SEMICONDUCTOR DEVICES WITH SCREENING COATING TO INHIBIT DOPANT DEACTIVATION

摘要

Semiconductor devices (10, 15, 17, 19) having gate- source/drain extension regions (6, 7) are provided together with methods of fabricating such devices. The devices (10, 15, 17, 19) include a doped semiconductor having a source region (2), a drain region (3), a channel (4) between the source and drain regions (2, 3), and extension regions (6, 7) between the channel (4) and each of the source and drain regions (2, 3). A gate (5) is formed on the channel (4), and a screening coating (11, 11a, 11b, 11e) is formed on each extension region (6, 7). The screening coating (11, 11a, 11b, 11e) comprises an insulating layer (12), having a dielectric constant no greater than about half that of the extension region (6, 7), formed directly on the extension regions (6, 7) and a screening layer (13, 13a, 13b, 13c) on the insulating layer (12). The coating is such that the screening layer screens the dopant ionization potential in the extension regions (6, 7) to inhibit dopant deactivation.