JP3115112B2 - Semiconductor inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor inspection apparatus for inspecting electrical characteristics of a semiconductor chip formed on a semiconductor wafer.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a semiconductor chip is inspected on a semiconductor wafer to find a defective chip, and the defective chip is not subjected to a subsequent assembling step to improve the manufacturing efficiency. ing. This inspection is for inspecting the electrical characteristics of each semiconductor chip, and a semiconductor inspection device combining a prober and a device called a test head is used.

FIG. 2 is a diagram showing a configuration of a conventional semiconductor inspection apparatus. In order to perform an inspection, it is necessary to apply a test signal through an electrode pad of each semiconductor chip and detect an output signal. Since there are several tens of electrode pads having a length of about 10 mm, finely arranged fine styluses are brought into contact with the electrode pads. In FIG. 2, reference numeral 200 denotes a semiconductor wafer. Reference numeral 21 denotes a probe card, and a stylus 22
have. Reference numeral 25 denotes a wafer chuck for fixing the semiconductor wafer 200 by vacuum suction. Wafer chuck 2
5 is moved three-dimensionally by the wafer moving device 26.

[0004] Reference numeral 24 denotes a test head, which makes a pass / fail judgment based on the generation of a test signal and a detection signal according to the semiconductor chip to be inspected. Reference numeral 23 denotes a performance board fixed to the test head 24, which forms a connection between an input / output terminal of the test head 24 and a frog ring 30 described below. The frog ring 30 is also called a bird cage and forms a connection portion between the probe card 21 and the performance board 23, and the probe card 21 and the performance board 23 are connected via pogo pins.

Reference numeral 27 denotes a guide for mounting the test head 24, reference numeral 28 denotes a base for holding the probe card 21 and frog ring 30, and reference numeral 29 denotes a base of the entire inspection apparatus. Test head 24 is required to be removable, 4 1 to 4 3 are moving mechanism therefor. 43 is a holding member for the test head 24,
4 to move along the 2. Support 4 2 moves vertically along the pillar 4 1. Here, the moving mechanism as described above is used, but there is also a type in which the test head is rotated to be detached.

Normally, a part for connecting the electrode pads of each semiconductor chip 200 and the test head 24 except for the test head 24 and the performance board 23 is called a prober. The performance board 23 is integrally attached to the test head 24, and can be said to form a part of the test head 24. In the inspection of the semiconductor wafer, first, the wafer chuck 25 is moved to the transfer position of the semiconductor wafer 200 to suck the semiconductor wafer 200. Then, the position of each semiconductor chip on the held semiconductor wafer 200 is detected using a TV camera, a microscope, or the like, and adjustment is performed so that the X axis and the Y axis of the wafer moving device 26 coincide with the arrangement direction of the semiconductor chips. Then, the relative relationship between the arrangement position of the semiconductor chips and the reference position of the wafer moving device 26 is set. Thus, the positional relationship between the electrode pads of each semiconductor chip and the stylus 22 of the probe card 21 is determined. Thereafter, the inspection is performed by sequentially bringing the stylus 22 into contact with the electrode pad.

[0007] Since the electrode pads are different for each type of semiconductor chip, it is necessary to change the arrangement of the stylus 22 in accordance therewith, and the probe card 21 needs to be exchangeably mounted. In FIG. 2, the entire frog ring 30 is replaced, but there is also a type in which only the probe card 21 is replaced from below. The test head 24 needs to be replaced with another one depending on the kind of the semiconductor chip to be inspected, and needs to be detachable from the prober for maintenance. Since the test head 24 becomes quite heavy, it is not easy to move it precisely. To move it precisely, a large and expensive moving mechanism must be provided. Therefore, at present, a highly accurate moving mechanism is not used at present.

In the probe card 21, since the stylus 22 needs to be in contact with the electrode pad, the position and the rotational position (inclination) are required to be accurate. In particular, most of the conventional semiconductor inspection devices do not have a function of adjusting the inclination of the wafer chuck 22 in the wafer moving device 26, and therefore it is necessary that the wafer inspection device 26 be precisely parallel to the surface of the semiconductor wafer. If it is tilted, the stylus does not evenly contact the electrode pad, resulting in an inspection failure. Therefore the probe card 21 is configured to be accurately solid <br/> constant to the body.

In the inspection apparatus, the probe card 21
If the stylus 22 is connected to the corresponding input / output terminal of the test head 24, the inspection can be performed. However, as described above, since the moving mechanism of the test head 24 does not provide sufficient moving accuracy, if the connecting terminals of the probe card 21 and the connecting terminals of the test head 24 are directly contacted, a contact failure due to the inclination occurs.

Therefore, a frog ring 30 is provided to absorb a positional error between the probe card 21 and the test head 24. Frog ring 30 is provided on the probe server <br/> side, it is connected via the pogo pins 32 and the connection terminals of the probe card 21. Pogo pins 31 are also provided on the upper surface, and are connected to connection terminals of the performance board 23 via the pogo pins 31. The pogo pins 31 on the upper surface and the pogo pins 32 on the lower surface are connected by, for example, aerial wiring.

