Patent ID: 8697518
Filing Date: 2014-04-15
Classification: H01L

Abstract:
1. A method for producing a trench MOSFET with trench contact holes, the MOSFET comprising: an N type substrate, an N type epitaxial layer formed on the N type substrate; a P well region formed on top of the N type epitaxial layer region; a source region formed on the P well region; an oxide layer covered on the source region; wherein the MOSFET further comprises: a plurality of trenches which traverse the source region and the P well region and contact the N type epitaxial layer, a gate oxide layer and polysilicon being formed in the trenches; a source contact hole which traverses the oxide layer and the source region and contacts the P well region, wherein the source contact hole has a titanium metal layer, a titanium nitride layer, and tungsten metal sequentially; a gate contact hole which traverses the oxide layer into the trenches, wherein the gate contact hole has a titanium metal layer, a titanium nitride layer, and tungsten metal sequentially; a P+ implanted region located in the P well region below the source contact hole; and a source electrode formed above the source contact hole and a gate electrode formed above the gate contact hole; wherein when said N type is replaced with P type, P is replaced with N, the method comprising the steps of: Step Step Step Step Step Step Step Step Step Step wherein when said N type is replaced with P type, P is replaced with N, wherein the step etching a plurality of trenches in Step Step Step Step Step Step