AlN epitaxial film with atomically flat surface for GHz-band saw devices

K. Uehara, C. M. Yang, H. Nakamura, Suguru Kameda, H. Nakase, K. Tsubouchi

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)


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 languageEnglish
Pages (from-to)135-138
Number of pages4
JournalProceedings of the IEEE Ultrasonics Symposium
Publication statusPublished - 2002
Event2002 IEEE Ultrasonics Symposium - Munich, Germany
Duration: 2002 Oct 82002 Oct 11

ASJC Scopus subject areas

  • Acoustics and Ultrasonics


Dive into the research topics of 'AlN epitaxial film with atomically flat surface for GHz-band saw devices'. Together they form a unique fingerprint.

Cite this