Treatments to improve device performance

Patent metadata

Field	Value
Publication number	US-12249511-B2
Application number	US-202117192213-A
Country	US
Kind code	B2
Filing date	Mar 4, 2021
Priority date	May 3, 2019
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

A method of forming a semiconductor structure includes annealing a surface of a substrate in an ambient of hydrogen to smooth the surface, pre-cleaning the surface of the substrate, depositing a high-κ dielectric layer on the pre-cleaned surface of the substrate, performing a re-oxidation process to thermally oxidize the surface of the substrate; performing a plasma nitridation process to insert nitrogen atoms in the deposited high-κ dielectric layer, and performing a post-nitridation anneal process to passivate chemical bonds in the plasma nitridated high-κ dielectric layer.

First claim

What is claimed is:

1. A method of forming a semiconductor structure, the method comprising:
annealing a silicon surface of a substrate in a hydrogen (H 2 ) ambient at a temperature in a range of from 500° C. to 700° C. such that the hydrogen (H 2 ) reacts with the silicon surface to form a smooth surface having hydrogen-silicon (H—Si) bonding termination;
followed by, in a processing system without breaking vacuum:
depositing a high-κ dielectric layer directly on the smooth surface, the high-κ dielectric layer having vacancies and defects when deposited;
performing a re-oxidation process through the high-κ dielectric layer in an ambient of oxygen (O 2 ), nitrous oxide (N 2 O), and hydrogen (H 2 ) at a temperature in a range of from 400° C. to 900° C. to thermally oxidize the smooth surface and form an oxide-containing interfacial layer on the silicon surface of the substrate at an interface with the high-κ dielectric layer, the oxide-containing interfacial layer having a thickness in a range of from 3 Å to 10 Å;
performing a plasma nitridation process at a temperature of about 0° C. to about 500° C. and for a time period in a range of from about 10 seconds to about 300 seconds to insert nitrogen atoms in the vacancies and defects of the high-κ dielectric layer to form a plasma nitridated high-κ dielectric layer; and
performing a post-nitridation anneal process to passivate chemical bonds in the plasma nitridated high-κ dielectric layer,
the depositing of the high-κ dielectric layer, the performing of the re-oxidation process, the performing of the plasma nitridation process, and the performing of the post-nitridation anneal process being performed in the processing system without breaking vacuum.

2. The method of claim 1 , wherein the plasma nitridation process comprises exposing the high-κ dielectric layer to a plasma comprising a mixture of nitrogen (N 2 ) and ammonia (NH 3 ).

3. The method of claim 1 , wherein the post-nitridation anneal process comprises spike annealing the high-κ dielectric layer in a nitrogen (N 2 ) and argon (Ar) ambient at a temperature in a range of from 700° C. to 850° C.

4. The method of claim 1 , wherein the high-κ dielectric layer comprises hafnium oxide.

5. The method of claim 1 , further comprising pre-cleaning the silicon surface of the substrate prior to annealing the silicon surface of the substrate.

6. The method of claim 5 , wherein pre-cleaning the silicon surface comprises flowing a fluorine-containing precursor and a hydrogen-containing precursor over the silicon surface to remove a native oxide and form a pre-cleaned surface.

7. The method of claim 5 , wherein pre-cleaning the silicon surface comprises exposing the silicon surface to a dry etch process including N 2 , NF 3 , and NH 3 plasma by-products to remove native oxide and form a pre-cleaned surface.

Assignees

• Applied Materials Inc

Inventors

• Hung Steven C H
• Dong Lin
• Colombeau Benjamin
• Swenberg Johanes F
• Wang Linlin

Classifications

• H10P14/69392

  the material containing hafnium, e.g. HfO2 · CPC title

• H10P14/668

  the materials being characterised by the deposition precursor materials · CPC title

• H10D64/01342

  by deposition, e.g. evaporation, ALD or laser deposition (H10D64/01344 takes precedence) · CPC title

• H10D64/0134

  with a treatment, e.g. annealing, after the formation of the insulator and before the formation of the conductor · CPC title

• H10D64/01344 Primary

  in a nitrogen-containing ambient, e.g. N2O oxidation · CPC title