AISI type 316 Stainless Steel 용접부위에서의 부식특성

마재평,백수현,강성군 한국부식방식학회 1991 Corrosion Science and Technology Vol.20 No.2

저전압용 ZnO varistor 계의 nonohmic 특성에 대한 Bi₂O₃의 영향

馬在坪 호남대학교 1991 호남대학교 학술논문집 Vol.12 No.2

Two systems orienting low voltage varistor were investigated by electrical and mocrostructural methods. Zn, Bi, Co, Mn-oxide system has so relatively large grain size that this showed low breakdown voltage, hence in the development of low voltage varistor this system can be used it as basic system. Its nonlinear exponents were 20 or more, and nonlinear resistances were 40 V/mm or less, but real breakdown voltage in Ⅴ-Ⅰ plotting was about 30 V/mm. Adequate Bi₂O₃ amount is about 1.0mol%.

초고집적회로의 커패시터용 PZT박막의 입열 조건에 따른 유전특성 -1- 비정질 PZT를 사용한 PZT 박막의 누설전류 개선에 관한 연구

마재평,백수현,황유상 대한전자공학회 1995 전자공학회논문지-A Vol.32 No.12

To improve the leakage current, we developed two step sputtering method where PZT thin film in first deposited at room temperature followed by 600.deg. C deposition. The method used an amorphous PZT layer deposited at room temperature to keep a stable interface during sputtering at high temperature. PZT thin films were deposited on Pt/Ti/SiO$_{2}$/Si substrate at room temperature and 600.deg. C sequentially. The effect of the layer deposited at room temperature was investigated with regard to I-V characteristics and P-E hysteresis loop. In the case of the sample with the layer deposited at room temperature, both leakage current and dielectric constant were decreased. The thicker the layer deposited at room temperature was, the lower dielectric constant was. However, leakage current was indepenent of the variation of the thickness ratio. The sample with 200$\AA$ of the layer deposited at room temperature showed the most promising results in both dielectric constant and leakage current.

높은 비직선지수를 갖는 ZnO varistor의 기본구성

馬在坪 호남대학교 1992 호남대학교 학술논문집 Vol.13 No.-

In order to determine the standard composition of ZnO varistor having higher nonlinear exponent, various contents of Mn - and Co-oxides were added to ZnO-1.0 Bi₂O₃system. Also, the samples that contain small amount of Sb - and Si -oxides in the ZnO varistor with the standard composition determined above were fabricated. As a result, the standard composition of the ZnO varistor orienting higher nonlinearity was established as ZnO -1.0 Bi₂O₃-1.0 MnO₂O₃Nonlinear exponents were largely enhanced by addition of Sb-and Si- oxide.

2단계 스퍼터링으로 형성시킨 강유전 박막의 누설전류 개선

마재평,신용인,Mah Jae-Pyung,Shin Yong-In 한국마이크로전자및패키징학회 2006 마이크로전자 및 패키징학회지 Vol.13 No.1

2단계 스퍼터링으로 강유전 PZT 박막을 형성시켜 유전특성과 전도기구를 조사하였다. 또한 PZT 박막 내의 carrier를 보상해주기위해 도너 불순물을 도핑하였다. 2단계 스퍼터링으로 상온층 두에를 조절하여 누설전류를 $10^{-7}A/cm^2$ order까지 줄일 수 있었다. 전도기구가 bulk-limited의 하나임을 확인하였고 따라서 적정한 도너 불순물을 채택하였다. 도너 불순물을 도핑한 경우 2단계 스퍼터링한 PZT 박막의 누설전류 특성은 $10^{-8}A/cm^2$ order까지 개선되었다. Ferroelectric PZT thin films were formed by 2-step sputtering and their dielectric properties and conduction mechanisms were investigated. Also. donor impurity doping was tried to compensate the carriers in PZT thin films. The leakage current density was able to reduce to $10^{-7}A/cm^2$ order by 2-step sputtering with thickness control of room temp.-layer. The conduction mechanism was confirmed as bulk-limited, and optimum donor impurities on PZT thin film were taken. Especially, leakage current characteristics was improved to $10^{-8}A/cm^2$ order in donor-doped PZT thin films formed by 2-step sputtering.

