• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2013년도 춘계학술대회 논문집
• /
• pp.454-459
• /
• 2013

For the purpose of rapid development and superior design quality assurance, sophisticated finite element model for SOM(Spatial Optical Modulator) piezo actuator of MOEMS device has been developed and evaluated for the accuracy of dynamics and residual stress analysis. Parametric finite element model is constructed using ANSYS APDL language to increase the design and analysis performance. Geometric dimensions, mechanical material properties for each thin film layer are input parameters of FE model and residual stresses in all thin film layers are simulated by thermal expansion method with psedu process temperature. $6^{th}$ mask design samples are manufactured and $1^{st}$ natural frequency and 10V PZT driving displacement are measured with LDV. The results of experiment are compared with those of the simulation and validate the good agreement in $1^{st}$ natural frequency within 5% error. But large error over 30% occurred in 10V PZT driving displacement because of insufficient PZT constant $d_{31}$ measurement technology.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.105-106
• /
• 2006

The ferroelectric materials of the PZT, SBT attracted much attention for application to ferroelectric random access memory (FRAM) devices. Through the last decade, the lead zirconate titanate (PZT) is one of the most attractive perovskite-type materials for the ferroelectric products due to its higher remanant polarization and the ability to withstand higher coercive fields. FRAM has been currently receiving increasing attention for one of future memory devices due to its ideal memory properties such as non-volatility, high charge storage, and faster switching operations. In this study, we first applied the damascene process using chemical mechanical polishing (CMP) to the fabricate the $Pb_{1.1}(Zr_{0.52}Ti_{0.48})O_3$ thin film capacitor in order to solve the problems of plasma etching such as low etching profile and ion charging. The structural characteristics were compared with specimens before and after CMP process of PZT films. The scanning electron microscopy (SEM) analysis was performed to compare the morphology surface characteristics of $Pb_{1.1}(Zr_{0.52}Ti_{0.48})O_3$ capacitors. The densification by the vertical sidewall patterning and charging-free ferroelectric capacitor could be obtained by the damascene process without remarkable difference of the characteristics.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
• /
• pp.14-14
• /
• 2010

Recently, low temperature co-fired ceramic (LTCC) technology has gained a remarkable application potential in sensors, actuators and micro systems fields because of its very good electrical and mechanical properties, high reliability and stability as well as possibility of making 3D micro structures. In this study, we investigated the effects of annealing treatment on the electrical properties of $Pb(ZrTi)O_3$ (PZT) thin films deposited on LTCC substrate. PZT thin films were deposited on Au / LTCC substrates by RF magnetron sputtering method. Then, the change of the crystallization of the films were investigated under various annealing temperatures and times. The results showed that the crystallization of the films were enhanced as increasing annealing temperatures. The film, annealed at $700^{\circ}C$, 3min, was well crystallized in the perovskite structure.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 하계학술대회 논문집 B
• /
• pp.1106-1109
• /
• 1993

Ferroelectric thin films of PZT with differnt Zr/Ti ratio were prepared by sol-gel processing and annealed by rapid-thermal-annealing at $500^{\circ}C-700^{\circ}C$ for 10sec-1min. The structure of the annealed films were examined by X-ray diffraction and SEM. Maximum remnant polarization of 10.24 ${\mu}m/cm^2$ and coercive field of 70 KV/cm were obtained from hysteresis curve or the film.

• 한국진공학회지
• /
• 제15권2호
• /
• pp.173-179
• /
• 2006

Pulsed laser deposition 방법으로 증착한 $PbZr_{0.3}Ti_{0.7}O_{3}$ (PZT)박막의 구조적, 전기적 성질에 대한 연구를 하였다. PZT 박막은 $LaAlO_3$ 기판위에 동일한 조건으로 증착된 $LaMnO_3$ (LMO) 산화물을 하부 전극으로 하여 증착시간을 변화시키며 증착하였다. High-resolution x-ray diffraction 결과를 통해 LMO 하부 전극과 PZT 박막이 방향성 있게 자란 것을 확인할 수 있었고 박막의 두께는 field-emission scanning electron microscope을 통하여 측정할 수 있었다. 또한 우리는 atomic force microscopy을 이용하여 박막의 표면 거칠기를 구하였고 국소적인 범위의 전기적 특성은 piezoelectric force microscopy 모드를 이용하여 측정하였다. 그 결과 PZT/LMO 구조는 나노 스토리지의 미디어로 쓰이기 위해 필요한 성질들을 갖추었음을 알 수 있었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.123-124
• /
• 2006

