Patent ID: 7872306
Filing Date: 2011-01-18
Classification: H01L

Abstract:
1. A trench Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) comprising: a plurality of trenches formed on top of an epi layer, wherein the epi layer is formed on a heavily-doped substrate; a gate oxide layer formed on sidewalls and bottoms of the plurality of trenches; a conductive layer filled in the plurality of trenches to be used as a gate structure of the MOSFET; a plurality of source and body regions formed in the epi layer; an insulating layer deposited on the epi layer formed with a plurality of metal contact holes therein; a separating part formed on the insulating layer, wherein the separating part includes a bottom surface abutting with the insulating layer, a top surface opposite to the bottom surface, and a peripheral surface extending between the top and bottom surfaces; a metal contact layer filled in the plurality of metal contact holes, wherein at least one of the plurality of metal contact holes with the metal contact layer filled therein is formed in the conductive layer for contacting the gate structure, and at least another one of the plurality of metal contact holes with the metal contact layer filled therein is formed for contacting respective source and body regions; a first barrier metal layer formed on sidewalls and bottoms of the plurality of metal contact holes in direct contact with respective source and body regions and the gate structure; a second barrier metal layer formed on the insulating layer and on sidewalls of the separating part, with the second barrier metal layer formed on the peripheral surface of the separating part; a copper metal layer formed on the second barrier layer and on the sidewalls of the separating part, with the metal contact layer forming source and gate metal layers of the MOSFET, wherein the source metal layer is connected to respective source and body regions through the metal contact layer filled in the at least another one of the plurality of metal contact holes, the gate metal layer is connected to the gate structure through the metal contact layer filled in the at least one of the plurality of metal contact holes, and the source metal layer is separated from the gate metal layer by the separating part, with the top surface of the separating part being free of the second barrier metal layer and the copper metal layer.