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US 8,575,011 B2Granted
Method of fabricating a device with a concentration gradient and the corresponding device
AssigneesSTMicroelectronics S.r.l., STMicroelectronics (Crolles 2) SAS
InventorsDaniel-Camille Bensahel, Yves Morand
Life of this patent
Estimating the term…
Abstract
A semiconductive device is fabricated by forming, within a semiconductive substrate, at least one continuous region formed of a material having a non-uniform composition in a direction substantially perpendicular to the thickness of the substrate.
Claims14
A method, comprising:
- forming, within a semiconductive substrate, at least one continuous region of an alloy having a composition with a non-uniformity extending in a direction substantially perpendicular to the thickness of the substrate;
- and
- wherein forming the continuous region comprises:
- forming a cavity in the substrate;
- and
- forming a plurality of zones of a semiconductive alloy within the cavity, the zones having different compositions in said direction;
- and
- wherein forming the plurality of zones comprises forming, at least on vertical walls of the cavity, a stack of layers of the semiconductive alloy having respectively different compositions of the semiconductive alloy, each layer in the stack having a first side edge directly adjacent a bottom surface of the cavity and a second side edge directly adjacent a top surface of the cavity.
5 more elements
A method, comprising
- forming, within a semiconductive substrate, at least one continuous region of a material having a composition with a non-uniformity extending in a direction substantially perpendicular to a thickness of the substrate;
- and
- wherein forming the continuous region comprises forming a plurality of zones of a semiconductive alloy, the zones having different compositions in said direction;
- and
- etching of a top surface of the zones of the continuous region, the etching having different characteristics depending on the composition.
2 more elements
A semiconductive device, comprising:
- a semiconductive substrate having a cavity, and
- at least one continuous region of an alloy having a composition with a non-uniformity extending in a direction substantially perpendicular to the thickness of the substrate filling the cavity to form a plurality of zones of a semiconductive alloy within the cavity, the zones having different compositions in said direction,
- wherein the plurality of zones comprises a stack of layers, each layer in the stack having a first side edge directly adjacent a bottom surface of the cavity and a second side edge directly adjacent a top surface of the cavity.
A semiconductor device, comprising:
- a semiconductive substrate including a cavity formed in a top surface,
- a stack of material layers provided in the cavity, the stack having a thickness extending through the layers of the stack which is parallel to the top surface of the semiconductive substrate, the stack having a side edge defining with the top surface of the semiconductive substrate a top face;
- in which the side edge portion of the top face comprises a profile that is sloping relative to the top surface of the substrate.
A method, comprising
- forming, within a semiconductive substrate, at least one continuous region of a material having a non-uniform composition in a direction substantially perpendicular to the thickness of the substrate, wherein forming the continuous region comprises depositing a plurality of conformal layers in a trench, each layer formed of an alloy material, and each alloy material layer having a gradually differing material concentration so as to form the non-uniform composition;
- and
- etching a top surface of the deposited layers which fill the trench.
Dependencies are inferred from the claim text.