- Email: [email protected]
Application of analytical electron microscopy to the investigation of some aspects of the precipitation hardening by ordered coherent particles
Abstracts of The X1V Congressof the Italian Society of Electron Microscopy
x-RAY M I C R O A N A L Y S I S R. Rinaldi I s t i t u t o di M i n e r a l o g i a e Petrologia, Universita di M o d e n a , 4 1 1 0 0 M o d e n a , Italy
Recent d e v e l o p m e n t s in X - r a y microanalysis s t e m from a number of technical innovations in both s p e c t r o m e t e r design and, p r e d o m i n a n t l y , c o m p u t e r i z e d data handling. In w a v e l e n g t h - d i s p e r s i v e s p e c t r o m e t r y (WDS) o s c i l l a t i n g crystals and i n c l i n e d s p e c t r o m e t e r s are aimed at o v e r c o m i n g d e f o c u s s i n g effects due to variations in s pe c i m e n h e i g h t and large raster size (low m a g n i f i c a t i o n ) X-ray mapping, respectively. A four-crystal automated s p e c t r o m e t e r is cost competitive, w h e n c o m p a r e d w i t h more t r a d i t i o n a l systems, relative to w a v e l e n g t h coverage. The a v a i l a b i l i t y of u s e r - o r i e n t e d a u t o m a t i o n s oftwa r e packages in the last g e n e r a t i o n of WDS e l e c t r o n probe m i c r o a n a l y z e r s (EPMA) offers sizeable i m p r o v e m e n t s in a n a l y t i c a l c a p a b i l i t i e s ranging from fast q u a l i t a t i v e analysis with typical high r e s o l u t i o n and d e t e c t i o n e f f i c i e n c y to on-line r e s o l u t i o n of classical interference p r o b l e m s (i.e. NK~ - TiLl). Energy-dispersive spectroscopy (EDS) is a s t a n d a r d a n a l y t i c a l option for all u p - t o - d a t e e l e c t r o n b e a m instruments (SEM, STEM, EPMA) where the m a n u f a c t u r e r tends to m i n i m i z e artifacts and interferences due to i n s t r u m e n t a l setup and d etect o r environment. W i n d o w l e s s detectors e x t e n d the lower atomic number limit to Z ~ 5 a l t h o u g h with s t r i c t e r v a c u u m requirements. Digital image p r o c e s s i n g enhances the a n a l y t i c a l c a p a b i l i t i e s of EDS systems in both s c a n n i n g (EDS) and t r a n s m i s s i o n m i c r o s c o p e s (AEM). In the latter, X-ray i n t e n s i f y i n g c h a n n e l l i n g effects can be e x p l o i t e d in a new technique for the d e t e r m i n a t i o n of isomorphic s u b s t i t u t i o n s and site o c c u p a n c y assignments w i t h i n regions of a few h u n d r e d angstroms in a crystal structure. The d e c r e a s i n g cost of c o m p u t e r memory is m a k i n g larger q u a n t i t a t i v e analysis pr o g r a m s available for on-line operation. R e p r e s e n t a t i v e examples include the s i m u l t a n e o u s t r e a t m e n t of data c o l l e c t e d by h y b r i d (WDS+EDS) systems and thin film a p p r o x i m a t i o n programs b a s e d on Monte Carlo s i m u l a t i o n also i n c l u d i n g s e c o n d a r y fluorescence. Beam-sensitive m a t e r i a l s o f f e r a new challenge to the study of b e a m - i n d u c e d effects on the atomic scale.
