Fluorine implantation effects on Ta2O5 dielectrics on polysilicon treated with post rapid thermal annealing

• Published in: Applied surface science 2013-10, Vol.283, p.694-698
• Main Authors: Chen, Hsiang, Kao, Chyuan Haur, Huang, Bo Yun, Lo, Wen Shih
• Format: Article
• Language: English
• Subjects: Annealing; Atomic properties; Chemical bonds; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Dielectrics; Exact sciences and technology; Fluorine; Fluorine implantation; High-k dielectric; Implantation; Implantation dosage; Physics; Secondary ion mass spectrometry; Surface roughness; Ta2O5; Tantalum oxides
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.07.004

•High-k Ta2O5 dielectrics with fluorine implantation has been fabricated.•Effects of fluorine implantation and post rapid thermal annealing has been investigated.•Multiple electrical and material analyses have been conducted.•Distribution of implanted atoms after annealing has been examined. This paper investigates effects of fluorine implantation with post rapid thermal annealing on electrical characteristics and material properties of tantalum pentoxide (Ta2O5) dielectrics. The electrical behaviors of the dielectrics under various implantation doses were measured. To investigate annealing effects, secondary ion mass spectrometry (SIMS) was used to measure depth profiles of various atoms inside the dielectrics with and without annealing. In addition, atomic force microscopy measurements visualize the surface roughness and material properties of the dielectrics with different implantation doses. The dielectric performance can be significantly improved by an appropriate fluorine implantation dose of 1×1015ions/cm2 with post annealing at 800°C. The improvements in electrical characteristics were caused by the appropriate incorporation of the fluorine atoms presented in SIMS profiles and the removal of the dangling bonds and traps. The Ta2O5 dielectric incorporated with appropriate fluorine implantation and annealing treatments shows great promise for future generation of memory applications.