Exceptional hardness and corrosion resistance of Mo 5 Ru 3 and W 3 Ru 2 films
- PDF / 428,475 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 68 Downloads / 248 Views
T
H
I
N
f i l m d e p o s i t i o n t e c h n i q u e s often l e a d to the o c c u r r e n c e of p h a s e s which a r e new o r a r e s t r o n g l y m o d ified b y a d o m i n a n t and c h a r a c t e r i s t i c m i c r o s t r u c t u r e . The a p p e a r a n c e of new p h a s e s in thin f i l m s a m p l e s can depend v e r y m a r k e d l y on the d e p o s i t i o n t e m p e r a t u r e T D p a r t i c u l a r l y at T _< 1000~ At l e a s t in s o m e i n s t a n c e s they r e p r e s e n t the e q u i l i b r i u m p h a s e s at t h e s e t e m p e r a t u r e s which g e n e r a l l y cannot be a c h i e v e d f r o m bulk s a m p l e s b e c a u s e of the slow t r a n s f o r m a t i o n k i n e t i c s at the l o w e r t e m p e r a t u r e s . The new p h a s e s can be o b s e r v e d in f i l m s which a r e m a n y m i c r o n s thick, and a r i s e , t h e r e f o r e , f r o m the p r e p a r a t i o n technique r a t h e r than a " t w o d i m e n s i o n a l " n a t u r e of the s a m p l e . T h e s e " n e w m a t e r i a l s " p r o v i d e p o t e n t i a l l y useful p r o p e r t i e s s o m e t i m e s u n d i s c o v e r e d in the s p e c i a l i z a tion of thin f i l m r e s e a r c h . In this note we r e p o r t on s e v e r a l such p r o p e r t i e s , both u n e x p e c t e d and unique, found d u r i n g a s e a r c h f o r new s u p e r c o n d u c t o r s ~ in a l l o y s of M o - R u and W - R u p r e p a r e d b y s p u t t e r i n g . Our r e s u l t s show that MosRu s and WsRu 2 d e p o s i t e d at T D ~ 500 to 700~ (773 to 973 K) a r e a m o n g the h a r d e s t known e l e c t r i c a l c o n d u c t o r s . They a l s o e x h i b i t unusua l l y high r e s i s t a n c e to a t t a c k d u r i n g etching. T h e s e m a t e r i a l s a d h e r e well to the s a p p h i r e s u b s t r a t e s and show e x c e l l e n t s c r a t c h r e s i s t a n c e . The p r o p e r t i e s of f i l m s d e p o s i t e d at l o w e r t e m p e r a t u r e s a r e l e s s a t t r a c t i v e . F r o m X - r a y and s u p e r c o n d u c t i v e T c m e a s u r e m e n t s it is concluded that a p h a s e change has p r o b a b l y o c c u r r e d a t t e m p e r a t u r e s n e a r 500~ (773 K). M e a s u r e m e n t s of the e l e c t r i c a l r e s i s t i v i t y at s e v e r a l t e m p e r a t u r e s show that the t e m p e r a t u r e c o e f f i c i e n t of r e s i s t i v i t y can be m a d e n e g a t i v e , z e r o , o r p o s i t i v e d e p e n d i n g upon the d e p o s i t i o n t e m p e r a t u r e . Optical r e f l e c t i v i t y m e a s u r e m e n t s f r o m the u l t r a v i o l e t to the i n f r a r e d show a r e a s o n a b l y~ high r e f l e c t i v i t y with l i t t l e s t r u c t u r e e x c e p t n e a r 8000A.
u l t r a s o n i c w a s h in a 1 p c t Alconox s o l u t i o n followed b y r i n s i n g in d e i o n i z e d w a t e r and a 15 m i n t r e a t m e n t in b o i l i n g p h o s p h o r i c a c i d . This was followe
Data Loading...
