High-k Zr-silicate를 이용한 MIS소자 제작과 공정최적화

초록

In this paper, etching charateristics of Zr-silicate in Ar/Cl2/CH4 palsma is studied, and possible plasma damage is investigated by fabricating MIS capacitors. We could increase the selectivity to near 2 while keeping the etch rate Zr-silicate to about 70 nm/min. Leakage current and flat band voltage shift of Pt/Zr-silicate/Si capacitors are measured before and after plasma etching. Using capacitor patterns with the same area but different circumference lengths, we try to sepearate etching damage mechanisms and to optimize the process. The leakage current of 1.2X10^(-3) A/cm^2 and smaller capacitance variation of 0.2 nF at -2V are obtained in Ar/Cl2/CF4 plasma at 200 W RF power.