Jpn. J. Appl. Phys. 44 (2005) pp. L564-L565 |Previous Article| |Next Article| |Table of Contents|
|Full Text PDF (156K)| |Buy This Article|
Temperature Dependence of Surface Acoustic Wave Characteristics of GaN Layers on Sapphire Substrates
NTT Photonics Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198, Japan
1Kanagawa Institute of Technology, 1030 Shimo-Ogino, Atsugi-shi, Kanagawa 243-0292, Japan
(Received January 31, 2005; accepted March 7, 2005; published April 15, 2005)
We measured surface acoustic wave (SAW) characteristics along the [01-10] and [2-1-10] directions of 1.5- and 2-µm-thick GaN layers on (0001) sapphire substrates at ambient temperatures between -50 and 200°C. The extracted thermal coefficient of delay (TCD) for the SAW propagating along the [01-10] direction, which is smaller than that for the SAW propagating along the [2-1-10] direction, decreases when GaN layer thickness, h, multiplied by SAW wave number, k, increases. The TCD for hk = 3.9, which might be close to that in bulk GaN, is as small as 28.3 ppm/deg. These results indicate that GaN is promising for SAW device operation over a wide range of ambient temperatures.
- S. J. Pearton, J. C. Zolper, R. J. Shul and F. Ren:
J. Appl. Phys. 86 (1999) 1[AIP Scitation].
- O. Ambacher:
J. Phys. D 31 (1998) 2653[IoP STACKS].
- S.-H. Lee, H.-H. Jeong, S.-B. Bae, H.-Choi, J.-H. Lee and Y.-H. Lee:
IEEE Trans. Electron Devices 48 (2001) 524[CrossRef].
- H.-H. Jeong, S.-K. Kim, Y.-C. Jung, H.-C. Choi, J.-H. Lee and Y.-H. Lee:
Phys. Status Solidi A 188 (2001) 247[CrossRef].
- T. W. Grudkowski and M. Gilden:
Appl. Phys. Lett. 38 (1981) 412[AIP Scitation].
- K. Uehara, C. M. Yang, H. Nakamura, S. Kaneda, H. Nakase and K. Tsubouchi: Proc. 2002 IEEE Ultrasonics Symp. (2002) p. 135.
- K. Tsubouchi and N. Mikoshiba: IEEE Trans. Sonics and Ultrasonics 32 (1985) 634.