複合物半導體元件研究中心以GaAs與GaN等三五族相關的半導體為主要的研究方向，各自包含了材料磊晶、元件製程、封裝等技術，應用範圍涵蓋行動通訊、雷達系統、電動車、太陽能電池等，近年來的研究課題如下：
l. III-V/Si整合於Post-CMOS之應用
lI. 次毫米波三五族高頻元件之應用及其封裝
lII. GaN-on-Si高功率元件之磊晶及製程研發
lV. GaN高頻元件之磊晶及製程研發
V. 銅金屬化製程
l. III-V/Si整合於Post-CMOS之應用
交大與加州大學柏克萊分校共同成立「國際頂尖異質整合綠色電子研究中心」，此跨國研究中心由張翼教授之研發團隊與柏克萊胡正明院士所主持，研究主軸為後矽世代(post-silicon)前瞻之綠能半導體相關技術之研究，以矽基板為基礎的III-V on Silicon異質整合技術為主，率先研發三五族半導體及矽基板整合技術，多項指標已達世界領先。在Ⅲ-Ⅴ/Si整合方面，張教授在high K/Ⅲ-Ⅴ之界面研究上，成果堪稱全球領先，先後與Intel、TSMC合作，並應用至Ⅲ-Ⅴ FinFET元件。元件之界面缺陷密度、Subthreshold slope、EOT、DIBL皆屬世界最低值，進行低電壓操作、低漏電、低功耗、高速操作的元件設計及製程整合等研究。研究層面包含材料製備、元件製作、可靠性到元件與電路整合、三維 IC，研究次世代III-V on Silicon異質整合互補式金氧半電晶體積體電路(CMOS IC)的實作，以提升未來5至10年，電子高科技產業所需的半導體核心技術。本計畫先後與Intel、台積電從事技術開發，2013年與台積電簽訂合作協議，成立「交大－台積電聯合研發中心」，以建立更密切的長期夥伴關係，推動下一世代半導體前瞻技術研發暨多元性專業人才培育。
lI. 次毫米波三五族高頻元件之應用及其封裝
在新穎InAs高頻微波通訊元件領域，發展高速HEMT奈米元件之最高截止頻率已達700 GHz以上，最高震盪頻率為600 GHz以上，領先全國，最高截止頻率為世界第一，該結果並被Applied Physics Express雜誌選為2013年spotlight (亮點研究)，未來將可應用於提升成像品質之影像雷達與生醫檢測等產品。過去的研究更被Semiconductor Today雜誌選為2009年三五族奈米電子元件最重要兩件成果之一，除引起國際半導體學界注意，陸續受邀至各知名國際會議演講超過40場，更獲得美國Intel公司的主動邀約，執行為期五年的「開發22奈米下世代之新穎元件發展計畫」。目前則與日本及美國等公司簽訂產學合作計畫，並將與其他國外廠商洽談合作，讓新技術實際應用於產品。
lII. GaN-on-Si高功率元件之磊晶及製程研發
交大執行經濟部學界科專計畫，目標為開發與設計出具有高功率應用價值的GaN元件，期以從功率元件與功率模組的研發，做出跨學科整合，並以電源供應器出發，以達到電動車輛的應用範疇。國外相關研究機構已積極地開發GaN應用於電動車輛市場，本計畫研發為國內先驅，有助於台灣進入歐美日等國之技術領先群。目前已成功研發GaN-on-Si高崩潰電壓磊晶結構，透過LT-AlGaN插入層及DH-FET結構之設計，開發出崩潰電壓大於600V之壓磊晶結構。此外，亦研發新耐壓元件結構佈局，並結合光學步進曝光機，成功製作600V/20A之80 mm大型高功率元件，並進行元件封裝及模組組裝等研發，多項技術更被Semiconductor Today雜誌及Compound Semiconductor雜誌轉載報導。目前也與多家日本及台灣廠商合作，進一步推廣相關技術。
lV. GaN高頻元件之磊晶及製程研發
發展GaN高頻功率元件，操作頻率為2 GHz時之元件輸出功率可達7 W/mm；在高頻低噪音元件應用方面，所做出之100 nm AlGaN/GaN HEMT元件最高截止頻率及最高震盪頻率分別為48 GHz及75 GHz，此元件之最小噪音值在30 GHz只有1.6 dB，為目前國際期刊所報導之最低者，以上這些數據皆為國內之最佳紀錄。此外，最近使用Neutral Beam 於元件掘入式閘極製作，已成功製作ft為150 GHz，fmax為200 GHz之氮化鎵元件，此技術為未來通訊領域(如5G、相位雷達)之關鍵技術。 而所製作之GaN RF元件，磊晶Mobility達2000 cm2/Vsec，功率密度達7 W/mm，皆為國內首創。 除此之外，在發展GaN高頻元件上，亦從磊晶結構進行研發，以InAlN/GaN HEMT為主，進一步提升在高頻操作下的特性。目前，除有歐洲的研究機構一同針對此課題進行研發外，亦有台灣公司一同加入團隊。
V. 銅金屬化製程
在三五族半導體金屬化製程方面，本研究中心亦為GaAs微波和GaN元件銅金屬化製程的技術原創者。使用銅金屬取代金具有降低生產成本與改良元件電性、散熱與機械性質等優點。透過研究各種不同的銅金屬化結構，並添加不同的擴散障礙層，諸如Ta, TaN, Pt, WNx, W，防止銅原子擴散進入元件主動區域，所研究的銅金屬化技術，已整合至MESFET, HEMT, HBT等各類GaAs元件及GaN HEMT元件，均為國際首見，近年金價大漲，不僅具備多項專利外並技轉此技術給台灣公司。而GaN HEMT金屬化研究成果更為Semiconductor Today所報導。
業界合作
張翼教授所領導的複合物半導體元件研究中心，在III-V族元件、材料及製程研發上，與國內外產業界密切合作，所研發之前瞻技術皆能獲得業界青睞，並進一步承接關鍵技術。同時藉由產學合作計畫的執行，使碩博士生能在進入職場前獲得充分的技術能力，成為業界迫切需要的研發人才。近年國內外合作對象如下：
