JPH08138608A - Pattern shape measurement device - Google Patents

Abstract

PURPOSE: To easily recognize causes of measurement fault and abnormality during automatic measurement even after completing the measurement processing by recording information concerning to an image in the case of measuring a pattern shape, in a shape measurement result. CONSTITUTION: A scanning electron microscope 1 measures a chip prescribed beforehand according to a prescribed order. The measurement results are transmitted to a computer 5 one by one so as to be stored in an outer memory 6 and displayed on a display 7. The computer 5 reads out the data of the image memory 9 so as to store it in the outer memory 6. A measurement abnormality detector 12 detects normality/abnormality of a pattern under measurement and reports its result to the computer 5. If measurement abnormality occurs, the computer 5 records the number of wafers and a position of a chip, the present state of the microscope 1 and the data of the memory are read out and stored in the outer storage device along with the measurement results.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an automatic measuring device, and more particularly to
The present invention relates to an automatic measuring device suitable for use in an electron microscope for inspecting semiconductor wafers.

[0002]

2. Description of the Related Art In the prior art, a pattern with an abnormal shape is detected during automatic measurement or semi-automatic measurement, an observation image at that time is stored, and after a series of measurement operations, the image at abnormal time is newly observed The shape of the wafer is judged to be good or bad, and it is an object of the invention to save labor in the operation of a wafer pattern shape measuring device used in an automated semiconductor manufacturing line and to secure reliability of measurement results.

[0003]

The above-mentioned prior art focuses on image storage when a shape abnormality occurs, and does not consider a method of referring to the stored image. Manufacturing of a semiconductor wafer is completed through many steps, but the results measured by the shape measuring device during that time are enormous. Even if the image at the time of abnormality is saved to prevent the returning work, the result cannot be processed. In order to prevent such a decrease in workability, a mechanism that can easily refer to an image at the time of abnormality is required.

[0004]

Means for Solving the Problems The measurement result is stored in association with the lot number, wafer number, etc. of the measurement target. The manager of the semiconductor manufacturing line refers to the measurement result in accordance with the above-mentioned association to judge pass / fail. That is, if the image at the time of abnormality can be directly extracted from the measurement result, it is possible to prevent the processing efficiency from decreasing even if the image data increases. In the present invention, the information of the stored image is directly or indirectly stored in the measurement result so that only the image data does not exist alone. Further, when referring to the measurement result, a mark indicating that the abnormal image is stored is displayed to call attention to the administrator.

[0005]

[Operation] Since the image data is always linked to the measurement result, the administrator is not aware of the existence of the image data. Therefore, it is possible to concentrate on the management of the measurement result. Moreover, the administrator does not pull out wrong image data. These effects are
This will improve the efficiency of process management.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The scanning electron microscope 1 is used to measure the pattern line width of a semiconductor wafer. The operator 2 sets the wafer cassette 3 in the sample introduction port of the scanning electron microscope 1 and presses the execution start button 4. The scanning electron microscope 1 first loads the first wafer into the measurement sample chamber. Semiconductor wafer
A regular chip arrangement is formed as shown in FIG. The scanning electron microscope 1 measures a tip designated in advance according to a predetermined order. The measurement result is sequentially transferred to the computer 5, stored in the external memory 6, and displayed on the display 7. An image signal is output from the scanning electron microscope 1, discretized by the A / D converter 8, accumulated in the image memory 9, and then displayed on the image display monitor 10. The computer 5 can read the data in the image memory 9 and store it in the external memory 6. Further, the current state of the scanning electron microscope 1 (acceleration voltage, probe current, etc.) can be read out and stored at any time.

The measurement abnormality judging device 12 judges whether the pattern being measured is normal or abnormal, and reports the result to the computer 5. If a measurement abnormality occurs, the computer 5 records the wafer number and the chip position where the abnormality has occurred, reads the current state of the scanning electron microscope 1 and the data in the image memory 9, and outputs the measurement result to the outside. Save to storage. Since the image at the time of abnormality is not used for the measurement, it is not necessary to store the details accurately. Therefore, the image compressed by the image compressor 13 may be stored. The degree of compression is set by the computer 5.

Up to 25 wafers are set in the wafer cassette 3, and the scanning electron microscope 1 reports the completion of measurement to the computer 5 when the measurement of all wafers is completed. The computer 5 reports the measurement completion to the operator 2 and displays the measurement result on the display 7. The operator 2 confirms the measurement result by reporting the end of measurement,
The wafer cassette 3 for which the measurement has been completed is removed from the sample introduction port of the scanning electron microscope 1, and the measurement is completed. The scanner does not have to be by the measuring device during the measurement.

When an abnormality occurs, a mark is displayed at the corresponding position of the measurement result displayed on the display 7.
The operator inputs a reading instruction from the measurement abnormality determiner 12. In response to this instruction, the computer 5 displays the state of the scanning electron microscope 1 and the image data stored in the external memory 6. Of course, the image may be displayed at the same time when the measurement result is displayed.

FIG. 3 shows an example of a storage form of measurement results. FIG. 7A shows a case where image data is recorded in the same file together with normal measurement results. FIG. 6B shows a case where the image file is a separate file and the file name is stored in the measurement result file (index method).

FIG. 4 shows a mark display example when an abnormal image occurs. The measurement results are usually displayed in tabular form. The mark of abnormal image generation is displayed in a superimposed manner on the measurement result display field. Characters used as marks may be arbitrary. Further, it does not necessarily have to be a mark, and for example, it can be substituted or used together by changing the color of the character or background for displaying the measurement result, or changing the size or shape of the character.

[0012]

According to the present invention, the cause of the measurement failure or the measurement abnormality during the automatic measurement can be easily confirmed even after the measurement process is completed, so that the operator does not need to be attached to the measuring device.
The labor can be reduced. Further, since the measurement result and the image data are linked, the operator does not refer to the wrong image data, and human error can be prevented. Furthermore, no special attention is required because the abnormal shape can be confirmed during the normal confirmation work of the measurement results. Further, if the display color is a warning color (for example, red), warning transmission more effective than simple numerical expression can be performed.

[Brief description of drawings]

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

FIG. 2 is an explanatory view of a chip arrangement of a typical semiconductor wafer.

FIG. 3 is an explanatory diagram of a data structure for storing an abnormal image.

FIG. 4 is an explanatory diagram of a mark display example of abnormal image generation.

[Explanation of symbols]

1 ... Scanning electron microscope, 2 ... Operator, 3 ... Wafer cassette, 4 ... Execution start button, 5 ... Computer, 6 ... External memory, 7 ... Display, 8 ... A / D converter, 9 ... Image memory, 10 ... Image display monitor, 11 ... Pattern abnormality detector, 12 ... Measurement abnormality determiner, 13 ... Image compressor.

Claims (4)

[Claims] 1. A means for scanning the sample with an electron beam to image the information obtained from the sample, a means for automatically or manually executing a specific pattern shape measurement on the obtained image, Means for saving the results of pattern shape measurement,
A pattern shape measuring apparatus having means for storing the image at the time of measuring the pattern shape, wherein the pattern shape measuring apparatus also records information about the image at the time of measuring the pattern shape in the shape measurement result. 2. The pattern shape measuring apparatus according to claim 1, wherein the pattern shape measurement result records the image itself at the time of pattern shape measurement. 3. The pattern shape measuring device according to claim 1, wherein an index of an image at the time of pattern shape measurement is recorded in the pattern shape measurement result. 4. The pattern shape measuring device according to claim 1, wherein when the pattern shape measurement result is displayed, an image saved mark is also displayed.