Process for manufacturing high-sensitivity accelerometric and gyroscopic integrated sensors, and sensor thus produced
AssigneeSTMicroelectronics S.r.l.
InventorsPaolo Ferrari, Benedetto Vigna
Life of this patent
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Abstract
A movable mass forming a seismic mass is formed starting from an epitaxial layer and is covered by a weighting region of tungsten which has high density. To manufacture the mass, buried conductive regions are formed in the substrate. Then, at the same time, a sacrificial region is formed in the zone where the movable mass is to be formed and oxide insulating regions are formed on the buried conductive regions so as to partially cover them. An epitaxial layer is then grown, using a nucleus region. A tungsten layer is deposited and defined and, using a silicon carbide layer as mask, the suspended structure is defined. Finally, the sacrificial region is removed, forming an air gap.
Claims13
A process for manufacturing an accelerometric and gyroscopic integrated sensor, comprising the steps of:
- forming a sacrificial region on a substrate of semiconductor material;
- growing an epitaxial layer on said substrate and said sacrificial region;
- and
- removing selective portions of said epitaxial layer and said sacrificial region to form a movable mass surrounded at the sides and separated from fixed regions by trenches and separated from said substrate by an air gap and
- forming a weighting region of tungsten at said movable mass.
A method for producing an integrated sensor comprising the steps of:
- forming a sacrificial support layer on a semiconductor substrate;
- forming an epitaxial layer on the sacrificial support layer and on the semiconductor substrate;
- depositing a tungsten layer on the epitaxial layer;
- removing the sacrificial support layer;
- and
- forming a movable mass from portions of the epitaxial and tungsten layers by forming trenches to separate the movable mass from fixed regions of the epitaxial and tungsten layers.
Dependencies are inferred from the claim text.