Method for verifying semiconductor device tester
First Claim
1. A method for analyzing the functional stability of a semiconductor device tester of the type that has:
- 1) A tester-check mode for analyzing correct operation and functional stability of the tester by reference to characteristic data of a pre-tested standard semiconductor device; and
,
2) a standard-device-creation mode for creating a new standard device for use with the tester, the method comprising;
reading a mode of operation selected by a test engineer; and
,if in the standard-device-creation mode, then;
reading the type number and serial number of a candidate standard device loaded in the tester;
determining whether a standard device having identical type and serial numbers is available, and if such standard device is available, determining whether to replace such standard device; and
,if such standard device is not available, or if it is determined to replace such standard device, then;
repeatedly testing the candidate device a predefined number of times to measure during each test a predefined set of test items comprising electrical characteristics of the candidate device;
calculating the mean values and standard deviations of every test item in the sets; and
,determining whether the candidate device is suitable for use as a standard device, based on whether the calculated values and standard deviations are within predetermined distribution ranges; and
,if in the tester-check mode, then;
reading the type number and serial number of a standard device loaded in the tester;
fetching reference data comprising a set of previously measured electrical characteristics of the standard device;
repeatedly testing the standard device with the tester a predefined number of times to measure during each test a set of electrical characteristics of the standard device corresponding to the previously measured electrical characteristics of the standard device fetched;
calculating a mean value X of every electrical characteristic measured in the sets;
comparing the test data with the reference data to determine whether the tester is functionally stable; and
,if the calculated data is outside of a predetermined range;
checking the tester.
1 Assignment
0 Petitions
Accused Products
Abstract
A method for verifying correct operation and functional stability of a tester for semiconductor devices is disclosed. In addition, a method for creating a standard device for use with the tester is also disclosed. In creating a standard device according to the present invention, the tester repeatedly tests a candidate device a predefined number of times and evaluates the test results to determine whether the candidate device is suitable for use as a standard device. In verifying the operation and functional stability of a semiconductor device tester, data generated by repeatedly testing a standard device a predefined number of times are compared to recorded reference data of previous tests of the standard device.
-
Citations
16 Claims
-
1. A method for analyzing the functional stability of a semiconductor device tester of the type that has:
- 1) A tester-check mode for analyzing correct operation and functional stability of the tester by reference to characteristic data of a pre-tested standard semiconductor device; and
,
2) a standard-device-creation mode for creating a new standard device for use with the tester, the method comprising;reading a mode of operation selected by a test engineer; and
,if in the standard-device-creation mode, then; reading the type number and serial number of a candidate standard device loaded in the tester; determining whether a standard device having identical type and serial numbers is available, and if such standard device is available, determining whether to replace such standard device; and
,if such standard device is not available, or if it is determined to replace such standard device, then; repeatedly testing the candidate device a predefined number of times to measure during each test a predefined set of test items comprising electrical characteristics of the candidate device; calculating the mean values and standard deviations of every test item in the sets; and
,determining whether the candidate device is suitable for use as a standard device, based on whether the calculated values and standard deviations are within predetermined distribution ranges; and
,if in the tester-check mode, then; reading the type number and serial number of a standard device loaded in the tester; fetching reference data comprising a set of previously measured electrical characteristics of the standard device; repeatedly testing the standard device with the tester a predefined number of times to measure during each test a set of electrical characteristics of the standard device corresponding to the previously measured electrical characteristics of the standard device fetched; calculating a mean value X of every electrical characteristic measured in the sets; comparing the test data with the reference data to determine whether the tester is functionally stable; and
,if the calculated data is outside of a predetermined range; checking the tester. - View Dependent Claims (2, 3, 4, 5, 6)
- 1) A tester-check mode for analyzing correct operation and functional stability of the tester by reference to characteristic data of a pre-tested standard semiconductor device; and
-
7. A method for verifying the correct operation of a tester for semiconductor devices, comprising:
-
loading a standard device into the tester; identifying the standard device to the tester by entering the type number and serial number of the standard device; fetching reference data comprising a set of previously measured electrical characteristics of the standard device, the reference data including a mean value m and a standard deviation value σ
'"'"' of each measured characteristic of the standard device;repeatedly testing the standard device with the tester a predefined number of times to measure during each test a set of electrical characteristics of the standard device corresponding to the previously measured electrical characteristics of the standard device; generating test data from the measured electrical characteristics of the standard device resulting from the repeated testing of the standard device, including calculating a mean value X of each measured electrical characteristic; comparing the test data to the reference data; and
,determining whether the tester is functioning correctly, based on the comparing of the test data and the reference data. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. A method for creating a standard device for use by a tester for semiconductor devices comprising:
-
loading a candidate standard device into the tester; identifying the candidate device to the tester by entering a type number and a serial number of the candidate device; repeatedly testing the candidate device with the tester a predefined number of times to measure during each test a predefined set of electrical characteristics of the standard device; calculating from the repeated tests of the candidate device a mean value, a standard deviation and a distribution index of each of the electrical characteristics of the candidate device in the set, wherein the distribution index is defined as (mean value-lower limit)/(upper limit-lower limit)/2, wherein the upper limit and the lower limit are respectively the highest and lowest allowable values within a predefined specification for each of the electrical characteristics of the device; and
,determining whether the distribution index calculated for the candidate device is within the allowable range. - View Dependent Claims (14, 15, 16)
-
Specification