97
A P P L I C A T I O N OF A N A L Y T I C A L E L E C T R O N M I C R O S C O P Y TO THE I N V E S T I G A T I O N OF SOME A S P E C T S OF THE P R E C I P I T A T I O N H A R D E N I N G BY O R D E R E D C O H E R E N T PARTICLES M. V i t t o r i E N E A , D i v i s i o n e S c i e n z a dei C.R.E. C a s a c c i a , C.P. 2400, Italy
Materiali, Roma,
In the p r e s e n t c o n t r i b u t i o n two examples are r e p o r t e d on the use of e l e c t r o n m i c r o s c o p y in the i n v e s t i g a t i o n of the p r e c i p i t a t i o n h a r d e n i n g b e h a v i o r of a F e N i C r steel h a r d e n e d by a small amount of y' phase (Ni3(AI,Ti)). The i n v e s t i g a t e d alloy (Alloy 800) is a candidate m a t e r i a l for the s t e a m g e n e r a t o r tubing of L i q u i d M e t a l Fast B r e e d e r N u c l e a r Reactors (LMFBR), operating at a m a x i m u m t e m p e r a t u r e of 525°C to 550oc. The first example refers to the study of the e x p e r i m e n t a l l y o b s e r v e d effect that in some alloy heats the y' particles grow with the same rate everywhere, w h i l e some o t h e r heats show a y' average size c h a n g i n g from grain to grain after a l o n g - t e r m e x p o s u r e to a t e m p e r a t u r e around 600°C. A simple model has been p r o p o s e d to e x p l a i n this effect, in which the p r e c i p i t a t i o n of Cr-rich carbides on the grain b o u n d a r i e s is taken into account. On the basis of this model a reduction in the Cr content of the single grains can be expected, d e p e n d i n g on their size. Since the Cr c o n c e n t r a t i o n affects the solid solubility of the y ' - f o r m i n g elements, one of the p a r a m e t e r s a p p e a r i n g in the coarsening rate equation, a d i f f e r e n t coarsening rate results for p a r t i c l e s growing in grains of d i f f e r e n t size. Both TEM and SEM with m i c r o a n a l y t i c a l facilities were used to give e x p e r i m e n t a l support to the above c o n s i d e r a t i o n s . The WDS m i c r o p r o b e was used to obtain q u a n t i t a tive i n f o r m a t i o n on the Cr content of the single grains as a function of their size. On the other hand, the q u a n t i t a tive image analysis p e r f o r m e d on TEM pictures gave the average p a r t i c l e size in several grains, w h i c h Cr content was o b t a i n e d again by WDS analyses. The e x p e r i m e n t a l results are in good agreement with the p r o n o s e d model, even if some points require further e x p e r i m e n t a l i n v e s t i g a t i o n s by using an analytical T E M The second example refers to the correlation of the chemical c o m p o s i t i o n of the Y' p a r t i c l e s to their A n t i p h a s e B o u n d a r y (APB) energy. The APB energy
Abstracts oJ' The XIV Congress of the Italian Society of £'lectron Microscopy
98
is the s p e c i f i c e n e r g y r e q u i r e d to c r e a t e an A P B in the o r d e r e d y' l a t t i c e , and it is o n e of the m a i n p a r a m e t e r s i n v o l v e d in the h a r d e n i n g by o r d e r e d a n d c o h e r e n t particles. T h e r e is a g e n e r a l f e e l i n g in the l i t e r a t u r e t h a t the A P B e n e r g y s h o u l d d e p e n d on the Ti a n d A1 c o n t e n t s of the p a r t i c l e s , b u t no e x p e r i m e n t a l e v i d e n c e is r e p o r t e d . The A P B e n e r g y can be d e r i v e d b y a g e i n g e x p e r i m e n t s f o l l o w e d by a m e c h a n i c a l a n d m i c r o s t r u c t u r a l chara c t e r i z a t i o n o f the a g e d s a m p l e s . The c h e m i c a l c o m p o s i t i o n of the y' p a r t i c l e s g r o w n in f o u r h e a t s of A l l o y 800 d i f f e r i n g f r o m e a c h o t h e r by s m a l l v a r i a t i o n s in the Ti a n d A 1 has b e e n d e r i v e d in the f o l l o w i n g way. Carbon extraction replicas w e r e o b t a i n e d b y m e a n s of a p o t e n t i o s t a t i c e t c h i n g , and t h e y w e r e a n a l y z e d in a T E M e q u i p p e d w i t h an e n e r g y - d i s p e r sive microanalytical system. This experi m e n t a l s e t u p w a s able to s h o w the diff e r e n c e s in the c h e m i c a l c o m p o s i t i o n of the p a r t i c l e s e x t r a c t e d f r o m the d i f f e r e n t h e a t s , m a k i n g p o s s i b l e the c o r r e l a t i o n w i t h the A P B e n e r g i e s . This kind of a n a l y s i s a l l o w e d us to p r o p o s e a rel a t i o n s h i p b e t w e e n the two p a r a m e t e r s a n d to p u t s o m e l i g h t on the c o n t r i b u t i o n to the A P B e n e r g y of the T i - A I a t o m i c p a i r s f o r m e d a c r o s s the APB.
