No blister formation Pd/Pt double metal gate MISFET hydrogen sensors

Blister formation in palladium gate MISFET hydrogen sensors occurs even at low hydrogen pressures and the sensors fail in long-time operation. The blisters in the Pd gate are due to hydrogen-induced lattice expansion of the Pd film. By making a double metal gate of Pd/Pt, the problem is avoided without any loss of the hydrogen sensitivity.