1. 美國Intel
2. 美國Entegris
3. 美國Applied Materials
4. 美國Sharp
5. 美國Qunistar
6. 日本Panasonic
7. 日本ULVAC
8. 馬來西亞TMR&D
9. 台灣多家一流公司(台積電、穩懋、漢民、漢威等)
國際合作
張翼教授所領導的複合物半導體元件研究中心與歐美日各國的頂尖大學實驗室及研究機構互動頻繁，除了研究計畫上的合作及支援外，張翼教授更鼓勵博士生到各地進行實驗交流或交換學生，甚至取得雙學位的機會，每年實驗室會有將近10位博士生到各機構進行短期的實驗及參訪，且至少1名博士生在國外實驗室從事相關研究一年以上。
1. 瑞典Chalmers大學：２名雙學位博士
2. 德國FBH：４名交換學生各一年
3. 日本NTT：3名交換學生各一年
4. 日本TIT：６名交換學生各兩個月及1名交換學生一年
5. 日本Fukui大學：２名交換學生各一個月
6. 美國UCB大學：１名學生及１名博士後訪問學者共四年
7. 美國UCLA大學：2名雙學位博士
8. 比利時魯汶大學/Imec校際微電子中心：2名交換學生及1名雙學位博士生
Research Field
The main research fields of Compound Semiconductor Device Research Center is III-V related semiconductors including GaAs and GaN. We develop technologies such as epitaxy, device design, and package. The applications include mobile communication, radar system, electric car, and nano electronics. The research fields are as below.
I. III-V/ Si integration (Ge, SiGe, GaAs, InP) for Post-CMOS applications
II. InP, GaAs based compound materials and devices (HEMT, HBT) for wireless communication
and sub-millimeter wave imaging applications
III. GaN-on-Si high power electronics (HEMT) applications
IV. GaN high frequency electronics (HEMT) applications
V. Copper metallization process
I. III-V/ Si integration (Ge, SiGe, GaAs, InP) for Post-CMOS applications
NCTU and UCB have established “International Research-Intensive Centers of Excellence in Taiwan”, denoted as “I-RiCE Research center”. This center is led by Prof. Edward Yi Chang and Prof. Chenming Hu. The main research is III-V/ Si integration (Ge, SiGe, GaAs, InP) for Post-CMOS applications. The research focuses on low voltage operation, low leakage current, low power consumption, and high speed device design and process integration. The research includes material preparation, device fabrication, reliability, integration of device and circuit, and 3D-IC. By conducting these researches, the key technology of semiconductor industry was enhanced. Compound Semiconductor Device Research Center cooperated with many companies in the past including Intel, Applied Materials and now with TSMC and Panasonic for the development of the research. In 2013, Compound Semiconductor Device Research Center signed a cooperation agreement with TSMC and established I-RiCE Research center in order to build a closer long-term partnership and develop advanced technologies and human resources.
