Zhang Lin-Tao

Design optimization of beam-like ferroelectrics-silicon microphone and microspeaker

Design optimization of beam-like ferroelectrics-silicon integrated microphone and microspeaker is studied. The Pt/Pb(Zr,Ti)O3/Pt/SiO2/Si3N4 cantilever structure is designed theoretically using multimorph model. The sensitivity and the sound pressure level (SPL) of the integrated microphone and microspeaker are calculated. It is found that the sensitivity of the microphone and the SPL of the microspeaker are very high. This integrated microphone and microspeaker will be valuable for high quality micro-acoustic devices.

Electrical properties of a silicon-based PT/PZT/PT sandwich structure

Abstract A new silicon-based PbTiO3/Pb(Zr0.53Ti0.47)O3/PbTiO3 (PT/PZT/PT) sandwich structure is prepared in this paper. A simple and low-cost sol-gel method is used to fabricate the ferroelectirc thin films. The annealing temperature (700 °C) is greatly reduced compared with 900 °C of that without PT layers. Capacitance-voltage (C-V), polarization-field (P-E) and dielectric-frequency properties of the sandwich structure are tested. The PZT films are proved to have good dielectric and ferroelectric properties. The relative dielectric constant, the coercive field and the remnant polarization of the PZT films are measured to be about 900, 18 kV/cm and 16 μC/cm2 respectively. The dielectric constant of the structure keeps constant at low frequency, and decreases in some degree at high frequency.

Preparation and characterization of a sol-gel prepared ferroelectric sandwich structure

A novel silicon-based PbTiO3/Pb(Zr,Ti)O3/PbTiO3 (PT/PZT/PT) sandwich structure has been prepared using a sol-gel method. The annealing temperature is greatly reduced compared with those structures without PT layers. Capacitance-voltage (C-V), leakage current-voltage (I-V), polarization-field (P-E), dielectric-frequency response and polarization fatigue of the sandwich structure are examined. The relative dielectric constant, the coercive field and the remanent polarization of the PZT films are measured to be about 900, 18 kV/cm and 16 μC/cm2 respectively. The current density is less than 5 × 10−9 A/cm2 below 200 kV/cm. The dielectric constant of the structure remains constant at low frequency, and decreases to some degree at high frequency. The retained polarization does not change significantly after 8 × 109 read/write cycles. The PZT films are proved to have very good dielectric and ferroelectric properties. The new PT/PZT/PT sandwich structure can be valuable for memory devices and other applications.

New silicon-based ferroelectric sandwich structure

A new silicon-based PbTiO/sub 3//Pb(Zr,Ti)O/sub 3//PbTiO/sub 3/ (PT/PZT/PT) sandwich structure is prepared using a sol-gel method. The annealing temperature is greatly reduced compared with that without PT layers. Capacitance-voltage (C-V), current density - electric field (J-E), polarization-field (P-E) and dielectric-frequency responses of the sandwich structure are studied. The maximum dielectric constant of about 900 is obtained at the coercive field 18 kV/cm, and the remnant polarization is 16 /spl mu/C/cm/sup 2/. The current density is 5 /spl times/ 10/sup -9/ A/cm/sup 2/ below 200 KV/cm. The dielectric constant of the structure stays constant at low frequency, and decreases to some degree at high frequency. The PZT films are proved to have very good dielectric and ferroelectric properties. The PT/PZT/PT sandwich structure will have a use in memory devices and other applications.

Design of a new ferroelectrics-silicon integrated microphone and microspeaker

A new ferroelectrics-silicon integrated microphone and microspeaker is proposed. The Pt/Pb(Zr,Ti)O/sub 3//Pt/SiO/sub 2//Si/sub 3/N/sub 4/ cantilever structure is designed theoretically using multimorph model. The sensitivity and the sound pressure level (SPL) of the integrated microphone and microspeaker are calculated. It is found that the sensitivity of the microphone and the SPL of the microspeaker are very high. The new integrated microphone and microspeaker will be valuable for high quality micro-acoustic devices.

A Silicon-Based Ferroelectric Capacitor for Memory Devices

We study a silicon-based PbTiO3/Pb(Zr0.53Ti0.47)O3/PbTiO3 capacitor, prepared by an improved sol-gel method. The ferroelectric capacitor has a high remanent polarization of 15 µC/cm2 at a coercive field of about 30 kV/cm, an ultra-low leakage current density of 0.1 nA/cm2, and almost fatigue free properties. It can be used as a promising candidate for ferroelectric memory devices.

Design of a new PZT based microphone and microspeaker

Abstract A new ferroelectrics-silicon integrated microphone and microspeaker is proposed. A Pt/Ti/Pb(Zr0.53Ti0.47)O3/Pt/Ti/SiO2/Si3N4 cantilever structure is adopted as the main component of the microphone and microspeaker. The cantilever structure is theoretically designed and simulated using multimorph model. The sensitivity and the sound pressure level (SPL) of the integrated microphone and microspeaker structure are calculated. It is found that the sensitivity of the microphone and the SPL of the microspeaker are both higher than those of other microphones and microspeakers that have ever been reported.

A New Silicon-Based Ferroelectric Sandwich Structure

A new silicon-based PbTiO3/Pb(Zr0.53Ti0.47)O3/PbTiO3 sandwich structure is fabricated by a sol-gel method. Compared with other fabrication processes without PbTiO3 buffer layers, the annealing temperature is greatly reduced by as much as 100°C. Capacitance-voltage, polarization-electric field and dielectric-frequency properties of the sandwich structure are studied. The Pb(ZrxTi1-x)O3 films are proved to have good dielectric and ferroelectric properties. PACS: 85. 50. +k, 77. 84. -s