以低溫多晶矽薄膜電晶體製程設計13.56MHz射頻辨識應答器

Design of 13.56MHz Radio Frequency Identification Transponder in Low Temperature Polysilicon Thin Film Transistor Technology

李原江(Yuan-Jiang Lee)

指導教授 ： 陳怡然

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.01899

摘要

射頻辨識系統（RFID）自從1990年代開始商用化以來，已經對人類生活的世界產生極大的影響。舉凡防竊系統、電子身份辨識系統、電子錢包、倉儲管理、自動化控制甚至生醫電子醫療系統等等都不脫射頻辨識系統的應用範疇。近年來射頻辨識系統也開始與消費性電子或可攜式的電子產品如手機結合。由於可攜式的電子產品內建的射頻辨識功能，使得周遭電子化資訊的存取變得更加容易，以下列舉幾個可能的應用：手機內建悠遊卡或是身分辨識的功能或是利用可隨身攜帶的電子產品取得商品的具體資訊如圖片、價格等以供消費者做決定。
目前的射頻辨識應答器晶片(或稱射頻辨識標籤)主要是以互補式金氧半導體（CMOS）的積體電路製程製造為主，價格偏高，且不易與產品做整合，這些缺點都是CMOS RFID應答器晶片在產品應用端上的重大限制。近年來由於顯示技術的快速發展，在低溫多晶矽的主動式矩陣液晶顯示面板製程上的薄膜電晶體在各方面的電性表現有著極大的突破，相較於傳統的非晶矽面板其電子遷移率提升了一百倍以上。這使得低溫多晶矽面板有能力將射頻辨識應答器電路整合於可攜式電子產品的面板之中，甚至可以是一個具無線傳輸能力的獨立可攜式顯示元件，晶片價格只有CMOS的百分之一。這不僅使得射頻辨識系統普及化的成本大大降低，也使得低溫多晶矽面板在面板中更具競爭優勢。
本論文第一部分首先探討過去二十年間發表於各類國際期刊上的各種射頻辨識應答器系統架構並歸納整理之。接著第二部分除了介紹射頻辨識系統的基本操作原理之外，也列舉目標規格ISO/IEC-14443的系統規範。第三部分則是研究低溫多晶矽薄膜電晶體的製程、材料物理以及其元件特性對電路的影響和相關議題的發展近況，並根據電路的需求將低溫多晶矽薄膜電晶體電性模型化。第四部分即是利用低溫多晶矽面板製程製作一個符合ISO/IEC-14443規格，低成本、高整合性並可內嵌於面板中的射頻辨識應答器晶片。主要使用於低頻短距離的應用（如悠遊卡、大樓門禁系統等)。為了克服低溫多晶矽薄膜電晶體元件上變異性的問題，傳統上的電路架構在低溫多晶矽製程下則顯得不夠穩定。本系統針對低溫多晶矽製程特性開發新電路架構，並提出新的數位編、解碼方式使得資料傳輸更加穩定。

關鍵字

射頻辨識系統 ； 射頻辨識標籤 ； 應答器 ； 振幅鍵移解調器 ； 時脈回復 ； 負載調變 ； 低溫多晶矽 ； 薄膜電晶體 ； 系統化面板

並列摘要

Since radio frequency identification (RFID) system has been commericalized in 1990s, it has had great impact on human daily life. Electronic article surveillance systems, electronic identification, electronic wallet, inventory management and automatic control systems, even the wireless bio-medical sensors (or capsules) are all belong to the category of RFID applications. Recently, RFID has been applied to consumer electronics or some other portable electonic devices such as cell phones.
Owing to the portable device with internal RFID function, it can become much easier to access digital information that has been loaded in the surrounding objects. For instance, Easy Card or building access identification can be embedded inside the cell phone or some information like pictures or prices of desired products can also be gotten by using customers‘ portable device with internal RFID function.
Currently, most RFID transponder (or tag) ICs are manufactured by CMOS process. Their costs are relative higher and they are not quite easy to integrate directly with products. All of these drawbacks are the critical limitation of CMOS RFID transponder on the implementation of RFID embedded device. Thanks to the rapid growth of display technology in recent year, electric characteristics of thin-film transistors (TFTs) in the low temperature polysilicon (LTPS) active matrix liquid crystal display (AMLCD) panel process has a great breakthrough. Then things become difference.
With comparing to the conventional α-Si process, the electron mobility of LTPS TFT device is over one hundred times larger than α-Si TFT. It gives rise the potential to integrate RFID transponder with any portable device with LTPS panel display or even becomes a single portable display device with wireless communication ability. A single
LTPS RFID transponder chip cost only 1% of CMOS RFID transponder. It not only dramatically reduces the cost for RFID system popularization but also gives rise to the predomination of LTPS panel over other panel displays.
In the first part of this thesis, the published RFID transponder among the journals and international conferences in recent twenty years are surveyed, discussed and organized. And then the second part is to introduce the basic principle of RFID system operation and ISO/IEC 14443 specification. The third part is about the investigation on the LTPS process, material physicals, device characteristics and recent development. How these factors affect LTPS circuit performance is also discussed in this part. Also, the LTPS TFTs DC and AC models are constructed.
The implementation an ultra-low cost, high integration and embeddable in panel display LTPS RFID transponder for ISO/IEC 14443 specification is stated in the fourth part. It focuses on low frequency and short distance applications such as Easy Card and building access control system. However, it lacks stable performance quality among each chip because conventional circuit architectures have been suffered a large amount of device/process variation due to LTPS TFT device mismatch. In order to overcome the device/process variation, brand new system and circuit architectures are developed. The innovative digital coding/decoding methods are proposed for reliable data transmission as well.

並列關鍵字

Radio frequency identification(RFID) ； Tag ； Transponder ； Tag on Glass(ToG) ； ASK Demodulator ； Clock Recovery ； Load Modulator ； LTPS ； TFT ； System on Panel (SoP) ； System on Glass (SoG)

參考文獻

[3] U. Kasier et al, ―A low-power transponder IC for high-performance identification systems,‖ IEEE J. Solid-State Circuit, vol. 30, no. 5, pp. 306–310, Mar. 1995.

[4] D. Friedman et al, ―A low-power CMOS integrated circuit for field-powered radio frequency identification tags,‖ in IEEE Int. Solid-State Circuits Conf. (ISSCC) Dig. Tech. Papers, Feb. 1997, pp. 294–295, 474.

[5] J. Bouvier et al, ―A smart card CMOS circuit with magnetic power and communications interface,‖ in IEEE Int. Solid-State Circuits Conf. (ISSCC) Dig. Tech. Papers, Feb. 1997, pp. 296–297, 474.

[6] Shoichi Masui et al, ―A 13.56 MHz CMOS RF identification transponder integrated circuit with a dedicated CPU,‖ in IEEE Int. Solid-State Circuits Conf. (ISSCC) Dig. Tech. Papers, Feb. 1999, pp. 162–163.

[7] André Abrial et al, ―A new contactless smart card IC using an on-chip antenna and an asynchronous micro controller,‖ IEEE J. Solid-State Circuit, vol. 36, no. 7, pp. 1101–1107, July. 2001.