JP2903356B2 - LSI chip coordinate deviation correction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting a coordinate shift of each LSI chip in an LSI inspection apparatus.

[0002]

2. Description of the Related Art Each LSI chip formed on a wafer is
At the stage of formation, the performance is inspected by the inspection device. In FIG. 2, XY coordinates with the orientation flat (OF) as the Y axis are set on the wafer 1, and a number of L coordinates are set.
SI chips are formed in a matrix in the XY directions. XY coordinate values are given to each LSI chip for inspection, and two LSI chips are used as a reference chip T for positioning and a start chip R for an inspection start point.
Is specified. In the case of the figure, the X coordinate of each LSI chip is
(1) to (9), the Y coordinate is in the range of (1) to (10), the reference chip T is specified at a position close to the lower end of the OF, and the start chip R is specified at a substantially symmetrical position. And
The reference coordinate value is (9,3), and the start point coordinate value is (4,10). There are various sizes of the wafer 1 and dimensions of the LSI chip.
If the size of the chip is 3 mm square, the total number is 1000
More than one. Also, there are quite a number of combinations of sizes and dimensions.

FIG. 3 shows a schematic configuration of an LSI inspection apparatus 10. The inspection apparatus 10 includes a wafer moving unit 2, a movement control unit 3, and a measuring unit 4. The wafer moving unit 2 has a mounting table 21 for mounting the wafer 1 to be inspected, and an XY moving mechanism 22 for moving the wafer 1 in the X or Y direction. The movement control unit 3 includes a microprocessor (MPU) 31. And memory 32,
It comprises an operation panel 33 and a control circuit 34, which are connected as shown. The memory 32 stores a movement control program for the XY movement mechanism 22, and XY coordinate values of each LSI chip. The measuring part 4 is a probe pin
411, a test probe 41 having a data processing section 42, and an output section 43.

[0004] Referring to FIG. 2 and FIG. 3, an inspection procedure of each LSI chip will be described. First, while visually checking the reference chip T, the user operates the movement button of the operation panel 33 to input a step movement signal to the MPU 31, and the XY movement mechanism 22 is operated by the control circuit 34 to move the wafer 1 so that the reference chip T is moved. T is positioned at a position corresponding to the inspection probe 41 and stopped. When the setting button is operated, the reference coordinate value is set in the MPU 31. Then, when the inspection start button is operated, an inspection start signal is input to the MPU 31, the movement program is read from the memory 32, the XY movement mechanism 22 is operated, and the wafer 1 is moved from the reference chip T in the X or Y direction in a predetermined coordinate order. The step moves and stops when the inspection start point reaches a position corresponding to the inspection probe 41. Here, the probe pin 41 is attached to the start tip R.
The circuit is measured by touching 1, the measurement signal is input to the data processing unit 42 and processed, the coordinate value (4,10) of the start chip R is added to the measurement data, and the measurement signal is output to the output unit 43. Then, the wafer 1 is step-moved in a predetermined order to
The measurement of the I chip is sequentially performed, and the coordinate value is added to each measurement data and output. Inspected LS
With respect to the I chip, a non-defective product and a defective product are distinguished based on the measurement data and the added coordinate values, and the defective product is reworked by the rescue device to be a non-defective product.

[0005]

In the above, in the first visual check, an adjacent or nearby chip may be erroneously recognized as the reference chip T. This erroneous recognition occurs particularly when the LSI chip is minute. Easy to do. For example, if the chip indicated by S in FIG. 2 is mistaken as the reference chip T, the coordinate difference (1,1) between the chips T and S is added to the coordinate values of the processing data of all the LSI chips. More specifically, it is assumed that the operation of the setting button correctly positions the inspection probe 41 with respect to the reference chip T irrespective of the presence or absence of misidentification, and based on this, the moving program steps the wafer 1 in a predetermined order. Moving. However, since the inspection probe 41 has no ability to detect coordinate values, each chip is measured with unknown coordinate values. Coordinate values shifted by misidentification are added to the measurement data of each chip measured in this way, so that data misinterpretation occurs, non-defective products are regarded as defective products, and unnecessary remedy processing is performed. Confusion, such as a defective product being overlooked, lowers the reliability of the inspection. The present invention has been made in view of the above, and an object of the present invention is to provide a method of correcting a coordinate thread of each LSI chip, which is caused by misidentification of a reference chip T, to a correct coordinate value.

