Toei Scientific Industrial Co., Ltd.

Adv Antest Corporation

Ryoichi Utsumi

Shigeyuki Sato

Naoyoshi Watanabe

Tomokazu Yamashiro

Hiroyuki Kenju

A test apparatus tests a wafer under test on which devices under test each including magnetoresistive memory or a magnetic sensor are formed. In a test process, the wafer under test is mounted on a stage. In the test process, a magnetic field application apparatus applies a magnetic field Bto the wafer under test. A test probe card is used in the test process. Multiple magnetization detection units are formed on a diagnostic wafer. In a diagnostic process of the test apparatus, the diagnostic wafer is mounted on the stage instead of the wafer under test. Each magnetization detection unit is capable of measuring a magnetic field Bgenerated by the magnetic field application apparatus. In the diagnostic process, the diagnostic probe card is used instead of the test probe card.

Test apparatus

The test apparatus tests a wafer under test on which devices under test each including magnetoresistive memory or a magnetic sensor are formed. In a test process, the wafer under test is mounted on a stage. A test probe card is configured such that it can make probe contact with the wafer under test in the test process. A wafer connection HiFix is arranged between the test probe card and a test head. A magnetic field application apparatus is provided to the wafer connection HiFix. In the test process, the magnetic field application apparatus applies a magnetic field Bto the wafer under test.

There is provided a prober chuck capable of carrying out low leakage evaluation on a magnetic memory under environment in which a magnetic field is applied. A prober chuckfor a magnetic memory retains a wafer W having a magnetic memory formed thereon. The chuckincludes: a chuck topthat is made of a conductive material and has a wafer W placed thereon; an insulating layerthat is made of an insulating material and is adapted to support the bottom surface of the chuck top; and a guard layerthat is made of a conductive material and is arranged under the insulating layer, the guard layer being insulated from the chuck topvia the insulating layer. All of the members constituting the chuckincluding the chuck topand the guard layerare made of a non-magnetic material.

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Sendai, Japan

Ryoichi Utsumi