the wafers are loaded, so that the wafers are sequentially transferred from the lowest stage to the supply conveyor 5. On the other hand, the first and second
The wafer storage jig 11 on the unloader sections 3 and 4 is set at the lowest position, and each time it is unloaded, it rises one step at a time, and the wafer 1 is sequentially stored in the empty wafer storage groove 12 at the top. It is becoming more and more common. In this state, the wafers 1 are sequentially sent from the loader section 2 to the inspection section 8 by the conveyance operations of the supply conveyor 5 and the transfer conveyor 7. The second unloader section 4 is moved by the transfer conveyor 7 and the first transfer conveyor 6.
The wafer is stored in the upper wafer storage jig 11. In addition, the defective wafers 14 determined to be defective are transferred to the wafer storage jig on the first unloader section 3 via the transfer conveyor 7, the first carry-out conveyor 6, the second carry-out conveyor 9, and the third carry-out conveyor 10. 11
stored inside. Furthermore, each conveyor in this apparatus is adapted to transport wafers in one direction as described above.

However, with such a device, there is no problem in the case of 100% inspection in which all wafers stored in one wafer storage jig are inspected.
In the case of a sampling inspection in which several wafers in one wafer storage jig are sampled, the following drawbacks occur. That is, in the loader section 2, the wafer 1 can only be extracted from below. Therefore, the wafer cannot be freely removed from any position on the wafer storage jig 11. In addition, in the method of sequentially picking out several wafers from the wafers below, two to three wafers are placed in the wafer storage jig 11 in the first unloader section 3 or the second unloader section 4 at the end of the sampling inspection. , the remaining large number of wafers 1 are in the wafer storage jig 11 of the loader section 2. Therefore, the operator must transfer the good wafers 13 in the wafer storage jig 11 of the second unloader section 4 to the wafer storage jig 11 on the loader section side. Also,
In this case, since the wafers are transferred by being pinched with tweezers, the wafers are likely to be damaged, and work efficiency is extremely low since the wafers are transferred one by one.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wafer inspection apparatus that can automatically load and unload wafers even during wafer sampling inspection.

The gist of the present invention for achieving such objects is to include: a first storage section for storing a plurality of wafers; an inspection section for inspecting the plurality of wafers stored in the first storage section; a first transfer section that transfers the plurality of wafers in the storage section from the first storage section to the inspection section; and a second storage section that stores some of the plurality of wafers inspected in the inspection section. ,
A second storage unit that transfers some of the plurality of wafers inspected in the inspection unit from the inspection unit to the second storage unit.
and a third transfer section for returning the remainder of the plurality of wafers inspected in the inspection section, excluding a portion stored in the second storage section, to the first storage section. A wafer inspection apparatus is characterized in that it has the following features: The present invention will be explained below with reference to Examples.

FIG. 3 is a schematic diagram showing an embodiment of the wafer inspection apparatus of the present invention. In the figure, a loader section 15 and an unloader section 16 are arranged apart from each other. Further, a table 18 for guiding the wafer 17 from the loader section 15 to the unloader section 16 is disposed on the front side of the loader section 15 and the unloader section 16, and the table 18 has two rows of small holes. A first conveyance mechanism 19 having an air conveyor structure is provided. As shown in FIG. 4, this air conveyor structure consists of small holes 20 that are inclined upward to the left, and these small holes 20 communicate with air supply holes 21 in the table 18. Therefore, the wafer 17 is lifted off the top surface of the table 18 by the air jetted out from the small holes 20, and since the jetting direction is inclined, the wafer 17 is transported to the left.

Further, a notch is provided in the center of the table 18, and a sample stage 22 on which the wafer 17 is placed is disposed in the notch. This sample stage 22 is fixed on an XY table 23 that can be freely adjusted in the plane XY direction, and a suction mechanism consisting of a suction hole 24 for vacuum suctioning the wafer 17 is provided in the center of this sample stage 22. There is.