CHARACTERIZATION OF S E M I C O N D U C T I N G MATERIALS BY ELECTRON MICROSCOPY A.
Camanzi Assoreni,
Monterotondo,
Rome
The a i m of this c o m m u n i c a t i o n is to r e v i e w b r i e f l y the role p l a y e d by e l e c t r o n m i c r o s c o p y in s t u d y i n g s e m i c o n d u c t ing m a t e r i a l s . W e can d i v i d e the a r g u ment into a traditional part, concerning m o r p h o l o g y , c h e m i c a l c o m p o s i t i o n a n d mic r o s t r u c t u r e s , a n d a less t r a d i t i o n a l part, concerning electrical information o b t a i n e d by e l e c t r o n - b e a m - i n d u c e d charges s e p a r a t e d by a j u n c t i o n (EBIC) . S c a n n i n g Electron Microscopy (SEM) and X - r a y Microanalysis (Energy Dispersion and/or Wave Dispersion EDS/WDS) techniques would a l l o w u n d e r s t a n d i n g of the p r e p a r a t i v e processes, starting from basic materials up to f i n a l d e v i c e s . S o m e e x a m p l e s of a p p l i c a t i o n to s o l a r g r a d e s i l i c o n p r o d u c t i o n r e l a t e d to o t h e r t e c h n i q u e s of a n a l y s i s (Atomic A b s o r p t i o n a n d N u c l e a r A c t i v a t i o n ) are shown. S t e r e o l o g y m e t h o d s (image a n a l y s i s ) a n d EDSW D S t e c h n i q u e s are p a r t i c u l a r l y u n d e r l i n e d to s h o w t h e i r a p p l i c a t i o n to q u a n t i t a t i v e d e t e r m i n a t i o n of the p u r i t y of m a t e r i a l s .
As c o n c e r n s t h o s e a p p l i c a t i o n s w o r k i n m on b a r r i e r e f f e c t s , E B I C a n d S c a n ning Transmission Electron Beam Induced C u r r e n t (STEBIC) t e c h n i q u e s are g e n e r a l l y a d o p t e d : b o t h use s h o r t - c i r c u i t currents induced by electron beam into p - n or S c h o t t k y j u n c t i o n s ; the c u r r e n t s i q n a l m a y be a m p l i f i e d a n d p r o c e s s e d in o r d e r to r e a l i z e E B I C m a p s , on w h i c h it is p o s s i b l e to d e t e c t s o m e c h a r g e recombination regions (precipitates, grain sub-boundaries and boundaries, dislocations). O t h e r w i s e the c u r r e n t s i g n a l m a y be u s e d for l o c a l m e a s u r e m e n t s f r o m which we may obtain some electrical para m t e r s to c o r r e l a t e w i t h the d e v i c e efficiency. C a u t i o n s h o u l d be a p p l i e d to the i n t e r m r e t a t i o n of t e x t u r i z e d or r o u g h n e s s s u r f a c e s in E B I C , b e c a u s e t h e s e i m a g e s m a y be c o n f u s e d w i t h adsorbed current images. Some examples are shown. Moreover, quality control a s s u r a n c e , a n a l y s i s of d e f e c t s on o p e r a t i v e d e v i c e s , are i m p o r t a n t a c t i v i t i e s t h a t a g o o d l a b o r a t o r y of e l e c t r o n m i c r o s c o p y a p p l i e d to the c h a r a c t e r i z a t i o n of s e m i c o n d u c t i n g m a t e r i a l s s h o u l d b e able to p e r f o r m . Finally, high resolution transmission electron microscopy (TEM) m a y p e r m i t one to h a v e i n f o r m a t i o n on: - - i m p u r i t y role a n d i m p u r i t y - g r a i n boundary; --crystallographic f e a t u r e s of l i n e a r a n d p l a n a r d e f e c t s r e l a t e d to t h e i r electrical activity. A p p l i c a t i o n a r e a s of e l e c t r o n m i c r o s c o p y to s e m i c o n d u c t i n g m a t e r i a l s m a y be t e n t a t i v e l y r e p