Appeal No. 1998-1548 Page 10
Application No. 08/660,304
agree with the examiner's statement (answer, page 6) that it
would have been obvious to provide Oka with an anti-
reflective-coating below the insulative layer in order to
increase the visibility of the Oka mark. According to the
examiner, since the mark is viewed in reflected light, one
would want more light to reflect from the NEC pattern.
We find that in the APA (pages 4 and 5) the TiN ARC film
20 is applied over the metal layer "prior to the metal
lithography to prevent radiation from the photoresist exposure
from reflecting off the metal and exposing resist outside of
the designated pattern." In Oka (Figures 1 and 2, and page
3), an opening is made in the CVD silicon oxide film 4 for a
bonding pad. At the same time, accessory patterns, such as
the letters NEC, are formed by removing film in the shape of
the accessory patterns 5 from the oxide film 4 on wire 3. Oka
discloses that in the prior art, patterns such as product
names, manufacturing dates etc., had visibility problems due
to miniaturization of the chips and their accessory patterns.
In the prior art disclosed by Oka, wire 3 was etched to form
the accessory patterns. However, large amounts of exposed
wiring were not desirable. Oka's solution to this problem was
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Next
Last modified: November 3, 2007