F 62. The 143 Specification says that resistivities of the order of 10,000 :ohms-cm/sq5 and above
are unacceptable for TiN barrier layer materials:
After exposure to air, the sheet resistivity of these titanium nitride films can
increase to values of about 10,000 up to about 100,000 :ohms-cm/sq, which
is highly undesirable when using the film as a barrier layer for conductive
contacts and vias.
Application 09/128,143, Specification, p. 7, ll. 13-17.
F 63. The 143 Specification notes that for barrier layer films stable sheet resistivities preferably
should be on the order 1000 :ohms-cm/sq:
For that application, stable sheet resistivities on the order of about 1000
:ohms-cm/sq or less are desired.
Application 09/128,143, Specification, p. 7, ll.17-19.
F 64. The 143 Specification reports the resistivity and stability of a number of CVD TiN “control”
films, said to have been made using prior art CVD parameters. Application 09/128,143,
Specification, p. 9, l. 5 - p. 10, l. 2; p. 10, ll. 15-19; p. 12, l. 15.
F 65. These TiN films were reported as having resistivities between about 11,000 and 16,000
:ohms-cm. Application 09/128,143, Specification, p. 9, ll. 21-22; p. 10, l. 19, p. 12, l. 15.
F 66. One set of “prior art” TiN films were said to have unacceptably high average resistivity of
11,360 :ohms-cm/sq which significantly increased on exposure to air. Application
09/128,143, Specification, p. 9, l. 5 - p. 10, l. 2 and Fig. 2.
F 67. These “prior art” films was said to show an unacceptably high level of carbon and oxygen.
Application 09/128,143, Specification, p. 10, ll. 3-11 and Fig. 3.
F 68. Another “prior art” film was said to be made according to the same prior art process as the
film referred to in F61, above was reported as having a resistivity of 16,000 :ohm-cm.
Application 09/128,143, Specification, p. 10, ll. 15-16 and Table 1.
5 We note that conventional unit of resistivity is ohms-cm and that a normal unit of sheet resistance or
resistivity is ohms/sq. or ohms/Q. The 143 Specification sometimes specifies resistivity as :ohms-cm/sq (e.g.,
Application 09/128,143, Specification, p. 7, ll. 4-19), other times as :ohms-cm (e.g., Application 09/128,143,
Specification, p. 10, Table I and p. 11, Table II) and still others as :ohms/sq (Application 09/128,143, Figure 2.). The
143 Specification appears to use these designations interchangeably and we have also considered them to be
interchangeable for the purpose of this opinion.
-14-
Page: Previous 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Next
Last modified: November 3, 2007