r e s e n t e d in the f o l l o w i n g s c h e m a : i) M A T E R I A L : Basic; S T R U C T U R E : P o w d e r s o r P o l y c r y s t a l s ; T Y P E OF STUDY: M o r p h o l o g y a n d c o m p o s i t i o n by S E M - E D S ( W D S ) ; G r a i n Size, C r y s t a l l o g r a p h y of I n c l u s i o n s , c h e m i c a l a n a l y s i s by S E M - E D S ( W D S ) a n d TEM. 2) M A T E R I A L : P u r i f i e d a n d / o r R e c r y s t a l l i z e d ; S T R U C T U R E : S i n g l e and P o l y c r y stals; T Y P E OF STUDY: G r a i n Size, C r y s t a l l o g r a p h y , P r e c i p i t a t e s by SEM, ECP (SAD), E D S - W D S , TEM, STEM. 3) M A T E R I A L : J u n c t i o n s , D e v i c e s (Cells and C h i p s ) ; S T R U C T U R E : S i n g l e a n d Poly; T Y P E OF STUDY: P r e c i p i t a t e , B a r r i e r , Grain, Local Electrical Activity and Electrical Parameters, Production and F u n c t i o n i n g D e f e c t s , 0 u a l i t y C o n t r o l by SEM, EBIC, E C P (SAD), TEM, STEM, S T E B I C . R e c e n t s p e c t r o s c o m i c t e c h n i q u e s in S T E M are s h o w n as e x a m p l e of a n a l y s i s a n d d e t e c t i o n of n a t i v e o r r a d i a t i v e d e f e c t s at v e r y low l e v e l of c o n c e n t r a t i o n (SDLTS t e c h n i q u e ) .
x-RAY M I C R O A N A L Y S I S R. Rinaldi I s t i t u t o di M i n e r a l o g i a e Petrologia, Universita di M o d e n a , 4 1 1 0 0 M o d e n a , Italy
Recent d e v e l o p m e n t s in X - r a y microanalysis s t e m from a number of technical innovations in both s p e c t r o m e t e r design and, p r e d o m i n a n t l y , c o m p u t e r i z e d data handling. In w a v e l e n g t h - d i s p e r s i v e s p e c t r o m e t r y (WDS) o s c i l l a t i n g crystals and i n c l i n e d s p e c t r o m e t e r s are aimed at o v e r c o m i n g d e f o c u s s i n g effects due to variations in s pe c i m e n h e i g h t and large raster size (low m a g n i f i c a t i o n ) X-ray mapping, respectively. A four-crystal automated s p e c t r o m e t e r is cost competitive, w h e n c o m p a r e d w i t h more t r a d i t i o n a l systems, relative to w a v e l e n g t h coverage. The a v a i l a b i l i t y of u s e r - o r i e n t e d a u t o m a t i o n s oftwa r e packages in the last g e n e r a t i o n of WDS e l e c t r o n probe m i c r o a n a l y z e r s (EPMA) offers sizeable i m p r o v e m e n t s in a n a l y t i c a l c a p a b i l i t i e s ranging from fast q u a l i t a t i v e analysis with typical high r e s o l u t i o n and d e t e c t i o n e f f i c i e n c y to on-line r e s o l u t i o n of classical interference p r o b l e m s (i.e. NK~ - TiLl). Energy-dispersive spectroscopy (EDS) is a s t a n d a r d a n a l y t i c a l option for all u p - t o - d a t e e l e c t r o n b e a m instruments (SEM, STEM, EPMA) where the m a n u f a c t u r e r tends to m i n i m i z e artifacts and interferences due to i n s t r u m e n t a l setup and d etect o r environment. W i n d o w l e s s detectors e x t e n d the lower atomic number limit to Z ~ 5 a l t h o u g h with s t r i c t e r v a c u u m requirements. Digital image p r o c e s s i n g enhances the a n a l y t i c a l c a p a b i l i t i e s of EDS systems in both s c a n n i n g (EDS) and t r a n s m i s s i o n m i c r o s c o p e s (AEM). In the latter, X-ray i n t e n s i f y i n g c h a n n e l l i n g effects can be e x p l o i t e d in a new technique for the