Dislocation multiplication inside contact holes

Ion implantation into contact holes has been widely used to dope the specif ic contact area and to reduce the contact resistance. In this study, mask e dge defects were observed at the edge area of small contact holes with high aspect ratio, which resulted in multiplied dislocations penetrating into S i substrate for more than 0.3 mu m after backend processings. Those disloca tions were identified to be Schockley partial dislocations and stair rod di slocations lying on 4 sets of inclined {111}Si planes. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.