AVS 50th International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP4
The Electrical Properties of SBT Thin Films Etched in BCl@sub 3@/Cl@sub 2@/Ar Plasma

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: J.K. Kim, Chung-Ang University, Korea
Authors: J.K. Kim, Chung-Ang University, Korea
C.I. Kim, Chung-Ang University, Korea
K.T. Kim, Chung-Ang University, Korea
D.P. Kim, Chung-Ang University, Korea
Correspondent: Click to Email
SrBi@sub 2@Ta@sub 2@O@sub 9@ (SBT) thin films have a lot of good features such as high resistance to polarization fatigue due to the charge-compensating role of the (Bi@sub 2@O@sub 2@)@super 2+@. The 200-nm SBT thin films were deposited on the Pt electrode by metal organic deposition (MOD). Until now, there is no report on the etching characteristics of SBT thin films in BCl@sub 3@/Cl@sub 2@/Ar inductively coupled plasma (ICP). Therefore, SBT thin films were etched in BCl@sub 3@/Cl@sub 2@/Ar with using ICP etching system. The etch rates and selectivity of SBT thin films were investigated as functions of gas mixing ratio, rf power, dc-bias voltage and pressure. With adding 20% BCl@sub 3@ in Cl@sub 2@/Ar plasma, increasing rf power and dc bias voltage, and lowering pressure, the etch rate of SBT increased. The etching byproducts were investigated with using quadruple mass spectroscopy (QMS). The heterogeneous reaction of plasma on the surface of the etched SBT was investigated with x-ray photoelectron spectroscopy (XPS). The etching profiles of samples have been investigated with using scanning electron microscopy. The chemical states on the etched surface were investigated with XPS. After the etching, the electrical properties of SBT capacitors were characterized in terms of hysteresis curves, leakage current and switching polarization. After etching in BCl@sub 3@/Cl@sub 2@/Ar plasma, the remanent polarization decreased and the leakage current increased. After the annealing at 600°C in an O@sub 2@ atmosphere for 10 min, the ferroelectric properties were significantly recovered. The degradation of electrical properties after the etching was considered due to the physical effect of ion bombardment and chemical residue contamination.