Accession Number:

ADP012167

Title:

Nano-Structured Amporphous Carbon Films Synthesised Using DECR Plasma

Descriptive Note:

Proceedings

Corporate Author:

CORK INST OF TECHNOLOGY (IRELAND) CENTRE FOR SURFACE AND INTERFACE ANALYSIS

Report Date:

2001-04-01

Pagination or Media Count:

6.0

Abstract:

A Distributed Electron Cyclotron Resonance plasma reactor powered by a microwave generator operating at 2.45 GHz was used to deposit ta-CH Diamond-Like Carbon, DLC thin films at RT. A graphite sputtering target immersed in an argon plasma was used as carbon source. The Ar plasma density was about 5x10Aexp10cmexp-3. Single crystal 100 Si substrates were RF biased to a negative voltage of -80 V. Atomic force microscopy AFM, X-ray photoelectron spectroscopy XPS, nuclear reaction analysis NRA using the resonance at 6.385 MeV of the reaction 15N 1H--12C 4He gamma, elastic recoil detection analysis ERDA and Rutherford backscattering RBS were used to investigate the early phase of the growth. The morphology of the films grown at low pressure 0.3 mTorr is shown to be dominated by stress-mediated nucleation leading to formation of basket-like clusters of circular hillocks 20 nm high surrounded by a planar, mostly spexp2 bonded film 8 nm thick. With increasing plasma pressure the spatial frequency of the hillocks becomes random and the growth is dominated by the Stranski-Krastanov mode. The XPS data taken at decreasing emergence angles show that the structure of the hillocks is dominated by spexp3 bonded carbon. The XPS argon signal disappears at 100 emergence angle indicating that integration of argon occurs mainly within the spexp2 bonded regions. The NRA and ERDA analysis show that the amount of integrated hydrogen decreases with increasing substrate current density. RIBS data indicate that increasing bias enhances argon integration.

Subject Categories:

  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE