THz影像系統---子計畫四：THz CMOS被動式影像接收機

Abstract

兆赫茲波由於其物理性質及頻段之獨特性，使兆赫茲技術廣泛地應用於天文觀測、 氣體光譜、生物醫學影像、安全性偵測及高速無線通訊系統等。目前利用互補式金氧半 導體製程(CMOS)所發表的研宄，多注重於影像系統中的單一電路區塊實現，整合性低， 而且電路實現的方法，是將耗面積的天線陣列放置於昂貴的先進CMOS晶片上，成本 極高，未來難以應用於商用電子。為了解決上述問題，本計畫提出利用兆赫茲異質晶片 系統級封裝整合技術，實現體積小、低成本、高整合性之兆赫茲被動影像感測系統。此 系統將整合低穿透損耗之兆赫茲透鏡、高增益之兆赫茲天線陣列、低等效雜訊功率及高 響應係數之兆赫茲CMOS共焦平面陣列於單一載具上，俱有整合於可攜式裝備上的潛 力。本計畫使用的兆赫茲異質晶片整合技術，將採用本研宄群所發展的金金熱壓合技 術、三維晶片封裝技術及寬頻兆赫茲共振器耦合技術來實現；兆赫茲透鏡將利用和標準 CMOS相容的微機電技術於便宜的矽晶片上實現；兆赫茲天線陣列將利用低成本的矽基 板或玻璃基板實現；兆赫茲CMOS共焦平面陣列，將整合高響應係數之CMOS功率偵 測器、低雜訊放大器及低功率鎖相放大器，可以達到高響應係數及低等效雜訊功率的目 的，以增進影像感測系統的動態範圍。

THz technologies have been applied in many applications, such as astronomy, gas spectroscopy, bio-medical imaging, security, and high-speed wireless communications, because of their unique frequency allocation and physical properties. However, up to recently, designs using the CMOS technology mainly focus on a circuit-block design of a THz imaging system. The integration level is quite low. Moreover, bulk antenna arrays are placed on a chip, implemented in a very expensive process. The cost is dramatically high and, therefore, it is not easy to implement the THz technologies in commercial electronics in the near future. To solve the aforementioned issues, this project proposes a compact, low-cost and high-integration THz passive imaging system using THz heterogeneous system-on-package (SoP) integration. The proposed system is going to integrate a low-loss THz lens, a THz antenna array with high antenna gain, and a THz focal plane array with high responsivity (RV) and low noise equivalent power (NEP), onto a single carrier. The proposed imaging system has a potential to be integrated on portable devices. The market benefits are expected to be extremely high. The THz SoP integration used in this project will adopt several packaging techniques proposed by our research group, including Au-Au thermo-compressive technique, 3-dimentional packaging technique, and broadband THz packaging using resonator coupling technique. The THz lens will be realized in a cheap silicon wafer and easily integrated with other chips using CMOS compatible MEMS technique. Silicon and GIPD (Glass-Integrated Passive Devices) processes will be chosen for realizing a low cost THz antenna array. These adopted technologies are very cheap since no active devices are required. The CMOS focal plane array will integrate a high RV CMOS power detector, a low noise amplifier, and a lock-in amplifier. The array which possesses a low NEP and high RV properties can increase the dynamic range of the THz imaging system, i.e., the quality of THz images.