Insulation structure forming method
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorsNorbert Moussy, Cédric Giroud-Garampon
Life of this patent
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Abstract
A method of forming an insulation structure inside and on top of a first semiconductor substrate, including the steps of: a) forming a trench vertically extending in the first substrate from a first surface of the first substrate; b) filling the trench, from the first surface of the first substrate, with a polysilicon region; c) thinning the first substrate on the side of a second surface of the first substrate, opposite to the first surface, to expose the polysilicon region at the bottom of the trench; d) removing the polysilicon region from the second surface of the first substrate; and e) filling the trench, from the second surface of the first substrate, with a metal.
Claims8
Method of forming an insulation structure inside and on top of a first semiconductor substrate, comprising the steps of:
- a) forming a trench vertically extending in the first substrate from a first surface of the first substrate;
- b) filling the trench, from the first surface of the first substrate, with a polysilicon region;
- c) thinning the first substrate on the side of a second surface of the first substrate, opposite to the first surface, to expose the polysilicon region at the bottom of the trench;
- d) removing the polysilicon region from the second surface of the first substrate;
- and
- e) filling the trench, from the second surface of the first substrate, with a metal the method further comprising:
- between step a) and step b), a step of forming of a first electrically-insulating layer on the lateral walls and the bottom of the trench;
- and
- between step a) and the step of forming of the first electrically-insulating layer, a step of deposition of a polysilicon layer coating the lateral walls and the bottom of the trench.
Method of forming an insulation structure inside and on top of a first semiconductor substrate, comprising the steps of:
- a) forming a trench vertically extending in the first substrate from a first surface of the first substrate;
- b) filling the trench, from the first surface of the first substrate, with a polysilicon region;
- c) thinning the first substrate on the side of a second surface of the first substrate, opposite to the first surface, to expose the polysilicon region at the bottom of the trench;
- d) removing the polysilicon region from the second surface of the first substrate;
- and
- e) filling the trench, from the second surface of the first substrate, with a metal, the method further comprising, between step b) and step c), a step where:
- the polysilicon region is removed from across a portion of the depth of the trench;
- a second electrically-insulating layer is formed on a free upper surface of the poly silicon region;
- and
- the filling of the trench is completed.
Dependencies are inferred from the claim text.