MRI: Development of A New High Temperature Source Metalorganic Chemical Vapor Deposition System (HTS-MOCVD) for Next Generation IIIA/B-Nitrides

摘要标题：新型高温研究仪器，用于制造电动汽车和未来电网电力电子的下一代半导体。III族氮化物是硅以外的半导体，可用于笔记本电脑、手机和其他消费电子产品的电源充电器，以及混合动力和电动汽车（HEV）的电子产品。 这些半导体还用于制造用于高效照明和显示器的绿色、蓝色和白色发光二极管（LED），2014年诺贝尔物理学奖由此获得。 III族氮化物半导体也是紫外线LED的核心，用于消毒和空气-水净化。 这些独特而重要的半导体材料是使用称为金属有机化学气相沉积（MOCVD）的高温生长工艺生产的，该工艺在独特的高温设备中进行，以获得具有非常高纯度的高质量晶体材料。 已经提出，过渡金属（例如钛和钪）的结合可以通过将压电产生的电荷增加约2-10倍来增强这些用于电力电子的半导体材料的性能。这种更高的充电可以使更高的电流水平在混合动力汽车的。 这里的挑战是生产高质量的材料，这反过来又需要更高的温度生长和化学过程，目前还没有可用的商业工具。在本提案中，我们将开发硬件工具、化学工艺和测量技术，以证明这种新的高温、大电流、高电压技术的潜力。该Track-I NSF MRI提案旨在开发一种新的高温源金属有机化学气相沉积系统（HTS-MOCVD），用于在单个生长反应器中沉积新兴的IIIB-过渡金属氮化物（如ScN）和传统的IIIA-氮化物（GaN-AlN-InN）。III-B氮化物具有非常高的压电热释电系数，使其成为高性能传感器的理想选择。此外，它们与III-A族氮化物的异质结可以潜在地产生性能水平远高于当前器件的功率电子和UVB-C光电器件。我们的系统设计将有几个创新的特点，如一个新的高温源设计，和一个新的前体注射器设计。这种新的注入器设计实质上将允许像在常规MOCVD反应器中那样非常靠近生长基座的源注入。这种近距离注入模式和高温源将使得能够提高前体注入效率，从而使得ScN的生长速率与AlxGa 1-xN的生长速率兼容。接近基座/衬底注入还将导致加合物形成的显著减少，从而同时提高生长质量，生长速率比常规MOCVD系统高得多。因此，我们独特的系统设计将允许在同一系统中同时生长较厚的缓冲区和器件结构的有源区（通常薄得多）。这也将是理想的沉积AlxGa 1-xN/AlySc 1-yN异质结和量子威尔斯，以探索其性质。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Abstract Title: Novel High Temperature Research Instrument to fabricate next generation semiconductors for Power Electronics for electric vehicles and future electric grid.Group III-Nitrides are semiconductors beyond silicon that enable unique electronic and optical devices for power chargers for laptops, cell phones and other consumer electronics, and the electronics for hybrid and electric vehicles (HEV’s). These semiconductors are also used to manufacture the green, blue, and white light emitting diodes (LED’s) for high efficiency lighting and displays for which the 2014 Nobel Prize in physics was awarded. The III-Nitride semiconductors are also at the core of ultraviolet LEDs for disinfection and air-water purification. These unique and important semiconductors materials are produced using a high temperature growth process called Metalorganic Chemical Vapor Deposition (MOCVD) that is carried out in a unique high temperature equipment to allow high quality crystalline materials with a very high purity. It has been proposed that the incorporation of transition metals, such as Titanium and Scandium can enhance the performance of these semiconductor materials for power electronics by increasing the piezoelectrically produced electrical charge by ~2-10 times. This higher charge can will enable higher current levels in HEV’s. The challenge here is to produce high quality materials, which in turn require even higher temperature growth and chemical processes, for which there are currently no commercial tools available. In this proposal, we will develop both the hardware tools, and the chemical processes, and measurement techniques required to demonstrate the potential for this new high temperature, high current, high voltage technology. This Track-I NSF MRI proposal aims to develop a New High Temperature Source-Metalorganic Chemical Vapor Deposition System (HTS-MOCVD) for depositing the emerging IIIB-Transition- Metal Nitrides (such as ScN), and conventional IIIA-Nitrides (GaN-AlN-InN) in a single growth reactor. The III-B nitrides have very high piezo-pyroelectric coefficients making them ideal for high performance sensors. Moreover, their heterojunctions with III-A nitrides can potentially yield power electronic and UVB-C optoelectronic devices with performance level well above those of current devices. Our system design will have several innovative features such as a new high temperature source design, and a new precursor injector design. This new injector design will in essence allow source injection like in conventional MOCVD reactors very close to the growth susceptor. This nclose injection mode, and the high temperature source, will enable increased precursor injection efficiency and thus growth rates for ScN compatible with those of AlxGa1-xN. The close to susceptor/substrate injection will also lead to a significant reduction in the adduct formation thereby simultaneously improving the growth quality with a growth rate much higher than conventional MOCVD systems. Thus, our unique system design will allow the growth of thicker buffer regions and the active regions (typically much thinner) of the device structures simultaneously in the same system. It will also be ideal for depositing AlxGa1-xN/AlySc1-yN heterojunctions and quantum wells to explore their properties. MOCVD systems with our high temperature source and the dual injector design are commercially not available.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.