US 12,241,926 B2
Test apparatus
Naoyoshi Watanabe, Tokyo (JP); Shigeyuki Sato, Sendai (JP); and Ryoichi Utsumi, Sendai (JP)
Assigned to ADVANTEST CORPORATION, Tokyo (JP); and TOEI SCIENTIFIC INDUSTRIAL CO., LTD., Sendai (JP)
Filed by ADVANTEST CORPORATION, Tokyo (JP); and TOEI SCIENTIFIC INDUSTRIAL CO., LTD., Sendai (JP)
Filed on Oct. 27, 2021, as Appl. No. 17/512,021.
Application 17/512,021 is a continuation of application No. PCT/JP2020/046821, filed on Dec. 15, 2020.
Claims priority of application No. 2020-020831 (JP), filed on Feb. 10, 2020.
Prior Publication US 2022/0050136 A1, Feb. 17, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G01R 31/26 (2020.01); G01R 1/04 (2006.01); G01R 1/073 (2006.01); G01R 31/28 (2006.01)
CPC G01R 31/2601 (2013.01) [G01R 1/0491 (2013.01); G01R 1/07342 (2013.01); G01R 31/2831 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A test method for testing, by a test apparatus, a wafer under test on which devices under test each comprising magnetoresistive memory or a magnetic sensor are formed, the method comprising:
mounting the wafer under test on a stage in a test process;
applying, by a magnetic field application apparatus, a magnetic field to the wafer under test in the test process;
making, by a test probe card, probe contact with the wafer under test in the test process;
removing the wafer under test;
mounting a diagnostic wafer on the stage in a diagnostic process of the test apparatus after the removing the wafer under test, wherein a plurality of magnetization detection units are formed on the diagnostic wafer, and the diagnostic wafer is structured to measure a magnetic field generated by the magnetic field application apparatus by means of each magnetization detection unit in the diagnostic process;
removing the test probe card; and
using a diagnostic probe card in the diagnostic process after the removing the test probe card, and making probe contact with the diagnostic wafer.