Semiconductor-Nanowire-Based Memory and Logic Devices for Flexible Electronic Systems
- 주제(키워드) Semiconductor , Nanowire , Nanoparticle , Silicon , Galium arsenide , Zinc oxide , Bottom-up , Top-down , Nano floating gate memory , Al2O3 , Metal-semiconductor field-effect transistors , Logic gates , Strain effect , Bending test , Reproducibility , Flexible electronics
- 발행기관 고려대학교 대학원
- 지도교수 김상식 교수
- 발행년도 2012
- 학위수여년월 2012. 2
- 학위구분 박사
- 학과 일반대학원 미세소자공학협동과정
- 세부전공 반도체소자전공
- 원문페이지 185 p
- 실제URI http://www.dcollection.net/handler/korea/000000032600
- 본문언어 영어
- 제출원본 000045696558
초록/요약
Nanowire-based flexible electronics have been widely researched, due to the increasing demand for portable and wearable applications. Especially, the development of high-performance electronic devices based on nanomaterials such as nanowires and nanoparticles is essential for the realization of flexible electronics, because they are the basic building blocks in integrated electronic devices. This thesis focused on the developing of fabrication process and the better understanding of characterizations for nanowire-based memory and logic devices on flexible plastics. Si nanowire-based field-effect transistors (FETs) (Chapter 2.1), Si and ZnO nanowire-based nano-floating gate memory (NFGM) devices (Chapter 2.3 and 2.4), arrayed Si nanowire-based NFGM devices on flexible plastics (Chapter 3.1), GaAs nanowire-based metal-semiconductor field-effect transistors (MESFETs) and various logic gates (Chapter 3.2 and 3.3) will be introduced. In the Chapter 2, many basic fabrication techniques for nanowire-based electronic devices on rigid Si substrate were studied here. In an effort to enhance electrical characteristics of Si nanowires by the modification of the gate geometry, back- and top-gate FETs based on Si nanowires synthesized by bottom-up methods were constructed on rigid Si substrates in Chapter 2.1. The memory behaviors of p-type Si nanowire-based NFGM devices with Au nanoparticles embedded in Al2O3 gate layers were investigated in Chapter 2.2. ZnO nanowire-based FETs having an omega-shaped floating gate (OSFG) have been successfully fabricated and compared to simultaneously prepared control devices without nanoparticles in Chapter 2.3. In the Chapter 3, there are many applications for nanowire-based flexible electronic devices were researched here. Many techniques based on Chapter 2 were applied for these applications. Firstly, arrayed Si nanowire-based NFGM devices with Pt nanoparticles embedded in Al2O3 gate layers were successfully constructed on flexible plastics by top-down methods in Chapter 3.1. High-performance GaAs-nanowire-based MESFETs and various logic gates (NOT, NAND, and NOR) composed of these MESFETs were constructed on flexible plastics through a noble top-down route in Chapter 3.2 and 3.3. Superior electrical characteristics of the GaAs-nanowire-based MESFETs such as a high mobility (~3300 cm^2/Vs), large Ion/Ioff ratio (~10^8), and small subthreshold swing (~70 mV/dec) were basis for high-performance GaAs nanowire-based logic gates (NOT, NAND, and NOR). Most of flexible devices successfully retained their electrical characteristics during several thousand bending cycles. Furthermore, the logic gates were well operated by square-wave signals of up to 100 MHz under various strain conditions. The high performances demonstrated in this thesis open the way to the realization of high-speed flexible logic devices.
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