
112 Semiconductor Device-Based Sensors for Gas, Chemical, and Biomedical Applications
© 2011 by Taylor & Francis Group, LLC
height of the MOS and Schottky gates of 30–50 mV 10% H
2
/90% N
2
ambient relative to pure N
2
and is due to catalytic dissociation of the H
2
on the Pt contact, followed by diffusion to the W–GaN
or Sc
2
O
3
–GaN interface. The presence of the oxide lowers the temperature at which the hydrogen
can be detected and, in conjunction with the use of the high temperature, stable W metallization
enhances the potential applications of these wide-bandgap sensors. Figure3.20 shows that the rela-
tive change in current is larger with the MOS ...