Manufacturing method for a semiconductor device having local interconnections
AssigneeFujitsu Limited
InventorHiromi Hayashi
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Abstract
A semiconductor device and a method for manufacturing a semiconductor device having local interconnections for making electrical connection among conductive regions. The semiconductor device and the method for manufacturing the same utilizes interconnections made of a material of which selectivity of etching is high with respect to a semiconductor layer. The local interconnection is formed by patterning a tungsten nitride film with an etchant gas including a gas comprising fluorine. In addition to the gas comprising fluorine, a gas comprising hydrogen is introduced, at the latest, when the tungsten nitride film becomes thinned.
Claims6
A method for manufacturing a semiconductor device, said method comprising the steps of:
- forming an impurity diffusion region as a first conductive region within a semiconductor layer;
- forming a tungsten nitride film on a region including said impurity diffusion region;
- selectively forming an etch mask on said tungsten nitride film located extending from said impurity diffusion region to a second conductive region;
- and
- removing said tungsten nitride film by dry etching in accordance with said etch mask, said dry etching including the steps of
- a) introducing a gas comprising fluorine, and
- b) introducing a gas comprising hydrogen after said tungsten nitride film is initially thinned by etching with said gas comprising fluorine.
Dependencies are inferred from the claim text.