Appeal No. 2002-0934
Application No. 09/392,276
The Examiner asserts that the claimed invention is obvious over the
combination of Tran, Hshieh and APA. Specifically, the Examiner states:
APA teaches in figure 1 a semiconductor device 100 receiving
power from first and second power supply voltages (page 3, line 19 to
page 4, line 3) different from each other for utilizing within the die, a
power supply arrangement comprising a semiconductor die having a
top side and a back side, the die including a P+ semiconductor
substrate 102 having an exposed bottom surface and providing the
back side of the die, a P- first epitaxial semiconductor layer 104 over
the substrate, an N type well 106 having a top surface remote from the
bottom surface, and a second power supply conductor coupled to the
top surface of the N type well 106 via region 114.
APA teaches that the device of figure 1 is not suitable for
routing power supply voltages through the substrate when using 1
micron technology, because the resistivity of the substrate is about 2
ohm-cm (page 7). However, the device of figure 1 is suitable for
routing power supply voltages through the substrate when using 0.2
micron technology, because then the resistivity of the substrate is only
about 0.2 ohm-cm (page 8). Therefore, the device of figure 1 is
suitable for routing power supply voltages through the substrate. Note
that nowadays it is well known in the art to use 0.2 micron technology
for semiconductor devices, of which official notice is taken.
Regarding the claimed limitations of first and second power
supply voltages different from each other, any device must include
first and second power supply voltages different from each other,
because the device would not operate if the first and second voltages
are not different from each other (devices need source voltage and
ground voltage to operate).
APA does not teach a first power supply conductor coupled to
the back side of the die. Tran et al. teach figure 2 a first power supply
conductor coupled to the back side of the die (column 3, lines 63-66).
Hshieh teaches forming an epitaxial layer having a thickness of
about 3 microns and resistivity of about 0.1 ohm-cm.
It would have been obvious to a person of ordinary skill in the
art at the time the invention was made to form the APA device using
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