Chemical composition and light emission properties of Si-rich-SiOx layers prepared by magnetron sputtering

Abstract

The process of thermal decomposition of SiOx layers prepared by magnetron sputtering is studied with the use of photoluminescence and Auger and SIMS spectroscopies. From these measurements, we obtained the distributions of the emission properties and the chemical composition over the depth. The effect of the redistribution of silicon and oxygen over the depth is found after the high-temperature annealing which results in the formation of a Si nanocrystal. These redistributions result in the appearance of a Si-depleted region near the layer-substrate interface. The formation of a depletion layer is dependent on the excess of Si. A decrease of the silicon content over the depth of annealed layers is accompanied by a decrease of the Si nanocrystal size, as it is evidenced by the blue shift of the photoluminescence maximum. The mechanism of decomposition of SiOx and the possible reasons for the appearance of a Si-depleted region are discussed.