The Improvement of Thin Polymer Film Properties Through Plasma Immersion Ion Implantation and Deposition Technique
- PDF / 61,635 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 93 Downloads / 206 Views
The Improvement of Thin Polymer Film Properties Through Plasma Immersion Ion Implantation and Deposition Technique Elidiane C. Rangel1, Nilson C. Cruz1, Rogério P. Mota1, Maurício A. Algatti1, Roberto Y. Honda1, Carlos Kuranaga and Marcos D. da Silva Laboratório Associado de Materiais e Sensores – Instituto Nacional de Pesquisas Espaciais São José dos Campos, SP 12201-970, Brazil. 1 Laboratório de Plasmas e Aplicações – Universidade Estadual Paulista Guaratinguetá, SP 12516-410, Brazil.
ABSTRACT
Thin polymer films were deposited from acetylene and argon mixtures by plasma immersion ion implantation and deposition. The effect of the pulse frequency, ν, on molecular structure, optical gap, contact angle and hardness of the films was investigated. It was observed progressive dehydrogenation of the samples and increment in the concentration of unsaturated carbon bonds as the pulse frequency was increased. Film hardness and contact angle increased and optical gap decreased with ν. These results are interpreted in terms of the chain unsaturation and crosslinking.
INTRODUCTION
Plasma immersion ion implantation and deposition, PIIID, [1] enables thin film deposition by means of ion bombardment. Substrates are placed in plasmas from gases or compounds that polymerize and biased with high voltage negative pulses. During the off time of the pulses, low energy species are deposited as in the conventional plasma polymerization process. During the application of the pulses (on time), ions are driven to the polarized sample and implanted with energies ranging from tens to thousands of electron volts. Thus, PIIID allows modification of the growing layer as well as of the film-substrate interface. The properties of films deposited by PIIID will depend on the characteristics of the plasma as well as of the pulses. The pulse duty cycle, D, [2] is an important parameter that indicates the influence of the implantation and deposition phases in a PIIID process and is defined as: D=
t (t + toff )
(1)
where t is the pulse width (on time) and toff is the time between the pulses. Samples deposited/bombarded with high duty cycles, i.e., with t values high compared to toff, will have the implantation process more effective. In this case, the film deposition will proceed at very low rates. To low duty cycles, i.e., to large periods between the pulses the deposition process will be favored. So, film properties can be tailored by changing the pulse bias regime. O8.17.1
In this work different pulse frequencies, ν, were used to polarization of the sample in order to investigate the effect of this parameter on the structural, optical and mechanical properties of films prepared by PIIID.
EXPERIMENTAL DETAILS
Films investigated in this work were deposited from C2H2 and Ar radiofrequency (13.56 MHz, 45 W) plasmas by PIIID in a stainless steel vacuum chamber fitted with two parallel plate electrodes. Argon and acetylene pressures in the reactor were 5.8X10-1 and 0.1X10-1 Pa, respectively. The substrate holder was biased with negative pulses o
Data Loading...
