Stmicroelectronics S.r.l.

Francesco Cazzaniga

Lorena Beghin

Francesca Canali

Carmelo Romeo

Maria Luisa Polignano

Luca Riva

Marzio Brambilla

Federica Zanderigo

Giuseppe Pavia

A process for etching a dielectric layer, including the steps of forming, over the dielectric layer, a layer of polysilicon, forming over the layer of polysilicon a photoresist mask layer, etching the layer of polysilicon using the photoresist mask layer as an etching mask for selectively removing the layer of polysilicon, removing the photoresist mask layer from over the layer of polysilicon, etching the dielectric layer using the layer of polysilicon as a mask. Subsequently, the layer of polysilicon is converted into a layer of a transition metal silicide, and the layer of transition metal silicide is etched for selectively removing the latter from over the dielectric layer.

Process for the definition of openings in a dielectric layer

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.

Determination of the thickness of a denuded zone in a silicon wafer

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Seveso, Italy

Francesco Cazzaniga