Phase-graded deposition of diamond-like carbon on nanotips by near-field induced chemical vapor deposition

Authors

J. Shi, University of Nebraska-Lincoln
Yongfeng Lu, University of Nebraska-LincolnFollow
X. Y. Chen, National University of Singapore
R. S. Cherukuri, University of Nebraska-Lincoln
K. K. Mendu, University of Nebraska-Lincoln
H. Wang, University of Nebraska-Lincoln
N. Batta, University of Nebraska-Lincoln

Document Type

Article

Date of this Version

3-22-2005

Comments

Published in APPLIED PHYSICS LETTERS 86, 131918 (2005). © 2005 American Institute of Physics. Used by permission.

Abstract

Diamond-like carbon sDLCd films were deposited on tungsten sWd tips under the KrF excimer laser in a laser chemical vapor deposition sLCVDd chamber. Raman spectroscopy showed that the deposited DLC films were phase-graded along the tips from the apexes. The DLC films were more diamondlike at or near the tip apexes. From numerical simulation, there is a strongly confined and enhanced optical field at the tip apexes. The simulation also indicates that there is an optical-field gradient from tip apexes to tip bodies. Therefore, the variations in the phases of deposited DLC films were attributed to the corresponding variations in local optical intensities along the tips. Hence, optical local near field was confirmed to be responsible to the DLC deposition.