EAGER: Exploring Graphene Mechanical Switch for Future RF ICs

项目名称：EAGER：探索用于未来RF IC的石墨烯机械开关（提案编号：2302688; PI：Albert Wang）半导体射频集成电路实现的无线通信的激增永远改变了我们的生活。今天，很难想象没有智能手机和无线互联网的生活。在万物互联的新兴时代中，当前对“始终连接”的世界的追求需要新一代（Next-G）无线技术，而不是第五代（5G），其依赖于先进的射频集成电路芯片来支持更高的频率、更宽的带宽和更多的频带，以便实现更高的数据速率、更低的功耗和更短的系统延迟。想象一下，同一地区的数百名用户同时使用智能手机，如何避免其间的串扰？这就是射频开关器件将在现代无线通信中发挥关键作用的地方，特别是对于Next-G无线系统。不幸的是，传统的基于半导体晶体管的射频开关由于其固有的技术问题，如串扰抗扰度差和信号损耗高，不能支持Next-G无线通信，这将通过所提出的研究来解决。该项目将探索一种颠覆性的新型射频开关技术，利用新型石墨烯基微机电系统开关设计并异构集成到半导体集成电路平台中，实现新型开关器件，具有低串扰隔离，超低信号传播损耗，超快开关速度，以支持Next-G无线通信。这项为期两年的EAGER提案将探索一种革命性的基于石墨烯的机械开关概念，以解决基于半导体场效应晶体管（FET）的射频（RF）开关技术所固有的基本技术挑战，包括隔离差、插入损耗高、不适合下一代（Next-G）无线通信。提出的新的基于无转移石墨烯的桥接触机械开关（gSwitch）器件结构将使用异质集成（HI）技术在互补金属氧化物半导体（CMOS）集成电路（IC）平台（CMOS-gSwitch）中设计和制造。gSwitch器件代表了一种颠覆性的新型开关器件，具有以下几个新颖性：gSwitch利用静电驱动和桥接触欧姆接触开/关开关机制，可能实现一种理想的开关，在关断状态下具有隔离，在导通状态下具有超低插入损耗，功耗可以忽略不计。石墨烯薄膜的轻质量密度和高杨氏模量可以潜在地实现皮秒级的开关速度。桥接触结构可以潜在地防止静摩擦问题。石墨烯的优异机械强度可以确保支持十亿次开关循环的gSwitch器件的高耐久性。该项目有几个任务：任务1，证明新的gSwitch器件概念;任务2，开发用于在硅晶片上制造gSwitch器件的基于无转移金属-碳-绝缘体界面的二氧化硅上石墨烯合成技术;任务3，开发用于将新的gSwitch器件集成到CMOS中的HI制造流程;任务4，演示用于Next-G系统的使用gSwitch的RF开关IC;任务5演示使用gSwitch的混频器。计划开展综合研究教育活动，并在该项目期间促进多样性、公平和包容。如果成功的话，将产生重大的社会影响，因为它将永远连接世界，实现无限的万物互联（IoET）应用，为缩小全球无线差距做出贡献。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。

Project Title:EAGER: Exploring Graphene Mechanical Switch for Future RF ICs(Proposal #: 2302688; PI: Albert Wang)Proliferation of wireless communications, enabled by semiconductor radio-frequency integrated circuits, has forever changed our life. Today, it is hardly to imagine a life without smartphone and wireless internet. The current pursuit for an “always connected” world in the emerging era of internet of everything demands for new generation (Next-G) wireless technologies, beyond the fifth generation (5G), which depends upon advanced radio-frequency integrated circuit chips to support higher frequencies, broader bandwidth, and more spectrum bands in order to achieve higher data rates, lower power consumption and shorter system latency. Imagine hundreds of users in the same area utilizing smartphones at the same time, how to avoid crosstalk in between? This is where a radio-frequency switch device will play a critical role in modern wireless communications, especially for Next-G wireless system. Unfortunately, the traditional semiconductor transistor based radio-frequency switch could not support Next-G wireless communications due to its inherent technical problems, such as poor crosstalk immunity and high signal loss, which will be addressed by the proposed research. This project will explore a disruptively new radio-frequency switch technology that utilizes a novel graphene-based microelectromechanical system switch to be designed and heterogeneous integrated into semiconductor integrated circuit platform to realize a new breed of switch devices featuring ultrahigh crosstalk isolation, ultralow signal propagation loss, ultrafast switching speed to support Next-G wireless communications. This two-year EAGER proposal will explore a revolutionarily new graphene-based mechanical switch concept to address the fundamental technical challenges inherent to semiconductor field-effect transistor (FET) based radio-frequency (RF) switch technologies, including poor isolation, high insertion loss, not suitable for next-generation (Next-G) wireless communications. The proposed new transfer-free graphene based bridge-contact mechanical switch (gSwitch) device structure will be designed and fabricated in complementary metal-oxide-semiconductor (CMOS) integrated circuit (IC) platform (CMOS-gSwitch) using heterogeneous integration (HI) technology. gSwitch device represents a disruptively new switching device with several novelties: gSwitch utilizes electrostatic actuation and bridge-contact ohmic contact on/off switching mechanisms to possibly realize an ideal switch with ultrahigh isolation in OFF state, super low insertion loss in ON state and negligible power consumption. The light mass density and high Young’s modulus of graphene membrane can potentially achieve pico-second level switching speed. The bridge-contact structure can potentially prevent the stiction problem. The excellent mechanical strength of graphene may ensure high endurance of gSwitch devices supporting billion switching cycles. This project has several tasks: Task-1 to prove the new gSwitch device concept; Task-2 to develop wafer-scale transfer-free metal-carbon-insulator interface based graphene-on-silicondioxide synthesis technology for making gSwitch devices on silicon wafers; Task-3 to develop a HI fabrication flow to integrate new gSwitch devices into CMOS; Task-4 to demonstrate RF switch ICs using gSwitch for Next-G systems; Task-5 to demonstrate a frequency mixer using gSwitch. Integrated research-education activities are planned, and diversity, equity and inclusion (DEI) will be promoted during this project. If successful, the societal impacts will be significant by always-connecting the world for unlimited internet of everything (IoET) applications, contributing to reduce the global wireless disparity.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.