As described above, in the conventional semiconductor inspection apparatus,
The probe card 21 is fixed to the prober side, and a frog ring 30 is provided to absorb the inclination and displacement between the probe card 21 and the test head 24.

[0012]

SUMMARY OF THE INVENTION Frog ring 30
Has pogo pins 31 and 32 on the upper surface and the lower surface. Pogo pins are absolutely necessary to absorb tilt errors on both sides to be connected. However, it is necessary to provide many fine pogo pins on the upper surface and the lower surface, and there is a problem that the frog ring 30 becomes very expensive.

It is desirable to connect the stylus 22 of the probe card 21 and the connection terminal of the test head 24 with a path as short as possible from the viewpoint of noise and the like. However, in the conventional inspection apparatus, the pogo pins 31 and 32 of the frog ring 30 are present, and a line connecting both the pogo pins is also required, which causes a problem of signal delay and noise generation. In addition, in recent semiconductor inspection devices, the wafer moving device 26 capable of performing not only parallel movement in three axial directions and rotation of the mounting surface of the wafer chuck 25 but also rotation in a plane perpendicular to the other two axes has increased. doing. However, the frog ring 30 is still used, and the above-described problem has occurred.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to realize at low cost a semiconductor inspection apparatus which does not cause problems of signal delay and noise generation.

[0015]

A semiconductor inspection apparatus according to the present invention includes a wafer chuck for adsorbing a semiconductor wafer, a wafer moving mechanism for moving the wafer chuck, a probe card, and a test head. The probe card has a stylus that contacts an electrode pad of a semiconductor chip formed on a semiconductor wafer, and a connection terminal that electrically connects the stylus to the outside. The test head has an input / output terminal that comes into contact with the connection terminal of the probe card, and tests the electrical characteristics of the semiconductor chip via the input / output terminal. In order to achieve the above object, in the semiconductor inspection apparatus of the present invention, the wafer moving mechanism includes a tilt adjusting mechanism and a rotating mechanism, which can adjust the tilt of the semiconductor wafer and rotate the semiconductor wafer, and The card is fixed to the test head and sucked by the wafer chuck.
Touch the probe card to different parts of the
The height of the wafer moving mechanism when the needle is in contact
Probe car calculated from the ratio of the difference and the distance between different parts
Wafer so that the difference between the tilt of
Adjust the tilt adjustment mechanism of the moving mechanism to
The semiconductor wafer can be adjusted so as to be parallel .

[0016]

The reason why the probe card needs to be fixed at a high position and with a high tilt accuracy is that in the early semiconductor inspection equipment, the wafer moving device was not provided with a tilt adjustment function. If a test head, which cannot be moved with sufficient accuracy, is moved and connected to the fixed probe card, a connection failure occurs due to a positional shift or a difference in inclination. The frog ring absorbs the positional deviation and the difference in inclination.

However, as described above, in recent semiconductor inspection devices, the wafer moving device often has a tilt adjusting function, and even if the probe card is tilted with respect to the mounting surface of the wafer chuck, it is parallel. Can be adjusted to perform inspection. Wafer movement mechanism originally 3
It has a function of moving in the dimensional direction and a function of rotating the mounting surface. Therefore, in the current semiconductor inspection apparatus, it can be said that inspection is possible regardless of the positional relationship of the probe card with respect to the wafer chuck.

If the probe card is fixed to the test head, there is no need to consider errors in connection, and no frog ring is required. When the probe card fixed to the test head is moved to the inspection position, the position and the inclination have large errors. However, this error can be absorbed by adjusting the wafer moving device, and the inspection can be performed. As described above, in the semiconductor device of the present invention, since the frog ring is not necessary, the occurrence of signal delay and noise is reduced, and the cost can be reduced. Furthermore, in a state where the test head is moved from the inspection position, the probe card can be directly accessed, so that the probe card can be easily replaced.

[0019]

FIG. 1 is a block diagram showing an embodiment of a semiconductor inspection apparatus according to the present invention. In FIG. 1, reference numeral 100 denotes a semiconductor wafer to be inspected, on which a large number of semiconductor chips are formed. Reference numeral 1 denotes a probe card having a stylus 2. 3 is a performance board. Reference numeral 4 denotes a test head. Performance board 3 is test head 4
The probe card 1 is also fixed to the performance board 3 with screws. That is, the probe card 2 is fixed to the test head 4, and each stylus 2 is connected to the input / output terminal of the test head 4. The test head 4 rotates about a rotation axis 12,
The test head 4 itself can be replaced and maintained, and the probe card 1 and the performance board 3 can be replaced.