Further, a stopper 25 is provided above the table 18 as a stopping mechanism for stopping the wafer 17 transferred from the loader section 15 onto the sample stage 22, and a vacuum stopper consisting of a suction hole 26 is provided on the surface of the table 18. There is. The former stopper 25 moves up and down, and when the wafer 17 is to be stopped, it is lowered onto the table, blocking the movement path of the wafer 17 and stopping it. The latter vacuum stopper is designed to vacuum-adsorb the wafer 17 to the table surface and stop its movement.

On the other hand, between the sample stage 22 insertion section and the loader section 15, an air conveyor structure is provided along the first conveyance mechanism 19, consisting of a small hole 27 and an air supply hole 28 on the upper right side, as shown in FIG. A second transport mechanism 29 is provided. This second transport mechanism 29
Now, the wafer 17 on the sample stage 22 is transferred to the loader side.

Further, an unloader push rod 30 is disposed on the back side of the loader section 15, and by one advance of the unloader push rod 30, one wafer is pushed out at its tip as shown in FIG. The wafer 17 in the wafer storage jig 31 of the structure is transferred to the first transport mechanism 19.
And the second transport mechanism 29 is pushed out onto the table 18 at one end. Further, when the unloader push rod 30 is retracted, its tip comes off the wafer storage jig 31 to the outside of the back hole, and the loader section 1
It is designed so that it does not interfere with the vertical movement of 5. Further, the front table 18 of the loader section 15
At the end, a first transport mechanism 19 and a second transport mechanism 2 are provided.
A loader pushing rod 32 is provided to insert the wafer 17 placed on one end of the wafer storage jig 31 into the wafer storage jig 31 on the loader section 15. It is designed to be fed into a storage groove. Further, a small hole 33 is provided at the end of the table 18 of the loader section 15, so that the wafer 17 can be attracted by vacuum suction. This suction mechanism plays the role of temporarily suctioning and stopping the wafer 17 transferred from the sample stage 22 at a fixed position, and the wafer 17 is stored on the loader side by the forward movement of the loader push rod 32. When the wafer is stored in the jig 31, it is designed to prevent the wafer from coming into contact with an undesired portion and being damaged.

On the other hand, a third conveyance mechanism 34 consisting of an air conveyor is provided between the other end of the first conveyance mechanism 19 and the unloader section 16, and a third conveyance mechanism 34 consisting of an air conveyor is provided to carry the wafers 17 transferred by the first conveyance mechanism 19. The wafer is stored in a wafer storage jig 31 on the unloader section 16 side. Further, the tip of the table 18 on the unloader section side provided with the third transport mechanism 34 extends into the interior of the wafer storage jig, so that the wafer 17 can be loaded reliably. Further, the structure of the third transport mechanism 34 is exactly the same as that of the first transport mechanism 19. Therefore, the first transport mechanism 19 and the third transport mechanism may have an integrated structure.

Note that the loader section 15 and the unloader section 1
6 is movable up and down. Further, guides 35 are provided at both edges of the table 18 along the movement path of the wafer 17.

Next, the state of use of such a wafer inspection apparatus will be explained. First, a wafer storage jig 31 containing a wafer 17 is placed on the loader section 15, and an empty wafer storage jig 31 is attached on the unloader section 16. At this time, for example, both the loader section 15 and the unloader section 16 are set at the lowest position and are sequentially transferred upward. Next, the wafer 17 is transferred onto the sample stage 22 by advancing the unloader push rod 30 once and operating the first transfer mechanism 19. Then, the XY table 23 is moved and the sample stage 22 is moved to the central inspection position 36 for inspection (measurement). After that, XY table 23 again
Move the sample stand 2 to the sample stand insertion part of the table.
2 is returned to place the wafer 17 on the first, second, and third transport mechanisms. Next, the wafer determined to be a good quality wafer is inserted into the original storage groove of the wafer storage jig 31 of the loader section 15 before being taken out by the operation of the second transport mechanism 29 and the loader push rod 32. Further, those determined to be defective wafers 37 are stored in the wafer storage jig 31 of the unloader section 16 by the first transport mechanism 19 and the third transport mechanism 34.

