Method of ammonia annealing of ultra-thin silicon dioxide layers for uniform nitrogen profile
US6632747B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2001 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Jun 24, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/693
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An embodiment of the present invention is a method of forming an ultra-thin dielectric layer by providing a substrate having a semiconductor surface; forming an oxygen-containing layer on the semiconductor surface; exposing the oxygen-containing layer to a nitrogen-containing plasma to create a uniform nitrogen distribution throughout the oxygen-containing layer; and re-oxidizing and annealing the layer to stabilize the nitrogen distribution, heal plasma-induced damage, and reduce interfacial defect density.This annealing step is selected from a group of four re-oxidizing techniques:Consecutive annealing in a mixture of H2 and N2 (preferably less than 20% H2), and then a mixture of O2 and N2 (preferably less than 20% 02);annealing by a spike-like temperature rise (preferably less than 1 s at 1000 to 1150° C.) in nitrogen-comprising atmosphere (preferably N2/O2 or N2O/H2);annealing by rapid thermal heating in ammonia of reduced pressure (preferably at 600 to 1000° C. for 5 to 60 s);annealing in an oxidizer/hydrogen mixture (preferably N2O with 1% H2) for 5 to 60 s at 800 to 1050° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.