THz醫學影像系統及元件---子計畫一：THz醫學影像系統之建構與技術發展(I)

Abstract

近年來，THz 電磁波(300 GHz-3THz，T-射線)在科學與工程上之應用已引起 廣泛之研究。相較於X- 射線(X-ray) 而言， T- 射線為非離子化幅射光源 (non-ionization radiation)，適合進行生物組織之非侵入式偵測而較無輻射疑 慮。因此其被公認為下世代醫學影像系統之重大關鍵技術。此外，其具備穿透衣 服及其他非金屬化材質之特性，因此可廣泛應用在安檢系統之影像監測、化學與 生物物質偵測，腫瘤、蛀牙之醫學影像等。 本三年期總計畫「THz 醫學影像系統及元件」具體目標為發展小型化THz醫 學影像系統，同時建構核心元件之自製能力及建立THz信號頻譜之量測能力，初 步應用設計為蛀牙之醫學影像。本總計畫延攬多方面領域之教授，涵蓋光學影像 系統、電路與微機電封裝、到基礎物理研究等領域。其下統合五項子計畫，分別 為：(一)THz醫學影像系統之建構與技術發展、(二) THz量測技術、(三)THz CMOS 信號源設計、(四)THz CMOS射頻照影偵測器陣列系統晶片、(五) 應用微機電之 兆赫波導結構設計。 依據ITRS預測，CMOS之fT 及fmax 在2015年以前將達0.5 THz，此一重大技術進 展開啟了矽製程在THz系統應用之序幕，同時對於降低THz 系統成本之可行度大 為增加。本子計畫(三)將以CMOS技術發展THz信號源，子計畫(四)將以CMOS技術 發展THz照影偵測器，子計畫(五)將配合子計畫(三)、(四)發展之微小信號源、 偵測器元件以矽製程技術發展系統載具、微機電波導結構與陣列天線整合設計， 達成微小系統構裝。本子計畫(一)「THz醫學影像系統之建構與技術發展」計畫 之目的則在搭配上述微小信號源、偵測器系統元件間，配合醫學影像應用目的建 構光學系統與發展相關技術，屬於該小型系統具體化必要之支援功能。另外，子 計畫(二)發展THz量測技術，並開發製作部份THz光學元件。本子計畫(一)亦將就 其已發展之光學元件替待購置之元件，增加整體系統內元件自行開發之比例。 配合上述整體總計畫目標，本子計畫(一)「THz醫學影像系統之建構與技術 發展」第一年將就商用之各子系統元件，建構蛀牙醫學影像目標之自組系統，並 定義系統與元件規格，以為其子計畫設計研發之依據；第二年則將子計畫(三)、 (四)開發製作之信號源、偵測器逐步替換購置之元件；第三年則將子計畫(三)、 (四)、(五)開發製作之信號源、偵測器子系統及子計畫(二)開發製作之光學元件 替換購置之元件，建構小型化THz蛀牙醫學影像系統之雛型。

THz wave (300GHz–3THz, T-ray) applications in scientific and engineering applications have drawn tremendous research efforts recently. In contrast to X-ray, it is a non-ionized light source for non-invasive detection of biological tissues without the concern of much radiation exposure. Thus it is believed as an emerging technology for next generation medical imaging system. Additionally, T-ray is capable to penetrate clothing and many (non-metallic) packaging materials. It opens up unique screening possibilities for detection of concealed weapons, chemicals and biological agents, tumors, cavities inside the teeth. As projected by ITRS, the fT and fmax of CMOS integrated circuit technologies will reach the regime of 0.5 THz by 2015. The great advancements have enabled silicon technology as an alternative means for realization of economical THz systems. The objective goal of this 3-year “THz Medical Imaging System and Devices”joint project is to build up a small THz medical imaging system through the developing of THz core devices as well as establishing the measurement techniques for THz spectrum. This project leverages efforts and experts from aspects of optical imaging system, circuits and packaging design, to fundamental physics researchers. It incorporates 5 sub-projects (1) Construction and development of a THz medical imaging system, (2) Terahertz measurement techniques, (3) THz signal generator design in CMOS technology, (4) Terahertz CMOS RF imaging detector array integrated system , and (5) MEMS-based THz guiding structure design. The action items are briefly described as follows. Sub-project (1) will setup the imaging system and define system specifications for other subprojects. Sub-project (2) focuses on the development of THz measurement techniques and develop some optical devices in the optical system. As THz spectrum is beyond the scope of most of the instrument vendors, it is essential to build up in-house facilities for system and device characterization. Sub-project (3) targets at the development of THz signal generator in CMOS technology for both the imaging screening and local oscillators for THz detectors. Sub-project (4) develops THz device modeling, THz system EDA design flow, and scalable detector array system IC. Sub-project 5 provides carrier platform, MEMs based guiding structure, and antenna array for packaging and system integration. For this sub-project (1) “Construction and Development of a THz Medical Imaging System, the imaging system will be setup with commercial parts in-house, and the system specifications will be defined for other subprojects in the first year. In the second year, the signal generator and detector devices developed by sub-projects (3) and (4) will replace the commercial parts in the system step by step. In the third year, the signal generator and detector subsystems developed by sub-projects (3) , (4), and (5), and optical devices developed by sub-projects (2) will replace the commercial parts to build up a prototype of a small THz medical imaging system .