Abstract
Deposition of SiO x layers of variable composition onto silicon wafers was performed by co-sputtering of spaced Si and SiO2 targets in argon plasma. Coordinate dependences of the thickness and refractive index of separately deposited Si and SiO2 layers and the SiO x layer grown during co-sputtering of targets were determined using optical techniques. It was shown that the SiO x layer composition is not equal to a simple sum of thicknesses of separately deposited Si and SiO 2 layers. The coordinate dependences of the Si and SiO2 layer thicknesses were calculated. To fit the calculated and experimental data, it is necessary to assume that no less than 10% of silicon is converted to dioxide during co-sputtering. A comparison of the coordinate dependences of the IR absorbance in SiO2 and SiO x layers with experimental ellipsometric data confirmed the presence of excess oxygen in the SiO x layer. Taking into account such partial oxidation of sputtered silicon, composition isolines in the substrate plane were calculated. After annealing of the SiO x layer at 1200°C, photoluminescence was observed in a wafer area predicted by calculations, which was caused by the formation of quantum-size Si nanocrystallites. The photoluminescence intensity was maximum at x = 1.78 ± 0.3, which is close to the composition optimum for ion-beam synthesis of nanocrystals.
Original language | English |
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Pages (from-to) | 731-736 |
Number of pages | 6 |
Journal | Semiconductors |
Volume | 42 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2008 |