Abstract
We have successfully developed (00·1) AlN film with atomically flat surface on (00·1) sapphire substrate using metalorganic chemical vapor deposition (MO-CVD) method. The atomically flat surface of less than Ra=2Å, Ra means mean roughness measured by atomic force microscope(AFM), within the thickness of 1.7μm has been achieved, whose conditions are high substrate temperature of 1200°C, low pressure of 30Torr, low V-III ratio of 500 and the numerous flow rate of trimethylaluminum (TMA)-back-up H2 gas of 5.0slm. The temperature-coefficient-of-delay (TCD) of the fabricated surface-acoustic-wave (SAW) device on (00·1) AlN/(00·1)Al2O3 combination with atomically flat surface are found to be 44.5ppm/°C at kH=2.25 and 28.5ppm/°C at kH=3.32, where kH is the normalized thickness by wave number, k is wave number and H is AlN film thickness. These measured TCD are agreed with simulated curve. AlN/Al2O3 combination with atomically flat surface has a potential for zero-TCD at kH=4.5.
Original language | English |
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Pages (from-to) | 135-138 |
Number of pages | 4 |
Journal | Proceedings of the IEEE Ultrasonics Symposium |
Volume | 1 |
Publication status | Published - 2002 |
Event | 2002 IEEE Ultrasonics Symposium - Munich, Germany Duration: 2002 Oct 8 → 2002 Oct 11 |
ASJC Scopus subject areas
- Acoustics and Ultrasonics