Controlling AlInGaN/Silicon Interface Kinetics

非技术描述：该项目的重点是发展对硅上氮基材料合成的更多理解，结合两种最广泛使用的半导体-硅和氮化物。尽管它们在发光二极管（led）、功率晶体管和高效太阳能电池等各种器件中都很重要，但在这些重要材料之间的界面上发生的晶体生长过程仍有很多未知。为了将这些材料集成到下一代器件中，需要更好地理解界面化学、生长机制、冶金反应以及在这一重要界面上产生的缺陷形成。该项目利用最近开发的低温晶体生长工艺，能够实现具有商业优势的高通量速率，通过各种分析来研究复杂的界面现象，并扩展iii -氮化物的使用，包括难以捉摸的材料AlGaInN。控制这些现象的机制，可能减少缺陷并支持未来的应用程序也是目标。该项目为研究生提供了接触物理学、材料科学和纳米电子学交叉领域的尖端技术和资源的途径。由此产生的设备平台有可能导致节能设备、通信、太阳能电池和医疗设备技术的创新。社会和学术拓展项目扩大到包括小学到高中学生的示范。本研究为实现(AlGaIn)-氮化物和硅器件集成的详细方法的传播和出版提供了新的机会。技术描述：本项目探索开发由季ⅲ氮化物（AlGaInN）和硅组成的异质结构，用于电子和光电子器件集成。虽然AlN on Silicon已经大量商业化，但所有其他常用的iii -氮化物合金，包括GaN、InN、AlGaN和InGaN，基本上都没有直接在硅衬底上实现。此外，在硅衬底上生长AlGaInN的令人生畏的挑战尚未掌握，特别是在硅衬底上。早期控制iii -氮化物/Si界面自然生长现象的尝试仅限于绝缘氮化铝中间层可接受的情况，如高电子迁移率晶体管（hemt）等横向晶体管。对于那些绝缘屏障不可接受的情况，如未来的垂直传导器件，如晶体管、led、太阳能电池和电源器件，科学理解有限，目前还没有商业成功的证明。最近的低温、快速生长方法的演示，如金属调制外延（MME），其生长速度高达9.8微米/小时，为“冻结”新相提供了新的可能性，这种新相以前被认为过于具有挑战性。由于MME是在极低的温度下进行的（氮化铟为300摄氏度，氮化镓为~500-600摄氏度），控制界面扩散的能力，消除共晶驱动的衬底蚀刻，以及控制界面平面度，所有这些都是通过使用动力学限制扩散是可行的。此外，MME已经被证明可以克服InGaN的相分离挑战，也可以克服第四纪AlGaInN的相同挑战。这项基础研究的目标是更好地理解和控制iii -氮化物/硅异质结的界面动力学，提供高质量的季系iii -氮化物材料，并为集成在硅上的垂直传导器件找到更好的解决方案，从而消除当今硅/氮化物电子产品中常用的绝缘AlN中间层。该项目的成功实施有可能导致iii -氮化物和硅之间的化学和冶金相互作用的详细了解，包括扩散和反应系数的量化。这是下一代硅基垂直功率晶体管所需的基础，这种晶体管集成了智能CMOS器件，具有iii -氮化物和led的增强功率处理能力，可用于在低成本（甚至可移动/一次性）大面积硅基板上生长的固态照明。

Nontechnical Description: The focus of this project is to develop an increased understanding of the synthesis of nitride-based materials on silicon, combining the two most widely available semiconductors - Silicon and Nitrides. In spite of their importance in a variety of devices such as light-emitting diodes (LEDs), power transistors, and high-efficiency solar cells, much remains unknown about the crystalline growth processes occurring at the interface between these important materials. In order to achieve the integration of these materials for next generation devices, an improved understanding of the interface chemistry, growth mechanisms, metallurgical reactions, and resulting defect formation at this important interface is needed. This project utilizes a recently developed low temperature crystal growth process, capable of achieving commercially advantageous, high-throughput rates with various analyses to study the complex interfacial phenomena and extend the use of III-Nitrides to include the elusive material AlGaInN. A mechanism to control these phenomena, possibly reducing defects and enabling future applications is also targeted. This project provides graduate students access to cutting-edge technology and resources at the intersection of physics, materials science, and nanoelectronics. The resulting device platform has the potential to lead to innovations in energy saving devices, communications, solar cells, and medical device technologies. Social and academic outreach programs are expanded to include demonstrations for elementary to high school students. This research provides new opportunities for the dissemination and publication of detailed methods for achieving (AlGaIn)-Nitride and Silicon device integration.Technical Description: This project explores the development of heterostructures composed of quaternary III-Nitrides (AlGaInN) and Silicon for electronic and optoelectronic device integration. While AlN on Silicon is largely commercialized, all other commonly available III-Nitride alloys including GaN, InN, AlGaN and InGaN are substantially not implemented directly on Silicon substrates. Furthermore, the daunting challenge of growing quaternaries of AlGaInN has not been mastered, especially not on silicon substrates. Early attempts to control the naturally occurring growth phenomena at III-Nitride/Si interfaces were limited to the case where an insulating aluminum nitride interlayer was acceptable, as in lateral transistors like high-electron mobility transistors (HEMTs). For those cases where insulating barriers are not acceptable, as in future vertical conduction devices, e.g. transistors, LEDs, solar cells, and power devices, limited scientific understanding and no existing commercial success has been demonstrated. The recent demonstration of low temperature, rapid growth methods such as Metal Modulated Epitaxy (MME) with growth rates up to 9.8 microns/hr is providing new possibilities to "freeze in" new phases thought previously too challenging. Since MME is performed at extremely low temperatures (300 degrees C for indium nitride and ~500-600 degrees C for gallium nitride), the ability to control the interface diffusion, elimination of eutectic driven substrate etching, and control of interface planarity, all by using kinetically limited diffusion is viable. Furthermore, having already been proven to overcome phase separation challenges of InGaN, MME is viable for overcoming the same challenges of quaternary AlGaInN as well. The goal of this basic research effort is to better understand and control the interface kinetics of III-Nitride/Silicon heterojunctions, provide high quality quaternary III-Nitride materials and identify a better solution for vertical conduction devices integrated on silicon that eliminates the insulating AlN interlayer commonly used in silicon/nitride electronics today. The successful execution of this project has the potential to lead to a detailed understanding of the chemical and metallurgical interactions between III-Nitrides and Silicon including quantification of diffusion and reaction coefficients. This is the foundation required for next generation vertical power transistors on silicon that integrate smart CMOS devices with the enhanced power handling capabilities of III-Nitrides and LEDs for solid-state lighting grown on low-cost (even removable/disposable) large area silicon substrates.