JPH04284640A - Inspection apparatus for semiconductor wafer - Google Patents

Abstract

PURPOSE:To enhance the production yield of semiconductor chips by a method wherein whether a probe needle has come into contact with a semiconductor wafer or not is detected by using a contact detection part, an operation is executed by using an operation device on the basis of its result and a control device adjusts the reference face of a semiconductor-wafer mounting-stage movement device according to the swell of the semiconductor wafer. CONSTITUTION:A wafer mounting stage 1 is raised largely and coarsely to the upper part up to a coarse raise face by using a wafer mounting-stage movement device 9; after that, the wafer mounting stage 1 is raised fine and slightly a plurality of times. Then, a probe-needle movable part 3 comes into contact with a chip electrode 5 on a semiconductor wafer 2; the movable part 3 is separated form a probe-needle fixation part 4; the movable part 3 and the fixation part 4 are changed from a contact state to a noncontact state. A change in the state is detected by using a contact detection part 6, and an operation is executed by using an operation device 7. A control part 8 adjusts the reference face of the movement device 9 according to the swell of the semiconductor wafer 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer inspection apparatus.

0002

2. Description of the Related Art Conventionally, when manufacturing semiconductor devices, a wafer prober has been used to inspect the electrical characteristics of a plurality of semiconductor chips formed on a semiconductor wafer. FIG. 3 is a diagram showing the structure of a probe card of a conventional semiconductor wafer prober. In the figure, the probe card is provided with an opening 15 on a substrate 10, a semiconductor wafer 2 to be inspected is placed under this opening, and the probe needles 11 to 14 are in contact with the semiconductor wafer 2. In addition to confirming the existence of FIG. 4 is a diagram showing the structure of the probe needles 11 and 14 for confirming the presence of the semiconductor wafer 2. The probe needles 11 and 14 are composed of a fixed needle 4 and a movable needle 3. FIG. 4A shows the state before the probe needle 11 comes into contact with the semiconductor wafer 2. Before the probe needle 11 contacts the semiconductor wafer 2, the fixed needle 4 and the movable needle 3 of the probe needle 11 are in contact with each other and are in a conductive state. Figure 4(b)
shows a state in which the movable needle 3 is pushed up after the probe needle 11 contacts the semiconductor wafer 2. After the probe needle 11 contacts the semiconductor wafer 2, the fixed needle 4 and the movable needle 3 of the probe needle 11 are separated and become non-conductive, and depending on the conductive or non-conductive state of the probe needle 11, the semiconductor wafer and the probe needles 11- 14 is detected.

0003

However, as shown in FIG. 2, a semiconductor wafer has undulations D over its entire surface. In FIG. 2, the width of this undulation D is several hundred μ at the maximum. For this reason, when the chip to be detected is located at the bottom of the undulations of the semiconductor wafer, the probe needle movable section 3 cannot come into contact with the chip of the semiconductor wafer. Also,
If the chip to be detected is located at the height of the undulations of the semiconductor wafer, the probe needle movable section 3 will apply too much pressure to the semiconductor wafer, resulting in damage to the electrode on the semiconductor wafer or the probe needle movable section. . For this reason, the manufacturing yield of semiconductor chips deteriorates. The present invention provides a semiconductor wafer that is configured such that even if the semiconductor wafer has waviness, the semiconductor wafer inspection device follows the waviness and always brings the movable probe needle of the wafer prober into contact with the surface of the wafer with an appropriate pressure. Our objective is to provide inspection equipment.

0004

[Means for Solving the Problems] The present invention provides a semiconductor wafer inspection apparatus for inspecting the electrical characteristics of a plurality of semiconductor chips formed on a semiconductor wafer. a contact detection section that detects the contact state of the probe needle; a calculation device that performs calculations according to the results of the contact detection section; a wafer table moving device that moves the semiconductor wafer; and a wafer table movement device that moves the wafer placement table based on the results of the calculation device. and a control device for controlling movement of the device, and the wafer stage moving device is controlled so that the pressure of the probe needle is substantially constant following the undulations of the semiconductor wafer.

[0005]

[Operation] In the present invention, the contact detection unit detects whether or not the probe needle has contacted the semiconductor wafer, the arithmetic unit performs calculations based on the result, and the control unit controls the semiconductor wafer mounting table moving device. Adjust the surface according to the waviness of the semiconductor wafer.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a semiconductor wafer inspection apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a wafer mounting table, 2 is a semiconductor wafer, 3 is a probe needle movable part, 4 is a probe needle fixing part, 5 is a chip electrode, 6 is a contact detection part, 7 is a calculation device, 8 is a control device, Reference numeral 9 denotes a wafer mounting table moving device, which is movable in the horizontal direction of the X and Y axes and the vertical direction of the Z axis. In the figure, for the first chip at the start of measurement, the wafer mounting table moving device 9
The wafer mounting table 1 is roughly raised upwards to a roughly raised surface that is, for example, 25 μm in front of the semiconductor wafer surface, although it varies slightly depending on the waviness state of the semiconductor wafer, and then in small steps (for example, by 10 μm) multiple times. When the wafer mounting table 1 is slightly raised by 30 μm, the probe needle movable part 3 comes into contact with the chip electrode 5 on the semiconductor wafer 2, the probe needle movable part 3 separates from the probe needle fixed part 4, and the probe needle movable part 3 Then, the probe needle fixing portion 4 changes from a contact state to a non-contact state. The contact detection section 6 detects this state change and stores it in a memory section (not shown) in the arithmetic unit 7. After this, the electrical characteristics of the chip are measured.

