| 학회 | 한국재료학회 |
| 학술대회 | 2007년 봄 (05/10 ~ 05/11, 무주리조트) |
| 권호 | 13권 1호 |
| 발표분야 | 전자재료 |
| 제목 | Fabrication and testing of thin film bulk acoustic wave resonator using deep Si etch process |
| 초록 | Rapid growth in wireless communications handset market is remarkable and there is a great demand for miniaturized devices. Improvements in the miniaturization of the conventional ceramic and Surface Acoustic Wave (SAW) devices enable small sized front-end RF and IF filters. However, they have difficulties in on-chip implementation and also have poor electrical power handling capability and limited range characteristics. Film Bulk Acoustic wave Resonator (FBAR) technology is considered as an alternative in miniaturization of those filters. The FBAR filter has many features superior to those of other small filters such as a SAW filter. As it has a high Q factor that leads to low-loss and sharp-cut off characteristics and a high power durability particularly in the high frequency range. Furthermore, it has the potentiality of integrated devices on a Si substrate. FBAR is composed of piezoelectric layer(AlN) sandwiched between top and bottom electrodes(Mo) on Si wafer. To improve the device performance, electrodes contact with air or vacuum. So, we fabricated FBAR using surface micromachining technology and especially deep Si etch process. Merits of FBAR using deep Si etch process are low acoustic loss and possible to apply to high radio frequency. In order to fabricate high performance FBAR filter, high effective electromechanical coupling coefficients(Keff2) of AlN films are needed. Keff2 of AlN films depends on full-width half maximum(FWHM) of AlN (0002) films. Thus, c-axis oriented AlN films are strongly required to application in wideband. AlN films were deposited by RF magnetron sputtering on Mo electrode and microstructure of the films was observed with FE-SEM and AFM, XRD. The fabricated FBAR is measured with network analyzer in wide(0.1~10GHz) and narrow(1.7~2.3GHz) frequency range. The measured series and parallel resonance frequencies are 1852MHz and 1899MHz, respectively. The measured Keff2 are 6.0% and FWHM of AlN films were 1.95°. |
| 저자 | 안영배1, 문정현1, 이종호1, 이재빈2, 정학준2, 김형준1 |
| 소속 | 1서울대, 2쌍신전자통신 |
| 키워드 | FBAR; AlN; piezoelectric; micromachining |
