Stmicroelectronics S.r.l.

Federica Zanderigo

Maria Luisa Polignano

Francesco Cazzaniga

Marzio Brambilla

Giuseppe Pavia

The depth of a denuded layer with respect to a relatively defective bulk region of a monocrystalline semiconductor wafer is estimated in a nondestructive way. The depth is determined by measuring the lifetime or diffusion length of injected excess minority charge carriers on a surface of the wafer having such a denuded layer and on a different portion of the surface of the wafer from where the denuded layer has been previously stripped-off by lapping and/or etching. The depth is calculated through a best-fit procedure or through numerical processing of the measurement results on the basis of the diffusion equations of excess minority carriers.

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Padua, Italy

Federica Zanderigo