SELECTIVE DOPING OF CHEMICALLY SENSITIVE LAYERS ON A MULTISENSING CHIP

A method of selectively doping the polyaniline gates of chemically sen sitive field-effect transistors (CHEMFETs) has been demonstrated. Acti vated and inactivated gates located on the same chip were exposed to a solution containing palladium. The activated gate was doped by pallad ium by the electroless relaxation process I,ut the inactivated gate wa s not modified. High selectivity of the doping process was proved by e xposing the devices to hydrogen. The method has potential applications in manufacturing single-chip heterogeneous microsensor arrays.