Controlled doping in a gate dielectric layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsShahaji B. More, Chandrashekhar Prakash Savant
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Abstract
The present disclosure describes method to form a semiconductor device having a gate dielectric layer with controlled doping. The method includes forming a gate dielectric layer on a fin structure, forming a diffusion barrier layer on the gate dielectric layer, and forming a dopant source layer on the diffusion barrier layer. The gate dielectric layer includes an interfacial layer on the fin structure and a high-k dielectric layer on the interfacial layer. A dopant of the dopant source layer diffuses into the gate dielectric layer. The method further includes doping a portion of the interfacial layer with the dopant and removing the dopant source layer. The portion of the interfacial layer is adjacent to the high-k dielectric layer.
Claims20
A semiconductor device, comprising:
- a fin structure on a substrate;
- an interfacial layer on the fin structure, wherein;
- the interfacial layer comprises a top portion and an undoped bottom portion,
- the top portion of the interfacial layer comprises a metal dopant,
- the top portion has a first thickness, and
- the undoped bottom portion has a second thickness greater than the first thickness;
- a high-k dielectric layer on the top portion of the interfacial layer and comprising a high-k dielectric material;
- and
- an intermixing layer on the high-k dielectric layer, wherein the intermixing layer is a mixture of the high-k dielectric layer and a diffusion barrier layer comprising nitrogen.
A semiconductor device, comprising:
- a first gate dielectric layer on a first fin structure, wherein the first gate dielectric layer comprises a first interfacial layer and a first high-k dielectric layer, and wherein a top portion of the first interfacial layer comprises a dopant at a first concentration;
- a second gate dielectric layer on a second fin structure, wherein the second gate dielectric layer comprises a second interfacial layer and a second high-k dielectric layer, and wherein a top portion of the second interfacial layer comprises the dopant at a second concentration different from the first concentration;
- a first intermixing layer on the first high-k dielectric layer, wherein the first intermixing layer comprises the first high-k dielectric layer and a first diffusion barrier layer comprising nitrogen;
- a second intermixing layer on the second high-k dielectric layer, wherein the second intermixing layer comprises the second high-k dielectric layer and a second diffusion barrier layer comprising nitrogen;
- the first diffusion barrier layer on the first intermixing layer, wherein the first diffusion barrier layer has a first thickness;
- and
- the second diffusion barrier layer on the second intermixing layer, wherein the second diffusion barrier layer has a second thickness different from the first thickness.
A semiconductor device, comprising:
- a first interfacial layer on a first fin structure, wherein the first interfacial layer comprises a first undoped portion and a first top portion doped with a dopant, and wherein the first interfacial layer has a first thickness and the first top portion has a second thickness;
- a first high-k dielectric layer on the first interfacial layer, wherein the first high-k dielectric layer comprises a high-k dielectric material;
- a second interfacial layer on a second fin structure, wherein the second interfacial layer comprises a second undoped portion and a second top portion doped with the dopant, and wherein the second interfacial layer has the first thickness and the second top portion has a third thickness different from the second thickness;
- a second high-k dielectric layer on the second interfacial layer, wherein the second high-k dielectric layer comprises the high-k dielectric material;
- and
- an intermixing layer on the first and second high-k dielectric layers, wherein the intermixing layer comprises the high-k dielectric material and a diffusion barrier layer comprising nitrogen.
Dependencies are inferred from the claim text.