Control of junction depth and channel length using inter-lattice gradients to prevent dopant diffusion

摘要

PURPOSE: An ion-implantation method is provided to control a junction depth and a channel length by using interstitial gradients generated to oppose dopants diffusion. CONSTITUTION: The improved manufacturing process and an improved device made by the process for retarding diffusion of implanted dopants during subsequent high temperature processing. A layer of an electrically inactive species (62) is implanted well below the active dopant layers (52, 70), and the excess interstitial due to damage from the electrically inactive species layer form a retarding gradient which opposes dopant diffusion. Using this process, shallow source-drain junctions (76) can be achieved, and lateral encroachment of LDD implants (52) under the gate (55) can be minimized.