JPS6321344B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor measuring device for measuring electrical characteristics of a plurality of semiconductor devices (chip and package products) with respect to a plurality of items.

[Technical background of the invention]

Conventionally, this type of electrical characteristic measurement has generally been carried out as shown in FIG. That is, the electrical characteristics of the IC 1 to be measured are automatically measured by the tester 2 in the program order of the test program 3. Here, the test program 3 includes the conditions necessary to measure the electrical characteristics of the IC under test 1, such as the voltage and current applied to the input terminal and output terminal of the IC under test, the bias measurement time, and the time for judgment. The conditions for measuring the so-called characteristics, such as standard values, and determining pass/fail are created in code that matches the functional (software) specifications of the tester 2 for each measurement item.
Each measurement item is automatically measured sequentially by the tester 2.

In addition, various devices such as a prober in the case of a chip and a handler in the case of a package are used to transport the IC 1 to be measured and to connect it to the measurement section of the tester 2.

[Problems with background technology]

In such a measurement system, when measuring products on a mass-produced basis, the measurement ability is determined by the test program for each product.

By the way, as shown in FIG. 2, the conventional measuring system measures all lots 4 of the measured products (generally treated as a manufacturing unit, each lot) using a test program determined for each product.

However, among the electrical property items, as a result of measurement, there are items in which no defects occur at all, and items with defective rates that pose no problem in terms of quality assurance.
To improve processing performance, it is desirable to exclude these items from the test program. However, measurement items with a low or no defect rate vary depending on the product lot, and it is impossible to create multiple test programs for the same product and use the test programs according to the level of the product lot. Ta.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to reduce measurement time by automatically selecting the minimum necessary measurement items for the product lot being measured and reducing the number of measurement items. An object of the present invention is to provide a semiconductor measuring device that can improve processing capacity and reduce the price of the product.

[Summary of the invention]

When measuring the electrical characteristics of semiconductor products, the present invention measures all predetermined measurement items for the number of samples necessary to determine the quality control of the product lot in advance, and as a result, it is possible to detect problems in the product lot. For items without , those items are deleted and the minimum necessary measurement items are re-edited, and then the remaining samples are measured using the re-edited measurement items.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 3, the tester 11 measures the electrical characteristics of the IC under test 13 in the order of the test program 12.

FIG. 4 shows a specific configuration of the tester 11. This tester 11 includes a control section (CPU) 21, a measurement section 22, a measurement power supply section 23, a test head matrix section 24, a test program memory section 25, a system memory section 26, a tester main panel section 27, a prober (handler) I/O
28 and an input/output device I/O section 29. The test head matrix unit 24 connects the IC to be measured 13 and various measurement conditions set by the test program 12. The program input of the test program 12 is stored in the test program memory section 25 by the input/output device 30 via the input/output device I/O section 29 . The measurement start signal is sent from the start switch on the tester main panel section 27 or the prober (or handler).
The data is input via the prober (or handler) I/O section 28. As a result, the control unit (CPU) 21 controls the measurement unit 22, measurement power supply unit 23, test head matrix unit 24, etc. according to the contents stored in the test program memory unit 25, and controls the IC under test 13 for measurement. The input (supply) conditions are set. IC13 to be measured
The output data is measured by the measurement unit 22 and compared with standard values for quality determination for each measurement item set in the test program 12. The quality determination results and measurement data are displayed on a display section (not shown).

