Process for obtaining passive thin-layer circuits with resistive lines having different layer resistances and passive circuit made by said process

Claim 1

A process for obtaining passive thin-layer circuits with resistive lines having a proper layout and a different layer resistance formed by the steps of: laying a first high resistivity layer made of tantalum treated with a first dopant of nitrogen and oxygen on an insulator substrate; superimposing a second low resistivity layer made of titanium treated with a second dopant of nitrogen to said first layer; superimposing to said second layer a third layer made of palladium having barrier function against diffusion of titanium to said second layer; superimposing to said third layer a fourth layer made of high conductivity metal to form conducting lines on said third layer; removing said first, second, third and fourth layer outside the layout of said resistive lines having different resistance; such that the resistive lines having high resistivity are obtained by the substep of a first selective removal of said fourth, third and second layer effected in correspondence with the layout of said resistive lines having high resistivity; and such that the resistive lines having low resistivity are obtained by the further substep of a second selective removal of said fourth and third layer effected in correspondence with the layout of said resistive lines having low resistivity.