JPS6369245A - Prober device - Google Patents

Abstract

PURPOSE:To secure the contact between a probe and a wafer to be tested, by mounting a supersonic pickup on a probe in contact with a semiconductor wafer to be tested and detecting a supersonic signal. CONSTITUTION:while a stage 2 is lowered, a wafer to be tested 1 is fixed on the stage 2. A supersonic oscillator 4 is operated in this state and a supersonic vibrator 3 is operated to provide minute supersonic vibration for the wafer to be tested 1. Thereafter, the stage 2 is moved upward so that a probe 5 approaches a pad of the wafer to be tested 1 which is positioned in advance. When the wafer to be tested 1 comes in contact with the probe 5, the supersonic vibration of the wafer to be tested 1 is conveyed to the probe 5. This supersonic vibration is converted into an electrical signal by the use of a supersonic pickup 6 mounted on the probe 5 and so the existence of the supersonic vibration of the probe is determined by a detection circuit 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an LSI testing machine, and particularly to a prober device used for P/W testing (testing on wafers).

[Prior Art] In an LSI manufacturing process, a large number of LSI chips fabricated on a semiconductor wafer-L are first sorted for non-defective products in the wafer state.

This P/W (Pro Rubbing by Wafer [Pro
In the test, a prober is used to connect the chip under test to an LSI tester.

That is, the LSI tester and the chip under test are electrically connected by placing the probe of the prober on the input/output pad of the LSI chip.

Now, in a P/W test using a conventional prober device, the stage on which the wafer under test is placed is positioned before the test. Using the same dummy wafer, determine the vertical position at which the probe reliably contacts the wafer under test. In this case, contact between the dummy wafer and the probe is confirmed by the presence or absence of conduction between the probe and the dummy φ wafer.

[Problems to be solved] However, positioning using a dummy wafer is rarely carried out because the procedure is complicated.In actual P/W, the wafer under test is placed on the stage and the procedure described above is performed. Move the stage to a predetermined position and set up the probe.

At this time, contact between the wafer and the probe is not directly confirmed. Therefore, when performing a P/W test, there is a risk that the test will fail due to poor contact of the probe, and this risk increases as the number of bins increases.

Furthermore, it is not easy to find out the cause of a test failure due to poor contact, and it takes a lot of time for p7w.

[Means for solving problems] This invention was made in view of the above circumstances, and includes a stage on which a semiconductor wafer to be tested is fixed and can be slightly moved in horizontal and vertical directions, and an ultrasonic transducer attached to this stage. , an ultrasonic oscillator that excites this ultrasonic transducer, a probe that contacts the semiconductor wafer under test, an ultrasonic big-up attached to this probe, and a device that increases the output signal of this big-up. It is characterized by comprising a detection circuit that detects a width-wide ultrasonic signal.

[Example code] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. A wafer under test 1 is fixed to a stage 2 that can be moved slightly in the horizontal and vertical directions. An ultrasonic vibrator 3 is mounted on this stage 2, and this is connected to an ultrasonic oscillator 4.

As a result, when the ultrasonic vibrator 3 is excited by the ultrasonic oscillator 4, the stage 2 vibrates, and the wafer under test 1 vibrates. An ultrasonic pickup 6 is attached to the probe 5, and its output is connected to a detection circuit 7. Vibration of the probe 5 is detected by this detection circuit 7.

The prober device of the present invention sets a probe on a wafer using the following procedure. The wafer 1 to be tested is fixed to the stage 2 while the stage 2 is lowered. In this state, the ultrasonic oscillator 4 is operated to excite the ultrasonic vibrator 3 to apply minute ultrasonic vibrations to the wafer 1 under test. Thereafter, the stage 2 is moved upward, and the probe 5 is brought closer to the pad of the wafer 1 to be tested that has been positioned in advance.

When the wafer under test 1 and the probe 5 come into contact, ultrasonic vibrations of the wafer under test 1 are transmitted to the probe 5. This ultrasonic vibration is converted into an electrical signal by an ultrasonic kick-up 6 attached to the probe 5, and a detection circuit 7 determines whether or not there is ultrasonic vibration of the probe. In this way, contact between the wafer under test 1 and the probe 5 is confirmed.

[Effects of the Invention] As explained above, according to the present invention, a semiconductor wafer to be tested is fixed, a stage that can be slightly moved in the horizontal and vertical directions, an M-sonic transducer attached to this stage, and An ultrasonic oscillator that excites a sonic transducer, a probe that comes into contact with the semiconductor wafer under test, an ultrasonic big-up attached to this probe, and amplified output signal of this big-up to generate ultrasonic waves. Since it is comprised of a detection circuit that detects signals, it is possible to ensure contact between the probe and the wafer under test without performing positioning work in advance using a dummy wafer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a prober device of the present invention. 1: Wafer under test 2 = Stage 3: ML sound wave transducer 4: Ultrasonic oscillator 5: Probe 6ft sonic pickup up 7: Detection circuit

Claims (1)

[Claims] A stage on which a semiconductor wafer under test is fixed and can be slightly moved in the horizontal and vertical directions, an ultrasonic transducer attached to this stage, an ultrasonic oscillator that excites this ultrasonic transducer, The contacting probe, the ultrasonic pickup attached to this probe, and this pick
1. A prober device comprising a detection circuit that amplifies an output signal of an ultrasonic wave and detects an ultrasonic signal.