JP2951971B2 - Semiconductor evaluation apparatus and method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor evaluation device and a method for evaluating the quality of a semiconductor element such as a memory.

FIG. 2 is a schematic configuration diagram of a conventional semiconductor evaluation device. This semiconductor evaluation device is for evaluating the quality of a memory. Reference numeral 1 denotes a memory tester. This tester 1 probes a pad of a memory under test (not shown), inputs a test signal in accordance with a test program, and adjusts the voltage level and timing of an output signal from the memory under test. It is determined whether the error occurs as desired, and the result is output to the defect position display device 2.

The defective position display device 2 displays all the bits of the memory under measurement in association with the display dots, and based on the output of the tester 1, increases the brightness of the display dots corresponding to the defective bits as compared with the other display dots. To display. Further, the display contents are printed out by the printer 8.

Next, the measured memory is set on the microscope 6o, and the inspector determines the position of the defective dot from the reference point of the measured memory in the X-axis direction based on the data printed by the printer 8.
The pattern is identified by counting the pattern in the Y-axis direction, and the position of the pattern is adjusted with the microscope 6o to observe the defective dot to analyze the cause of the defect.

[Problem to be Solved by the Invention] However, in such a conventional semiconductor evaluation device, when specifying the position of a defective dot in the memory to be measured and observing it with a microscope, the inspector sets the reference of the memory to be measured. It is necessary to count the patterns in the X-axis direction and the Y-axis direction from the point, and adjust the microscope. This requires time, and there is a problem that counting errors occur.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a semiconductor evaluation apparatus and a method for automatically adjusting a microscope to a defective position when observing the defective position of the semiconductor with a microscope.

Means for Solving the Problems According to the present invention, a test signal is input according to a test program by probing, and it is determined whether the voltage level and timing of an output signal from a semiconductor device to be measured are generated as desired. A tester that determines the pass / fail of the semiconductor to be measured, derives a faulty position by calculation and outputs a faulty signal, and, based on the output of the tester, checks each spot of the semiconductor to be tested for pass / fail according to display dots. A defective position display device for displaying in a pattern of the following, a microscope for observing a defective portion of the semiconductor to be measured, a display means for performing the same display as the defective position display device, and the measured Input means for designating and inputting a portion to be observed of a semiconductor by moving a cursor, and data corresponding to display contents of the defective position display device Is given, based on the designation input of the observation location by the input means, the distance from the predetermined reference point of the semiconductor to be measured to the observation location is calculated based on the failure signal of the tester, and the microscope is operated. A calculating means for outputting, and a test stage provided on the microscope and driving a test stage on which the semiconductor to be measured is mounted, based on an output of the calculating means, so that a specified defective position can be observed by the microscope. And a control unit.

Also, the present invention provides a tester which inputs a test signal in accordance with a test program and determines whether or not a voltage level and a timing of an output signal from the semiconductor to be measured are generated as desired by the test program. Determining the pass / fail of the semiconductor device, outputting a fault signal by calculating the fault position, and outputting a fault signal. Based on the output of the tester, displaying the fault position in a pass / fail pattern by associating each portion of the semiconductor under test with display dots. A defect position display step to be displayed on the device, an input step of specifying and inputting a portion to be observed of the semiconductor to be measured by moving a cursor while viewing the same display on another display device and viewing the defect position display device. , Data corresponding to the display content of the defective position display step is given, A microscope for observing a defective portion of the semiconductor to be measured by calculating a distance from a predetermined reference point of the semiconductor to be measured to the observation position based on a failure signal output from the tester based on the input. A step of driving the sample stage of the microscope, on which the semiconductor to be measured is mounted, based on the output of the operation step, and controlling the drive so that a designated defective position can be observed by the microscope. And a semiconductor evaluation method.

[Operation] According to the above configuration, by specifying and inputting the defective portion to be observed by the input unit,
The distance from a predetermined reference point of the semiconductor to be measured to a specified defective portion is calculated and output to the microscope. In the microscope, the sample stage is driven based on the data. In addition, it is not necessary for the inspector to count the pattern in the X-axis direction and the Y-axis direction from the reference point of the semiconductor to be measured and adjust the microscope to the defective portion, and the microscope can be automatically adjusted to the defective portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a semiconductor evaluation device according to one embodiment of the present invention, and portions corresponding to the conventional example in FIG. 2 are denoted by the same reference numerals.

This semiconductor evaluation device is for evaluating the quality of a memory. A memory tester 1 probes a pad of a memory to be measured (not shown), inputs a test signal in accordance with a test program, and It is determined whether or not the voltage level and timing of the output signal from the memory are generated as desired, and the result is output to the defective position display device 2 (defective signal).

The defective position display device 2 displays all the bits of the memory under measurement in association with the display dots, and based on the output of the tester 1, increases the brightness of the display dots corresponding to the defective bits as compared with the other display dots. To display. That is,
Each bit of the memory under test is displayed in a pass / fail pattern.

