Materials science in semiconductor processing vol:5 issue:6 pages:511-514
140keV Zn channeled implantations in GaN are performed at room temperature and in a dose range from 1 x 10(13) to 4 x 10(16)/cm(2), respectively. The lattice expansion is calculated from (0 0 0 2) and (0 0 0 4) X-ray diffractions of GaN after channeled implantation. Three dose dependence regimes are observed: the perpendicular lattice parameter initially increases with dose, subsequently varies slowly in an intermediate dose range, and finally diminishes at very high dose. The high-resolution XTEM observations show the different defects, such as the clustered point defect, the thread defects and loops, the broken crystals and the amorphous in nanometer sizes. The variation of lattice expansion is attributed to the changes of density and types of defects. (C) 2003 Elsevier Science Ltd. All rights reserved.