Electric field initiated electroless metal deposition

A method of depositing a metallic material onto a conductive layer formed on a semiconductor wafer by electroless deposition, comprising the steps of:

• placing said wafer between a first electrode and a second electrode;
• applying a voltage to said two electrodes in order to subject said conductive layer to an electric field generated between said two electrodes;
• subjecting a surface of said conductive layer to an electroless deposition solution, which includes ions of said metallic material;
• said electric field causing said ions of said metallic material in said solution to be attracted to said surface of said conductive layer;
• said ions contacting said surface and losing their ionic charges to charges of opposite polarity distributed along said surface to form deposition sites of said metallic material on said conductive layer.

A method of depositing copper onto a conductive layer formed on a semiconductor wafer by electroless deposition for forming a copper deposit on said wafer, comprising the steps of:

• placing said wafer between a first electrode and a second electrode;
• applying a voltage to said two electrodes in order to subject said conductive layer to an electric field generated between said two electrodes;
• subjecting a surface of said conductive layer to an electroless deposition solution, which includes copper ions;
• said electric field causing said copper ions in said solution to be attracted to said surface of said conductive layer;
• said copper ions contacting said surface and losing their ionic charges to electrons distributed along said surface to form deposited copper sites on said conductive layer.

An apparatus for depositing a first conductive material onto a second conductive material by electroless deposition comprising:

• a first electrode;
• a second electrode, wherein an electric field is generated there between by said two electrodes;
• a housing for containing said second conductive material and an electroless deposition solution which includes ions of said first conductive material, said housing coupled between said two electrodes and within said electric field;
• a field shifting means coupled to said first and second electrodes for shifting said electric field to have a moving pattern across said second conductive material;
• said electric field causing said ions of said first conductive material in said solution to be attracted to a surface of said second conductive material;
• said ions contacting said surface and losing their ionic charges to charges of opposite polarity distributed along said surface to form deposition sites of said first conductive material on said second conductive material.

An apparatus for depositing a metallic material onto a conductive layer formed on a semiconductor wafer by electroless deposition comprising:

• a first electrode;
• a second electrode, wherein an electric field is generated there between by said two electrodes;
• a housing for containing said wafer and an electroless deposition solution which includes ions of said metallic material, said housing coupled between said two electrodes and within said electric field;
• said electric field causing said ions of said metallic material in said solution to be attracted to a surface of said conductive layer;
• said ions contacting said surface and losing their ionic charges to charges of opposite polarity distributed along said surface to form deposition sites of said metallic material on said conductive layer.

An apparatus for depositing copper onto a conductive layer formed on a semiconductor wafer by electroless deposition comprising:

• a first electrode;
• a second electrode, wherein an electric field is generated there between by said two electrodes;
• a housing for containing said wafer and an electroless deposition solution which includes copper ions, said housing coupled between said two electrodes and within said electric field;
• said electric field causing said copper ions in said solution to be attracted to a surface of said conductive layer;
• said ions contacting said surface and losing their ionic charges to electrons distributed along said surface to form deposited copper sites on said surface.