EAGER: Exploring Graphene Mechanical Switch for Future RF ICs

项目标题：EAGER：探索未来射频IC的石墨烯机械开关(提案#：2302688；PI：Albert Wang)半导体射频集成电路实现的无线通信的激增，已经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，当前对“始终连接”的世界的追求要求新一代(Next-G)无线技术超越第五代(5G)，后者依赖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谱，以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，数百名用户在同一地区同时使用智能手机，如何避免两者之间的串扰？这就是射频开关设备将在现代无线通信中发挥关键作用的地方，特别是在下一代无线系统中。遗憾的是，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而不能支持Next-G无线通信，如串扰抗扰性差和高信号损失，这将通过拟议的研究来解决。本项目将探索一种颠覆性的新型射频开关技术，利用设计的新型石墨烯基微型机电系统开关并异质集成到半导体集成电路平台，实现具有超高串扰隔离、超低信号传播损耗、超快开关速度的新型开关器件，以支持下一代无线通信。这份为期两年的热切提案将探索一种全新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)开关技术固有的基本技术挑战，包括隔离性差、高插入损耗、不适合下一代(Next-G)无线通信。提出的新型无转移石墨烯基桥接机械开关(GSwitch)器件结构将采用异质集成(HI)技术，在互补金属氧化物半导体(CMOS)集成电路(IC)平台上设计和制造。GSwitch器件代表了一种具有几个新颖性的颠覆性新型开关器件：gSwitch利用静电驱动和桥接触欧姆接触开/关开关机制，可能实现理想的开关，在关断状态具有超高的隔离度，在接通状态具有超低的插入损耗，并且功耗可以忽略不计。石墨烯薄膜的质量密度轻，杨氏模数高，有可能达到皮秒级的开关速度。这种桥接结构可以潜在地防止粘连问题。石墨烯优异的机械强度可能会确保支持十亿次开关循环的gSwitch器件的高耐久性。该项目有几项任务：任务-1，以证明新的gSwitch器件概念；任务-2，开发晶片规模的无转移金属-碳绝缘体接口的石墨烯-二氧化硅合成技术，以在硅晶片上制造gSwitch设备；任务-3，开发HI制造流程，以将新的gSwitch设备集成到CMOS中；任务-4，演示在Next-G系统中使用gSwitch的射频开关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，并将在该项目期间促进多样性、公平和包容性。如果成功，通过始终连接世界以实现无限的万物互联(IoET)应用，将产生重大的社会影响，有助于减少全球无线差异。该奖项反映了NSF的法定使命，并已通过使用基金会的智力优势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.