초고집적소자의 커패시터용 PZT 박막의 특성

마재평 호남대학교 정보통신연구소 1997 정보통신연구 Vol.6 No.-

초고집적소자의 커패시터용 PZT 박막의 형성 및 특성을 살펴보았다. Pt/Ti/Si기판 위에서 RF magnetron sputtering 방법으로 PZT 박막을 증착하였다. 후속 annealing은 furnace 및 RTA로 550에서 750도 사이에서 시행하였다. 상 형성, 막막의 조성 그리고 계면 반응 등을 XRD, XPS과 RBS 등으로 각각 조사하였고 I-V 및 C-V 특성은 각각 HP4145B와 HP4194A로 측정하였다. 후속 annealing때 Ti층의 상부는 바깥쪽으로부터의 산소 확산에 의해 Ti-oxide로 변화하였고 Ti층의 하부는 Pt이 확산해 들어와 silicide를 형성하였다. Ti-oxide의 형성은 PZT의 성장 방향에 영향을 주었다. RTA로 후속 annealing할 때 얇은 Pt층은 산소 확산을 억제하지 못했으나 1000Å으로 두껍게 입힌 Pt 층은 효과적으로 억제하였다. RTA 처리한 경우가 보다 좋은 강유전특성을 나타냈는데, 이때 누설전류는 3.35㎂/㎠였으며 breakdown voltage는 0.63MV/cm로 나타났다. The formations and properties of PZT thin films were investigated to survey applicability for ULSI's capacitor. PZT films were deposited by RF magnetron sputtering on Pt/Ti/Si substrates followed by furnace-and rapid thermal annealing at 550℃ to 750℃. Phase formations, film compositions and interface reactions were analyzed by XRD, XPS and RBS, respectively. I-V and C-V characteristics were investigated by HP4145B and HP4194A. The upper Ti layer is transformed into Ti-oxide by oxygen diffusion and lower Ti layer into silicide with in-diffused Pt for post-annealing. The formation of Ti-oxide layer seems to affect the orientation of the PZT layer. During rapid thermal annealing process, Pt(250Å) layer could not prevented oxygen diffusion but thicker Pt(1000Å) did, effectively. Rapid-thermal-annealed film shows better ferroelectric and electrical properties with a leakage current of 3.35 ㎂/㎠, breakdown voltage of 0.63 MV/cm.

초고집적반도체의 커패시터용 강유전 박막의 전기적 특성 개선

마재평,박삼규,Mah Jae-Pyung,Park Sam-Gyu 한국마이크로전자및패키징학회 2004 마이크로전자 및 패키징학회지 Vol.11 No.3

PBT thin films were formed by rf-magnetron sputtering on $Pt/Ti/SiO_2/Si$ substrate. Bulk-PZT target containing $5\%$-excess PbO was used. After PZT thin films had been deposited at room temperature, remaining portion of the thin film was formed by in-situ process. The ferroelectric perovskite phase was formed at $650^{\circ}C$. The leakage current property was improved dramatically by 2-step sputtering, and in the sample containing optimum thickness of room temp.-layer very low leakage current of $2{\times}10^{-7}A/cm^2$ was shown. As a result of the investigation on the leakage current mechanism, the electrical conduction mechanism in all PZT thin films formed by several conditions was confirmed as bulk-limited mechanism. PZT 박막을 rf-마그네트론 스퍼터링으로 $Pt/Ti/SiO_2/Si$ 기판 위에 형성시켰다. $5\%$ 과잉 PbO 를 포함한 bulk PZT 타겟을 사용하였다. 상온에서 PZT 박막을 얇게 입힌 후 나머지 두께를 $650^{\circ}C$에서 in-situ 방법으로 형성시켰다. 강유전 특성을 갖는 PZT 상은 $650^{\circ}C$에서 형성되었다. 2단계 스퍼터링에 의해 누설전류 특성을 크게 증진시킬 수 있었고, 적절한 두께의 상온층을 포함시킨 경우 $2{\times}10^{-7}A/cm^2$의 매우 작은 누설전류를 나타냈다. 누설전류 기구에 대한 조사 결과, 여러 조건에서 제조된 PZT 박막의 전기전도는 모두 bulk-limit 기구에 의한 것임을 알 수 있었다.

각 층에 따른 염료감응형 태양전지의 특성 개선 - I (-상부전극을 중심으로)

마재평,박치선,Mah, Jae-Pyung,Park, Chi-Sun 한국반도체디스플레이기술학회 2011 반도체디스플레이기술학회지 Vol.10 No.2

Photovoltaic effect is confirmed in DSSC fabricated under the common conditions. In upper electrodes, validity of ZnO as new TCO material was investigated and an improvement of characteristics in DSSC was tried by control of process conditions at semiconductive powder layer. ZnO thin film showed very high resistivity, therefore efficiency of solar cell was lower than that of conventional ITO-related material. DSSC characteristics was able to improve by thin blocking layer doposited between the TCO and semiconductor layer.

초고집적반도체의 커패시터용 SrTiO₃박막의 도핑에 의한 특성

마재평 호남대학교 2003 호남대학교 학술논문집 Vol.24 No.2

단결정 Si 기판상에서 PZT의 상 형성

마재평 호남대학교 2000 호남대학교 학술논문집 Vol.21 No.2

The phase formations of PZT thin films sputtered on the single Si substrate were investigated to establish the base in this field. Perovskite phase was not shown in PZT films furnace-annealed, and lead-oxide,-silicates were formed. This phenomena were due to the severe dissociation and/or diffusion of PZT's components and Si. PZT thin films were undergone by too high heat-input by furnace-annealing and their polarization characteristics were degradaded, so it was proposed that the substrate for diffusion-barrier and the RTA as post-annealing were needed in the formation of ferroelectric PZT films.