[0006]

According to the present invention, there is provided a method of correcting a coordinate deviation of an LSI chip, wherein the LSI inspection apparatus is provided with a moving program at a time when an inspection probe is stopped at a position corresponding to an inspection start point by a moving program. Then, the correct coordinate value indicated by the moving program is compared with the coordinate value corresponding to the moving distance of the wafer indicated by the moving mechanism. When the two coordinate values are different and there is a coordinate deviation, a microprocessor is provided with a confirmation program for displaying a positioning error on an output unit, the reference chip is reconfirmed based on the displayed positioning error, and the position of the reconfirmed reference chip is determined. Inspection probe is changed to each LSI, and each LSI
This is to correct the coordinate deviation of the chip.

[0007]

In the above coordinate deviation correcting method, the correct coordinate value indicated by the moving program and the coordinate value corresponding to the moving distance of the wafer indicated by the moving muzzle at the time when the inspection probe stops at the inspection start point are determined by the checking program. Are compared, and when the two coordinate values are different, a positioning error is displayed on the output unit, so look at it, reconfirm the reference chip, and change the inspection probe to this position,
The coordinate deviation of each LSI chip is corrected, and the correct coordinate value is added to the measurement data.

[0008]

FIG. 1 is a flow chart for explaining a procedure for correcting a coordinate shift according to an embodiment of the present invention. Steps 1 to 5 are the same as those in the prior art. This is a step for manual work. Note that the LSI inspection apparatus in this case has substantially the same configuration as that of FIG. 3, except that the MPU 31 is provided with the above-described confirmation program K, and further, the moving distance of the moving mechanism for sequentially moving the wafer stepwise is counted. It has a function of calculating an actual coordinate value.

Hereinafter, a method of correcting a coordinate shift will be described with reference to FIGS. As in the conventional case, the reference chip T is visually confirmed, and the wafer 1 is moved to position and set the reference chip T at a position corresponding to the inspection probe 41. Next, when the inspection start button is operated to start the movement program, the wafer 1 moves and the inspection start point stops at the position corresponding to the inspection probe 41. Here, the confirmation program K is started, and the correct coordinate value indicated by the moving program with respect to the inspection start point is compared with the actual coordinate value by the moving mechanism. If the two do not match (NO), the output unit
A positioning error is displayed at 43. The measurer sees this display and knows that there is a coordinate deviation, and reconfirms the reference chip T. Returning to the step, similarly to the above, the positioning setting (resetting) of the inspection probe 41 with respect to the reference chip T is performed, and the coincidence determination is performed through the following.
If the two coordinate values match (YES), the coordinate deviation must have been corrected.
The measurements on the chips are made in order. By correcting the above coordinate deviation, the measurement data of each LSI chip
Correct coordinate values are added to each other, eliminating confusion in quality control.

[0010]

As described above, in the coordinate deviation correcting method according to the present invention, the correct coordinate value of the inspection start point is obtained by the confirmation program provided in the microprocessor.
The actual coordinate values indicated by the moving mechanism are compared with each other. When the two coordinate values are different, a positioning error displayed on the output unit is detected, the reference chip is reconfirmed, and the inspection probe is set to this, and each LSI is changed. It corrects the coordinate deviation of the chip and adds the correct coordinates to the measured data.
This eliminates confusion in quality control such as mixing up a good chip with a defective chip, and contributes to the improvement of the reliability of LSI inspection.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a procedure for correcting a coordinate shift according to an embodiment of the present invention.

FIG. 2 shows an LSI chip formed on a wafer and its X
It is explanatory drawing of a Y coordinate.

FIG. 3 is a schematic configuration diagram of an LSI inspection apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Wafer moving part, 21 ... Mounting table, 22
... XY moving mechanism, 3 ... movement control unit, 31 ... MPU, 32 ... memory, 33 ... operation panel, 34 ... control circuit, 4 ... measuring unit, 41 ... inspection probe, 411 ... probe pin, 42 ... data processing unit,
43: output unit, 10: LSI inspection apparatus, ... step numbers in flowchart.

Claims (1)

(57) [Claims] An LSI chip at two suitable locations on a wafer is designated as a reference chip and a start chip, respectively.
The reference chip is visually confirmed, an inspection probe is positioned and set at the position of the reference chip, and a moving mechanism is operated by a moving program of a microprocessor to move the wafer in a predetermined coordinate order. In the LSI inspection apparatus which sequentially inspects each LSI chip by the inspection probe using the inspection probe as the inspection start point, the movement program indicates that the inspection program stops at the position corresponding to the inspection start point, The coordinate value is compared with a coordinate value corresponding to the moving distance of the wafer indicated by the moving mechanism, and when the two coordinate values are different from each other and there is a coordinate deviation, a confirmation program for displaying a positioning error on an output unit is provided. Provided in the microprocessor, re-confirming the reference chip by the displayed positioning error, And instead set the test probe at the position of the reference chips reconfirmed, the reference chip, characterized in that to correct the coordinate shift of each LSI chip caused by misidentification of the coordinate shift correction method of the LSI chip.