Process monitoring during AlN deposition by reactive magnetron sputtering

The effect of pressure on the reactivity of sputtered Al during reactive magnetron deposition was monitored by optical emission spectroscopy (OES) and a Langmuir probe. The deposition experiments were carried out varying the total pressure from 0.1 Pa to 1.2 Pa in an Ar/N2 7:1 flow ratio gas mixture. The deposited layers were analyzed by scanning electron microscopy (SEM) + energy dispersive analysis (EDS), glancing angle X-ray diffractometry (GAXRD) and X-ray photoelectron spectroscopy (XPS). Analysis of the films formed was based on the process parameters via plasma characterization. A correlation was found between the OES results and the amount of Al deposited. Under the present conditions, the base pressure was found to have a significant effect on the nature of the products deposited.