CAREER: Continuous-flow microplasma synthesis of Group IV semiconductor nanoparticles

CBET-0746821，Sankaran在半导体工业中，基于等离子体的表面工艺，如薄膜的反应离子蚀刻和化学气相沉积，对集成电路的制造至关重要。 在某些操作条件下，已经观察到在气相中形成小颗粒，称为尘埃等离子体。 虽然等离子体合成的纳米粒子是有吸引力的纳米技术应用，在这些？一批？在纳米颗粒分散过程中，难以控制颗粒成核和生长以获得纳米尺寸颗粒的窄分散体。 此外，低的操作压力（10托）和大型基础设施通常与这些过程，使其难以扩大规模的商业应用。这项研究的重点是窄分散，表面功能化的第四族半导体纳米粒子，包括硅和金刚石的合成。 第IV族半导体由于其优异的电学和化学性质以及与微电子加工的兼容性而成为重要的材料。 然而，由于合成的挑战，对这些材料的纳米级性质的基本理解仍然未知。 在这里，提出了一种合成方法的基础上连续流动，大气压微等离子体。 微等离子体是直流辉光放电的小型化版本，其特征在于高浓度的高能电子（1-10 eV），其在高压下稳定等离子体。 由于由微等离子体限定的小体积（小于InL），颗粒生长受到限制，从而允许产生纳米尺寸的非团聚颗粒。 将通过气溶胶尺寸分类来监测在大气压力下纳米颗粒的连续生产，以获得真实的时间的颗粒尺寸分布。 此外，将收集颗粒并通过高分辨率透射电子显微镜（HRTEM），显微拉曼光谱和光致发光（PL）进行表征。 精确调谐的硅和金刚石纳米粒子的可用性将导致对这些材料中电子约束的基本理解。更广泛的影响：该研究与教育活动紧密结合，包括为K-12学校的年轻女性建立一个新的计划。 该计划由两部分组成：1）通过新的研究型选修课，让初中和高中学生接触当前技术领域的研究，包括纳米技术; 2）为高中学生提供在大学进行独立研究的机会。 预计这些推广活动将通过让学生接触科学和工程实践，加强对他们的数学和科学教育。

CBET-0746821, SankaranIn the semiconductor industry, plasma-based surface processes such as reactive ion etching and chemical vapor deposition of thin films are vitally important to the manufacturing of integrated circuits. Under certain operating conditions, the formation of small particles in the gas phase has been observed known as a dusty plasma. While plasma synthesis of nanoparticles is attractive for nanotechnological applications, in these ?batch? processes, it is difficult to control particle nucleation and growth in order to obtain narrow dispersions of nanometer-sized particles. In addition, the low operating pressures (10 Torr) and large infrastructure normally associated with these processes makes it difficult to scale-up for commercial applications.This research focuses on the synthesis of narrowly dispersed, surface-functionalized Group IV semiconductor nanoparticles including silicon and diamond. The Group IV semiconductors are important materials because of their excellent electrical and chemical properties and compatibility with microelectronics processing. However, fundamental understanding of nanoscale properties in these materials remains unknown because of synthetic challenges. Here, a synthesis methodology is proposed based on a continuous-flow, atmospheric-pressure microplasma. Microplasmas are miniaturized versions of direct-current (dc) glow discharges characterized by large concentrations of energetic electrons (1-10 eV) which stabilize the plasma at high pressures. Because of the small volume defined by the microplasma (less than 1 nL), particle growth is restricted, allowing the production of nanometer-sized, non-agglomerated particles. Continuous production of nanoparticles at atmospheric pressure will be monitored by aerosol size classification to obtain particle size distributions in real time. In addition, the particles will be collected and characterized by high-resolution transmission electron microscopy (HRTEM), micro-Raman spectroscopy, and photoluminescence (PL). The availability of precisely tuned silicon and diamond nanoparticles will lead to a fundamental understanding of electronic confinement in these materials.Broader impacts: The research is closely integrated with educational activities that include the establishment of a new program for young women in K-12 schools. The program is comprised of two components: 1) expose middle school and high school students to research in current technological areas including nanotechnology through a new research-based elective class and 2) provide high school students an opportunity to conduct independent research at the university. The outreach activities are expected to enhance the education of students in math and science by exposing them to the practice of science and engineering.