Luminescence from erbium oxide grown on silicon
- PDF / 90,521 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 37 Downloads / 219 Views
Luminescence from erbium oxide grown on silicon E. Nogales1, B. Méndez1, J.Piqueras1, R.Plugaru2, J. A. García3 and T. J. Tate4 1 Universidad Complutense de Madrid, Dpto. Física de Materiales, 28040 Madrid, Spain. 2 Inst. of Microtechnology, Bucharest, Romania. 3 Universidad del Pais Vasco, Dpto. Física Aplicada II, Vizcaya, Spain. 4 Imperial College, Dpt. of Electrical and Electronic Engineering, London, United Kingdom. ABSTRACT The luminescence properties of erbium oxide grown on crystalline and amorphous silicon substrates were studied by means of photo- and cathodoluminescence techniques. Differences in the luminescence spectra for samples grown on the two types of substrates used are explained in terms of the different types of erbium centers formed by taking into account the substrate properties and the thermal treatments during growth. For comparison, erbium implanted and oxygen coimplanted crystalline and amorphous silicon have been also investigated by luminescence techniques. In the implanted samples, the sharp transitions from erbium ions in the visible range were quenched and the main emission corresponds to the intraionic transitions in Er3+ ions in the infrared range peaked at 1,54 µm. INTRODUCTION The efficiency of luminescence emission associated to the intraionic Er3+ radiative transitions in different matrix is related to the mechanism of energy transfer from the hosts to the complexes formed by erbium and the surrounding atoms [1, 2]. The presence of other codopant elements in the Er neighborhood as well as the structure of the host matrix was found essential in determining the Er complexes formation [3, 4]. The presence of oxygen in the neighborhood of the erbium ions causes a strong enhancement of the efficiency of Er emission at 1.5µm wavelength [5]. Other luminescence bands of the Er related transitions from visible to infrared range could be observed by a selective excitation. In this work, the influence of the host matrix and of the excitation energies on the luminescence emission of erbium oxide grown on amorphous and crystalline substrates was investigated. The techniques used were photoluminescence (PL) and cathodoluminescence (CL) in the scanning electron microscope. The different emission bands detected are suggested to be originated at different types of Er centers formed in the erbium oxide overlayer. EXPERIMENTAL DETAILS Two sets of erbium doped silicon samples were investigated: erbium deposited and erbium implanted silicon films. In the former case, erbium vapor was deposited on amorphous and crystalline silicon substrates and the samples were then submitted to a thermal treatment at 950 ºC during 1 hour in oxygen or nitrogen atmosphere. On the other hand, crystalline and amorphous silicon substrates were implanted with 200 keV 166Er ions at doses of 5 x 1015 ions/cm2. Some of the amorphous silicon substrates were coimplanted with 200 keV Er ions and 40 keV 16O ions at doses of 5 x 1015 and 1016 ions/cm2 respectively. All the implanted samples
H9.14.1
Table I. Summary of the sam
Data Loading...
