Method of forming a TiN/W barrier layer for a hot Al plug
AssigneeMosel Vitelic, Inc.
InventorsPei-Jan Wang, Yeong-Ruey Shiue, Yung-Tsun Lo, Hsien-Liang Meng
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Abstract
The present invention relates to a method of forming a barrier metal layer for a hot Al plug and its structure and more particularly to remarkably ameliorate the performance of a barrier metal layer preventing Al metal used as an interconnection layer from diffusing into a silicon substrate. A barrier metal layer according to the present invention is a stacked structure comprising a top layer of Tungsten (W) formed by a Chemical Vapor Deposition (CVD) method and a bottom layer of TiN. Then, a Al interconnection layer deposited at high temperature fills a plug and finishes a plug structure having advantages of low manufacturing cost and full prevention of Al diffusion.
Claims5
In a method for forming plugs which comprises the steps of depositing an intermetal dielectric layer over a silicon substrate or a patterned metal layer;
- and forming vias of said intermetal dielectric layer;
- wherein the improvement comprises:
- a. forming a multiple layered barrier layer on said vias wherein said barrier layer consists of a TiN layer and a W layer and said barrier layer is formed by coating said vias with said TiN layer and depositing said W layer on said TiN layer;
- and then
- b. filling said vias with aluminum to form said plugs by depositing aluminum on said W layer, wherein said aluminum is deposited at a temperature above the melting point of aluminum.
Dependencies are inferred from the claim text.