Shallow trench contact structure to solve the problem or schottky diode leakage

摘要

A method for fabricating a Schottky diode using a shallow trench contact to reduce leakage current in the fabrication of an integrated circuit device is described. A thermal oxide layer is provided overlying a silicon semiconductor substrate. An insulating layer is deposited overlying the thermal oxide layer. A contact opening is etched through the insulating layer and the thermal oxide layer to the silicon substrate. The contact opening is overetched whereby a shallow trench is formed within the silicon substrate underlying the contact opening wherein the shallow trench has a bottom and sidewalls comprising the silicon substrate. A first metal layer is deposited over the insulating layer and within the contact opening and within the shallow trench. The first metal layer is sintered whereby the first metal layer is transformed to a silicide layer where the silicide layer contacts the silicon substrate at the bottom and sidewalls of the shallow trench and wherein the first metal layer contacting the insulating layer and thermal oxide layer is not transformed. The untransformed first metal layer is removed. A barrier metal layer is deposited overlying the insulating layer and the silicide layer within the shallow trench. A second metal layer is deposited overlying the barrier metal layer to complete fabrication of a Schottky diode in an integrated circuit device.