Plasma immersion ion implantation and deposition (PIIID) is an attractive technique for creating ultra-shallow dopant distributions with extremely high levels of active dopant concentration, with the added value of conformal doping. The latter is crucial for the realization of tridimensional transistor structures like fin-FETs or similar. While many reports about boron PIII doping of silicon can be found in literature, n-type doping reports are sparse, particularly concerning arsenic. In this work, samples obtained by implanting high fluences (~1E15 at./cm2) of AsH3+ on (100) Si by ultra low energy (<2 kV) PIIID (AsH3/ H2 plasma atmosphere) were examined using SEM, SIMS, XPS, ToF-SIMS, INAA, TEM, Raman spectroscopy, and EXAFS. ‘As-implanted’ arsenic distributions were found to be confined within <10 nm depth with a < 2 nm/decade profile abruptness corresponding to the SIMS depth resolution (300 eV/ 45° Cs+ beam). Additionally, two phenomena were observed at very high arsenic surface concentrations: 1) the spontaneous formation of arsenolite micro-crystals at the samples surface when exposed to atmosphere [1]; 2) a rapid growth of the native Si oxide reaching an equilibrium value of several nanometers after a few weeks of air exposure. We will report recent results of further investigations of these effects, carried out in order to identify their root cause and their impact on successive annealing. [1] F. Meirer, et al., Applied Physics Letters, 101, 232107 (2012)
Time-dependent observations of arsenic ultra shallow junctions formed by AsH3 Plasma Immersion Ion Implantation and Deposition in Silicon
Meirer, Florian;Demenev, Evgeny;Giubertoni, Damiano;Gennaro, Salvatore;Vanzetti, Lia Emanuela;Pepponi, Giancarlo;Bersani, Massimo;
2013-01-01
Abstract
Plasma immersion ion implantation and deposition (PIIID) is an attractive technique for creating ultra-shallow dopant distributions with extremely high levels of active dopant concentration, with the added value of conformal doping. The latter is crucial for the realization of tridimensional transistor structures like fin-FETs or similar. While many reports about boron PIII doping of silicon can be found in literature, n-type doping reports are sparse, particularly concerning arsenic. In this work, samples obtained by implanting high fluences (~1E15 at./cm2) of AsH3+ on (100) Si by ultra low energy (<2 kV) PIIID (AsH3/ H2 plasma atmosphere) were examined using SEM, SIMS, XPS, ToF-SIMS, INAA, TEM, Raman spectroscopy, and EXAFS. ‘As-implanted’ arsenic distributions were found to be confined within <10 nm depth with a < 2 nm/decade profile abruptness corresponding to the SIMS depth resolution (300 eV/ 45° Cs+ beam). Additionally, two phenomena were observed at very high arsenic surface concentrations: 1) the spontaneous formation of arsenolite micro-crystals at the samples surface when exposed to atmosphere [1]; 2) a rapid growth of the native Si oxide reaching an equilibrium value of several nanometers after a few weeks of air exposure. We will report recent results of further investigations of these effects, carried out in order to identify their root cause and their impact on successive annealing. [1] F. Meirer, et al., Applied Physics Letters, 101, 232107 (2012)I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
