• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.30A no.10
• /
• pp.59-66
• /
• 1993

PZT thin film deposited by rf magnetron sputtering was annealed by rapid thermal process(RTP) in PbO ambient to prevent vaporing of Pb and interface reactions. Si and TiN/Ti/Si substrates were prepared to survey application of TiN/Ti layer which can prevent interface interaction with Si and crack of PZT thin films. As temperature increased. PZT thin films surface on Si substrate appeared more severe cracks which should affect electrical properties deadly. TiN/Ti(40-150${\mu}{\Omega}{\cdot}cm$) layer applied for buffer layer suppressed interface interaction and film cracking. The measured leakage current(LC) and breakdown voltage(BV) of PZT thin film on TiN/Ti/Si substrate annealed at 650$^{\circ}$C for 15 sec (thickness of 2500$\AA$) were 38 nA/cm2 and 3.5 MV/cm and dielectric constant was 310 at 1 MHz, and remanent polarization (Pr) and coercive field (Ec) were 6.4${\mu}C/cm^{2}$ and 0.2MV/cm at 60 Hz, respectively.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.4
• /
• pp.558-561
• /
• 1996

PZT powders were prepared by the molten salt synthesis method. The porous PZT ceramics were made from a mixture of PZT and polyvinylalcohol(PVA) by BURPS(Burnout Plastic Sphere) technique. The porous PZT bodies were fabricated from the green compacts with various amounts of PVA spheres. The piezoelectric coefficient d$_{33}$ (334~350*10$^{-12}$ C/N)of porous PZT ceramics(364*10$^{-12}$ C/N). The figure of merit(d$_{h}$g$_{h}$) of porous PZT specimens evaluating the sensitivity for ultrasonic transducer applications was improved significantly(11~70times) in comparison with that of single phase PZT ceramics(100*10$^{-15}$ m$^{2}$/N). The thickness mode coupling factor k$_{t}$(0.5~0.6) of porous specimens was comparable with that of single phase PZT ceramics(k$_{t}$=0.7). The mechanical quality factor of porous PZT specimens was smaller than 10, and thus these porous PZT ceramics would be believed as a good candidate for broad band hydrophone applications. (author). 10 refs., 7 figs.igs.igs.

• Journal of the Korean Ceramic Society
• /
• v.41 no.1
• /
• pp.30-35
• /
• 2004

PMW-PZT thick films of about $30{\mu}m$ thickness were fabricated on Pt/$TiO_2$/$SiN_x$Si substrate by the hybrid method of screen printing and PZT sol application. With the increase of the number of the sol application times, the sintered density and electrical properties of PMW-PZT thick films were evidently increased. For the PMW-PZT thick film with PZT sol application of 10-times, the dielectric constant ($\varepsilon_r$) was 745 at the frequency of 100 KHz and thepiezoelectric coefficient ($d_33$) was 155 pC/N at the applied pressure of 1 atm.

• Korean Journal of Materials Research
• /
• v.3 no.1
• /
• pp.19-27
• /
• 1993

Abstract The PZT thin film was deposited by usin. RF magnetron sputtering with PZT(52/48) target. The formation of perovskite structure PZT thin film started at 55$0^{\circ}C$ on Si substrate. The AES results showed an oxide layer formed at the between Si and PZT film during the annealing. And, Ti$O_2$ layer appeared at the between TiN and PZT film for the annealing. But, the perovskite phase PZT film was formed after the annealing on the Si$O_2$/Si substarte. The ratio in PZT film was constant across the asdeposited PZT film, but, Pb have diffused into the Si substrate and Si have out-diffused into PZT layer during the post annealing at 75$0^{\circ}C$. The dielectric constants of PZT film indicated about 1300( thickness: 1500$\AA$, at 10KHz) but, the cracks were appeared to surface for annealing.

• Electrical & Electronic Materials
• /
• v.9 no.3
• /
• pp.251-258
• /
• 1996

Sol-Gel derived ferroelectric Pb(Z $r_{0.52}$ $Ti_{0.48}$) $O_{3}$ thin films have been fabricated on Pt/Ti/ $SiO_{2}$/Si substrate. Two kinds of fast annealing methods, F-I (six times of intermediate and final annealing) and F-II(one final annealing after six times of intermediate annealing) were used for preparation of multi-coated PZT thin films. As the annealing temperature was increased, high capacitance could be obtained, for instance, 2700.angs.-thick PZT thin film annealed at 680.deg. C had a capacitance value of approximately 20nF at 1kHz. In addition, it is found that the dielectric constant is a function of the perovskite phase fraction. In case of F-I method, PZT thin film had a remanent polarization(Pr) of 8-15.mu.C/c $m^{2}$ and a coercive field( $E_{c}$) of 35-44kV/cm according to annealing temperature, whereas PZT film fabricated by F-II method had as high as 24-25.mu.C/c $m^{2}$ and 48-59kV/cm, respectively. As a result of measuring Curie temperature, PZT thin film had a range of 460-480.deg. C by F-I method and more or less higher range of 525-530.deg. C by F-II method, which implied that different microstructures could cause the different Curie temperature. Through I-V measurement, leakage current of PZT thin film fabricated by F-I and F-II methods was 64nA/c $m^{2}$ and 2.2.mu.A/c $m^{2}$ in the electric field of 100kV/cm, respectively.y.y.y.

