PECVD (plasma enhanced chemical vapor deposition) method for deposition of tungsten or layers containing tungsten by in situ formation of tungsten fluorides.

摘要

The invention comprises a PECVD method for the deposition of refractory metal layers or layers containing refractory metal by the in situ formation of refractory metal fluorides. For this purpose, an etch gas, such as CF4, NF3, SF6 etc., is introduced into a plasma deposition chamber (10) which comprises cathode (18) and refractory metal sheet (24) electrically connected thereto, and anode (26) carrying wafers (28). In a preferred example, CF4 is introduced into chamber (10) and via gas shower (22) into cathode region (20). After ignition of a plasma the ionized etch gas acts on tungsten sheet (24), generating WFxions that diffuse towards target (26) with wafers (28). The WFx ions thus produced are suitable for the deposition of a tungsten layer or a layer containing tungsten on silicon wafers (28).