SiC precipitates formed in Si by simultaneous dual beam implantation of C+ and Si+ ions

Nanometer-sized SiC precipitates were synthesized at 450 degreesC in Si by simultaneous dual beam implantation of C+ and Si+ ions and subsequent annealing. The results are compared with those of sequential dual beam implantation and of single beam implantation. Two types of SiC precipitates were found. Precipitates of type I with a diameter of d = 4-5 nm consist of 3C-SiC epitaxially oriented with the Si matrix. They were formed already in the as-implanted state and do not grow further during subsequent annealing. The SiC precipitates of type 11 with d approximate to 10 nm are not oriented with the Si matrix and grow exclusively during the subsequent annealing. The high growth velocity, the misorientation in regard to the Si matrix and the lower concentration of type 11 precipitates can be explained by the assumption that these precipitates were formed in an amorphous substrate which modifies their interface energy. (C) 2003 Elsevier Science B.V. All rights reserved.