catalysts, silane as reactant, and

catalysts, silane as reactant, and diborane as p-type dopant with
a B
Si ratio of 1:4,000. Arrays of silicon nanowire devices were
defined by using photolithography with Ni metal contacts (14)
on silicon substrates with a 600-nm-thick oxide layer. The metal
contacts to the nanowires were isolated by subsequent deposition
of
50-nm-thick Si3N4 coating. The spacing between
source-drain electrodes (active sensor area) was 2
m in all
experiments.
Virus samples were delivered to the nanowire device arrays by
using fluidic channels formed by either a flexible polymer
channel (8) or a 0.1-mm-thick glass coverslip sealed to the device
chip. Virus samples were delivered through inlet
outlet connection
in the polymer or holes made through the back of device
chip in the case of the coverslip. Similar electrical results were
obtained with both approaches, although the latter was used for
all combined electrical
optical measurements.