Effect of N<sub>2</sub> Gas Pressure Ratio and DC Bias on Formation of Iron Nitride Thin Film by RF Sputtering Method

Abstract

In this paper, we investigated the effect of N2 gas pressure ratio and DC bias on the formation of iron nitride thin films deposited by RF sputtering method. As a result, the amounts of γ'-Fe4N and ε-Fe3N, which had high N2 content than that of α”-Fe16N2, increased with increasing N2 gas pressure ratio. From the result of x-ray diffraction, the Fe-N film at the N2 gas pressure ratio of 15% became the single phase of γ'-Fe4N. Therefore, we attempted the formation of α'-martensite and α”-Fe16N2 by applying DC bias voltage. It revealed that it was possible to control the N2 content and the coercive force by applying DC bias voltage. However, the formation of α”-Fe16N2 was not observed.