UNCORRECTED PROOF Physica B ] (]]]]) ]]]–]]] Single impurity centers embedded in self-assembled silicon microcavities N.T. Bagraev*, A.D. Bouravleuv, L.E. Klyachkin, A.M. Malyarenko A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, 26 Polytechnicheskaya ul, St. Petersburg 194021, Russia Abstract We present the findings of high efficient light absorption in self-assembled quantum wells (SQW) embedded in silicon microcavities that exhibit a distributed feedback identified by the FIR transmission spectra. The photo and electroluminescence from SQW is found to be enhanced in the range of the Rabi splitting. The intraband hole transitions are shown to give rise to a fast energy transfer into the d-shell transitions of the center incorporated into the microcavity which is caused by the strong sp-d mixing in the built-in electric field and revealed by the intracenter emission. r 2001 Published by Elsevier Science B.V. Keywords: Single centers; Microcavity; Scanning tunneling microscopy 1. Introduction Dopant diffusion in silicon is known to be amenable to control by means of adjusting the fluxes of self- interstitials and vacancies emerging from the mono- crystalline surface [1]. The diffusion of boron has been found to be enhanced along the /111S axis in the Si(1 0 0) wafer covered by the thin oxide overlayer, whereas the presence of thick oxide overlayer on the Si(1 0 0) wafer raises the boron diffusion along the /100S axis [2]. These indications point out the crystallographic orientation of the excess fluxes of self- interstitials and vacancies that seem to involve dopants in the diffusion process and to be split into space- independent parts generated by the oxidized working side. The goal of the present work, which studied the absorption and emission from self-assembled quantum wells (SQW) inside the ultra-shallow boron diffusion profile, is to exhibit silicon microdefects induced by the excess fluxes of self-interstitials that form the micro- cavities embedded in SQW. 2. Methods The short-time boron diffusion was carried out from the gas phase into 350mm thick n-type monocrystalline Si(1 0 0)-wafers with resistivities 20 O cm. The wafers were previously oxidized at 11501C in dry oxygen containing CCl 4 vapors. Short-time impurity doping was done under fine surface injection of both self-interstitials and vacancies into windows which were cut in the oxide after preparing a mask and performing the subsequent photolithography. Additional replenishment with dry oxygen into the gas phase during the diffusion process provides the generation of excess fluxes of intrinsic point defects from the working side. The variable parameters of the diffusion experiment were the oxide overlayer thickness, the diffusion temperature and the Cl levels in the gas phase during the diffusion process. Diffusion profiles were studied using the four-point probe, SIMS, cyclotron resonance (CR), infrared Fourier spectroscopy and scanning tunneling microscopy (STM) techniques. 3. Results Using SIMS and four-point probe technique under layer-by-layer etching, the analysis of the structures ARTICLE IN PRESS 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 101 103 105 107 109 111 3b2v7 PHYSB : 22776 Prod:Type: TYP pp:124ðcol:fig::NILÞ ED: JAYASHREE SANYASI PAGN: TNN SCAN: SUJATHA *Corresponding author. Tel.: +7-812-247-9311; fax: +7- 812-247-1017. E-mail address: impurity.dipole@pop.ioffe.rssi.ru (N.T. Bagraev). 0921-4526/01/$ - see front matter r 2001 Published by Elsevier Science B.V. PII:S0921-4526(01)00899-7