STUDY OF THE FABRICATION OF THE CHANNEL WAVE-GUIDE IN TI-SAPPHIRE LAYERS

The reactive ion etching (RIE) and the laser ablation by KrF excimer l aser of Ti : sapphire have been investigated as a potential means for micropatterning thin deposited layers for preparation of the channel w aveguide lasers. The RIE was performed in BCl3 : He atmosphere. To obt ain the high etching selectivity between sapphire and mask, the photor esist, SiO2, tantalum, and platinum were used as masks. Dependencies o f etched rate and etched selectivity between masks and sapphire on the reactor pressure, on the rf power and on the ratio BCl3 : He were inv estigated. The maximum etch rate of Ti : sapphire and 11.9 nm/min toge ther with etch selectivities between sapphire platinum equal to 3.87 a nd between sapphire and SiO2 equal to 0.55 were achieved. The rib guid es were fabricated from thin layers. The laser patterning of Ti : sapp hire by using KrF excimer laser was also studied. To optimize the patt erning process, the ablation threshold 1.36 J/cm(2) and absorption coe fficient alpha = 1.81 x 10(5) cm(-1) were determined. The etch rate an d quality of the irradiated surface for KrF laser ablation of Ti : sap phire were examined.