Patent ID: 7465978
Filing Date: 2008-12-16
Classification: H01L

Abstract:
1. A transistor with a high breakdown voltage, comprising: a semiconductor substrate having a trench which defines an active region; an insulation layer filling the trench; at least one recessed portion being disposed in the active region; a gate structure disposed on a central portion of the active region; a protective oxide layer disposed between the gate structure and the insulation layer, the recessed portion being filled with the protective oxide layer; lightly doped source/drain regions disposed at surface portions of the substrate around the protective oxide layer; and heavily doped source/drain regions disposed at surface portions of the semiconductor substrate between the protective oxide layer and the insulation layer, wherein, at the surface portions of the semiconductor substrate, the heavily doped source/drain regions are physically separated from the protective oxide layer by a portion of the lightly doped source/drain regions positioned between the protective oxide layer and the heavily doped source/drain regions, respectively.