Effect of Titanium (Ti)-Seed and In Vacuo Process Flow on Sputtered Lead Zirconate Titanate Thin Films
Abstract
In a process improvement study to optimize a platinum (Pt) bottom electrode for lead zirconate titanate (PZT) film growth, PZT thin films were grown on Pt bottom electrodes on thermally oxidized silicon substrates. The PZT depositions on Pt were made with no underlying layer, a nucleation layer, a titanium (Ti)-seed layer, or a combination of nucleation on Ti-seed layer. X-ray diffraction and electrical characterization determined that a Ti-seed deposited on top of the Pt, rather than on a PZT nucleation layer, was critical to produce PZT with preferred {001} orientation while minimizing secondary phases. Best electrical performance was characterized by a dielectric constant epsilon = 1150 +/- 100, tan delta = 0.019 +/- 0.001 at E = 0, and maximum polarization of 34.7 +/- 0.6 micro C/cm2 at 200 kV/cm. In contrast, characterizations performed also indicate that exclusion of the Ti-seed from the PZT stack process results in dominant diffraction peaks that appear to be generated by a pyrochlore or highly strained 110 PZT phase with pinned domains.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2019
- Accession Number
- AD1081729
Entities
People
- Christopher Cheng
- Daniel M. Potrepka
- Glen R. Fox
- Jeffrey S. Pulskamp
- Robert R. Benoit
- Ryan Q. Rudy
- Susan Trolier-McKinstry
Organizations
- United States Army Research Laboratory