Resistive structure integrated in a semiconductor substrate
AssigneeSTMicroelectronics S.r.l.
InventorsSalvatore Leonardi, Roberto Modica
Life of this patent
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Abstract
A resistive structure integrated in a semiconductor substrate and having a suitably doped polysilicon region that is completely surrounded by a dielectric region so that the resistive structure is isolated electrically from other components jointly integrated in the semiconductor substrate.
Claims17
A resistive structure integrated in a semiconductor substrate, comprising:
- a plurality of successive trenches of different widths formed in the substrate and lined with dielectric material to form a single dielectric trench;
- and a polysilicon region, at least a portion of which is doped, the polysilicon region surrounded by the dielectric trench so that the resistive structure is isolated electrically from other components jointly integrated in the semiconductor substrate, and wherein portions of the dielectric trench are formed with the plurality of trenches to form a single dielectric region having a width that increases along the resistive structure in which a voltage drop increases.
An integrated resistive structure, comprising:
- at least one trench having a width that increases along a length thereof and formed in a semiconductor substrate from a plurality of successive trenches of different widths to have a depth greater than a depletion region;
- a dielectric layer formed of a dielectric oxide entirely coating all walls, including a bottom wall, of the at least one trench, the dielectric layer having a width that increases along a length of the at least one trench to form a fill trench of constant width;
- and
- a polysilicon region filling the fill trench to be isolated dielectrically from the semiconductor substrate, the polysilicon region having at least a portion that is doped.
The structure of claim 12 wherein the dielectric layer has vertical and horizontal dimensions that are greater than vertical and horizontal dimensions of the polysilicon region.
The structure of claim 13 wherein the first layer of polysilicon is implanted by angled implantation and has a thickness dimension conforming to the walls of the dielectric-coated at least one trench.
An integrated resistive structure, comprising:
- a trench formed in a semiconductor substrate from a plurality of contiguous trenches of different widths;
- a dielectric layer entirely coating all walls of the trench, the dielectric layer having a width that increases along a length of the trench to form a fill trench;
- and
- a polysilicon region comprising first and second layers of polysilicon filling the fill trench, the second layer being undoped and the first layer implanted with a dopant.
Dependencies are inferred from the claim text.