Extended Depth Profiling with the Iap

Depth p r o f i l i n g w i t h the FIM/IAP can be ext remely accurate i f -.p done i n conjunct ion w i t h r i n g c o l lapse counting. However, under UHV cond i t i ons depth sca les are n o t e a s i l y assigned, especia l l y i f depths o f 0.1 um o r more are required, such as those needed f o r range determinat ions i n i o n imp lan ta t ion studies. We describe a method us ing the IAP s igna l from the matr ix , and t i p parameters measured by FIM and transmission e l e c t r o n mi croscopy (TEM). Ni specimens were dc f i e l d evaporated t o 6 kV. Both FIM and TEM images were recorded before and a f t e r the I A P data was c o l l e c t e d . The image was observed dur ing a n a l y s i s and the p u l s e number recorded when a r i n g c o l l apsed. Each spectrum was s igna l -averaged t o minimize storage. The p u l s e number i s c o r r e l a t e d w i t h the spec t ra l data. The cumula t i ve Ni s igna l versus the r i n g number was then generated.