IC to be measured obtained with this tester 11
The measurement data and pass/fail judgment results for each of the 13 items are sent to the data analyzer 14. As shown in FIG. 5, this data analyzer 14 includes a control unit (CPU) 31, a system memory unit 32,
It is composed of a test data memory section 33 and a data analysis/data I/O section 34.
The system memory section 32 stores data for operating the data analyzer 14, and the test data memory section 33 stores measurement data and pass/fail determination results for each item output from the tester 11. The data analyzer 14 is provided with a sample number setting section on the front panel (not shown) for setting the number of samples necessary for measuring in the tester 11 to determine the quality assurance level of the product lot. The data analysis/data I/O unit 34 analyzes the tester 1 with respect to the samples set in the sample number setting unit.
1, analyze the measurement data and pass/fail judgment results obtained by measuring all the measurement items set in the test program 12, and select electrical measurement items that are unnecessary for the product lot (the criteria for determining whether they are unnecessary or not is , set on the system hardware or externally). The analysis results of this data analysis data I/O section 34 are as follows:
It is displayed on a display section of the front panel (not shown). The tester 11 is connected to the control unit 31 via the data analyzer I/O unit 35.
In response, a test skip command is sent to control the unnecessary measurement items to be removed from the measurement items set in the test program 12.

That is, in the semiconductor measuring device of the present invention, first, as shown in FIG. Set the measurement IC) 41a. Thereby, the tester 11 measures the sample 41a for all the measurement items (1 to 30) defined in the test program 12, and determines whether each measurement item is good or bad. The data analyzer 14 receives the measurement data and the quality determination results for the sample 41a output from the tester 11, and calculates the quality distribution for each measurement item. As a result, as shown in FIG. 6b, the items for which there are no problems in quality control of the product lot 41 are deleted and the measurement items are re-edited. In other words, for minor defective items such as those with a small amount of leakage current, items with no defective items in sample 41a (11 to 13, 15, 16, 18,
19, 21, 22, 24-29) will be deleted. In addition, critical items (1 to 10) such as circuits not working are excluded from deletion targets. Thereafter, the data analyzer 14 sends a test skip command for controlling the deletion items to be removed from the measurement items (1 to 30) set in the test program 12. As a result, the tester 11 uses the program of the re-edited measurement items (1 to 10, 14, 17, 20, 23) to perform
is measured.

Therefore, this device significantly improves processing capacity. For example, at the general-purpose C ² MOSIC level, the product lot unit is approximately 5000 pieces, and the number of samples required to determine the quality control of that lot is sufficient to be approximately 300 to 500 pieces. As a result, the number of measurement items for the remaining 4,500 to 4,700 products can be reduced, and therefore the measurement time for the entire product lot can be shortened.

Furthermore, since the quality level difference between product lots can be automatically grasped on a normal measurement line and the number of measurement items can be automatically reduced, there is no need to create and replace the test program 12 of the tester 11 for each product lot.

After the measurement of the product lot is completed, simply pressing the memory clear switch on the front panel of the data analyzer 14 clears the analysis results of the product lot and the test skip command to the tester 11, and sets them to the initial state.

〔Effect of the invention〕

As described above, according to the present invention, when measuring the electrical characteristics of a plurality of semiconductor products, it is possible to reduce the number of measurement items by automatically measuring the minimum required measurement items for the product lot being measured. Therefore, the measurement time can be significantly shortened and the processing capacity can be improved, thereby making it possible to reduce the price of the product.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional semiconductor measurement system, FIG. 2 is a diagram showing measurement results by the above system, FIG. 3 is a block diagram showing a semiconductor measurement system according to an embodiment of the present invention, and FIG. 4 3 is a block diagram showing the configuration of a tester used in the system of FIG. 3, FIG. 5 is a block diagram showing the configuration of a data analyzer, and FIG. 6 is a diagram showing the distribution of defective products by lot sampling. 11...Tester, 12...Test program, 13
...IC under test, 14...Data analyzer, 41
...Product lot, 41a...Sample.

Claims (1)

[Claims] 1. A tester for measuring the electrical characteristics of a plurality of semiconductor devices, a sample number setting means for setting the number of samples necessary to ascertain the quality assurance level of a product lot of the semiconductor devices, and a sample number setting means for setting the number of samples necessary to ascertain the quality assurance level of a product lot of the semiconductor devices; Analyzing the data obtained by measuring predetermined measurement items on the sample, detecting measurement items unnecessary for quality control of the product lot, and detecting the unnecessary items from among the measurement items measured by the tester. A semiconductor measuring device characterized by comprising a data analyzer that controls the data to be removed.