 The above configuration is the same as the configuration example in FIG.

In the semiconductor evaluation device of this embodiment, when identifying the position of the defective dot in the memory to be measured and observing it with a microscope, the inspector counts the patterns in the X-axis direction and the Y-axis direction from the reference point of the memory to be measured. In order to save time and effort, the following configuration is adopted.

That is, the semiconductor evaluation device of this embodiment includes a computer 3 to which data corresponding to the display content of the defective position display device 2 is provided, and a display similar to that of the defective position display device 2 based on the display data from the computer 3. And a keyboard 5 as input means for designating and inputting a defective dot to be observed in the memory to be measured while watching the display contents of the display device 4 by moving a cursor. The microscope 6 for observing a defective dot in the measurement memory is provided with a drive control unit 7 for driving a sample stage based on data described later output from the computer 3.

The computer 3 receives a designated input of a defective dot to be observed in the memory to be measured by the keyboard 5 based on the input.
A predetermined reference point of the memory under measurement, for example,
X from the corner of the rectangular memory to be measured to the defective dot
It has a function as a calculation unit that calculates each distance in the axial direction and the Y-axis direction and outputs the distance to the microscope 6. Data necessary for this calculation is stored in the memory of the computer 3 in advance.

The microscope 6 drives the sample stage on which the memory to be measured is mounted in the X-axis direction and the Y-axis direction based on the output corresponding to the distance from the computer 3, whereby the microscope 6 is designated by the microscope 6. Bad dots can be observed.

As described above, by moving the cursor with the keyboard 5 and specifying the defective dot to be observed while watching the display on the display device 4, the sample stage of the microscope 6 moves, and the microscope 6 automatically moves to the specified defective dot. Will fit together.

In the above embodiments, the semiconductor memory has been described. However, the present invention is not limited to the semiconductor memory.
Needless to say, the same can be applied to the evaluation of other semiconductor elements.

[Effects of the Invention] As described above, according to the present invention, by specifying and inputting a defective portion to be observed by the input means, the arithmetic means can specify the defective point from a predetermined reference point of the semiconductor to be measured. The distance to the defective part is calculated and output to the microscope, and the microscope drives the sample stage based on the data. Therefore, as in the conventional example, the inspector moves the X-axis from the reference point of the semiconductor to be measured. There is no need to count the pattern in the direction and the Y-axis direction to adjust the microscope to the defective portion, and the microscope can be automatically adjusted to the defective portion.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a semiconductor evaluation device according to one embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a conventional example. DESCRIPTION OF SYMBOLS 1 ... Tester, 2 ... Defective position display device, 3 ... Computer (arithmetic means), 6 ... Microscope.

Claims (2)

(57) [Claims] A test signal is input by probing according to a test program, and it is determined whether the voltage level and timing of an output signal from the semiconductor device under test are generated as desired, and the quality of the semiconductor device under test is determined. And a tester that derives a defect position by calculation and outputs a defect signal, and a defect position display that displays each part of the semiconductor under test in a pass / fail pattern corresponding to display dots based on the output of the tester. An apparatus, a microscope for observing a defective portion of the semiconductor to be measured, display means for performing the same display as the defective position display device, and a cursor for observing a part of the semiconductor to be measured while looking at the display means. Input means for specifying and inputting by movement; and data corresponding to display contents of the defective position display device are provided. Calculating means for calculating a distance from a predetermined reference point of the semiconductor to be measured to the observation point based on a failure signal of the tester and outputting the distance to the microscope, A drive control unit that is provided on the microscope and drives a sample stage on which the semiconductor to be measured is mounted based on the output of the arithmetic unit, so that a designated defective position can be observed by the microscope. A semiconductor evaluation device characterized by the above-mentioned. 2. A test signal is inputted according to a test program by probing of a tester, and it is determined whether a voltage level and a timing of an output signal from the semiconductor under test are generated as desired by the test program. Determining the pass / fail of the semiconductor device, calculating the fault position and outputting a fault signal, and, based on the output of the tester, displaying the fault position in a pass / fail pattern by associating each portion of the semiconductor under test with display dots. A defect position displaying step to be displayed on the device; an input step of performing the same display as the defect position display device on another display device and specifying and inputting a portion to be observed of the semiconductor to be measured by moving a cursor while looking at the same. The data corresponding to the display content of the defective position display step is provided, and the finger of the observation point in the input step is provided. A microscope for observing a defective portion of the semiconductor to be measured by calculating a distance from a predetermined reference point of the semiconductor to be measured to the observation position based on a failure signal output from the tester based on the input. A step of driving the sample stage of the microscope, on which the semiconductor to be measured is mounted, based on the output of the calculation step, and controlling the drive so that a designated defective position can be observed by the microscope. A semiconductor evaluation method, comprising: