Appeal No. 2004-0859
Application 08/866,456
THE INVENTION
The appellants claim a structure for electrically connecting
levels of a semiconductor device. Claim 39 is illustrative:
39. An electrical connection structure for an integrated
circuit device, comprising:
a first conductive layer;
an insulating layer overlying the first conductive layer,
the insulating layer having an upper surface and an opening
exposing a region of the first conductive layer, the opening
being defined by a side-wall of the insulating layer and having a
lower diameter adjacent the first conductive layer and a larger,
upper diameter at a top portion thereof adjacent the upper
surface of the insulating layer, the lower and upper diameter
portions having been made using the same mask and being self-
aligned with respect to each other and thus assured of having
their respective centers aligned with each other;
a thin barrier layer covering the side-wall of the
insulating layer within the opening and the first conductive
layer region exposed within the opening;
a conductive plug overlying the barrier layer and filling
the opening in the insulating layer, the plug having a lower
diameter adjacent the first conductive layer and a larger, upper
diameter adjacent the upper surface of the insulating layer, the
upper diameter of the plug being larger than the lower diameter
of the opening and the barrier layer being of a material that is
selectively etchable with respect to the plug such that the upper
portion of the plug is an etch stop that prevents etching of the
barrier layer adjacent the bottom portion of the contact opening
during any subsequent anisotropic etches; and
a second conductive layer overlying at least a portion of
the plug and being of material that is selectively etchable with
respect to the plug.
2
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007