Hafnium Nitride(x): Phase Composition, Microstructure, and Physical Properties of Epitaxial and Polycrystalline Layers

The phase-compositions obtained in HfNx grown on SiO 2 at 350°C are alpha-Hf:N (x ≤ 0.6); multiphases (0.6 ≤ x ≤ 0.9); delta-HfN single-phase (0.9 ≤ x ≤ 1.3); and mixtures of delta-HfN and higher nitrides (x ≥ 1.3). HfNx layers with 0.9 ≤ x ≤ 1.2 grown under mild ion-irradiation are underdense with mixed orientation, low in-plane stress, and rough surfaces due to limited adatom mobilities resulting in kinetic roughening during film growth. However, the use of intense ion-irradiation leads to dense HfNx layers with 111 texture, compressive in-plane stress, and smooth surfaces due to enhanced adatom surface mobilities and thus, lower electrical resistivity and higher hardness are obtained. For HfNx layers with 1.2 ≤ x ≤ 1.6, the correspondingly higher steady state atomic N surface coverages during deposition alter growth kinetics in favor of 001 texture with a fully dense structure and compressive in-plane stress.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science and Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Seo, Hwan-Seok

Contributors dc:contributor

• Greene, J.E.

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI3223714

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/82782