JPH05343497A - Wafer inspecting apparatus - Google Patents

Abstract

PURPOSE:To provide a wafer inspecting apparatus wherein it shortens the inspection and treatment time, per cassette, of a cassette in which many wafers have been housed. CONSTITUTION:Out of four cassettes 36A to 36D which have been stocked in a cassette stock part 14, wafers under test which have been housed in the cassette 36A are taken out one by one from the cassette 36A by means of a self-propelled vehicle 40 in a wafer conveyance apparatus 16. The wafers 56 which have been taken out are conveyed respectively to a plurality of wafer probers 22A to 22H by means of a self-propelled vehicle 30. The wafers whose inspection has been finishes by means of the wafer probers 22A to 22H are sequentially conveyed to, and housed, in the original cassette 36A by means of the self-propeller vehicles 30, 40. In addition, wafers under test are taken out from the cassette 16A and conveyed to the wafer probers 22A to 22H. Thereby, the inspection and treatment time, per cassette, of the title inspection apparatus can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer inspection apparatus,
In particular, the present invention relates to a wafer inspection device for inspecting the electrical characteristics of semiconductor element circuits formed in large numbers on a semiconductor wafer.

[0002]

2. Description of the Related Art A semiconductor wafer has a large number of identical electric element circuits formed on its surface. A wafer prober is used to inspect the formation quality of each electric element circuit before cutting the electric element circuit into chips. A wafer inspecting device called a “good” or “bad” judgment is made for each electric element circuit.

The wafer inspection apparatus is composed of a cassette storage section, a wafer transfer section, a table, an apparatus control section determination section, and the like. A cassette accommodating a large number of wafers to be inspected is attached to the cassette accommodating portion, and the wafers are taken out from the cassette one by one by the wafer conveying portion and conveyed to the table. The table sucks the wafer and horizontally moves in the XY directions and vertically moves in the Z direction according to the element arrangement when the element is inspected.

The device control section determination section is composed of a probe stage, a tester and the like. The probe stage has
A probe card corresponding to the wafer to be inspected is attached, and each electrode pad of the electric element circuit is brought into contact with the probe needle provided on the probe card, whereby the formation quality of each electric element circuit is measured by the tester. The inspection is judged sequentially.

The inspected wafer is transferred from the table to the cassette by the wafer transfer unit and stored in the original shelf of the cassette.

[0006]

However, in the conventional wafer inspection apparatus, since a large number of wafers stored in one cassette are processed by one wafer inspection apparatus, the inspection time per cassette becomes long. There is a drawback.
In addition, a plurality of wafer inspection devices are arranged, a cassette corresponding to the number of wafer inspection devices is stored in the wafer stock unit, the wafer is taken out from the cassette by the wafer transfer device, and the wafer inspection corresponding to the wafer is performed. Although there is a wafer inspection apparatus that sequentially conveys the wafer to the apparatus, this wafer inspection apparatus also has a drawback that the inspection time per cassette becomes long as described above.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wafer inspection apparatus that shortens the inspection processing time per cassette.

[0008]

In order to achieve the above-mentioned object, the present invention provides a plurality of wafer inspection parts arranged at a predetermined interval and a large number of cassettes containing a large number of wafers to be inspected. The stockable cassette stock unit and the wafers stored in a predetermined cassette of the cassette stock unit are taken out from the cassette one by one and conveyed to the plurality of wafer inspection units, respectively, and the inspection is completed by the wafer inspection unit. Wafer transfer means for transferring the wafer to the original cassette and storing it in the cassette.

[0009]

According to the present invention, first, of the plurality of cassettes stocked in the cassette stock section, the inspection target wafers stored in the first cassette are taken out one by one from the cassette by the wafer transfer means. The wafers are transferred to a plurality of wafer inspection units. Next, the wafers that have been inspected by the plurality of wafer inspection units are sequentially transferred to the original cassette by the wafer transfer means and stored therein, and the wafers to be inspected are taken out from the cassettes and transferred to the wafer inspection units that have been inspected. Transport.

As a result, the inspection processing time per cassette can be shortened by the number of wafer inspection units. For example, if eight wafer inspection units are installed, the inspection processing time can be shortened to 1/8 as compared with the conventional wafer inspection apparatus in which one wafer inspection unit inspects one cassette.
When all the wafers stored in the first cassette have been inspected, the inspection of the wafers stored in the second cassette of the cassette stock unit is started. And the first
The cassette is removed from the cassette stock section and replaced with a new cassette containing the wafer to be inspected. In this way, the cassette after the inspection of the wafer is sequentially replaced with a new cassette, and the cassettes are sequentially sent to the subsequent process.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a wafer inspection apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. In Figure 1,
A top view showing an embodiment of a wafer inspection device 10 according to the present invention is shown. The wafer inspection device 10 includes a wafer inspection unit 1
2, a cassette stock unit 14, a wafer transfer device 16, and a controller unit 18.