The sandwiched PZT/$BaTiO_3$/PZT thick films were fabricated by two different methods thick films of the PZT by screen printing method on alumina substrateselectrodes with Pt, thin films of $BaTiO_3$ by the spin-coating method on the PZT thick films and once more thick films of the PZT by the screen printing method on the $BaTiO_3$ layer. The structural and the dielectric properties were investigated for effect of various stacking sequence of sol-gel prepared $BaTiO_3$ coating solution at interface of the PZT thick films, The insertion of BaTi03 interlayer yielded the PZT thick films with homogeneous and dense grain structure with the number of $BaTiO_3$ layers. The leakage current density of the $PZT/BaTiO_3-1$ film is less that $4.41{\times}10^{-9}A/cm^2$ at 5 V.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.55-56
• /
• 2006

In this paper, we first applied the chemical mechanical polishing (CMP) process to the planarization of ferroelectric film in order to obtain a good planarity of electrode/ferroelectric film interface. BST ($Ba_{0.6}Sr_{0.4}TiO_3$), PZT ($Pb_{1.1}(Zr_{0.52}TiO_{0.48})O_3$) and BTO ($BaTiO_3$) ferroelectric film are fabricated by the sol-gel method. And then, we compared the structural characteristics before and after CMP process of BST, PZT, BTO films. Their dependence on slurry composition was also investigated. We expect that our results will be useful promise of global planarization for ferroelectric random access memories (FRAM) application in the near future.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
• /
• pp.139-140
• /
• 2006

PZT박막은 비휘발성 재료로 유전율이 높고 항전력이 작으면서 잔류 분극랑이 크기 때문에 적합한 특성을 가지고 FeRAM에 매력적인 물질이다. CMP(chemical mechanical polishing)는 기존의 회생막의 전면 식각 공정과는 달리 특정 부위의 제거 속도를 조절함으로써 평탄화 하는 기술로 wafer 전면을 회전하는 탄성 패드 사이에 액상의 Slurry를 투입하여 연마하는 기술이다. 본 논문에서는 CMP 공정으로 제조한 PZT박막 캐패시터에서 CMP 후처리공정(세척)의 유무 및 종류에 따라 피로특성에 대하여 연구하였다, PZT 박막의 캐패시터의 피로 특성을 연구한 결과 CMP 후처리공정 SC-l용액을 사용하여 세정공정을 하였을때 가장 향상된 PZT 캐패시터의 피로특성이 나타났다.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
• /
• pp.125-128
• /
• 2003

Low-velocity impact damage is a major concern in the design of structures made of composite materials, because impact damage is hidden inside and cannot be detected by visual inspection. The piezoelectric thin film sensor can be used to detect variations in structural and material properties for structural health monitoring. In this paper, the PVDF and PZT sensors were used for monitoring impact damage initiation in Gr/Ep composite panel to illustrate this potential benefit. A series of impact test at various impact energy by changing impact mass and height is performed on the instrumented drop weight impact tester. The wavelet transform(WT) is used to decompose the piezoelectric sensor signals in this study. Test results show that the particular waveform of sensor signals implying the damage initiation and development are detected above the damage initiation impact energy. And it is found that both PZT and PVDF sensors can be used to detect the impact damage.

• 한국재료학회지
• /
• 제10권5호
• /
• pp.360-363
• /
• 2000

다양한 Zr/Ti 비율을 갖고 있는 강유전체 PZT박막을 졸-겔 법으로 증착하였고 상부 백금전극의 제조방법과 열처리온도의 변화에 따라 강유전체 특성을 측정하여 이력곡선의 변형 원인을 조사하였다. Pt/PZT/Pt 캐패시터는 상부 백금전극을 반응성 이온 식각(RIE) 하는 과정에서 생성된 dc plasma 전압에 의하여 양의 방향으로 분극되었고 도메인 계면에 포획된 전하에 의해 내부전장이 발생되었다. PZT 박막은 sputtering으로 상부전극을 증착하는 과정에서 이력곡선의 중간에 잘룩하게 되는 시효현상이 관찰되었다. 상부전극을 제작한 후 열처리는 포획된 전하흫 제거시켜 양호한 이력곡선 특성을 되찾게 하였다. Zr/Ti 비율이 감소함에 따라 내부전장이 증가하였으며 내부전장이 없어지는 열처리온도가 증가하였다.