JP2617422B2 - Wafer prober and semiconductor wafer measuring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The disclosed technology relates to the technical field of measuring the electrical characteristics of a semiconductor wafer.

[0002]

2. Description of the Related Art In a semiconductor wafer prober which performs a final check step of a semiconductor wafer, recently, the size of the semiconductor wafer has been required to be large, super-integrated, and multi-pinned. In order to cope with the problem, a technique of processing by applying overdrive has been proposed.

[0003] As shown in FIGS. 3 and 4, the conventional general semiconductor wafer measurement technique employs a probe card 7.
Are provided at a lower portion substantially at the center of the head plate 21, and the tips of the needles 3, 4 (only two are shown for convenience of illustration) are all connected to the mounting table 5 before and after the attachment. The fulcrum 1 is arranged so as to keep the same height, and the fulcrum 1 which rotates with respect to the head plate 21 and the screw 6 which raises and lowers the application point 2 side with respect to the mounting table 5 of the semiconductor wafer 13 with respect to the application point 2 are provided. The probe card 7 is provided at a midpoint position on a straight line connecting the fulcrum 1 and the action point 2, and the tips 15, 16 of the needles 3, 4 are arranged side by side on the lower surface thereof.

[0004] The rotation of the screw 6 about the front fulcrum 1 at the front of the head plate 21 causes the opposite side of the head plate 21 to pivotally descend with respect to the mounting table 5 so that the semiconductor wafer on the mounting table 5 can be rotated. The measurement is performed in such a manner that the needle tips 15 and 16 are brought into contact with 13.

When the overdrive is applied, as shown in FIG. 5, the tip 16 of the needle 4 closer to the fulcrum 1 is placed in front of the tip 15 of the needle 3 closer to the other working point 2 by the semiconductor. When the screw 6 is rotated so that the needle tip 15 of the needle 3 which is in contact with the wafer 13 but is closer to the action point 2 comes into contact with the semiconductor wafer 13, the needle 3 which is closer to the action point 2 The needle tip 15 also contacts the semiconductor wafer 13 as shown in FIG. 4, but the needle tip 16 of the needle 4 closer to the fulcrum 1 is held down by the semiconductor wafer 13 during that time, and as shown in FIG. The needle L is bent in the vertical direction, and the gap L between the needles 4 and 3 is shifted by p.

[0006]

In such a state, applying overdrive from the outside in such a state results in applying uneven needle pressure to the entire electrode pad surface formed on the semiconductor wafer 13, The needles 3 and 4 may protrude from the electrode pads.

[0007] In recent years, with the rapid integration of semiconductor circuits built on the semiconductor wafer 13, the number of pins of the probe card 7 has been accelerated, and the stylus load of the entire probe card 7 has also rapidly increased. Due to the increase in the needle pressure load, the amount of deformation of the fixed portion of the probe card 7 and the like also increases, and it is becoming difficult to perform precise alignment and stable measurement.

[0008]

SUMMARY OF THE INVENTION An object of the invention of this application is to solve the problem of the contact between the probe tip of the probe card and the semiconductor wafer at the time of overdrive based on the prior art described above. It is necessary to provide an excellent wafer prober and a method for measuring semiconductor wafers that can provide a good and reliable electrical connection between the electrode pad and the probe tip of the probe card and that is beneficial to the application of measurement technology in the semiconductor manufacturing industry. Is what you do.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a configuration of the invention of the present application for solving the above-mentioned problems is provided by a pad for a semiconductor wafer provided on a mounting table. In a wafer prober that raises the mounting table and contacts a probe tip with a probe card provided above the mounting table that is fixed to the mounting table and measures the electrical characteristics of the semiconductor wafer, The mounting table is raised with respect to the probe card in a parallel posture by a screw mechanism via a switch, so that all of the probe tips of the probe card are brought into contact with the electrode pads of the semiconductor wafer in a parallel state. Is checked by a visual recognition means such as a microscope, an edge sensor, or a television camera, and the mounting table is further switched by the overdrive amount set by the computer. A wafer prober for automatically measuring the electrical characteristics by being raised by a screw mechanism is used as a backbone, and all of the electrode pads of the semiconductor wafer provided on the mounting table and the probe card fixed to a fixed table. In a wafer prober for measuring the electrical characteristics of the semiconductor wafer, the probe card is fixed, and the mounting table is raised by a screw mechanism via a switch in a parallel posture. hand,
A first step of bringing all the tips of the probe card into contact with the semiconductor wafer in a parallel state, and a second step of confirming the contact state of the parallel state with a visual recognition means such as a microscope, an edge sensor, or a television camera. And a third step of raising the mounting table by a screw mechanism via a switch while maintaining the needle point and the semiconductor wafer in a parallel state and applying an overdrive by an amount set by a computer. A technical measure was taken as a semiconductor wafer measurement method.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the invention of this application will be described below with reference to FIGS.

The same parts as those in FIGS. 3 to 5 are described using the same reference numerals.

