Reactive Magnetron Sputtering 법을 이용한p-type SnO 투명산화물반도체 합성 및 특성분석 = Characterization of transparent p-type SnO thin films deposited by reactive magnetron sputtering )

다국어 초록 (Multilingual Abstract)

Transparent conducting oxides(TCOs) are widely used as transparent electrodes in optoelectronic devices such as organic light-emitting diodes(OLEDs), solar cells, liquid crystal displays(LCDs) due to combined properties of high optical transparency in the visible region(>80%) and high electrical conductivity(>1000 S/cm). Most transparent conducting oxides are n-type semiconductors. One of the key issues for realization of high performance electronic devices such as pn-junctions or transparent complementary metal-oxide-semiconductor thin-film transistors(COMS TFTs) is to develop p-type TCOs. There are a few reported p-type TCOs literature.
Tin oxides have three well-known phases of SnO2, Sn2O3, SnO. SnO of those three different phases has p-type characteristics. Stannous oxides receive lots of attention because it has high hole mobility compared with different p-type TCOs. SnO thin films have been synthesized by varied methods such as the phase transferation of SnO2, the oxidation of Sn metal, the evaporation of SnO. However, it is hard to obtain single phase of SnO with high crystallinity, because SnO is unstable at high temperature. One of suitable method to obtain single phase of SnO is sputtering at low temperature.
In this study, SnO thin films were deposited on different substrate (i.e. (100) oriented SrTiO3, c-plane Al2O3, m-plane Al2O3, r-plane Al2O3) by reactive magnetron sputtering to investigate the effects of deposition rate and the characteristics of their properties. In order to investigate the contact resistance between p-type SnO and metal electrodes, SnO thin films deposited on Si wafer and Ni, ITO electrodes deposited on p-type SnO thin films. P-type SnO thin films were deposited by using high-purity Sn metal target with different RF-powers and oxygen partial pressures. The characteristics of SnO thin films were examined by Hall effect measurement, X-ray diffraction and pole figure measurement.
SnO thin films were deposited at different deposition rate. By Hall effect measurement, the electrical characterizations were compared with different sputtering condition. SnO thin films deposited at 22nm per min showed higher conductivity and lower resistivity than at 9nm per min. Those SnO thin films deposited at different deposition rate didn't show epitaxial growth on varied single crystal substrates.
To characterize the contact resistance between p-type SnO and Ni, ITO electrodes, transmission line method was used. Space between electrodes was widened two times from 1nm to 1024nm. The I-V characteristics of contact behavior were measured. Measured specific contact resistance about Ni electrodes showed ρC : 3.4 ⅹ 10-2 Ω∙㎠, and about ITO electrodes showed ρC : 3.6 ⅹ 10-2 Ω∙㎠.

목차 (Table of Contents)

• Chapter Ⅰ. 서 론
• Chapter Ⅱ. 이론적 배경
• 2.1 박막 합성
• 2.2 Sputtering
• 2.2.1 Sputtering 원리
• 2.2.2 Sputtering yield
• 2.2.3 Sputtering의 종류
• 2.2.3.1 DC Sputtering
• 2.2.3.2 RF Sputtering
• 2.2.3.3 Magnetron Sputtering
• 2.2.4 Reactive Magnetron Sputtering
• 2.3 Metal - Semiconductor Contacts
• 2.4 p-type 투명 산화물 반도체 SnO
• 2.4.1 SnO의 electrical conduction path 및 defects
• Chapter Ⅲ. 실험 방법
• 3.1 실험장비
• 3.1.1 RF-magnetron Sputtering 장치
• 3.2 박막 특성 분석
• 3.2.1 박막의 구조적 특성 분석
• 3.2.1.1 X선 회절(XRD) 분석
• 3.2.1.2 SEM 분석
• 3.2.2 박막의 전기적 특성 분석
• 3.2.1.1 Hall measurement
• Chapter Ⅳ. 결과 및 고찰
• 4.1 RF-magnetron Sputtering으로 제작된 SnO 박막 성장 및 특성평가
• 4.1.1 산소 비율에 의한 SnO 박막 성장
• 4.1.2 Target - 기판 사이 거리에 따른 SnO 박막 성장
• 4.1.3 기판 종류에 따른 SnO 박막 성장
• 4.2 Transmission Line Method 소자 제작을 통한 SnO 박막과 전극 간의 contact resistance 특성
• Chapter Ⅴ. 결 론
• Chapter Ⅵ. 참고 문헌
• Chapter Ⅶ. 영문 초록