Process for obtaining thin-film circuits and passive circuit made by said process

Claim 2

Process for obtaining passive thin-layer circuits with resistive lines having different layer resistances formed by superimposition of an upper layer (3) having less resistivity and a lower layer having greater resistivity character­ized in that it uses for the lower layer (2) having greater resistivity tantalium treated with a first dope and for the upper layer (3) having less resistivity titanium treated with a second dope.

Claim 3

Process in accordance with claim 1 character­ized in that said first dope consists of nitrogen and oxygen.

Claim 4

Process in accordance with claim 1 character­ized in that said second dope consists of nitro­gen.

Claim 5

Process in accordance with claim 1 character­ized in that said lower layer (2) is thinner than said upper layer (3).

Claim 6

Process in accordance with claim 1 character­ized in that there is provided superimposition on part of said resistive layers (2, 3) of a thick layer (7) of electrically conductive material for formation of the conducting lines.

Claim 7

Process in accordance with claim 1 character­ized in that said conducting material is gold.

Claim 8

Process in accordance with claim 5 character­ized in that it includes the interposition between said resistive layers (2, 3) and said conducting layer (7) of a layer of palladium (4) with the function of a barrier against spreading of the titanium into the conducting material.

Claim 9

Process in accordance with claim 1 character­ized in that said layers of tantalium and titanium (2, 3) are deposited in a single vacuum cycle.

Claim 10

Process in accordance with claim 7 character­ized in that said layers of tantalium, titanium and palladium (2, 3, 4) are deposited in a single vacuum cycle).

Claim 11

Process in accordance with claim 1 character­ized in that it includes in order the following steps: A) cathodic pulverization in a vacuum of a lower layer (2) of tantalium doped with nitrogen and oxygen with high resistivity and limited thickness on an insulating substrate (1), B) cathodic pulverization in a vacuum in the same vacuum cycle of an upper layer (3) of titanium doped with nitrogen with low resistivity and greater thickness, C) cathodic pulverization in a vacuum in the same vacuum cycle of a layer of palladium (4), D) deposit of a thick layer of photoresist (5) and opening of windows (6) in said photoresist (5), E) deposit of conducting material (7) in the areas described by said windows (6), F) removal of the photoresist (5), G) removal of the palladium (4), titanium (3) and tantalium (2) at the sides of the area covered with conductive material (7), H) deposit of a thick layer of photoresist (8) and opening of windows (9) in said photoresist (8), I) removal by selective chemical etching of conducting material (7), palladium (4) and titanium (3) in the areas described by said windows (9), L) removal of the photoresist (8) and deposition of another thick layer of photoresist (11) with opening of windows (12), M) removal by selective chemical etching of conducting material (7) and palladium (4) in the areas described by said windows (12), and N) removal of the photoresist (11).

Claim 12

Passive thin-layer circuit with resistive lines of different layer resistances, the resis­tive lines with greater resistance (10) being formed of individual layers of a first material with greater resistivity (2) and the resistive lines with less resistance (13) being formed of multiple layers obtained by superimposition of a second material with less resistivity (3) to said first material with greater resistivity (2) char­acterized in that said first material (2) consists of tantalium treated with a first dope and said second material (3) consists of titanium treated with a second dope.

Claim 13

Passive thin-layer circuit with resistive lines of different layer resistances, the resis­tive lines with greater resistance (10) being formed of individual layers of a first material with greater resistivity (2) and the resistive lines with less resistance (13) being formed of multiple layers obtained by superimposition of a second material with less resistivity (3) to said first material with greater resistivity (2) char­acterized in that said first material (2) consists of tantalium treated with a first dope and said second material (3) consists of titanium treated with a second dope.

Claim 14

Passive circuit in accordance with claim 11 characterized in that said first dope consists of nitrogen and oxygen.

Claim 15

Passive circuit in accordance with claim 11 characterized in that said second dope consists of nitrogen.

Claim 16

Passive circuit in accordance with claim 11 characterized in that it includes another layer of palladium (4) superimposed on a part of said resistive layers (2, 3) and a layer of conducting material (7) superimposed on said layer of pallad­ium (4).