INTRINSIC STRESSES IN COATINGS DEPOSITED AT PLASMA IMMERSION ION IMPLANTATION

Abstract

The intrinsic stresses in the coatings deposited at plasma immersion ion implantation (PIII) in pulsed bias potential mode including case of differently charged ions are theoretically investigated. An expression for dependence of internal stress on ion species and its energy, as well as duration, and pulse repetition frequency is derived. The condition of applicability of the expressions for stress is discussed, that allows identifying the critical parameters of pulsed bias potential mode. The possibility of taking into account differently charged ions in calculation of internal stress by introducing the average charge of deposited ions is discussed. Calculation of stresses in TiN coatings during deposition of low-energy differently charged ions Ti+ from filtered vacuum arc plasma is executed. The comparison of the calculated stresses with the experimental data is carried out. It is shown that the approximation of the average charge can lead to large errors at stress determination in the coating deposited from the ion beam. The important role of deposition temperature in the control of internal stress in deposited coating is noted.