Temperature effect on bonding structures of amorphous carbon containing more than 30at.% silicon

• Published in: Diamond and related materials Vol. 16; no. 10; pp. 1823 - 1827
• Main Authors: Ong, Soon-Eng, Zhang, Sam, Du, Hejun, Tan, Gladys
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2007; Elsevier
• Subjects: Amorphous carbon; Bonding configurations; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Hardness; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Physical properties of thin films, nonelectronic; Physics; Specific materials; Sputtering; Surface and interface electron states; Surface states, band structure, electron density of states; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Amorphous carbon; Hardness; Sputtering; Bonding configurations; Annealing; Amorphous thin film; Mechanical properties; Raman spectroscopy; Deposition process; Thin films; Cathode sputtering; Electronic structure; Temperature effects; Ambient temperature; Physical vapor deposition; Chemical bonds; Silicon; Sputter deposition; Atomic structure; X-ray photoelectron spectra
• DOI: 10.1016/j.diamond.2007.07.004
• ISSN: 0925-9635

Bonding evolution of amorphous carbon incorporated with Si or a-C(Si) in a thermal process has not been studied. Unhydrogenated a-C(Si) films were deposited by magnetron sputtering to undergo two different thermal processes: i) sputter deposition at substrate temperatures from 100 to 500 °C; ii) room temperature deposition followed by annealing at 200 to 1000 °C. The hardness of the films deposited at high temperature exhibits a monotonic decrease whereas the films deposited at room temperature maintained their hardness until 600 °C. X-ray photoelectron spectroscopy and Raman spectroscopy were used to analyze the composition and bonding structures. It was established that the change in the mechanical property is closely related to the atomic bonding structures, their relative fractions and the evolution (conversion from C–C sp 3 → C C sp 2 or C C sp 2 → C–Si sp 3) as well as clustering of sp 2 structures.