行政院國家科學委員會專題研究計畫 成果報告
最佳 Schottky 二極體設計及其應用
研究成果報告(精簡版)
計 畫 類 別 ： 個別型
計 畫 編 號 ： NSC 95-2221-E-151-014-
執 行 期 間 ： 95 年 08 月 01 日至 96 年 07 月 31 日
執 行 單 位 ： 國立高雄應用科技大學電機工程系
計 畫 主 持 人 ： 何彥仕
計畫參與人員： 碩士班研究生-兼任助理：陳詰文、蔡穎傑、丁奎耀、劉峰均
大學生-兼任助理：范綱宏、張登富
處 理 方 式 ： 本計畫涉及專利或其他智慧財產權，2 年後可公開查詢
中 華 民 國 96 年 08 月 13 日
行政院國家科學委員會補助專題研究計畫
□
□ 成 果 報 告
□
□期中進度報告
（計畫名稱）
最佳Schottky 二極體設計及其應用
Optimized Schottky diode design for rectifier application
計畫類別：□ 個別型計畫
□ 整合型計畫
計畫編號：
NSC -95-2221-E-151-014
執行期間：
95 年
8 月 1 日至
95
年
7
月
31 日
計畫主持人：
何彥仕
共同主持人：
計畫參與人員：
陳詰文,蔡穎傑,
,
丁奎耀,劉峰均,范綱宏,張登富
成果報告類型(依經費核定清單規定繳交)：□精簡報告
□完整報告
本成果報告包括以下應繳交之附件：
□赴國外出差或研習心得報告一份
□赴大陸地區出差或研習心得報告一份
□出席國際學術會議心得報告及發表之論文各一份
□國際合作研究計畫國外研究報告書一份
處理方式：除產學合作研究計畫、提升產業技術及人才培育研究計畫、
列管計畫及下列情形者外，得立即公開查詢
□涉及專利或其他智慧財產權，□一年□二年後可公開查詢
執行單位：
中
華
民
國
96
年
7
月
31
Abstract:
Ambient Power Scheme (APS) converts radio frequencies or ISM band frequencies to usable electrical power even only in milliwatts and microwatts range. It is sufficient to operate clocks, smoke alarms, Ni-Cd battery chargers, &solar cell etc. It also can provide early seismic warning since earthquake preparation generates radio frequencies. It also acts as a proximity detector for huge objects such as ships and vehicles and structures and small objects build up with RFIDs.
The Ambient Power Scheme (APS) is a simple electronic circuit which, when connected to antenna and earth ground, will deliver low voltage up to several milliwatts. The amount of voltage and power will be determined by local radio noise levels and antenna dimensions. Especially, the construction as a base station was widely built for wireless communication in order to transmit very directly radio frequency signal. To intercept the ambient radio frequency waves or GHz range waves as a power source is not just to re-use it to drive the powerless passive device but also to setup a power channel in wireless way, so-called wireless power transfer.
The actual circuit consists of two oppositely polarized voltage doublers. The DC output of each doubler is connected in series with the other to maximize voltage with using
transformers or not use. Single voltage doublers were often and widely found in older TV sets for converting 120 VAC to 240 VDC. In the TV circuit the operating frequency is 60 Hz. Now we need to convert it the miniature version for ISM bands frequencies in sub-GHz and GHz range.
Some studies for raising the frequencies up to several MHz were reported as Figure-1. The ambient power module operates at radio frequencies, receiving most of its power from below 1MHz. The basic circuit may be combined with a variety of voltage regulation schemes, some of which are shown in Figure 2.
It can be used to power small electronic devices with CMOS circuitry, like clocks, calculators and RFID or some smoke alarms detector or low voltage LEDs. This project is based on the APM circuitry but convert it to integrated circuit with specific design Schottky diode in up to date CMOS technology for receiving the power of ISM band frequencies. Then the power will be converted to drive low power
consumption device such as LED, and RFID. Hence the power conversion efficiency is the major subject of this project. The Schottky diode is used in this project is because the important figure of merit for microwave application. The Schottky diode can perform the forward bias cutoff frequency up to 10GHz which is not possible for typical p+/n or n+/p diode in current widely used CMOS technology for most electronic devices. Hence to make a clean and reliable and stable Schottky diode with large amount of contacts without increasing parasitic diode capacitance is very crucial for the ambient power scheme (APS).
