Trench transistor and method for fabricating a trench transistor with high-energy-implanted drain
AssigneeInfineon Technologies AG
InventorsFranz Hirler, Frank Pfirsch
Life of this patent
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Abstract
A method is disclosed for fabricating a trench transistor, in which there are formed, within an epitaxial layer deposited above a substrate of a first conductivity type, a trench and, within the trench, a gate dielectric and a gate electrode and, in a body region of a second conductivity type adjoining the trench a source region of the first conductivity type, a drift region of the first conductivity type forming a drain zone being formed at the end of the junction between the substrate and the epitaxial layer by means of one or more high-energy implantations, the lower end of the trench projecting into said drift region, and to a trench transistor of this type formed as a low-voltage transistor.
Claims19
A method for fabricating a trench transistor, comprising:
- providing an epitaxial layer disposed above a substrate, the substrate having a first conductivity type;
- providing a trench and, within the trench, a gate dielectric and a gate electrode;
- providing a body region of a second conductivity type adjoining the trench and a source region of the first conductivity type disposed within the body region;
- and
- forming a drift region of the first conductivity type at the end of a junction between the substrate and the epitaxial layer using one or more high-energy implantations, a lower end of the trench extending at least through a part of said drift region, the drift region including at least a portion of a drain zone.
A trench transistor comprising:
- a substrate having a first conductivity type;
- an epitaxial layer disposed above the substrate;
- a trench and, within the trench, a gate dielectric and a gate electrode;
- a body region of a second conductivity type adjoining the trench, the body region having formed therein a source region of the first conductivity type;
- and
- a drift region of the first conductivity type which forms a drain zone, the drift region disposed between the substrate and the epitaxial layer and directly adjoining an underside of the body region, a lower end of said trench extending at least through a part of said drift region.
Dependencies are inferred from the claim text.