Fabrication and Characterization of a PZT-Based Touch Sensor Using Combined Spin-Coating and Sputtering Methods

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Lead zirconate titanate (PZT) is a crucial material for piezoelectric applications.
• Developing robust PZT thin films on silicon substrates is essential for advanced sensor technology.
• Hybrid deposition methods offer unique advantages for tailoring film properties.

Purpose of the Study:

• To fabricate and characterize lead zirconate titanate (PZT) thin films on silicon (Si) substrates using a hybrid spin-coating and RF sputtering technique.
• To develop and evaluate a multilayer PZT-based touch sensor for tactile and pressure sensing applications.
• To investigate the electrical behavior and material non-idealities affecting sensor performance.

Main Methods:

• Hybrid deposition: spin-coating followed by RF sputtering for PZT film fabrication.
• Material characterization: XRD, SEM, EDX, and UV-VIS spectroscopy.
• Electrical characterization: I-V measurements, impedance-frequency (|Z|-f) analysis, and modified Butterworth-Van Dyke (BVD) model fitting.

Main Results:

• Successful fabrication of well-crystallized perovskite PZT films with a uniform surface and an optical band gap of ~3.55 eV.
• Demonstrated repeatable polarization behavior and dynamic electrical characteristics in the fabricated PZT-based touch sensor.
• Identified Ag+ ion diffusion as a source of non-idealities, addressed by extending the BVD model for accurate electrical performance analysis.

Conclusions:

• The hybrid deposition method yields high-quality PZT thin films suitable for sensor applications.
• The developed PZT-based sensor exhibits potential for tactile and pressure sensing interfaces.
• Modified equivalent circuit modeling provides critical insights into material degradation and electrical performance.