[0020] 5 is a wafer chuck for holding by vacuum adsorption of the semiconductor wafer 100 is moved in the vertical direction by the Z-axis moving mechanism. Reference numeral 6 denotes a Y-axis moving table that supports a Z-axis moving mechanism, which is moved in the front-rear direction (left-right direction in the figure) by the Y-axis moving mechanism. Reference numeral 7 denotes an X-axis moving table that supports the Y-axis moving mechanism, and is moved in the lateral direction by the X-axis moving mechanism.
Reference numeral 8 denotes a rotary table that supports the X-axis moving mechanism, which is supported by a rotary mechanism provided on the inclined table 9 and can rotate about the Z-axis. The tilt table 9 is supported by a tilt adjusting mechanism provided on the table 10. The tilt adjusting mechanism supports three or four arms extending from the tilt base 9 with a screw mechanism rotated by the motor 11 and holds the arm with a spring. By adjusting the screw mechanism, the tilt of the tilt base 9 can be reduced. Can be adjusted.

Reference numeral 13 denotes a discharge port for vacuum suction, which is connected to a vacuum pump. With the above-described mechanism, the mounting surface of the wafer chuck can perform parallel movement in three axial directions and rotation about the three axes, and the stylus 2 can be moved to each semiconductor chip regardless of the position and inclination of the probe card 1. Electrode pads can be accurately contacted. In FIG. 1, the XYZ parallel movement mechanism is supported by the rotation mechanism, and the entirety is supported by the tilt adjustment mechanism. However, since the tilt and rotation adjustment widths are not so large, the mutual support relationship between the respective movement / rotation mechanisms is as follows. Can be changed arbitrarily.

Next, the operation of setting the test head 4 on which the probe card 1 is mounted to the inspection position and then adjusting the inclination to adjust the probe card 1 and the wafer chuck 5 to be parallel will be described. Various methods can be considered for this adjustment. Here, a semiconductor wafer is first placed on the wafer chuck 5 and sucked. Next, after moving the portion near the end of the wafer chuck 5 directly below the stylus 2,
The wafer chuck 5 is raised slowly. The test head 4 can detect that the stylus 2 has come into contact with the surface of the semiconductor wafer, and stops moving at the moment when the stylus 2 comes into contact with the semiconductor wafer. Is stored. At this time, since the probe card 1 and the wafer chuck 5 are inclined, only a part of the stylus 2 comes into contact.

Next, after lowering the wafer chuck 5, the wafer chuck 5 is moved to the opposite side with respect to the center of the wafer chuck 5 to perform the same operation as described above. The inclination in this direction is determined from the difference in the Z-axis direction thus obtained and the interval between the measurement positions. By performing the same operation in the vertical direction, the difference between the inclination of the probe card 1 and the inclination of the wafer chuck 5 is calculated. Next, if the difference in the inclination is corrected by the inclination adjusting mechanism, the probe card 1 and the wafer chuck 5 become parallel.

After the completion of the tilt adjustment as described above, the position of the stylus 2 and the rotational position about the Z axis are detected. This detection is performed, for example, by raising the semiconductor wafer held on the wafer chuck 5 and bringing the semiconductor wafer into contact with the stylus, and detecting the contact trace by observation or image processing. By the above operation, the probe card 1 and the wafer chuck 5 become parallel, and the position of the stylus 2 is also determined.

In the inspection operation, the position of the semiconductor chip on the semiconductor wafer adsorbed is detected in the same manner as in the prior art, the semiconductor wafer is moved in accordance with the position of the stylus stored in the above operation, and the electrode pad of each semiconductor chip is moved. Is brought into contact with a stylus.

[0026]

As described above, according to the present invention,
A semiconductor inspection apparatus which does not need to use a frog ring which is expensive and has a problem of signal delay and noise generation can be realized, and performance can be improved and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a conventional semiconductor inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Probe card 2 ... Contact probe 3 ... Performance board 4 ... Test head 5 ... Wafer chuck 100 ... Semiconductor wafer

Claims (1)

(57) [Claims] 1. A wafer chuck (5) for attracting a semiconductor wafer (100), a wafer moving mechanism for moving the wafer chuck (5), and an electrode pad for a semiconductor chip formed on the semiconductor wafer (100). A stylus (2) that contacts the stylus, and the stylus (2)
A probe card (1) having a connection terminal for electrically connecting the semiconductor chip to the outside, and an input / output terminal for contacting the connection terminal of the probe card (1), and the semiconductor chip via the input / output terminal And a test head (4) for inspecting electrical characteristics of the semiconductor wafer, wherein the wafer moving mechanism includes a tilt adjustment mechanism and a rotation mechanism to adjust the tilt of the semiconductor wafer (100) and to adjust the tilt of the semiconductor wafer (100). (100) can be rotated, the probe card (1) is fixed to the test head (4), and the semiconductor wafer sucked by the wafer chuck (5).
C. The probe card is attached to a different part of (100)
(1) The wafer transfer when the stylus (2) is brought into contact with the wafer
Difference in height position of moving mechanism and distance between the different parts
The probe card (1) and the semiconductor calculated from the ratio of
So that the difference in inclination of the body wafer (100) becomes zero.
Adjust the tilt adjustment mechanism of the wafer moving mechanism to
Bucard (1) and the semiconductor wafer (100) are parallel
A semiconductor inspection apparatus characterized in that the semiconductor inspection apparatus is adjustable .