Abstract
The object of this thesis is the fabrication process of SAW device. In order to fabricate low-cost SAW filter, we used a simple RTA-MOCVD system to successively deposit piezoelectric AlN(002) film and aluminum electrodes on sapphire substrate without breaking vacuum, and fabricated IDT structure by nano-contact imprint technique. Firstly, the precursor TMAL is mixed with NH3 at various rate 1:10~1:25 with temperature 850℃~950℃ at operating pressure 0.6~4 torr to deposit aluminum nitride thin film on sapphire substrate and find out the optimal condition. TMAL is also used to deposit aluminum films on SiO2 at temperature 500℃~600℃. The aluminum nitride and aluminum films are analyzed from XRD、XPS、Auger in order to crystalline properties、film composition and atomic concentration percentage. Secondly, we prepared line width:space=1:1 and 1:10 molds with line width=150、200nm to transfer ink aminosilance on the mold. The nano-contact printing technique was developed to transfer aminosilane on aluminum film. The O2 plasma was applied on Al film to enhance the adhesion between Al film and aminosilance. The imprint pressure 15~25psi at temperature 100℃ for 30sec by Nanonex-2000 was performed from contact printing process. AFM and SEM were used to observe the aminosilance transferred patterns. Finally, we used aminosilance as the etching mask to pattern Al line. After dry etching with gas Cl2、BCl3 and N2 by RIE-200L we fabricated IDT Al nano-wire. The width and height of Al line was observed from AFM and SEM.