step described herein can be any gas, but is preferably a
non-oxygen-and-carbon-containing gas, such as nitrogen, ammonia, argon,
and the like”. Hydrogen gas is a non-oxygen-and-carbon-containing gas. It is
well known in the art, and was well known in the art at the time of the Leung
. . . specification, that a plasma of ammonia gas contains a plasma of hydrogen
gas. Additionally, on page, 11 in Table II, the . . . specification details
resistivity measurements obtained for a metal nitride sample film C5 pre- and
post-deposition plasma treated using a hydrogen (H2) plasma. At page 11,
lines 6-10, the metal nitride sample film C5 was plasma treated “using a low
power of 100 watts and without biasing the substrate”. Table II is a
continuation of Table I shown on page 10 of the . . . specification. In Table I,
the Control film has a resistivity of 16,000 microohmscentimeter (:S-cm). In
Table II, C5 has a resistivity of 13,500 :S-cm, which is approximately a 15
% decrease in resistivity as compared to the Control film (see calculation 1).
⎛ 16 000 13 500− , ⎞
⎝⎜ , 16 000 ⎠⎟×100% 15%=
,
Given the . . . specification’s recitation on page 8, lines 16-19 that plasma
treated metal nitride films are “more crystalline, contain more nitrogen, and
have reduced oxygen and carbon content” as compared to untreated metal
nitride films, and the 15 % decrease in resistivity for the metal nitride sample
film C5 plasma treated using a power of 100 watts and without substrate
biasing, one of ordinary skill in the art would be able to practice a method of
post-treating a metal nitride layer with a hydrogen gas plasma to reduce the
carbon concentration and decrease the resistivity of such layer, as required by
Leung claims 13, 19, 20 and 26.
LX 2021, pp. 4-6, ¶ 11.
The 143 Specification
Content of the Written Description
F 61. The 143 Specification notes that prior art CVD deposition of TiN using tetrakisdialkylamido
titanium results in resistivity that is too high and is unstable:
[T]he resistivity of the titanium nitride film is high and unstable. Over time
the resistivity increases to such an extent that the film is no longer usable for
semiconductor devices.
Application 09/128,143, Specification, p. 2. l. 23 - p. 3, l. 1.
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