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ANGLE RESOLVED XPS ANALYSIS OF SURFACE REGION DEFECTS IN RAPID THERMAL ANNEALED ANTIMONY IMPLANTED SILICON S.N. Kumar, G. Chaussemy and A. Laugier, Laboratoire de Physique de la Mati~re, Institut

National des Sciences Appliquies de Lyon, 69621 Villeurbanne, France

B. Canut, Ddpartement de Physique des Materiaux, and M. Charbonnier, DNpartement de Chimie Appliqude, Universitd Claude Bernard Lyon I, 69622 Villeurbanne, France. ABSTRACT Angle-resolved X-ray photoelectron spectroscopy characterization of the surface region of high-dose Sb+ ion implanted silicon, after rapid thermal treatments over various temperatures, is reported. The results obtained are compared with the Rutherford backscattering data and the capacitance-voltage measurements on the metal-oxide-semiconductor mesa structures built on them. Rapid anneal at 1100 'C of the 1.4x10 16 Sb+/cm 2 samples showed an anomalous deep oxygen diffusion inside the implanted region. INTRODUCTION High-dose ion implantation of silicon followed by rapid thermal annealing (RTA) is now a well established technique in metal-oxide-semiconductor (MOS) technology. Arsenic or antimony is the usually preferred n+ dopant in the fabrication of bipolar integrated circuits. However, for ultrashallow junctions, Sb is more advantageous owing to its reduced range, straggle, and a lower diffusion coefficient. Further, unlike in the case of As, there is a minimal

evaporative loss of dopant during the silicidation of the source-drain regions. Electrical

measurements [1] on supersaturated solid solutions of antimony in silicon have shown that carrier concentration can greatly exceed the solid solubility limits. The solid phase epitaxial regrowth of the damaged amorphous zone takes place at about 550 IC and the maximum incorporation of electrically active antimony at substitutional sites is complete at about 700 OC [2]. An anomalous depletion behavior of antimony from substitutional sites on annealing above 7000 C has been reported by Holland and Fathy [3]. This may be either due to a vacancy assisted Sb diffusion into the precipitates, as deduced from oxidation-retarded diffusion of Sb [4], or by an interstitialcy mechanism [5], due to the existence of a supersaturated interstitial solution upon SPE recrystallization. These contradictory observations thus point out the need for more information of the structural and chemical nature of the near surface region where enhanced Sb depletion is known to occur when annealing is carried out at temperatures higher than 700 'C. The objective of the present work is to carry out a systematic analysis of the surface region of the high-dose Sb implanted samples after RTA over a wide temperature range, namely, from 500 to 1100 0 C. We use the highly surface sensitive technique of angle resolved X-ray photoelectron spectroscopy (ARXPS) to identify the chemical states of Si, 0 and Sb after various RTA treatments of samples implanted with Sb with a dose in the range of 2x10 14 to l.4x10 16 2 Sb/cm with 40, 80 and 120 keV implant energies.These results a