Amorphous carbon films (a-C:H) were prepared on a microtrench (4-μm pitch and 4-μm depth), and the uniformity of film thickness and microstructure of the films on the top, sidewall, and bottom surfaces of the microtrench were evaluated by scanning electron microscopy and Raman spectroscopy. The a-C:H films were prepared by bipolar-type plasma based ion implantation and deposition (bipolar PBII&D), and the negative pulse voltage, which is the main parameter dominating the film structure, was changed from −1.0 to −15 kV. Moreover, the behavior of ions and radicals was analyzed simultaneously by combining the calculation methods of Particle-In-Cell/Monte Carlo Collision (PIC-MCC) and Direct Simulation Monte Carlo (DSMC) to investigate the coating mechanism for the microtrench. The results reveal that the thickness uniformity of a-C:H films improves with decreasing negative pulse voltage due to the decreasing inertia of incoming ions from the trench mouth, although the film thickness on the sidewall tends to be much smaller than that on the top and bottom surfaces of the trench. The normalized flux and the film thickness show similar behavior, i.e., the normalized flux or thickness at the bottom surface increases at low negative pulse voltages and then saturates at a certain value, whereas at the sidewall it monotonically decreases with increasing negative voltage. The microstructure of a-C:H films on the sidewall surface is very different from that on the top and bottom surfaces. The film structure at a low negative pulse voltage shifts to more of a polymer-like carbon (PLC) structure due to the lower incident energy of ions. Although the radical flux on the sidewall increases slightly, the overall film structure is not significantly changed because this film formation at a low negative voltage is originally dominated by radicals. On the other hand, the flux of radicals is dominant on the sidewall in the case of high negative pulse voltage, resulting in a deviation from the Raman behavior of a-C:H films deposited by bipolar PBII&D. This tendency intensifies as the negative voltage becomes greater. Also, the energy of incident ions on the sidewall of the trench increases with increasing negative voltage, which causes a shift in the Raman data of the sidewall to the bottom right corner on the figure depicting the relationship of the FWHM(G) and the G-peak position, indicating increased graphitization of a-C:H film.
Skip Nav Destination
Article navigation
28 August 2015
Research Article|
August 26 2015
Microstructure of a-C:H films prepared on a microtrench and analysis of ions and radicals behavior
Yuki Hirata;
Yuki Hirata
Department of Mechanical Engineering,
The University of Tokyo
, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Search for other works by this author on:
Junho Choi
Junho Choi
a)
Department of Mechanical Engineering,
The University of Tokyo
, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Search for other works by this author on:
a)
Author to whom correspondence should be addressed. Electronic mail: [email protected].
J. Appl. Phys. 118, 085305 (2015)
Article history
Received:
June 03 2015
Accepted:
August 11 2015
Citation
Yuki Hirata, Junho Choi; Microstructure of a-C:H films prepared on a microtrench and analysis of ions and radicals behavior. J. Appl. Phys. 28 August 2015; 118 (8): 085305. https://doi.org/10.1063/1.4929427
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
A step-by-step guide to perform x-ray photoelectron spectroscopy
Grzegorz Greczynski, Lars Hultman
Piezoelectric thin films and their applications in MEMS: A review
Jinpeng Liu, Hua Tan, et al.
Tutorial: Simulating modern magnetic material systems in mumax3
Jonas J. Joos, Pedram Bassirian, et al.
Related Content
Deposition of a-C:H films on inner surface of high-aspect-ratio microchannel
J. Appl. Phys. (August 2016)
Microtrenching resulting from specular reflection during chlorine etching of silicon
J. Vac. Sci. Technol. B (July 1998)
Effect of sidewall properties on the bottom microtrench during Si O 2 etching in a C F 4 plasma
J. Vac. Sci. Technol. B (March 2005)
Effect of precursor gas on the structure and mechanical properties of hydrogenated amorphous carbon films deposited on a trench sidewall
J. Appl. Phys. (February 2019)
Modeling of microtrenching and bowing effects in nanoscale Si inductively coupled plasma etching process
J. Vac. Sci. Technol. A (November 2023)