[Wafer Inspection Section 12] Wafer Inspection Section 12
Is the four wafer probers 22A and 22A on one side (upward in the figure) with the carrier rail 20 of the wafer carrier 16 interposed therebetween.
B, 22C, 22D, and 4 on the other side (downward in the figure)
Wafer probers 22E, 22F, 22G, and 22H on the table are arranged in parallel at a predetermined interval and facing each other. Also,
The four testers 24A, 24B, 24C and 24D are connected to the wafer probers 22A to 22H at a ratio of two to one.

The wafer prober 22A includes a first wafer transfer section 26, a probe stage 28, and the like. The wafer transfer unit 26 supplies a wafer transferred by a self-propelled carriage 30 of the wafer transfer device 16 described later to the supply unit 26a.
When it is received in step 1, it is conveyed to a table (not shown) arranged below the probe stage 28. The table is
When the element is inspected by sucking the wafer, horizontal movement in the XY direction and vertical movement in the Z direction can be performed according to the element arrangement.

Further, a probe card (not shown) corresponding to the wafer to be inspected is attached to the probe stage 28, and each electrode pad of the electric element circuit is brought into contact with a probe needle provided on this probe card. As a result, the formation quality of each electric element circuit is sequentially inspected and determined by the tester 24A. The inspected wafer is transferred to the supply section 26a by the first wafer transfer section 26. When the wafer is transferred to the supply unit 26a, a signal indicating the end of the transfer is output to the controller unit 18.

The wafer prober 22A is provided with a cassette housing 32. A cassette 34 in which a large number of wafers to be inspected are stored is attached to the cassette storage section 32. The wafers are taken out one by one from the cassette 34 by a second wafer transfer unit (not shown) provided in the wafer prober 22A and transferred to the table.

Since the wafer probers 22B to 22H have the same structure as the wafer prober 22A, the description thereof will be omitted. [Cassette stock section 14] Cassette stock section 14
The four cassettes 36A, 36B, 36C, and 36D that store a large number of wafers to be inspected are arranged at predetermined intervals in the depth direction in the drawing. These cassettes 36A to 36D can be moved up and down in the depth direction in the drawing by an elevator device (not shown) provided in the cassette stock section 14.

The elevating device is drive-controlled by the controller section 18 described above. [Wafer Transfer Device 16] The wafer transfer device 16 is indicated by X in the drawing.
Transport rails 20 arranged in the same direction, and the transport rails 2
And a carrier rail 38 arranged in the Y direction in the drawing orthogonal to 0, and the carrier rail 20 has a self-propelled carriage 30.
However, self-propelled carriages 40 are arranged on the transport rails 38 so as to be movable. Further, a wafer relay chuck 41 is disposed near the self-propelled carriage 40.

As shown in FIG. 2, the self-propelled chassis 30 is composed of a chassis body 42 and a robot section 44. The chassis main body 42 is movably attached to the transport rail 20, and travels along the transport rail 20 by rotating a wheel connected to a forward / reverse drive motor provided in the chassis main body 42. can do. Meanwhile, the robot unit 44 includes a chucking transfer unit 46 and a suction unit 4.
8 and. The chucking transfer unit 46 has a drive motor 50 fixed on the chassis main body 42, and a transfer jig 52 is connected to the drive motor 50.
The transfer jig 52 can be turned 180 degrees while being moved by the drive motor 52 while moving in the direction of the arrow in the figure. A wafer chucking arm 54 is fixed to the transfer jig 52. The wafer chucking arm 54 can hold the wafer 56 and place it on the transfer chuck 58 of the suction unit 48.

The wafer 56 placed on the delivery chuck 58 is placed on the delivery chuck 58 at the same time as it is placed.
Is adsorbed on the tray 60 and descends, and is stably held by the dish 60.
The structure of the self-propelled chassis 40 is the chassis body 42 described above.
Since it is composed of the chucking transfer section 46, the description thereof will be omitted. The controller unit 18 controls the traveling direction and traveling distance of the self-propelled chassis 30, 40, the drive motor 50, and the vertical movement of the transfer chuck 58.

Next, a control method by the controller section 18 of the wafer inspection apparatus 10 configured as described above will be described. First, the self-propelled carriage 40 is moved to the position shown in FIG. Next, the robot unit 44 of the self-propelled carriage 40 and the elevating device of the cassette 36A are controlled to take out the inspection target wafers 56 stored in the cassette 36A one by one from the cassette 36A by the wafer chucking arm 54 and transfer them. The jig 52 is rotated 180 ° and placed on the relay chuck 41.

