Oxidation-enhanced diffusion of boron in very low-energy N2+-implanted silicon

Abstract

In this article we study the interstitial injection during oxidation of very low-energy nitrogen-implanted silicon. Buried boron δ layers are used to monitor the interstitial supersaturation during the oxidation of nitrogen-implanted silicon. No difference in boron diffusivity enhancement was observed compared to dry oxidation of nonimplanted samples. This result is different from our experience from N2O oxynitridation study, during which a boron diffusivity enhancement of the order of 20% was observed, revealing the influence of interfacial nitrogen on interstitial kinetics. A possible explanation may be that implanted nitrogen acts as an excess interstitial sink in order to diffuse towards the surface via a non-Fickian mechanism. This work completes a wide study of oxidation of very low-energy nitrogen-implanted silicon related phenomena we performed within the last two years [D. Skarlatos, C. Tsamis, and D. Tsoukalas, J. Appl. Phys. 93, 1832 (2003); D. Skarlatos, E. Kapetanakis, P. Normand, C. Tsamis, M. Perego, S. Ferrari, M. Fanciulli, and D. Tsoukalas, J. Appl. Phys. 96, 300 (2004)].

Nitrogen Implantation and Diffusion in Crystalline Germanium: Implantation Energy, Temperature and Ge Surface Protection Dependence

“…In this context the study of anomalous diffusion phenomena of implanted species (apart for common dopants) could monitor indirectly Ge point defects kinetics and interactions with the Ge surface or thin films/Ge interfaces for an understanding of fundamental Ge point defects properties. Nitrogen implantation and diffusion in inert and oxidizing ambient has been extensively studied in silicon [13][14][15][16][17][18][19][20][21][22] where anomalous (non-Fickian) diffusion phenomena takes place at temperatures above 700 • C. Diffusion occurs toward the free Si surface or a SiO 2 /Si interface and is attributed to nitrogen atoms -Si z E-mail: dskar@physics.upatras.gr interstitials interactions as also to the interaction of Si interstitilas with the free Si surface or the SiO 2 /Si interface. 15,16,18 This individual diffusion behavior found also a variety of applications in Si MOS technology.…”

Strong Diffusion Suppression of Low Energy-Implanted Phosphorous in Germanium by N2 Co-Implantation

“…Indeed, the anomalous nitrogen interstitial-mediated diffusion has been successfully employed for the suppression of dopant enhanced diffusion in silicon. 13 Although this practice has been proposed 2 in order to suppress P diffusion in Ge, there was not up to date a systematic study on the subject. The experiment of Ref.…”

B profile alteration by annealing in reactive ambients

“…Pieces of wafers were annealed in a Heatpulse lamp oven at 950°C for 30 s, with ramp-up rate around 100°C / s and ramp-down rate around 70°C / s. Three different gas ambients during anneal were used, i.e., N 2 100%, H 2 10% +N 2 90% ͑stimulating the B desorption process͒, 15 and O 2 10% +N 2 90% ͑stimulating I injection͒. 15,16 After processing, B depth profiles were determined using secondary ion mass spectroscopy ͑SIMS͒ using an Atomika 4500 instrument, and the electrical activation was extracted from the sheet resistance measurements based on standard mobility data. 17 In order to prevent any substrate contribution due to probe penetration, the sheet resistance was extracted from variable probe spacing measurements using spreading resistance probes with less than 5 nm penetration.…”