d e t e r m i n a t i o n of isomorphic s u b s t i t u t i o n s and site o c c u p a n c y assignments w i t h i n regions of a few h u n d r e d angstroms in a crystal structure. The d e c r e a s i n g cost of c o m p u t e r memory is m a k i n g larger q u a n t i t a t i v e analysis pr o g r a m s available for on-line operation. R e p r e s e n t a t i v e examples include the s i m u l t a n e o u s t r e a t m e n t of data c o l l e c t e d by h y b r i d (WDS+EDS) systems and thin film a p p r o x i m a t i o n programs b a s e d on Monte Carlo s i m u l a t i o n also i n c l u d i n g s e c o n d a r y fluorescence. Beam-sensitive m a t e r i a l s o f f e r a new challenge to the study of b e a m - i n d u c e d effects on the atomic scale.
97
A P P L I C A T I O N OF A N A L Y T I C A L E L E C T R O N M I C R O S C O P Y TO THE I N V E S T I G A T I O N OF SOME A S P E C T S OF THE P R E C I P I T A T I O N H A R D E N I N G BY O R D E R E D C O H E R E N T PARTICLES M. V i t t o r i E N E A , D i v i s i o n e S c i e n z a dei C.R.E. C a s a c c i a , C.P. 2400, Italy
Materiali, Roma,
In the p r e s e n t c o n t r i b u t i o n two examples are r e p o r t e d on the use of e l e c t r o n m i c r o s c o p y in the i n v e s t i g a t i o n of the p r e c i p i t a t i o n h a r d e n i n g b e h a v i o r of a F e N i C r steel h a r d e n e d by a small amount of y' phase (Ni3(AI,Ti)). The i n v e s t i g a t e d alloy (Alloy 800) is a candidate m a t e r i a l for the s t e a m g e n e r a t o r tubing of L i q u i d M e t a l Fast B r e e d e r N u c l e a r Reactors (LMFBR), operating at a m a x i m u m t e m p e r a t u r e of 525°C to 550oc. The first example refers to the study of the e x p e r i m e n t a l l y o b s e r v e d effect that in some alloy heats the y' particles grow with the same rate everywhere, w h i l e some o t h e r heats show a y' average size c h a n g i n g from grain to grain after a l o n g - t e r m e x p o s u r e to a t e m p e r a t u r e around 600°C. A simple model has been p r o p o s e d to e x p l a i n this effect, in which the p r e c i p i t a t i o n of Cr-rich carbides on the grain b o u n d a r i e s is taken into account. On the basis of this model a reduction in the Cr content of the single grains can be expected, d e p e n d i n g on their size. Since the Cr c o n c e n t r a t i o n affects the solid solubility of the y ' - f o r m i n g elements, one of the p a r a m e t e r s a p p e a r i n g in the coarsening rate equation, a d i f f e r e n t coarsening rate results for p a r t i c l e s growing in grains of d i f f e r e n t size. Both TEM and SEM with m i c r o a n a l y t i c a l facilities were used to give e x p e r i m e n t a l support to the above c o n s i d e r a t i o n s . The WDS m i c r o p r o b e was used to obtain q u a n t i t a tive i n f o r m a t i o n on the Cr content of the single grains as a function of their size. On the other hand, the q u a n t i t a tive image analysis p e r f o r m e d on TEM pictures gave the average p a r t i c l e size in several grains, w h i c h Cr content was o b t a i n e d again by WDS analyses. The e x p e r i m e n t a l results are in good agreement with the p r o n o s e d model, even if some points require further e x p e r i m e n t a l i n v e s t i g a t i o n s by using an analytical T E M The second example refers to the correlation of the chemical c o m p o s i t i o n of the Y' p a r t i c l e s to their A n t i p h a s e B o u n d a r y (APB) energy. The APB energy