Next, the self-propelled chassis 30 is moved to the right end in FIG. Then, the robot section 44 and the suction section 48 of the self-propelled vehicle platform 30 are controlled to hold the wafer 56 placed on the relay chuck 41 by the wafer chucking arm 54 of the self-propelled vehicle platform 30 and transfer the wafer 56. The tool 52 is rotated by 180 ° and placed on the transfer chuck 58, adsorbed by the transfer chuck 58, lowered, and held on the tray 60.

Next, the self-propelled carriage 30 is moved to the left in FIG. 1 and stopped at the position of the wafer transfer section 26 of the wafer prober 22A. Then, the transfer chuck 58 is lifted to separate the wafer 56 from the dish 60, and
After holding the wafer 56 by the wafer chucking arm 54, the transfer jig 52 is rotated clockwise by 90 ° and placed on the supply unit 26 a of the wafer transfer unit 26. The wafer 56 placed on the supply unit 26 a is transferred to the wafer transfer unit 26.
Is transported to the table and inspected.

In this way, the remaining wafer prober 2
Wafer 5 of cassette 36A for 2B to 22H
6, 56 ... Are respectively transferred to each wafer prober 22B.
The inspection is started from 22H to 22H. Next, among the wafer probers 22A to 22H, the inspected wafer 56 is
When the wafers are transferred to the supply units 26a of the wafer probers 22A to 22H, the wafers 56 that have been inspected are sequentially processed.
The wafer transfer device 16 transfers and stores the wafer up to the cassette 36A. Since the wafer storage procedure by the wafer transfer device 16 is the reverse step of the wafer transfer procedure described above,
The description is omitted.

When the inspection of all the wafers 56, 56 ... In the cassette 36A is completed after repeating the transfer and storage of the wafers 56, the inspection of the wafers 56 stored in the cassette 36B is started. Then, the cassette 36A is taken out from the cassette stock unit 14 and replaced with a new cassette containing the wafer to be inspected. in this way,
The cassette after the wafer inspection is completed is replaced with a new cassette, and the wafers are sequentially sent to the subsequent process.

As a result, in this embodiment, the inspection processing time per cassette can be reduced by the number of wafer inspection units. For example, if eight wafer probers 22A to 22H are installed as in the present embodiment, the inspection processing time is reduced to 1/8 as compared with the conventional wafer inspection apparatus in which one wafer prober inspects one cassette. Can be shortened.

In the present embodiment, the inspection process of one type of wafer 56 has been described, but the present invention is not limited to this, and when different types of wafers are stored in each of the cassettes 36A to 36D. The wafer probers 22A to 22H may be divided into testers 24A to 24D and set so as to correspond to the type of wafer. Also, the wafer 5
If it takes time for the new wafer 56 to be transferred from the wafer transfer device 16 after the inspection of step 6, the wafer may be taken out from the cassette 34 mounted on each of the wafer probers 22A to 22H and inspected. .. As a result, the wafer inspection process can be performed efficiently.

Further, each wafer prober 22A to 22H
Alternatively, a wafer chucking arm may be provided to transfer the wafer 56 attracted by the transfer chuck 58 by the wafer chucking arm to the wafer probers 22A to 22H.

[0028]

As described above, according to the wafer inspection apparatus of the present invention, the wafer to be inspected stored in a predetermined cassette among the plurality of cassettes stocked in the cassette stock section is transferred to the wafer transfer means. The wafers are taken out from the cassette one by one and transported to a plurality of wafer inspection units, respectively, and the wafers inspected by the plurality of wafer inspection units are sequentially transported to the original cassette for storage. As a result, in comparison with the conventional wafer inspection apparatus in which one wafer inspection unit inspects one cassette,
The inspection processing time per cassette can be greatly shortened.

[Brief description of drawings]

FIG. 1 is a top view showing an embodiment of a wafer inspection apparatus according to the present invention.

FIG. 2 is a front view of a wafer transfer carriage applied to a wafer inspection apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Wafer inspecting apparatus 12 ... Wafer inspecting section 14 ... Cassette stock section 16 ... Wafer carrying apparatus 18 ... Controller section 22A, 22B, 22C, 22D, 22E, 22F, 2
2G, 22H ... Wafer prober 30, 40 ... Self-propelled carriage 36A, 36B, 36C, 36D ... Cassette

Claims (1)

[Claims] 1. A plurality of wafer inspection units arranged at a predetermined interval, a cassette stock unit capable of stocking a large number of cassettes containing a large number of wafers to be inspected, and a predetermined cassette of the cassette stock unit. Wafer transfer in which the stored wafers are taken out from the cassette one by one and transferred to the plurality of wafer inspection units, respectively, and the wafers inspected by the wafer inspection unit are transferred to the original cassette and stored in the cassette. A wafer inspection apparatus comprising: