Etching Study of AT-Cut Cultured Quartz Using Etchants Containing Fluoride Salts, Hydrofluoric Acid, and Ammonium Bifluorlde

T h i s p a p e r r e p o r t s t h e r e s u l t s o f a chemical e t c h i n g s t u d y o f A T c u t c u l t u r e d q u a r t z when t h e e t c h a n t s h y d r o f l u o r i c a c i d and amnonium b i f l u o r i d e a r e m o d i f i e d w i t h f l u o r i d e s a l t a d d i t i v e s . These f l u o r i d e s a l t s s u p p l y p o s i t i v e i o n s o t h e r t h a n H+ and NH3+ a t a d s o r p t i o n s i t e s on t h e q u a r t z s u r f a c e . R e s u l t s show t h a t s p e c i f i c f l u o r i d e s a l t s a f f e c t sur face topography and e tch de fec ts . The a d d i t i o n o f ca l c ium, a lum inum, and l i t h ium f l uo r ide reduce e tch p i t s and improve surface topography when added t o h y d r o f l u o r i c e t c h a n t s a t 60°C. A d d i t i o n o f p o t a s s i u m f l u o r i d e r e d u c e s e t c h p i t and e tch channe l f o rma t ion wnen added t o h y d r o f l u o r i c a c i d o r ammonium b i f l u o r i d e e t c h a n t s a t 25°C o r 60°C.