AVS 53rd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS1-TuP

Paper PS1-TuP5
Etch Characteristics of Na@sub 0.5@K@sub 0.5@NbO@sub 3@ Thin Films using Cl@sub 2@/BCl@sub 3@/Ar Inductively Coupled Plasma

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Etching of High-K, Compound Semiconductors and Advanced Materials Poster Session
Presenter: C.M. Kang, Chung-Ang University, Korea
Authors: C.M. Kang, Chung-Ang University, Korea
K.T. Kim, Chung-Ang University, Korea
G.H. Kim, Chung-Ang University, Korea
C.I. Kim, Chung-Ang University, Korea
Correspondent: Click to Email
Recently a unique combination of properties has been discovered in the perovskite Na@sub 0.5@K@sub 0.5@NbO@sub 3@(NKN) thin films. They possess very low loss at room temperature, high piezoelectric coefficient, and moderate dielectric constant, which is strongly dependent on electric field. It was shown that NKN thin films are able to overcome the drawbacks of other materials, such as (Sr,Ba)TiO@sub 3@ and Pb(Zr,Ti)O@sub 3@ for nonvolatile memory applications. Additionally, NKN films exhibit a self-assembly phenomenon despite high volatility of Na and K constituents, strongly c-axis oriented ferroelectric films can grow onto the Si substrates. NKN films are promising for a vast variety of emerging applications, such as nonvolatile memory and actuators. But, etch properties and etching mechanism of NKN have not established yet. In this study, we studied etch characteristics of NKN thin films using inductively coupled plasma for ferroelectric random access memories. The etch rate and etch selectivity in proportion to variations gas mixing ratios, input rf power, dc bias voltage and chamber pressure were obtained. As the ICP power and the rf power increased, the etch rate of NKN also increased. As the gas pressure increased, the etch rate of NKN decreased. The behaviors of active species in plasma were measured by optical emission spectroscopy (OES). Scanning electron microscopy (SEM) was used to investigate the etching profile. X-ray photoelectron spectroscopy (XPS) was carried out to investigate the chemical states of the etched surfaces.