Semiconductor device including test element group and method for testing therefor
View Patent ↗A semiconductor device, in which a test element group (TEG) including check patterns is formed together with a chip on a wafer so as to measure electric characteristics thereof, includes an interface circuit for selecting the check pattern from the test element group, a protection resistor connected in series with the test element group so as to protect the test element group, and a dummy element connected in series with the test element group. It allows the TEG test, which can be performed after packaging, to be easily performed at a high precision irrespective of dispersions of parasitic resistances and protection resistors. The test result is corrected based on the calculated values of the parasitic resistance and protection resistor and is then stored in a specific table form, wherein a pass/fail decision is made as to whether or not the test result falls within the prescribed range.
1. A semiconductor device in which a test element group including at least one check pattern is formed in connection with a chip formed on a wafer so as to measure electric characteristics thereof, said semiconductor device comprising:
an interface circuit for selecting the check pattern from among the test element group;
a protection resistor that is connected in series with the test element group in the interface circuit so as to protect the test element group; and
a dummy element that is connected in series with the test element group in the interface circuit.
2. A semiconductor device according to claim 1 , wherein the interface circuit has a first pad for receiving an input signal designating the check pattern selected from among the test element group in response to a control signal and a second pad for outputting a test result of the designated check pattern.
3. A semiconductor device according to claim 2 , wherein the dummy element is connected in series with the protection resistor in the interface circuit, and
wherein, when the dummy element is selected, a node between the check pattern and the protection resistor is connected to the second pad for outputting the test result.
4. A semiconductor device according to claim 1 , wherein a plurality of test element groups and a plurality of dummy elements are formed in a periphery of the chip.
5. A method for testing a semiconductor device, in which a test element group including at least one check pattern is formed in connection with a chip formed on a wafer so as to measure electric characteristics thereof and which includes an interface circuit for selecting the check pattern from among the test element group, a protection resistor that is connected in series with the test element group in the interface circuit so as to protect the test element group, and a dummy element that is connected in series with the test element group in the interface circuit, said method comprising:
controlling the interface circuit so as to test the check pattern of the test element group, wherein a parasitic resistance of the interface circuit and a resistance of the protection resistor are calculated based on the measured electric characteristics of the check pattern;
determining whether or not the measured electric characteristics of the check pattern fall within a prescribed range, which is determined in advance; and
storing a test result of the check pattern in a storage device in connection with a wafer number and a chip number indicating position information of the chip on the wafer.
6. The method for testing the semiconductor device according to claim 5 , wherein the interface circuit has a first pad for receiving an input signal designating the check pattern selected from among the test element group in response to a control signal and a second pad for outputting a test result of the designated check pattern.
7. The method for testing the semiconductor device according to claim 6 , wherein the dummy element is connected in series with the protection resistor in the interface circuit, and
wherein, when the dummy element is selected, a node between the check pattern and the protection resistor is connected to the second pad for outputting the test result.
8. The method for testing the semiconductor device according to claim 5 , wherein a pass or fail decision is made as to whether the measured electric characteristics of the check pattern fall within the prescribed range, and accordingly setting a flag with respect to the chip on the wafer.
9. The method for testing the semiconductor device according to claim 5 , further comprising correcting the test result of the check pattern based on the calculated parasitic resistance and the calculated resistance of the protection resistor.
10. The method for testing the semiconductor device according to claim 8 , further comprising correcting the test result of the check pattern based on the calculated parasitic resistance and the calculated resistance of the protection resistor.