Deposition-temperature-dependent stress of capping oxide and its effect on Pt/Pb(Zr1−xTix)O3/Pt ferroelectric capacitor

Abstract

Two different interlayer dielectric (ILD) materials, electron cyclotron resonance chemical vapor deposition oxide (ECR-OXIDE) and plasma enhanced chemical vapor deposition TEOS oxide (PE-TEOS), were prepared at 400 and 200 °C respectively, on silicon substrates and Pt/Pb(Zr1−xTix)O3 (PZT)/Pt capacitors. It was found that the ILD deposition temperature is a most important parameter for minimizing the degradation of remnant polarization (Pr) during the ILD deposition. Since the stress of PZT capacitor strongly depends on the ILD deposition temperature, the PZT capacitor with PE-TEOS showed more compressive stress than that with ECR-OXIDE, which results in severe Pr degradation of PZT capacitor with PE-TEOS. This large stress effect of PE-TEOS was confirmed by x-ray diffraction (XRD) patterns in which the d spacing of (111) PZT films with PE-TEOS was much larger than that of PZT films with ECR-OXIDE. Therefore, the low ILD deposition temperature is a key parameter for achieving an ILD integration without any Pr degradation.