Title :
Planar Two-dimensional Electron Gas (2DEG) IDT SAW Filter on AlGaN/GaN Heterostructure
Author :
Wong, King-Yuen ; Tang, Wilson ; Lau, Kei May ; Chen, Kevin J.
Author_Institution :
Hong Kong Univ. of Sci. & Technol., Kowloon
Abstract :
Surface acoustic wave (SAW) filters using two-dimensional electron gas (2DEG) as interdigital transducers (IDT) on AlGaN/GaN heterostructure has been demonstrated for the first time using a fluoride-based (CF4) plasma treatment technique. The CF4 plasma treatment is used to pattern 2DEG IDT on a planar surface without removing the top AlGaN layer. The RF characteristics of the SAW filters with planar 2DEG IDTs are compared with metal IDT SAW filters. It is shown that the massloading effects and the triple-transit-interference (TTI) are suppressed in the 2DEG IDT SAW devices owing to the removal of the metal IDTs. It is capable of reducing not only the passband ripple, but also the size of devices because 2DEG IDTs can be placed closer. In addition, the detection part of the SAW sensor can be performed on the top of the planar 2DEG IDTs rather than in the SAW propagation path. This novel SAW device can be integrated with high-electron mobility transistors (HEMTs) on AlGaN/GaN heterostructure to deliver a viable approach for single chip GaN wireless sensors.
Keywords :
III-V semiconductors; aluminium compounds; gallium compounds; high electron mobility transistors; interdigital transducers; interference suppression; plasma materials processing; semiconductor heterojunctions; surface acoustic wave filters; surface acoustic wave sensors; surface acoustic wave transducers; two-dimensional electron gas; AlGaN-GaN; GaN; HEMT; IDT; SAW; SAW sensor; TTI; fluoride-based plasma treatment technique; high-electron mobility transistors; interdigital transducers; massloading effects; metal IDT SAW filters; planar two-dimensional electron gas transducer; semiconductor heterostructure; single chip GaN wireless sensors; surface acoustic wave filters; triple-transit-interference; Aluminum gallium nitride; Electrons; Gallium nitride; HEMTs; Plasma properties; Plasma waves; SAW filters; Surface acoustic wave devices; Surface acoustic waves; Surface treatment; AlGaN/GaN; Two-dimensional electron gas; fluoride-based plasma treatment; interdigital transducers; planar process; surface acoustic wave filters;
Conference_Titel :
Microwave Symposium, 2007. IEEE/MTT-S International
Conference_Location :
Honolulu, HI
Print_ISBN :
1-4244-0688-9
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2007.380252