• Journal of the Korean Ceramic Society
• /
• v.30 no.4
• /
• pp.332-338
• /
• 1993

TiN/Ti is the best buffer layer between PZT thin film and si substrate among the Ti, TiN, ZrN, TiN/Ti, ZrN/Ti. The amorphous PZT films deposited on TiN/Ti buffer layer directly transform into perovskite phase when rapid thermal annealed for 30sec above 55$0^{\circ}C$. As Rapid Thermal Annealing(RTA) temperature increased, the remanent polarization(Pr) and dielectric constant($\varepsilon$r) increased and then showed Pr=21 $\varepsilon$r=593 when rapid thermal annealed 80$0^{\circ}C$ for 30sec. On the contrary the leakage current increased with increasing RTA temperature due to the formation of void made by Pb evaporationand grain cohesion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.1
• /
• pp.33-38
• /
• 2003

Highly homogeneous PZT powder was prepared by a partial oxalate method using chemicals of (Z $r_{0.53}$ $Ti_{0.47}$) $O_2$, Pb(N $o_3$)$_2$and (COOH)$_2$ㆍ2$H_2O$. N $b_2$ $O_{5}$ addition effect on microstructure and electrical properties of PZT ceramics was investigated. When the precursors were calcined at 71$0^{\circ}C$, a single perovskite phase was obtained. After sintering at 110$0^{\circ}C$, X-ray diffraction Patterns showed coexistence of rhombohedral and tetragonal phases regardless of the N $b_2$ $O_{5}$ content. As the content of N $b_2$ $O_{5}$ increased, grain size decreased but sintered density increased. The electromechanical coupling factor of kp and the piezoelectric constant of $d_{31}$ increased linearly with the content of N $b_2$ $O_{5}$, and those values reached 0.7 and -200, respectively, when 1.2 mol% of N $b_2$ $O_{5}$ is added. is added.ded.

• Electrical & Electronic Materials
• /
• v.6 no.5
• /
• pp.436-445
• /
• 1993

2단계하소법에 의해 낮은 하소온도에서 미세하고도 균일한 PZT분말을 합성하였다. 우선 Zr $O_{2}$와 Ti $O_{2}$ 혼합분말을 1차하소하여 (Z $r_{0.53}$ $Ti_{0.47}$) $O_{3}$(ZTO) 분말을 합성하고 이 ZTO 고용분말에 PbO와 N $b_{2}$ $O_{5}$을 혼합한 후 650-800.deg.C에서 2시간 하소하여 PZT 분말을 합성하였는데 얻어진 분말은 고상반응법에 비해 미세할 뿐만 아니라 XRD 분석결과 710.deg.C의 낮은 하소온도에서도 PZT 단일상을 나타내었다. 2단계하소법에 의해 하소온도를 낮출 수 있는 주된 이유로는 고상반응법에서는 중간생성물인 PbTi $O_{3}$상의 생성이 수반됨으로 850.deg.C 이상 되어야만 안전한 PZT가 생성될 수 있는 점을 들 수 있다. 또 2단계하소법에 의하면 950.deg.C이하의 낮은 소결온도에서도 치밀화가 미루어지는 소결이 가능함을 알 수 있었는데 이와같이 소결온도를 낮출 수 있는 것은 고상반응법에 비해 미세한 PZT 분말을 사용하였기 때문이라 풀이된다.이된다.

• Electrical & Electronic Materials
• /
• v.9 no.2
• /
• pp.146-151
• /
• 1996

PZT powders were prepared by the molten salt synthesis method. The porous PZT ceramics were made from a mixture of PZT and polyvinylalcohol(PVA) by BURPS(Bumout Plastic Sphere) technique. The 3-3 type composites were fabricated by impregnating an sintered porous PZT ceramics with various polymer matrices. The relative permittivity of 3-3 type composite specimens was shown 860-1,100 smaller than that of solid PZT ceramics(2,100), and the dissipation factors of composite specimens were about 0.02 to 0.03. The piezoelectric coefficient d$_{33}$ of composite specimens(285-328*10$^{12}$ C/N) was comparable with that of single phase PZT specimens(364*10$^{-12}$ C/N). The thickness mode coupling factor k$_{t}$(O.5-0.6) of composite specimens was comparable with that of single phase PZT specimens(k$_{t}$-0.7), and the mechanical quality factor of composite specimens was smaller than 10, and thus these 3-3 type composite specimens would be believed as a good candidates for broad band transducer applications.ons.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.389-390
• /
• 2010