Appeal No. 1998-2987 Page 2
Application No. 08/250,332
instance, aluminum (Al) series materials have often been used
in
view of their low resistivity and easy fabricability, and
Al series alloys have been generally used therefor. The Al
series alloys have usually been formed by a sputtering method.
When sputtering aluminum alloys such as aluminum-silicon
(Al-Si) wiring, however, Si nodules occur. The nodules have a
large cross section and, with the reduced size of
semiconductor devices, can be detrimental to the electrical
characteristics of the wiring and also cause problems in
forming the wiring structure.
The appellants’ process of forming metal wirings begins
with a semiconductor substrate having diffusion regions. An
insulating layer is deposited on the substrate. At least one
contact hole is formed by removing a portion of the insulating
layer to expose a selected portion of the surface of the
substrate. An underlying metal layer is then deposited on
both the interlayer and exposed portions of the substrate. An
electrically conductive layer of an aluminum material
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007