Defect structure of erbium-doped < 111 > silicon layers formed by solid phase epitaxy

Erbium-doped layers have been produced on < 111 > -oriented silicon wafers using high-energy amorphizing Er implants and solid phase epitaxy (SPE). Tr ansmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques , used to study the microstructure of these layers, revealed the presence o f microtwins and dislocations. The twins were found to be platelets with la teral dimensions of 15-30 nm and a thickness of about 2-9 nm, and their den sity throughout the regrown layer was nonuniform. The dislocation densities observed in the regrown layers were very high with densities exceeding 10( 10) cm(-2). Within the implant fluence range studied, between 1 x 10(14) an d 9 x 10(14) Er cm(-2), the twin and dislocation densities were observed to increase with fluence, while the twin dimensions were found to decrease. ( C) 2001 Elsevier Science B.V. All rights reserved.