Monolithic On-chip Integration of Electronics & Photonics Using III-nitrides for Telecoms

互联网和电信面临着数据流量的爆炸性增长，以每年50%的速度增长。这就需要开发单片集成的电子和光电子技术，这将大大降低占地面积和加工成本。如此紧凑的系统将需要高功率密度和出色的耐高温性能。在单个芯片上集成基于III-氮化物的电子学和硅基光子学将是满足电信制度要求的最有前途的方法。光子部分包括通过波导连接的有源(激光二极管)和无源(光电探测器)组件，其中激光二极管由高电子迁移率晶体管控制。电子和光子器件都需要满足高功率、高频和高温工作的要求，以及良好的温度稳定性和坚固的机械性能。传统的III-V半导体(GaAs或InP)面临许多基本限制，如耐高温、温度敏感性、有限的功率密度容量和易碎性。由于散射(高折射率)和多光子吸收，它们也表现出很高的损耗。III-氮化物半导体都有直接带隙，覆盖从深紫外光到红外的广阔光谱区域。与传统的III-V材料相比，III-氮化物由于其固有的高击穿电压、高饱和电子速度和优异的机械硬度，在制造高功率、高频和高温器件方面显示出巨大的优势。III-氮化物具有低的自由载流子吸收、可忽略的多光子吸收、低的折射率(GaN为2.3，而GaN为3.5)和优异的温度稳定性(比InP高一个数量级)。因此，III-氮化物提供了极大的潜力来革新当前的互联网和电信，并实现了超快的速度和超宽带，远远超过了迄今在电信体制(1.3-1.55微米)所取得的成就。到目前为止，对III-氮化物的研究主要局限在可见光谱范围内，但这并不是限制。III-氮化物设备在提供下一代电信所需的功率/效率方面表现出卓越的性能。这对通信行业很重要，预计到2025年，通信行业将使用全球20%的电力，其中很大一部分(&gt；30%)由数据中心冷却系统消耗。因此，在电信领域通过直接外延将III-氮化物电子和硅上光电子技术集成到单个芯片上将提供变革性的性能。我们雄心勃勃的愿景是采用针对III-氮化物的两种主要外延生长技术(MOVPE和MBE)，将谢菲尔德、卡迪夫和斯特拉斯克莱德公司建立的领先专业知识与美国密歇根州世界领先的研究团队相结合，以展示第一个将基于III-氮化物的电子和硅上光电子与电信体系中的操作相结合的单片集成。预计这将给当前的互联网和电信行业带来革命性的变化。

Internet and telecoms are facing an explosive growth in data traffic, increasing at 50% per year. This requires the development of monolithic on-chip integration of electronics and photonics, which offers a massive reduction in both footprint and processing costs. Such a compact system will require a high power density and excellent high temperature tolerance. Monolithically integrating III-nitride based electronics and photonics on silicon on a single chip will represent the most promising approach to meeting the requirements in the telecoms regime. The photonic parts include active (laser diodes) and passive (photodetectors) components linked by waveguides, where the laser diodes are controlled by high electron mobility transistors. The electronic and photonic parts both need to meet the requirements for high power, high frequency and high temperature operation, as well as excellent temperature stability and robust mechanical properties. Conventional III-V semiconductors (GaAs or InP) suffer a number of fundamental limitations such as intolerance to high-temperatures, temperature sensitivity, limited power density capacity and fragility. They also exhibit high losses due to scattering (high refractive index) and multiphoton absorption. III-nitride semiconductors all have direct bandgaps and cover a vast spectral region from deep ultraviolet to infrared. Compared with conventional III-V materials, the III-nitrides exhibit major advantages in the fabrication of high power, high frequency and high temperature devices due to their intrinsically high breakdown voltage, high saturation electron velocity and excellent mechanical hardness. III-nitrides exhibit low free carrier absorption, negligible multiphoton absorption, low refractive index (2.3 for GaN compared with 3.5 for GaAs) and superior temperature stability of the refractive index (one order of magnitude higher than that of InP). Therefore, III-nitrides offer great potential to revolutionise current internet and telecoms and enable ultra-fast speed and ultra-broad bandwidths, going far beyond that so-far achieved in the telecoms regime (1.3-1.55 um). Up to now research on III-nitrides has mainly been confined to the visible spectral range but this is not a limit. III-nitrides based devices exhibit superior properties in terms of delivering the power/efficiency required for next-generation telecoms. This is important to the communications industry, which is expected to use 20% of the global electricity by 2025, where a large proportion (>30%) is consumed by the data centre cooling systems. Monolithically integrating III-nitride electronics and photonics on silicon on a single chip by direct epitaxy in the telecoms regime would therefore offer transformative performance.Our ambitious vision is to employ the two major leading epitaxial growth techniques (MOVPE and MBE) for III-nitrides, combining the leading-expertise established at Sheffield, Cardiff and Strathclyde along with a world-leading research team at Michigan in USA in order to demonstrate the first monolithic on-chip integration of III-nitride based electronics and photonics on silicon with operation in the telecoms regime. This is expected to revolutionise current internet and telecoms.