Abstract: A method of fabricating a tungsten contact in a semiconductor device comprises providing an oxide layer on a region of a silicon substrate; depositing a sealing dielectric layer over the oxide layer; and depositing an interlevel dielectric layer over the sealing layer. The interlevel dielectric layer, the sealing dielectric layer and the oxide layer are then etched through as far as the substrate thereby to form a contact hole and to expose the said region. A dopant is implanted into the said region whereby the implanted dopant is self-aligned to the contact hole. The substrate is thermally annealed. Tungsten is selectively deposited in the contact hole and an interconnect layer is deposited over the deposited tungsten contact. The invention also provides a semiconductor device which incorporates a tungsten contact and which can be fabricated by the method.

Abstract: A method of fabricating a tungsten contact in a semiconductor device comprises providing an oxide layer on a region of a silicon substrate; depositing a sealing dielectric layer over the oxide layer; and depositing an interlevel dielectric layer over the sealing layer. The interlevel dielectric layer, the sealing dielectric layer and the oxide layer are then etched through as far as the substrate thereby to form a contact hole and to expose the said region. A dopant is implanted into the said region whereby the implanted dopant is self-aligned to the contact hole. The substrate is thermally annealed. Tungsten is selectively deposited in the contact hole and an interconnect layer is deposited over the deposited tungsten contact. The invention also provides a semiconductor device which incorporates a tungsten contact and which can be fabricated by the method.

Abstract: A method of fabricating a tungsten contact in a semiconductor device, the method including the steps of: (a) providing a silicon wafer structure including a dielectric layer and an underlying layer selected from a semiconductor or electrically conductive material, the dielectric layer being patterned to expose a contact portion of the underlying layer; and (b) depositing by chemical vapor deposition a tungsten layer over the dielectric layer and the contact portion, the deposition being carried out by reaction of a tungsten-containing component and a reducing agent which are introduced into the vicinity of the silicon wafer structure, the deposition step having a first phase in which the process conditions are controlled to form a seed layer of tungsten on the dielectric layer and a second phase in which the process conditions are modified from the first phase to form a blanket tungsten layer over the seed layer which acts as an adhesion layer between the dielectric layer and the blanket tungsten layer.

Abstract: A semiconductor device comprising a silicon substrate, an oxide layer on the silicon substrate, a doped polysilicon region disposed on the oxide layer, a dielectric layer which has been deposited over the doped polysilicon region and the silicon substrate, a contact hole which is formed in the dielectric layer and extends over respective laterally adjacent portions of the doped polysilicon region and the silicon substrate and a contact which has been selectively deposited in the contact hole which electrically connects the said portions together.