Spray Pyrolysis Synthesized Self-biased Hexagonal Ferrite Thin Film on GaN, AlN, Si Substrates for Millimeter-wave Devices

用于毫米波器件的 GaN、AlN、Si 衬底上喷雾热解合成自偏置六方铁氧体薄膜

基本信息

批准号：
1808147
负责人：
Mohammed Afsar
金额：
$ 40万
依托单位：
Tufts University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1808147&HistoricalAwards=false
关键词：
Spray Pyrolysis Synthesized Self biased

项目摘要

With the advent of advanced wireless communications the spectrum at lower frequencies are congested. To overcome this congestion an alternative approach is to develop compact and high efficient communication system using passive devices operating in millimeter-wave frequency band. The materials used at these frequencies are Ba- and Sr hexaferrites. The anisotropy of these ferrites exhibit strong ferromagnetic resonance up to 60 GHz (5 mm in wavelength). The oxygen molecule in the atmosphere exhibit a strong resonance absorption of electromagnetic waves at 60 GHz. Thus makes it a very attractive frequency band for shorter distance communication system. In current proposal, the use of self-biased hexagonal ferrite devices is suggested in millimeter wave frequencies. This led to shift from silicon, narrowband gap substrate technology to GaN, wideband gap substrate technology for efficient performance of communication system. The Ba- and Sr- ferrite nano size powders are now readily available from a number of manufacturers. Recently it has been found that nano-sized hexagonal ferrite powders can be mixed with commercially available photoresist and then sprayed as a layer on to the GaN substrate. It is proposed to use one ultrasonic generator with two ultrasonic spray nozzles with compressed air shaper for spraying. The next step turns out to be curing of the film in an oven up to 600 degrees centigrade for narrowing of the ferromagnetic resonance peak. It also leads to doubling of the resonance intensity. The comprehensive characterization study of deposited nano-ferrite film has been performed by employing a custom made quasi-optical millimeter wave spectrometer, scanning electron microscope, X-ray diffraction analysis and vibrating sample magnetometer.For a communication system, one would need a high efficient power amplifier, a low noise amplifier and a nano-ferrite circulator. However, the process to manufacture high quality nano-ferrite material with good grain size offer significant challenges. One of the problem is how to deposit self-bias hexagonal ferrite thin film with both good quality and acceptable cost has not been solved yet. Currently available wafers for MMIC design are about 100 mm in diameter with a thickness of about 100m. Typical thicknesses are 98 m of SiC and 2 m of GaN. The development of high purity GaN thick film film on SiC turns out to be big challenge in the near future. A thin film of highly pure wide bandgap semiconductor such as Aluminum Nitride can also be deposited on SiC. It is a new technology and it will be explored during the course of the proposed research period. Originally this work was explored on IBM silicon CMOS substrates. The lower temperature operation restricted the deposition of nano ferrite Ba- ferrite film to porosity and uneven flatness. The work with silicon CMOS substrate will also be continued. The collaborative partnership with QORVO has led to the use of GaN on SiC wafers routinely. The ultimate goal is to have Ba-ferrite circulator, power amplifier and low noise amplifier build on a single GaN on SiC wafer for operation at 60 GHz.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.

随着高级无线通信的出现，较低频率的频谱被拥挤。为了克服这种拥堵，另一种方法是使用以毫米波频带运行的被动设备来开发紧凑，高效的通信系统。在这些频率下使用的材料是BA和SR Hexaferrites。这些铁氧体的各向异性表现出强大的铁磁共振，高达60 GHz（波长为5 mm）。大气中的氧分子在60 GHz处表现出强烈的电磁波共振吸收。因此，它使其成为较短距离通信系统的非常有吸引力的频带。在当前的建议中，在毫米波频率中建议使用自偏的六边形铁氧体设备。这导致从硅，窄带差距基板技术转变为GAN，宽带间隙基板技术，以有效地执行通信系统。现在，许多制造商都可以轻松获得BA-和Sr-ferrite Nano尺寸粉末。最近发现，纳米尺寸的六角铁氧体粉末可以与市售的光固定抗命抗物混合，然后喷在GAN基板上作为层。提议将一个带有两个超声喷雾喷嘴的超声波发电机和压缩空气的空气塑形器进行喷涂。下一步事实证明是在烤箱中固化的，最高为600摄氏度，以缩小铁磁共振峰。这也导致共振强度增加一倍。通过使用定制的准精光毫米波光谱仪，扫描电子显微镜，X射线衍射分析和振动样品磁力计，对沉积的纳米粉状膜进行了全面的特征研究。对于通信系统。但是，生产具有良好谷物尺寸的高质量纳米粉料材料的过程带来了重大挑战。问题之一是如何以高质量和可接受的成本来沉积自偏的六角铁氧体薄膜。目前可用于MMIC设计的晶圆直径约为100毫米，厚度约为100m。典型的厚度为98 m的SIC和2 m的GAN。在SIC上，高纯度浓密的电影的发展在不久的将来是巨大的挑战。也可以将高度纯宽带隙半导体（例如氮化铝）的薄膜沉积在SIC上。这是一项新技术，将在拟议的研究期间进行探索。最初，这项工作是在IBM硅CMOS底物上探索的。较低的温度操作限制了纳米铁氧化甲醇甲酸酯膜的沉积至孔隙率和不均匀的平坦度。硅CMOS基材的工作也将继续进行。与Qorvo的合作伙伴关系导致了GAN在Sic Wafers上的使用。最终的目标是让BA-Ferrite循环器，功率放大器和低噪声放大器建立在SIC WAFER上的单个GAN上，以在60 GHz上进行操作。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来通过评估来获得支持的。