The physics of Schottky diode is extensively discussed in Sze’s book. Since the most famous IC foundry in Taiwan or rest of the world did not provide very clear Schottky diode model and characterization for the circuit designers to adapt it in voltage regulator circuit. The reason is due to the voltage circuit consume the silicon area is relatively small. However for the low power supply and low power consumption circuit do need more efficiency power regulation in order to not only extend battery charging cycle but also apply in wireless transponder devices.
KeyWords:
Ambient Power Scheme (APS), Schottky diode, voltage
technology
I. Introduction:
The actual circuit consists of two oppositely polarized voltage doublers (Figure 1). The DC output of each doubler is connected in series with the other to maximize voltage with using transformers or not use. Single voltage doublers were often and widely found in older TV sets for converting 120 VAC to 240 VDC. In the TV circuit the operating frequency is 60 Hz. Now we need to convert it the miniature version for ISM bands frequencies in sub-GHz and GHz range. Some studies for raising the frequencies up to several MHz was reported as Figure-1. The ambient power module operates at radio frequencies, receiving most of its power from below 1 MHz. The basic circuit may be combined with a variety of voltage regulation schemes, some of which are shown in Figure 2.
It can be used to power small electronic devices with CMOS circuitry, like clocks, calculators and RFID or some smoke alarms detector or low voltage LEDs. This project is based on the APM circuitry but convert it to integrated circuit with specific design Schottky diode in up to date CMOS technology for receiving the power of ISM band frequencies. Then the power will be converted to drive low power
consumption device such as LED, and RFID. Hence the power conversion efficiency is the major subject of this project. The Schottky diode is used in this project is because the important figure of merit for microwave application. The Schottky diode can perform the forward bias cutoff frequency up to 10GHz which is not possible for typical p+/n or n+/p diode in current widely used CMOS technology for most electronic devices. Hence to make a clean and reliable and stable Schottky diode with large amount of contacts without increasing parasitic diode capacitance is very crucial for the ambient power scheme(APS). The physics of Schottky diode is extensively discussed in Sze’s book. Since the most famous IC foundry in Taiwan or rest of the world did not provide very clear Schottky diode model and characterization for the circuit designers to adapt it in voltage regulator circuit. The reason is due to the voltage circuit consume the silicon area is relatively small. However for the low power supply and low power consumption circuit do need more efficiency power regulation in order to not only extend battery charging cycle but also apply in wireless transponder devices.
II. Experiments:
The so-called silicon Schottky diode is formed as a metal to silicon junction which needs to generate the good junction between metal and silicon by using the silicidation process. The typical Schottky diode process flow in current CMOS
technology is described as Figure-3.
Since the stable Schottky barrier height and forward bias cutoff frequency are very crucial in this project. In terms of understanding the Schottky diode characteristics, we design several types of Schottky diode layouts for extensively studying the Schottky diode performance as shown in Figuire-4.
Based on the above designed Schottky diode device structures, we need to have precise device measurement in DC and RF range for parameters extraction. We will use the extracted parameters tofit as the Schottky diode SPCIE model parameters for designing the rectifier circuit as APS schematic diagram. In order to direct convert the ISM band frequencies, we combine with the rectifying circuit and filter circuit elements and transformer and antenna couplers as a schematic diagram for wireless power conversion circuits shown in Figure-5.
inductors and capacitors which are built on the silicon wafers. So far there are available in current RFCMOS (radio frequency on complementary metal-oxide-semiconductor) process technology from Taiwan IC(integrated circuit) foundry. We will implement our design via NSC-CIC (chip implementation center) service to realize the APS circuit. The IC is designed and produced and characterized since then.
