Stmicroelectronics S.r.l.

Claudia Raffaglio

Alessandro Moscatelli

Alessandra Merlini

M Paola Galbiati

A process manufactures power MOS lateral transistors together with CMOS devices on a semiconductor substrate. The process forms a lateral MOS transistor having a gate electrode on the semiconductor region, a source comprising a first highly doped portion aligned with the gate electrode and a drain comprising a lightly doped portion aligned with the gate electrode and a second highly doped portion included in the lightly doped portion. The process forms on the lightly doped portion, a protective layer of a first material; forms on the lateral MOS transistor, a dielectric layer of a second material selectively etchable with respect to the first material; forms, in the dielectric layer first, second, and third openings; and fills the openings with a conductive layer that forms drain and source contacts electrically connected to the first and second highly doped portions, and one electrical shield substantially aligned with the protective layer.

Manufacturing process for lateral power MOS transistors

A process is disclosed for forming, on a common semiconductor substrate, CMOS transistors and vertical or lateral MOS transistors on at least first and second portions, respectively, of the substrate. A first dielectric layer is formed on the substrate. A first semiconductor material layer is then formed on the first dielectric layer, in the first portion. A stack structure comprising a second dielectric layer, second semiconductor layer, and low-resistance layer is then formed over the substrate. First ports are defined in the second semiconductor layer and the low-resistance layer to provide gate regions of the vertical or lateral MOS transistors. The second semiconductor layer and the low-resistance layer are then removed from the first portion of the substrate by using the second dielectric layer as a screen. Second ports in the second dielectric layer and the second semiconductor layer are then defined to provide gate regions for the CMOS transistors. The gate region of the vertical or lateral transistors is then covered with a protective layer. A low-resistance layer is then formed on the gate regions of the CMOS transistors.

Process for forming CMOS transistors and MOS transistors of the drain extension type, with a low gate region resistance, in the same semiconductor substrate

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Milan, Italy

Claudia Raffaglio