II. InP, GaAs based compound materials and devices (HEMT, HBT) for wireless communication
and sub-milimeterwave imaging applications
Compound Semiconductor Device Research Center has successfully developed InAs high electron mobility transistors (HEMTs) with the record cut-off frequency (ft) of 700GHz, and the Maximum oscillation frequency (fmax) of 600GHz, which is the record in the world. The results had been selected as the spotlight of 2013 in Applied Physics Express magazine. The InAs HEMTs can be applied in biomedical test and improve the quality of imaging radars. The past research works had been selected by Semiconductor Today magazine as one of the two most important achievements of the 2009 in III-V nano-electronic device field. In addition to attracting the attentions of the international semiconductor industry, Prof. Edward Yi Chang has given invited talks in international conferences for more than 60 sessions. Furthermore, Intel has taken the initiative in cooperation agreement with Compound Semiconductor Device Research Center for a five year project -The project of development of III-V channel novel devices for next generation. Recently, Compound Semiconductor Device Research Center has signed industry-university cooperation contracts with companies from Japan, the United States, and Taiwan to apply these new technologies to industrial products.
III. GaN-on-Si high power electronics (HEMT) applications
NCTU executed technical development plans of Ministry of Economic Affairs to develop GaN HEMTs for high-power applications. The related research is aimed at developing GaN technology for applications of electric cars. Compound Semiconductor Device Research Center is the domestic pioneer in this field and has developed world class technology. The epitaxial structure of GaN HEMTs with breakdown voltage higher than 600 V have been successfully developed by inserting a LT-AlGaN Layer and DH-FET structure. Besides, a large 80-mm high-power device with properties of 600V/20A have been successfully demonstrated. The device package and module assembly have also been under development. Many techniques have been reported by Semiconductor Today and Compound Semiconductor magazines. Recently, Compound Semiconductor Device Research Center cooperates with several Japanese and Taiwanese companies to develop the most advanced technologies in this field.
IV. GaN high-frequency electronics (HEMT) applications
High-frequency GaN HEMTs with output power density of 7 W/mm at 2 GHz have been successfully fabricated. The ft/fmax of the AlGaN/GaN HEMTs with gate length of 100 nm was 48 GHz/75 GHz. The minimum noise figure at 30GHz is only 1.6 dB. Furthermore, by using a novel gate recess approach, the ft/fmax of the AlGaN/GaN HEMTs is higher than 150/200 GHz. These performances are the best in Taiwan. The epitaxial structure for the GaN HEMTs features a high electron mobility of 2000 cm2/V-sec. The high-performance GaN HEMT is the key part in future communication applications including 5G and phase array radar system. Besides, we also develop the InAl(Ga)N/GaN HEMT with a higher polarization barrier layer to further improve the RF characteristics. Recently, Compound Semiconductor Device Research Centercooperates with European institutions and Taiwanese companies for development of GaN RF HEMTs.
V. Copper metallization process
In III-V semiconductor metallization process, Compound Semiconductor Device Research Center is the technological creator of Cu metallization of GaAs and GaN devices. By using Cu instead of Au, there are some advantages, such as lower production cost, electrical characteristic improvement, good thermal dissipation and mechanical properties of the devices. By studying various copper metallization structures and different diffusion barrier insertion layers such as Ta, TaN, Pt, WNx, W, to prevent copper atoms from diffusing into the active region of the devices. The copper metallization technology has been integrated into the MESFET, HEMT, HBT of GaAs and GaN HEMT. In recent years, the price of Au has risen sharply. A number of patents have been applied and has technological transferred to the Taiwanese companies. Furthermore, this copper metallization results were reported by Semiconductor Today.
Industry Cooperation
CSD Research Center led by Prof. Edward Yi Chang cooperates closely with industry. The advanced technologies including III-V devices, materials, and process was interested by companies. PHD and master students can be trained with sufficient abilities and become the needed research manpower in the industry through the execution of industry-university cooperative research projects. Some cooperating companies in recent years are as below.
- Intel (America)
- ATMI (America)
- Applied Materials (America)
- Sharp (America)
- Qunistar (America)
- Panasonic (Japan)
- ULVAC (Japan)
- TMR&D (Malaysia)
- TSMC、WIN Semiconductors、Hermes Epitek、Hexawave
International Cooperation
Compound Semiconductor Device Research Center cooperates with international research institutions through many renowned joint research projects. Prof. Edward Yi Chang also encourages PHD students to do research overseas through exchange program and dual degree program. Around 10 PHD students join the foreign institutions to do short-term academic exchange every year and at every PHD student is encouraged to do research at a foreign laboratory for more than 1 year.
- Chalmers University of Technology (Sweden)：2 dual-degree PHD students and 2 exchange students
- FBH (Germany)： 4 exchange students
- NTT (Japan)：3 exchange students
- TIT (Japan)：7 exchange students and 2 dual-degree students
- Fukui University (Japan)：2 exchange students
- UCB (USA)：１ exchange student and 1 post doctor for 4 years
- UCLA (USA)：2 dual-degree students
- KU Leuven/ Imec：2 exchange students and 1 dual-degree PHD student