III. Results and Diuscussions:
Design the most efficient Schottky diodes for rectifying circuit via layout engineering and diode device design architecture. The device layout is shown in Figure-6. Since the available Schottky diode layout cell and device characterization and modelling will be generated in first 1.5 years. The guess Schottky diode model with DC characteristics is shown as Figure-7. It is very comparable to the paper as shown from Jeon’s group.[1] As we integrate the rectifying circuit with existed passive devices such as a capacitor for wireless power conversion in ambient power scheme will be performed by the charge-pump circuit as shown in Figure-8. The output voltage versus the input RF power relationship is shown in Figure-9. The available output voltage and current for driving to the next stage circuit is eaisyl achieved from 0.871V to 1.732V and 8.7A to17.3A. In order to via inside island foundry service to producing the rectenna circuit, we are not able to change the process flow and process conditions from the foundry providers. Hence the circuit and device model are designed purely and fully utilized the existed model with some proprietary device
modeling. It extends out some silicon IP in wireless power conversion circuit. It will provide a reference not only in wireless voltage regulator but also chip inside regulator design and fast switch circuit with Schottky diodes. The silicon tapeout will be planned in September 2007 via CIC shuttle with device characterization layouts and rectenna design with simulator optimized Schottky diode device s. Since the key components of the passive RFID is the rectenna circuit. Once we have fully characterization in the rectifying circuit design sand , the RFID implementation with RF devices/RFIC measurement will greatly help for the students on the theoretical and practical experience built-ups and can be extended as the good IP and engineer in wireless communication for the related enterprise to hire and to use.
References:
[1] Jeon, W.; Melngailis, J.; Newcomb, R.W Newcomb “CMOS Schottky diode microwave power detector fabrication, SPICE modeling, and applications”2006. DELTA 2006. Third IEEE International Workshop on Electronic Design, Test and Applications,
[2] J. A. Hagerty, F. B. Helmbrecht, W. H. McCalpin, R. Zane,and Z.B.Popovic,“Recycling ambientmicrowave energy with broad band rectennaarrays.”,IEEE tran.on Microwave theory and tech., vol.52, No 3, pp 1014-1024, March 2004
[3]U.Karthausand M.Fisher,“Fullyintegrated passiveUHF RFID transponder IC with 16.7-μW MinimumRF input power,”IEEE Trans.Solid StateCircuits,vol.38,no.10,pp. 1602-1608, October, 2003
[4] V. Milanovic, M. Gaitan, J.C. Marshall, and M. E. Zaghloul,“CMOS foundryimplementationofSchottky diodesforRF detection,”IEEE Tran.Electrondev.Vol.43 No. 12, pp. 2210-2214, Dec. 1996
[5] N. Raza, V. Bradshaw, M. Hague, " Applications of RFID
technology," Proc. of the IEE Coll. On RFID Tech., London, pp. 1/1 - 1/5, October, 1999
[6] A. Cerino and W. P. Walsh, "Research and application of radio frequency identification (RFID) technology to enhance aviation security." Proc. of IEEE NatI Aero & Elec Conf., Dayton OH, USA, pp. 127 - 135, October, 2000 [7] R. Glidden, C. Bockorick, S. Cooper, C. Diorio, D. Dressler, V. Gutnik, C. Hagen, D. Hara, T. Hass, T. Humes, J. Hyde, R. Oliver, O.Onen, A. Pesavento, K. Sundstrom, and M. Thomas,“Design of ultra-low-cost UHF RFID tags for supply chain applications," IEEE Comm. Mag., Vol. 42, Iss. 8, pp.140 - 151, August, 2004
[8] A. DeMarco, W. Bandy, S. Parsa, H. Kaufmann and J. Melngailis, "Writing the identity in RFID tags with focused ion beam implantation of transistor gates," J. of Vac. Sci. Tech. B Nov/Dec, 2005
[9] H.T. Friss, n A note on a simple transmission formula," Proc. of the IRE, Vol. 41, pp. 254-256, May, 1946
Figures:
Figure-1: Ambient Power ModuleAPM-2 schematic diagram
Figure-3: Silicide formation process flow
Figure-4: Schottky diode layouts for studying the efficiency of rectifier current
Figure-5: Rectifying antenna circuit for wireless power conversion
Figure-6: An example Schottky diode layout is shown. The diode size is 0.66m by 1.38m with two contact array.
Figure-7: The DC characteristics of a two contacts Schottky.
Figure-8: A two stages charge pump circuit as design with proposed Schottky diodes with incident RF frequency in 915MHz.
Figure-9: The output voltage after the charge-pump circuit is shown. The output voltage can be ranged easily obtained from the dependence of incident RF power as the proposed circuit shown in Figure-8.
Figure-10: The output current after the charge-pump circuit is shown. The output voltage can be ranged easily obtained from the dependence of incident RF power as the proposed circuit shown in Figure-8.
