| 摘要 |
#CMT# #/CMT# Fabrication of semiconductor device, comprises forming at least one protective insulating layer on a copper line in substrate; forming a via hole in the at least one protective insulating layer to expose a portion of the copper line; forming hafnium-containing layer (26) in the via hole to cover the exposed portion of the copper line; and forming a conductive layer over the substrate including the hafnium-containing layer. #CMT# : #/CMT# An independent claim is also included for a metallization structure for a semiconductor device, comprising: (1) a copper (Cu) line in a substrate; (2) at least one protective insulating layer having a via hole to expose a portion of the Cu line; (3) a layer comprising hafnium (Hf) in the via hole to cover the exposed portion of the Cu line; and (4) conductive layer on the Hf-containing layer. #CMT#USE : #/CMT# For fabricating a semiconductor device. #CMT#ADVANTAGE : #/CMT# The method removes Cu oxide prior to the via plug formation using Hf deposition instead of etch pre-cleaning, thus preventing or minimizing an increase in the critical dimension (CD) of the via hole by the dry etch pre-cleaning and encroachment of the Cu oxide along the Cu surface. The method enables maintaining the via CD as designed, prevents the via bottom area from being increased by the cleaning solution during a wet etch pre-clean, and prevents oxygen or moisture from diffusing to the Cu wiring through the pad (due to the oxygen scavenging properties of the Hf layer). #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure is a cross-sectional diagram for explaining a method of fabricating a semiconductor device. 26 : Hafnium-containing layer 29 : Tungsten plug 30 : HfN x layer 31 : Al #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Method: The step of forming the Hf-containing layer comprises ionized physical vapor depositing Hf or an Hf precursor. The method further comprises performing radium frequency etch pre-cleaning using argon (Ar +>) ions before forming the Hf-containing layer. An oxide layer on the exposed portion of the embedded Cu line is reduced by the Hf-containing layer. The conductive layer forming step, comprises forming hafnium nitride (HfN x) layer (30) on the Hf-containing layer; forming a tungsten plug (29) on the HfN x layer in the via hole; and depositing Al over the substrate including the tungsten plug. The HfN x layer-forming step comprises rapid thermal annealing or furnace annealing. Preferred Component: The conductive layer further comprises a diffusion barrier between the Hf-containing layer and the conductive layer. The diffusion barrier comprises HfN x, titanium nitride, tantalum or tantalum nitride. #CMT#METALLURGY : #/CMT# Preferred Parameter: The Hf-containing layer has a thickness of 50-500Å. Preferred Component: The conductive layer comprises aluminum (Al) (31) and/or Cu. #CMT#ORGANIC CHEMISTRY : #/CMT# Preferred Method: The step of forming the Hf-containing layer comprises ionized physical vapor depositing Hf or an Hf precursor. The method further comprises performing radium frequency etch pre-cleaning using argon (Ar +>) ions before forming the Hf-containing layer. An oxide layer on the exposed portion of the embedded Cu line is reduced by the Hf-containing layer. The conductive layer forming step, comprises forming hafnium nitride (HfN x) layer (30) on the Hf-containing layer; forming a tungsten plug (29) on the HfN x layer in the via hole; and depositing Al over the substrate including the tungsten plug. The HfN x layer-forming step comprises rapid thermal annealing or furnace annealing. Preferred Component: The conductive layer further comprises a diffusion barrier between the Hf-containing layer and the conductive layer. The diffusion barrier comprises HfN x, titanium nitride, tantalum or tantalum nitride. |