In the illustrated embodiment, each of the needles 3 and 4 which are inclined to an intermediate portion which is juxtaposed on the lower surface of the probe card 7.
All of the needle tips 15 and 16 are previously attached to the lower side of the probe card 7 so as to be in a vertical shape parallel to the top surface 12 of the mounting table 5 of the semiconductor wafer 13.

The mounting table 5 on which the semiconductor wafer 13 is mounted is exclusively used until the semiconductor wafer 13 and the needle tips 15 and 16 of the respective needles 3 and 4 in parallel and vertical positions are brought into contact in a parallel state. Is raised in a parallel posture by a switch (not shown).

In this operation of raising the parallel state, the pad of the semiconductor wafer 13 and the tips 15, 16 of the needles 3, 4 in the vertical parallel state are connected to the pads of the semiconductor wafer 13 by visual recognition means such as a microscope, an edge sensor, or a television camera (not shown). Check the state of contact in the parallel posture.

Then, the mounting table 5 is further moved vertically by a dedicated switch (not shown) by the amount of overdrive previously input to the computer (not shown) from the outside in the vertical direction between the pad of the semiconductor wafer 13 and each of the tips 15 and 16. The posture, that is, the parallel state is maintained, and the body is raised in a substantially parallel posture to apply overdrive.

A screw mechanism (not shown) is used to raise the mounting table 5 in parallel movement with respect to the envelope formed by the collection of the needle tips 15 and 16 of the needles 3 and 4 during the overdrive. The mounting table 5 is moved up and down by rotating the screws.

The ascending movement of the mounting table 5 in the parallel posture and the overdrive operation control at that time are surely performed by a screw mechanism via a switch by appropriate control means using a microcomputer (not shown).

The invention of this application can be widely used for automatic measurement of various characteristics of the semiconductor wafer 13.

[0019]

According to the wafer prober of the first aspect of the present invention and the semiconductor wafer measuring method of the second aspect of the present invention, the probe tip of the probe card and the semiconductor wafer are placed in a parallel posture, that is, in a parallel state. After checking the contact with a visual recognition means such as a microscope, an edge sensor, or a television camera, the mounting table is overdriven in a parallel posture while maintaining the parallel state by an amount set by a computer. This brings about an effect that the state of the accurate vertical posture can be confirmed.

As a result, an excellent effect can be obtained in that the probe card or the semiconductor wafer can be prevented from malfunctioning without overdriving if the contact state or the position of the vertical posture is incorrect.

Further, by knowing the accurate vertical contact position / posture state, it is possible to set an appropriate overdrive amount set by the computer.

As a result, the electrical characteristics of the semiconductor wafer can be accurately measured, and an excellent effect of further improving the reliability of the product can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a mounting table according to an embodiment of the present invention before a parallel movement of a mounting table is overdriven.

FIG. 2 is a cross-sectional view after the mounting table is overdriven for parallel movement.

FIG. 3 is a cross-sectional view before overdrive is performed by a conventional overdrive mechanism.

FIG. 2 is a cross-sectional view after overdrive has been applied by a conventional overdrive mechanism.

FIG. 5 is a schematic diagram of a basic operation obtained by combining FIGS. 3 and 4;

[Explanation of symbols]

 1 fulcrum 2 action point 3, 4 needle 6 screw 5 mounting table 12 top surface 13 semiconductor wafer 7 probe card 15, 16 needle tip (invention of this application) 18, 19 head plate fixing base 21 head plate

Claims (2)

(57) [Claims] The mounting table is raised by raising the mounting table.
Semiconductor wafer pads provided on the table top
With the probe card needle fixed to the fixed table above the table
A wafer for measuring the semiconductor wafer by contacting
In the prober, the same as the above-mentioned fixed base without the vertical position adjustment mechanism
Without a vertical position adjustment mechanism.
Move the probe card and the mounting table
And a computer that controls the driving of the screw mechanism.
And only by moving the mounting table up and down
The wafer pad is separated from the probe card tip
Has a means for confirming the contact position from the position where
Pad up to the position where the specified overdrive is applied
And the needle of the probe card are almost parallel and automatically
A wafer prober characterized in that it can be controlled in position . 2. A semiconductor wafer measuring method for measuring the electrical characteristics of a semiconductor wafer by bringing a pad of a semiconductor wafer provided on a mounting table into contact with a probe tip of a probe card fixed to a fixing table. Fix the probe card and switch the mounting table
A first screw-in mechanism is used to raise all the needle tips of the probe card in parallel with each other, and to attach the needle tip formed vertically to the mounting table and the semiconductor wafer once vertically. And a second step of confirming the attachment in the vertical posture state by a visual recognition device such as a microscope, an edge sensor, or a television camera. The above-mentioned mounting table is connected to the probe card needle tip by a screw mechanism via a switch. A third step of ascending while maintaining the vertical posture and applying a set amount overdrive via microcomputer control.