| Autor: |
Chipta P. Laksana, Sheng-Rui Jian, Erik S. Jeng, Meei-Ru Chen, Hui-Ling Kao |
| Rok vydání: |
2010 |
| Předmět: |
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| Zdroj: |
2010 5th IEEE Conference on Industrial Electronics and Applications. |
| Popis: |
Epitaxial single crystal AlN thin films have been obtained on (001) sapphire substrates by helicon sputtering system at growth temperature of 450°C. Surface acoustic wave (SAW) filters were fabricated on AlN/sapphire. The center frequency is 354.2MHz, which corresponds to a phase velocity of 5667 m/s. The insertion loss and sidelobe rejection were about 24.9dB and 11.4dB, respectively. The value of TCF is measured to be −74.9 ppm/°C and −65.76 ppm/°C at 0.4 µm and 1 µm of film thickness, respectively. The temperature coefficient of frequency (TCF) of AlN/sapphire shows proportional to the film thickness. A frequency downshift about 43 KHz was observed when the UV source with the wavelength of around 200nm and 12 mW/cm2 of power density radiates the surface of SAW devices. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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