Implantation of P ions in SiO2 layers with embedded Si nanocrystals

Autor: Alexander G. Cherkov, David Tetelbaum, A.K. Gutakovsky, V. G. Kesler, Vladimir A. Volodin, A.V Bublikov, G. A. Kachurin, S. G. Cherkova
Rok vydání: 2004
Předmět:
Zdroj: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 222:497-504
ISSN: 0168-583X
DOI: 10.1016/j.nimb.2004.03.076
Popis: The effect of 10 13 –10 16 cm � 2 P ions implantation and of subsequent annealing on Si nanocrystals (Si-ncs), formed preliminarily in SiO2 layers by the ion-beam synthesis, has been studied. Photoluminescence (PL), Raman spectroscopy, high resolution electron microscopy (HREM), X-Ray Photoelectron Spectroscopy (XPS) and optical absorption were used for characterizations. The low fluence implantations have shown even individual displacements in Si-ncs quench their PL. Restoration of PL from partly damaged Si-ncs proceeds at annealing less than 1000 C. In the low fluence implanted and annealed samples an increased Si-ncs PL has been found and ascribed to the radiation-induced shock crystallization of stressed Si nanoprecipitates. Annealing at temperatures under 1000 C are inefficient when P ion fluences exceed 10 14 cm � 2 , thus becoming capable to amorphize Si-ncs. High crystallization temperature of the amorphized Si-ncs is attributed to a counteraction of their shell layers. After implantation of the highest P fluences an enhanced recovery of PL was found from P concentration over 0.1 at.%. Raman spectroscopy and HREM showed an increased Si-ncs number in such layers. The effect resembles the impurity-enhanced crystallization, known for heavily doped bulkSi. This effect, along with the data obtained by XPS, is considered as an indication P atoms are really present inside the Si-ncs. However, no evidence of free electrons appearance has been observed. The fact is explained by an increased interaction of electrons with the donor nuclei in Si-ncs. 2004 Elsevier B.V. All rights reserved.
Databáze: OpenAIRE
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