SGER UV-radiation assisted chemical vapor deposition of III-nitride functional nanostructures

摘要：Juan C.Rojo研究所：纽约州立大学石溪分校提议编号：0617760标题：SGER紫外光辅助化学气相沉积III-氮化物功能纳米结构III-氮化物材料(GaN、AlN、InN及其合金)是宽带隙半导体，在制造UV和蓝色发射器、探测器、高速场效应晶体管(FET)和大功率/高温器件方面具有重要应用。未来增强的电子和光子器件将需要使用低维结构。有两种不同的原理来制造功能性半导体纳米结构。自上而下的方法依靠图案化技术(光刻、纳米压印或离子束)将薄膜雕刻成纳米结构。然而，自下而上的合成技术利用原子和分子的自然自组装倾向来形成所需的纳米结构。这些技术具有目前自上而下方法无法实现的分辨率控制，并为不同材料的单片集成提供了优势，因为纳米结构不会受到晶格和热膨胀与衬底失配的太大影响。在自下而上制备纳米结构的技术中，化学气相沉积(CVD)技术已成功地用于合成多种类型的纳米材料。采用标准热CVD技术的合成过程主要受发生非均相化学反应的衬底表面的温度和传质条件控制。控制由此产生的低维结构的排列、成核和生长仍然是与CVD纳米制造策略相关的主要挑战。这项研究将致力于开发利用紫外光辅助化学气相沉积合成III-氮化物纳米结构的新策略。通过利用紫外光对化学物种和衬底表面进行局部、选择性的激发，将确定III-氮化物纳米结构的直接写入和形态控制的可能性。合成实验将利用布鲁克海文国家实验室(BNL)国家同步辐射光源(NSLS)产生的可调紫外光(3.5-9 eV)进行。所生产的纳米结构的化学和结构表征将在石溪大学和BNLS功能纳米材料中心使用SEM、EDAX和HRTEM进行。将与纽约城市大学的科学家合作，对合成的III-氮化物纳米结构进行光学表征。除了科学目标之外，这项研究将作为一个有价值的项目，向K-12、本科生和研究生介绍宽带隙半导体的技术重要性以及开发新的纳米材料合成技术的必要性。设想的研究项目将包括一名富布赖特博士后研究员、一名研究生和四名本科生。通过向K-12学生推广研究成果，将通过促进长岛高中生访问石溪大学来实现。国际学生联合会还将努力促进经济困难和代表性不足的学生参与拟议的研究。这项使命将通过与Stony Brooks NSF资助的CSEMS和AGEP项目以及西班牙裔专业工程师协会当地分会的密切合作来推动。这项拟议的研究将使四名人数不足的本科生能够获得研究经验，并将用于促进以西班牙裔为主的长岛社区的高中生对工程和科学的兴趣。这项研究的结果也可能产生重要的社会影响，为直写技术的开发产生开创性的结果，通过将现代紫外光刻技术的能力与用于传感器、光发射器和电子晶体管的半导体纳米结构的原位紫外光辅助CVD合成相结合，以成本效益的方式制造纳米级功能器件。

ABSTRACTPI: Juan C. Rojo Institution: SUNY Stony BrookProposal Number: 0617760Title: SGER UV-radiation Assisted Chemical Vapor Deposition of III-nitride Functional NanostructuresIII-nitride materials (GaN, AlN, InN and their alloys) are wide band-gap semiconductors with important applications in the fabrication of UV and blue emitters, detectors, high-speed field-effect transistors (FETs), and high-power/high-temperature devices. Future enhanced electronic and photonic devices will demand the utilization of low-dimensional structures. There are two different philosophies to produce functional semiconductor nanostructures. The top-down approaches rely on patterning techniques (lithography, nano-imprinting, or ion-beam) to literally sculpt thin films into nano-structures. Bottom-up synthesis techniques, however, make use of the natural self-assembly tendency of atoms and molecules to form the desired nanostructures. These techniques have a resolution control that is currently inaccessible to top-down approaches and offer an advantage for the monolithic integration of different materials since the nanostructures are not greatly affected by the lattice and thermal expansion mismatches with the substrate.Intellectual Merit. Among the bottom-up techniques for producing nanostructures, chemical vapor deposition (CVD) techniques have been successfully utilized to synthesize multiple kinds of nanomaterials. The synthesis process using standard thermal CVD techniques is mainly controlled by the temperature and mass transport conditions at the substrate surface where the heterogeneous chemical reaction takes place. Controlling the arrangement, nucleation, and growth of the resulting low dimensional structures remain as major challenges associated with CVD nanofabrication strategies. This research will be concerned with the development of novel synthesis strategies for III-nitride nanostructures using UV-radiation assisted CVD. By means of localized, selective excitation of chemical species and substrate surfaces using UV photons, the possibility for direct-writing and morphological control of III-nitride nanostructures will be determined. The synthesis experiments will be carried out utilizing a tunable UV beam-light (3.5-9eV) generated at the Brookhaven National Laboratory (BNL) National Synchrotron Light Source (NSLS). The chemical and structural characterization of the produced nanostructures will be carried out using SEM, EDAX, and HRTEM at both Stony Brook University and the BNLs Center for Functional Nanomaterials. Optical characterization of the synthesized III-nitride nanostructures will be carried out in collaboration with scientist at the City University of New York.Broader Impacts. Beyond the scientific objectives, the research will serve as a valuable program to introduce K-12, undergraduate, and graduate students to the technological importance of wide bandgap semiconductors and the need for developing novel synthesis technologies for nanomaterials. The envisioned research program will involve a Fulbright postdoctoral fellow, one graduate student, and four undergraduate students. Dissemination of the research results via outreach to K-12 students will be achieved by fostering visits of Long Island high school students to Stony Brook University. The PI will also strive to promote involvement of financially challenged and underrepresented students in the proposed research. This mission will be propelled through a close collaboration with Stony Brooks NSF-funded CSEMS and AGEP programs, and the local chapter of the Society for Hispanic Professional Engineers. The proposed research will enable access to research experiences for four underrepresented undergraduate students and be used to promote interest for engineering and science among high-school students from predominantly Hispanic Long Island communities. The outcome of this research could also have an important societal impact by generating seminal results for the development of direct-writing technologies to fabricate nanoscale functional devices in a cost-efficient manner by combining the capabilities of modern UV lithography with in situ UV-assisted CVD synthesis of semiconductor nanostructures for sensors, light emitters, and electronic transistors.