Abstracts oJ' The XIV Congress of the Italian Society of £'lectron Microscopy
98
is the s p e c i f i c e n e r g y r e q u i r e d to c r e a t e an A P B in the o r d e r e d y' l a t t i c e , and it is o n e of the m a i n p a r a m e t e r s i n v o l v e d in the h a r d e n i n g by o r d e r e d a n d c o h e r e n t particles. T h e r e is a g e n e r a l f e e l i n g in the l i t e r a t u r e t h a t the A P B e n e r g y s h o u l d d e p e n d on the Ti a n d A1 c o n t e n t s of the p a r t i c l e s , b u t no e x p e r i m e n t a l e v i d e n c e is r e p o r t e d . The A P B e n e r g y can be d e r i v e d b y a g e i n g e x p e r i m e n t s f o l l o w e d by a m e c h a n i c a l a n d m i c r o s t r u c t u r a l chara c t e r i z a t i o n o f the a g e d s a m p l e s . The c h e m i c a l c o m p o s i t i o n of the y' p a r t i c l e s g r o w n in f o u r h e a t s of A l l o y 800 d i f f e r i n g f r o m e a c h o t h e r by s m a l l v a r i a t i o n s in the Ti a n d A 1 has b e e n d e r i v e d in the f o l l o w i n g way. Carbon extraction replicas w e r e o b t a i n e d b y m e a n s of a p o t e n t i o s t a t i c e t c h i n g , and t h e y w e r e a n a l y z e d in a T E M e q u i p p e d w i t h an e n e r g y - d i s p e r sive microanalytical system. This experi m e n t a l s e t u p w a s able to s h o w the diff e r e n c e s in the c h e m i c a l c o m p o s i t i o n of the p a r t i c l e s e x t r a c t e d f r o m the d i f f e r e n t h e a t s , m a k i n g p o s s i b l e the c o r r e l a t i o n w i t h the A P B e n e r g i e s . This kind of a n a l y s i s a l l o w e d us to p r o p o s e a rel a t i o n s h i p b e t w e e n the two p a r a m e t e r s a n d to p u t s o m e l i g h t on the c o n t r i b u t i o n to the A P B e n e r g y of the T i - A I a t o m i c p a i r s f o r m e d a c r o s s the APB.
CHARACTERIZATION OF S E M I C O N D U C T I N G MATERIALS BY ELECTRON MICROSCOPY A.
Camanzi Assoreni,
Monterotondo,
Rome
The a i m of this c o m m u n i c a t i o n is to r e v i e w b r i e f l y the role p l a y e d by e l e c t r o n m i c r o s c o p y in s t u d y i n g s e m i c o n d u c t ing m a t e r i a l s . W e can d i v i d e the a r g u ment into a traditional part, concerning m o r p h o l o g y , c h e m i c a l c o m p o s i t i o n a n d mic r o s t r u c t u r e s , a n d a less t r a d i t i o n a l part, concerning electrical information o b t a i n e d by e l e c t r o n - b e a m - i n d u c e d charges s e p a r a t e d by a j u n c t i o n (EBIC) . S c a n n i n g Electron Microscopy (SEM) and X - r a y Microanalysis (Energy Dispersion and/or Wave Dispersion EDS/WDS) techniques would a l l o w u n d e r s t a n d i n g of the p r e p a r a t i v e processes, starting from basic materials up to f i n a l d e v i c e s . S o m e e x a m p l e s of a p p l i c a t i o n to s o l a r g r a d e s i l i c o n p r o d u c t i o n r e l a t e d to o t h e r t e c h n i q u e s of a n a l y s i s (Atomic A b s o r p t i o n a n d N u c l e a r A c t i v a t i o n ) are shown. S t e r e o l o g y m e t h o d s (image a n a l y s i s ) a n d EDSW D S t e c h n i q u e s are p a r t i c u l a r l y u n d e r l i n e d to s h o w t h e i r a p p l i c a t i o n to q u a n t i t a t i v e d e t e r m i n a t i o n of the p u r i t y of m a t e r i a l s .
