AVS 50th International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoM

Paper PS-MoM9
50nm Gate Electrode Patterning using a Neutral Beam Etching System

Monday, November 3, 2003, 11:00 am, Room 315

Session: Critical Dimension Etching
Presenter: S. Noda, Tohoku University, Japan
Authors: S. Noda, Tohoku University, Japan
S. Samukawa, Tohoku University, Japan
H. Nishimori, Semiconductor Leading Edge Technologies, Inc. (Selete), Japan
T. Ida, Semiconductor Leading Edge Technologies, Inc. (Selete), Japan
T. Arikado, Semiconductor Leading Edge Technologies, Inc. (Selete), Japan
K. Ichiki, Ebara Research Co., Ltd., Japan
Correspondent: Click to Email
The increased packing density of ultra large-scale-integrated circuits (ULSI) requires ultra thin dielectric films that have low leakage current and are extremely reliable in metal-oxide-silicon (MOS) devices. High-k dielectrics films have been identified as leading candidates to replace conventional SiO@sub 2@ gate dielectrics in future ultra large-scale integrated circuits. However, the high-k films are more fragile and defective materials in comparison with the SiO@sub 2@-based thin films. As a result, the process-induced damages are very serious problems, such as charge-build-damages, changes in film quality and generation of defects by the irradiation of charged particles (ions and electrons) and VUV photons during the plasma etching processes. To break-through these problems, we developed a high-efficiency neutral beam etching system using negative ions generated in the pulse-time-modulated inductively coupled plasma (TM-ICP).@footnote 1@ In this system, high-density (1-4mA/cm@super 2@) and low-energy (10-100eV) neutral beams are effectively extracted from the pulsed plasma. It is expected that the neutral beam etching is promising candidate for the damage-free high-k gate electrode patterning. In this paper, we evaluated characteristics of the poly-Si gate etching using fluorine (SF@sub 6@) and chlorine (Cl@sub 2@) based gas chemistries. Highly anisotropic 50nm poly-Si etching profiles could be obtained with no degradation of extremely fine resist patterns in the case of the chlorine based neutral beams. The electrical properties of MOS capacitors will also be presented in comparison with the results in the conventional plasma etching systems. @FootnoteText@ @footnote 1@ S. Samukawa, K. Sakamoto and K. Ichiki, J. Vac. Sci. Technol. A20, 1566 (2002).