Improvement of nitrogen retained dose using ammonia as a precursor in nitrogen plasma immersion ion implantation of silicon

Abstract

The low nitrogen retained dose due to competition from oxygen coimplantation diminishes the efficacy of nitrogen plasma immersion ion implantation in silicon. In this work, we aim at improving the nitrogen retained dose by using ammonia as a precursor. Ammonia is introduced into the nitrogen plasma during plasma immersion ion implantation of silicon to improve the nitrogen reactivity and reduce the competition from oxygen in the residual vacuum. Our x-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy results indicate that the ammonia precursor can indeed improve the N retained dose effectively, and the hydrophilic properties of the surface change with different ammonia to nitrogen ratios.

Controllable immobilization of polyacrylamide onto glass slide: synthesis and characterization

“…The –NH 2 groups probably interact with other silanol groups by hydrogen bonding, explaining the high binding energy values compared with the other examples from the literature data (399.7 vs. 399.3 eV) [21–23]. The N 1 s (400.9 eV) photoelectron peak confirms that nitrogen in the glass slide has different bonding states, possessing higher binding energy than that of Si–N configuration (400.3 eV) [24]. This is also a little difference from the reported peak positions of silicon oxynitride [25].…”

Behaviors of Platelets Adherent on Si-N(H) Surface Prepared from Ammonia Plasma-Implanted Silicon

“…According to XPS results, the nitrogen retained dose increases with the use of the ammonia precursor and that of oxygen changes in an opposite fashion. Oxygen contamination is a very common phenomenon for such vacuum technique, and usually mitigates the efficacy of the nitrogen implantation [3]. According to the binding energy of the N1s, the retained N is predominantly in the Si-N-O configuration with the peak position of 397.6eV for # 0 samples, and is extensively Si-N boding states of 397.2 eV (lower shifted) on A1 and A2 samples [5,6].…”

“…We report in this paper our investigations on platelets behaviors on the surface of ammonia implanted silicon, as the platelets adhesion testing is commonly used to evaluate the thrombosis risk of the biomaterials for blood contacting. We synthesize silicon nitride films by plasma immersion ion implantation (PIII) of ammonia as precursor to obtain higher retained doses of nitrogen [3], and PIII offers also an effective method to produce the films with high adhesion strength due to inherent ion mixing, and as a non-line-of-sight technique, this process is applicable to samples possessing a complex geometry such as mechanical sensing devices [4].…”