高速高效单载流子传输硅基光探测器关键技术研究

‘Broadband Chinese’ aims to build novel national basic network. Fiber to the Home (FTTH) and Smart Terminals are two key technologies for it. Both technologies require numerous higher cost performance photo-electronic devices. In this project, a SiGe/Si Uni-traveling-carrier (UTC) hetero-junction phototransistor (HPT) is studied to relieve the contradiction between optical responsivity and working speed and to improve both. The working mechanism of UTC transport and the physical interpretation for UTC increasing responsivity and working speed are studied and the physical model of SiGe/Si UTC HPT is build. A SiGe/Si UTC HPT is designed with considering the dependence of material parameters on Ge content， the hetero-junction characteristics and the structure parameters of emitter, base and collector of HPT. A complementary structure consisting of deep and shallow junction is also used during design, which to improve and balance optical detection and absorption both for visible light and near-infrared light. Finally, based on standard BiCMOS process, the proposed SiGe/Si UTC HPT will be fabricated and measured. The novel high efficiency and high speed silicon-based UTC HPT detector can provide a new method for Silicon-based OEIC and make developments for silicon-based photo-electronics.

“宽带中国”战略旨在构建国家新兴基础设施网络，急需的光纤入户技术和智能终端技术需要大量高性价比的光探测器支撑。针对硅基光探测器响应度和工作速度低，优化存在矛盾等问题，本项目以单载流子传输SiGe/Si光敏晶体管探测器为研究对象，揭示硅基光探测器单载流子传输的工作机制，分析单载流子传输机制提高光响应度和工作速度的机理，建立SiGe/Si 单载流子传输光敏晶体管探测器的物理模型。综合考虑Ge组分含量及分布，SiGe/Si异质结界面特性，晶体管结构参数如发射区、基区和集电区的厚度、掺杂浓度等，得到SiGe/Si单载流传输的实现策略和均衡可见光和近红外光吸收的深浅结互补结构，提供SiGe/Si 单载流子传输光敏晶体管的设计方法。基于BiCMOS工艺，摸索出一套完整的SiGe/Si 单载流子传输光敏晶体管制备技术，提供可见光和近红外波段的硅基高速高效探测器，为低成本硅基单片集成提供一种新方法。

硅基光子（Silicon Photonics）技术的不断成熟逐渐为光接入技术和光互连技术向短传输距离、高带宽和高集成度发展提供了技术实现基础。硅基光电探测器以低功耗、低成本、与互补金属氧化物半导体（CMOS）单片集成电路技术兼容等优点受到广泛关注。因此，高速高效硅基异质结光敏晶体管探测器（SiGe/Si HPT）成为符合光互联系统需求且具有发展前景的光电探测器之一。针对硅基光探测器响应度和工作速度低，优化存在矛盾等问题，本项目揭示了SiGe/Si UTC-HPT单载流子传输的工作机制；建立了SiGe/Si UTC-HPT的物理模型，探究了单载流子传输机制提高探测器光响应度和工作速度的机理。给出了SiGe/Si UTC-HPT纵向结构参数和横向结构参数的优化设计方法，优化设计发射区、基区和集电区的厚度、掺杂浓度，基区Ge组分的含量和分布等，保证单载流子传输和深浅结互补探测的实现。采用商用0.35um BiCMOS工艺（重庆中科渝芯电子有限公司），以来实际外延条件，优化调整以SiGe基区为主的纵向结构，摸索出一套完整的SiGe/Si 单载流子传输光敏晶体管制备工艺，制作了一种高速高效单载流子传输光敏晶体管探测器。项目开展的工作和取得的成果为低成本硅基单片集成技术提供了一种新的方法，能够促进硅基光电子学的方展具有一定的理论意义和实用价值。