US 12,072,368 B2
Deterioration checking apparatus and deterioration checking
Hideaki Majima, Minato Tokyo (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION, Tokyo (JP)
Filed by Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed on Mar. 8, 2022, as Appl. No. 17/689,729.
Claims priority of application No. 2021-092445 (JP), filed on Jun. 1, 2021.
Prior Publication US 2022/0381814 A1, Dec. 1, 2022
Int. Cl. G01R 31/26 (2020.01); G01R 31/28 (2006.01); H01L 21/66 (2006.01); H03K 17/687 (2006.01)
CPC G01R 31/2623 (2013.01) [G01R 31/2621 (2013.01); G01R 31/2884 (2013.01); H03K 17/687 (2013.01); H01L 22/34 (2013.01); H01L 2924/00 (2013.01); H01L 2924/0002 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A deterioration checking apparatus for a MOS transistor, the apparatus comprising:
an inductor that is connected in series to a main current path of the MOS transistor to be checked, and forms a closed loop together with the MOS transistor when the MOS transistor is in an ON-state;
a control circuit that controls ON/OFF of the MOS transistor;
a current sensor that detects a current released from the inductor; and
a processing circuit configured to:
calculate an ON-resistance of the MOS transistor from an attenuation characteristic of the current released from the inductor when the MOS transistor is in an ON-state, and calculate a threshold voltage of the MOS transistor from an attenuation characteristic of the current released from the inductor when the MOS transistor is in an OFF-state; and
determine a deterioration state of the MOS transistor by comparing an ON-resistance threshold and a threshold voltage threshold, which are set in advance, with the calculated ON-resistance and the calculated threshold voltage of the MOS transistor.