Denso Corporation

Takashi Kohyama

Katsuhiro Kutsuki

Keita Kataoka

Isao Aoyagi

Junya Muramatsu

Ryosuke Okachi

Main cells that constitute a semiconductor element having a trench gate structure include first cells, and second cells having a structure in which gate insulating films are more easily broken by energization than those in the first cells, and the number of which is smaller than that of the first cells. At a time of driving the semiconductor element, a common gate drive voltage is applied to gate electrodes of the first cells and the second cells. An electrical characteristic is measured to detect failure of the second cells due to energization at the time of driving. The gate electrodes of the failed second cells are electrically isolated from the gate electrodes of the first cells so that the gate drive voltage is not applied to the failed second cells. The failure of the first cells is predicted based on the failure of the second cells.

Growing community of inventors

Toyota, Japan

Takashi Kohyama