Method for fabricating a semiconductor device having copper layer
AssigneeSharp Kabushiki Kaisha
InventorsKatsuji Iguchi, Tsukasa Doi, Masanori Murakami, Takeo Oku
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Abstract
A semiconductor device comprises a plurality of transistors A semiconductor device comprising a plurality of transistors formed on a semiconductor substrate and a metal interconnection layer connected to at least one of the transistors, wherein the metal interconnection layer is composed of a single layer or multi layers, the single layer or at least one layer of the multi layers being formed of copper or a copper alloy, and is connected to at least one transistor wholly or partially through a barrier layer; and at least one of the transistor is controlled on its threshold voltage by a selective ion implantation after formation of the metal interconnection layer.
Claims4
A process for fabricating a semiconductor device, comprising the steps of:
- (i) forming a plurality of transistors on a semiconductor substrate;
- (ii) forming an insulating film on the resulting substrate including the transistors, followed by the formation of a contact hole and an interconnection trench in desired regions of the insulating film;
- (iii) forming a barrier layer in the contact hole and the interconnection trench, followed by filling the contact hole and the interconnection trench with copper or a copper alloy to form a metal interconnection layer on the barrier layer;
- (iv) conducting a selective ion implantation into at least one of the plurality of transistors using a resist pattern as a mask to control its threshold voltage after the completion of the interconnection layer;
- and
- (v) annealing the entire resulting substrate for activation, uniformly.
Dependencies are inferred from the claim text.