Method of increasing the stability of a copper to copper interconnection process and structure manufactured thereby

A method of forming a via contact between a first copper conductor and a second copper conductor in a thin film electronic device with a copper plug interconnecting said first copper conductor and said second copper conductor comprising:

• forming a stop layer over said first copper conductor,
• forming a dielectric layer over said stop layer,
• patterning said dielectric layer and said etch stop layer to etch a hole therethrough with a dry plasma etch down into first copper conductor leaving an exposed surface of said first copper conductor and exposed sidewalls of said dielectric layer and said etch stop layer,
• growing a copper germanide (Cu.sub.3 Ge) compound, thin film at the base of said hole on the exposed surface of said first copper conductor from in situ exposure to germane GeH.sub.4 gas,
• forming a barrier layer over, as follows:
• a) said copper germanide (Cu.sub.3 Ge) compound, thin film,
• b) said dielectric layer and
• c) said first copper conductor,
• said barrier layer forming a narrow via hole in said hole, and
• forming said second copper conductor including said copper plug over said barrier layer, said copper plug filling said narrow via hole.

A via contact between a first copper conductor and a second copper conductor in a thin film electronic device with a copper plug interconnecting said first copper conductor and said second copper conductor comprising:

• a stop layer over said first copper conductor,
• a dielectric layer over said stop layer,
• a hole through said dielectric layer and said etch stop layer down into first copper conductor with a copper germanium thin film at the base of said hole on the exposed surface of said first copper conductor,
• a barrier layer formed over, as follows:
• a) said copper germanium thin film,
• b) said dielectric layer, and
• c) said first copper conductor,
• said barrier layer forming a narrow via hole in said hole, and
• said second copper conductor including said copper plug over said barrier layer, and said copper plug filling said narrow via hole.

A via contact between a first copper conductor and a second copper conductor in a thin film electronic device with a copper plug interconnecting said first copper conductor and said second copper conductor comprising:

• a stop layer over said first copper conductor,
• a dielectric layer over said stop layer,
• a hole through said dielectric layer and said etch stop layer down into first copper conductor leaving an exposed surface of said first copper conductor with a copper germanide (Cu.sub.3 Ge) compound, thin film at the base of said hole on the exposed surface of said first copper conductor,
• a barrier layer formed over, as follows:
• a) said copper germanide (Cu.sub.3 Ge) compound, thin film,
• b) said dielectric layer, and
• c) said first copper conductor,
• said barrier layer forming a narrow via hole in said hole, and
• said second copper conductor including said copper plug over said barrier layer, said copper plug filling said narrow via hole.