In order to test the next chip, the arithmetic unit 7
The wafer stage moving device 9 moves the probe needle movable part 3 to the chip position next to the chip measured first.
is moved by a predetermined amount in the X and Y axis directions. Furthermore, the calculation device 7
controls the control device 8 and the wafer mounting table moving device 9 to raise the wafer mounting table 1 largely to the previously determined rough rising surface, and then moves it in small steps (for example, in increments of 10μ) a predetermined number of times (for example, (6 times) Slightly raise the wafer mounting table 1 upward. For example, when the wafer mounting table 1 is raised by 20 μm, the probe needle movable part 3 comes into contact with the chip electrode 5 on the semiconductor wafer 2, the probe needle movable part 3 separates from the probe needle fixed part 4, and the probe needle movable part 3 and the probe The needle fixing portion 4 changes from a contact state to a non-contact state. The contact detection section 6 detects this state change and stores it in a memory section (not shown) in the arithmetic unit 7. In the above state, it is determined that the wafer at the positions of the first chip and the next chip is undulated by 10 μm in the upward direction from the data in the memory. Therefore, when such a contact state continues, for example, twice in a row (generally n times), the arithmetic unit 7 resets the rough raised surface of the wafer mounting table 1 at that point to be lower, for example, by 10 μm.

When measuring the next chip, the wafer mounting table 1 is roughly raised to the previously determined rough rising surface, and then the wafer mounting stage 1 is slightly raised by 10 μm a certain number of times (for example, 6 times) to raise the probe. The needle movable part 3 and the tip electrode 5 can be brought into contact with high precision and quickly. After the probe needle and the chip come into contact with the wafer mounting table 1, for example, 5
If it is increased by more than 0 μm, the contact between the probe needle movable portion 3 and the tip electrode 5 will be too strong due to the overdrive amount during chip inspection, for example, 80 μm, and there is a risk that the electrode or the probe needle movable portion may be damaged. In this way, if the semiconductor wafer is undulated in a higher direction by, for example, 10 μm twice in a row (generally n times), the new rough raised surface of the wafer mounting table 1 is set to be lowered by 10 μm. However, if the semiconductor wafer is undulating in a lower direction, the rough raised surface of the wafer mounting table 1 is reset to a new rough raised surface raised by a predetermined height. After this, the electrical characteristics of the chip are measured.

The detection of contact between the probe needle movable part 3 and the tip electrode 5 has been described above. In actual measurement of the electrical characteristics of a semiconductor wafer chip, after the probe needle movable part 3 contacts the chip electrode 5, the probe needle movable part 3 is further overdriven (by bringing the probe needle and the wafer closer by, for example, 80 μm). This is performed after the wafer mounting table moving device 9 is pushed upward. Due to this overdrive, the probe needle movable part 3 bites into the tip electrode 5, breaks the oxide film of the tip electrode 5, and secures contact. As mentioned above, when the waviness of the wafer 2 is gradually rising, the rough rising surface of the wafer mounting table 1 is gradually lowered, and when the waviness is gradually descending, the wafer mounting table 1 is moved downward.
It is controlled so that the rough rising surface of
Chip electrode 5 on semiconductor wafer 2 and probe needle movable part 3
The contact pressure is always adjusted to an appropriate value.

0010

[Effects of the Invention] As explained above, according to the present invention,
Even if the semiconductor wafer has undulations, the semiconductor wafer inspection apparatus adaptively follows the undulations so that the probe needle of the wafer prober always follows the undulations and contacts the surface of the wafer with appropriate pressure. Furthermore, since the rough rising surface is set in advance, the probe needle movable portion can be quickly brought onto the chip surface of the semiconductor wafer during chip measurement. Furthermore, regardless of the waviness of the wafer, the electrodes and the probe needle movable section are always in contact with each other with appropriate pressure on the chip to be inspected, so that damage to the electrode or the probe needle movable section due to excessive pressure can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a semiconductor wafer inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing the state of waviness of a semiconductor wafer.

FIG. 3 is a diagram showing a substrate and a probe needle of a wafer prober of a conventional semiconductor wafer inspection apparatus.

FIG. 4 is a diagram showing the detailed structure of a probe needle of a wafer prober of a conventional semiconductor wafer inspection apparatus.

[Explanation of symbols]

1 Wafer mounting table 2 Semiconductor wafer 3. Probe needle movable part 4 Probe needle fixing part 5 Electrode 6 Contact detection part 7 Arithmetic device 8 Control device 9 Wafer mounting table moving device

Claims (1)

[Claims] 1. A semiconductor wafer inspection device that sequentially inspects the electrical characteristics of a plurality of semiconductor chips formed on a semiconductor wafer, wherein a contact state between a probe needle that contacts a chip on the semiconductor wafer and the probe needle is detected. a wafer platform moving device that moves a semiconductor wafer; and a control device that controls movement of the wafer platform moving device based on the results of the computing device. 1. A semiconductor wafer inspection apparatus, comprising: a semiconductor wafer inspection apparatus, wherein the wafer stage moving apparatus is controlled so that the pressure of the probe needle is substantially constant in accordance with the waviness of the semiconductor wafer.