In addition, if it is assumed that even one defective wafer is found in one wafer storage jig by sampling inspection, all wafers will be reprocessed, and all wafers inspected in the inspection department will be It may be stored in a wafer storage jig on the loader side.

According to this embodiment, good wafers or defective wafers are automatically inserted into the original wafer storage jig during sampling inspection, so there is no need to transfer wafers between wafer storage jigs after inspection. This improves work efficiency.

Furthermore, there is no need to transfer the wafer, and the wafer is not held with tweezers as in the conventional method. Therefore, damage to the wafer or adhesion of fine powder caused by the damage to other wafers does not occur, leading to the manufacture of high-quality, high-yield semiconductor devices.

Furthermore, according to this embodiment, by employing pushers such as an unloader push rod and a loader push rod mechanism, wafers can be taken out and put in from anywhere within the wafer storage jig.
Sampling inspections can now be performed automatically.

Further, according to this embodiment, since the wafer is transferred while floating by air,
Another advantage is that the wafer surface is not damaged.

Furthermore, the wafer storage jig for storing wafers only needs to be set at two locations, and a wafer transfer mechanism for these two locations only needs to be provided.
Each mechanism of the entire device is simplified and miniaturized, and as a result, there are practical benefits such as the device becoming cheaper.

Note that the present invention is not limited to the above-mentioned embodiments, and the vertical movement mechanism of the wafer storage jig and the wafer transport mechanism may be other general mechanisms.

As described above, according to the wafer inspection apparatus of the present invention, loading and unloading can be automatically performed during sampling inspection of wafers, thereby improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an overview of a conventional wafer inspection device, FIG. 2 is a perspective view of a jig for accommodating a wafer, FIG. 3 is a plan view showing an overview of a wafer inspection device of the present invention, and FIG. 5 is a partial cross-sectional view of a table showing the air conveyors of the first and third transport mechanisms, and FIG. 5 is a partial cross-sectional view of the table showing the air conveyors of the second transport mechanism. 1...Wafer, 2...Loader section, 3...First
Unloader section, 4...Second unloader section, 5...
Supply conveyor, 6...First unloading conveyor, 7
...Transfer conveyor, 8...Inspection section (inspection position), 9...Second carry-out conveyor, 10...Third carry-out conveyor, 11...Wafer storage jig,
12...Wafer storage groove, 13...Good wafer, 14...Defective wafer, 15...Loader section,
16... Unloader section, 17... Wafer, 18
...Table, 19...First transport mechanism, 20...
Small hole, 21... air supply hole, 22... sample stand,
23...XY table, 24...suction hole, 25...
...Stopper, 26...Suction hole, 27...Small hole, 2
8...Air supply hole, 29...Second conveyance mechanism, 3
0... Push rod for unloader, 31... Wafer storage jig, 32... Push rod for loader, 33... Small hole, 34... Third transport mechanism, 35... Guide, 3
6... Inspection position, 37... Defective wafer.

Claims (1)

[Claims] 1 a first storage section that stores a plurality of wafers;
an inspection section that inspects a plurality of wafers stored in the first storage section; a first transfer section that transfers the plurality of wafers in the first storage section from the first storage section to the inspection section; , a second storage section that stores a portion of the plurality of wafers inspected in the inspection section; and a portion of the plurality of wafers inspected in the inspection section is transferred from the inspection section to the second storage section. a second transfer section for transporting the plurality of wafers inspected by the inspection section, and a third transport section for returning the remainder of the plurality of wafers inspected by the inspection section, excluding a portion stored in the second storage section, to the first storage section.
A wafer inspection device comprising: a transfer section;