A DLTS AND RBS ANALYSIS OF THE ANGULAR-DEPENDENCE OF DEFECTS INTRODUCED IN SI DURING ION-BEAM CHANNELING USING 435 KEV ALPHA-PARTICLES

It is generally assumed that ion beams (IBs) used during channelling e xperiments create little damage when incidence along a direction of lo w crystallographic index of a crystal lattice. We have employed deep l evel transient spectroscopy (DLTS) to characterise the defects produce d by 435 KeV alpha-particles in a Si lattice incident along the [1 0 0 ] axis (alpha=0 degrees) as well as at small angles (alpha less than o r equal to 7 degrees) with respect to this direction. The commonly obs erved high energy (MeV) alpha-particle-induced point defects (V-O) and V-Sb pairs and the two charge states of divacancy, V-) could be obser ved for angles of incidence as small as 0.35 degrees. The concentratio n of the primary defects was observed to decrease for alpha greater th an or equal to 2.45 degrees. Furthermore, isochronal annealing experim ents showed that a DLTS defect peak which is superimposed on the V-2(= /-), and observed predominantly for alpha greater than or equal to 2.4 5 degrees, could be a V-related defect. Current-voltage (I-V) and capa citance-voltage (C-V0 measurements also showed that Schottky barrier d iodes (SBDs) fabricated on the exposed samples became less rectifying with increasing of incidence. (C) 1998 Published by Elsevier Science B .V.