As c o n c e r n s t h o s e a p p l i c a t i o n s w o r k i n m on b a r r i e r e f f e c t s , E B I C a n d S c a n ning Transmission Electron Beam Induced C u r r e n t (STEBIC) t e c h n i q u e s are g e n e r a l l y a d o p t e d : b o t h use s h o r t - c i r c u i t currents induced by electron beam into p - n or S c h o t t k y j u n c t i o n s ; the c u r r e n t s i q n a l m a y be a m p l i f i e d a n d p r o c e s s e d in o r d e r to r e a l i z e E B I C m a p s , on w h i c h it is p o s s i b l e to d e t e c t s o m e c h a r g e recombination regions (precipitates, grain sub-boundaries and boundaries, dislocations). O t h e r w i s e the c u r r e n t s i g n a l m a y be u s e d for l o c a l m e a s u r e m e n t s f r o m which we may obtain some electrical para m t e r s to c o r r e l a t e w i t h the d e v i c e efficiency. C a u t i o n s h o u l d be a p p l i e d to the i n t e r m r e t a t i o n of t e x t u r i z e d or r o u g h n e s s s u r f a c e s in E B I C , b e c a u s e t h e s e i m a g e s m a y be c o n f u s e d w i t h adsorbed current images. Some examples are shown. Moreover, quality control a s s u r a n c e , a n a l y s i s of d e f e c t s on o p e r a t i v e d e v i c e s , are i m p o r t a n t a c t i v i t i e s t h a t a g o o d l a b o r a t o r y of e l e c t r o n m i c r o s c o p y a p p l i e d to the c h a r a c t e r i z a t i o n of s e m i c o n d u c t i n g m a t e r i a l s s h o u l d b e able to p e r f o r m . Finally, high resolution transmission electron microscopy (TEM) m a y p e r m i t one to h a v e i n f o r m a t i o n on: - - i m p u r i t y role a n d i m p u r i t y - g r a i n boundary; --crystallographic f e a t u r e s of l i n e a r a n d p l a n a r d e f e c t s r e l a t e d to t h e i r electrical activity. A p p l i c a t i o n a r e a s of e l e c t r o n m i c r o s c o p y to s e m i c o n d u c t i n g m a t e r i a l s m a y be t e n t a t i v e l y r e p r e s e n t e d in the f o l l o w i n g s c h e m a : i) M A T E R I A L : Basic; S T R U C T U R E : P o w d e r s o r P o l y c r y s t a l s ; T Y P E OF STUDY: M o r p h o l o g y a n d c o m p o s i t i o n by S E M - E D S ( W D S ) ; G r a i n Size, C r y s t a l l o g r a p h y of I n c l u s i o n s , c h e m i c a l a n a l y s i s by S E M - E D S ( W D S ) a n d TEM. 2) M A T E R I A L : P u r i f i e d a n d / o r R e c r y s t a l l i z e d ; S T R U C T U R E : S i n g l e and P o l y c r y stals; T Y P E OF STUDY: G r a i n Size, C r y s t a l l o g r a p h y , P r e c i p i t a t e s by SEM, ECP (SAD), E D S - W D S , TEM, STEM. 3) M A T E R I A L : J u n c t i o n s , D e v i c e s (Cells and C h i p s ) ; S T R U C T U R E : S i n g l e a n d Poly; T Y P E OF STUDY: P r e c i p i t a t e , B a r r i e r , Grain, Local Electrical Activity and Electrical Parameters, Production and F u n c t i o n i n g D e f e c t s , 0 u a l i t y C o n t r o l by SEM, EBIC, E C P (SAD), TEM, STEM, S T E B I C . R e c e n t s p e c t r o s c o m i c t e c h n i q u e s in S T E M are s h o w n as e x a m p l e of a n a l y s i s a n d d e t e c t i o n of n a t i v e o r r a d i a t i v e d e f e c t s at v e r y low l e v e l of c o n c e n t r a t i o n (SDLTS t e c h n i q u e ) .