| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | A. 전자/반도체 재료 분과 |
| 제목 | Fabrication of orthorhombic Hf0.5Zr0.5O2 thin films through sol-gel methods |
| 초록 | HfO2 based thin films have been extensively studied for a wide range of applications such as high-k dielectric, optical coating, and memory devices. Recently, the ferroelectricity of HfO2 based films is known to be induced through the doping of various ions such as Si, Al, Ti, Ta, Zr, etc. Interestingly, Hf0.5Zr0.5O2(HZO) thin films grown on TiN can possess non-centrosymmetric orthorhombic phase in association with ferroelectricity, which is different from non-ferroelectric monoclinic phase of pure HfO2 thin film. The most common method to grow the HZO films is atomic layer deposition (ALD); however, the ALD process requires high cost for high vacuum and temperatureIn this study, we report the growth of orthorhombic Hf0.5Zr0.5O2 films using a cost effective and facile sol-gel technique in air. Hafnium isopropoxide isopropanol (C15H36O5Hf) and zirconium dinitrate oxide hydrate (N2O7Zr xH2O) were dissolved in 2-Methoxyethanol at 75oC for 12 hours. Prior to the deposition of HZO thin films, 10 nm thick TiN film was deposited on (100)-oriented n++ Si substrate using DC sputtering. The fabricated solution was spin casted on top of TiN/Si substrate at a spin speed of 3000 rpm for 30 s. Sequently, films were baked at 150oC for 10 min using hot plate and then the films were annealed at a temperature ranging from 500 to 1000 oC for 1 hour in N2 ambient. Pt top electrode with a thickness of 30 nm was deposited using an electron beam evaporator to form capacitor structures. The crystalline structure and ferroelectric properties of the films were characterized using X-ray diffractionpatterns and polarization-voltage hysteresis loops, respectively. We observed the orthorhombic crystal structure with an increase in annealing temperature up to 800oC. We also found weak ferroelectric properties possibly due to coexistence with non-ferroelectric crystal structure, i.e., monoclinic phase. |
| 저자 | Jun Young Lee1, Hyun Jun Lee2, Ji Young Jo1 |
| 소속 | 1School of Materials Science and Engineering, 2Gwangju Institute of Science and Technology |
| 키워드 | <P>sol-gel; orthorhombic; HfO<SUB>2</SUB>; ferroelectric</P> |
