Method for constructing contact formations

A method for forming contact formations on a semiconductor substrate comprising:

• placing said semiconductor substrate in an electrolytic solution, the semiconductor having at least one integrated circuit formed therein and at least one exposed conductive portion bordered by a non-conductive wall, the exposed conductive portion being electrically connected to the at least one integrated circuit, the electrolytic solution including a plurality of metallic ions and an accelerator, the accelerator comprising bis-(sodium sulfopropyl)-disulfide;
• and
• applying a voltage across the electrolytic solution and the at least one conductive portion of the substrate to cause the metallic ions to be reduced to metal and deposited on the at least one conductive portion to form at least one contact formation on the at least one conductive portion,
• wherein the deposition forms a domed upper surface.

A method for forming contact formations on a semiconductor substrate comprising:

• placing said semiconductor substrate in a first electrolytic solution, the semiconductor having at least one integrated circuit formed therein and at least one exposed conductive portion being electrically connected to the at least one integrated circuit, the first electrolytic solution including a plurality of metallic ions;
• applying a voltage across the electrolytic solution and the at least one conductive portion of the substrate while the semiconductor substrate is within the first electrolytic solution to cause a portion of the plurality of metallic ions to be reduced to metal and deposited on the at least one conductive portion;
• placing said semiconductor substrate in a second electrolytic solution, the second electrolytic solution including said plurality of metallic ions and an accelerator, the accelerator comprising bis-(sodium sulfopropyl)-disulfide;
• and
• applying a voltage across the electrolytic solution and the at least one conductive portion of the substrate while the semiconductor substrate is within the second electrolytic solution to cause the a portion of the plurality of metallic ions to be reduced to metal and deposited on the at least one conductive portion to form at least one contact formation on the at least one conductive portion.

A method comprising:

• preparing a pattern on a substrate to provide an exposed conductive portion bordered by a non-conductive wall;
• placing the substrate in an electrolytic solution, the electrolytic solution including a plurality of metallic ions and an accelerator, the accelerator comprising at least one of bis-(sodium sulfopropyl)-disulfide and 3-mercapto-1-propanesulfonic acid-sodium salt;
• applying a voltage across the electrolytic solution and the conductive portion of the substrate to cause the metallic ions to be reduced to metal and deposited on the conductive portion,
• wherein the deposited conductive portion is characterized as conductive bumps having a domed upper surface for connecting portions of the substrate to a package substrate;
• and
• removing the substrate pattern.

A method for forming contact formations on a semiconductor substrate comprising:

• preparing a pattern on said semiconductor substrate to provide at least an exposed conductive portion, the semiconductor substrate having at least one integrated circuit formed therein and the at least one exposed conductive portion bordered by a non-conductive wall, the exposed conductive portion being electrically connected to the at least one integrated circuit;
• placing the substrate in an electrolytic solution, the electrolytic solution including a plurality of metallic ions and an accelerator, the accelerator comprising at least one of bis-(sodium sulfopropyl)-disulfide and 3-mercapto-1-propanesulfonic acid-sodium salt;
• applying a voltage across the electrolytic solution and the at least one conductive portion of the substrate to cause the metallic ions to be reduced to metal and deposited on the at least one conductive portion to form at least one contact formation on the at least one conductive portion,
• wherein the contact formation on the conductive portion is characterized as conductive bumps having a domed upper surface for connecting portions of the substrate to a package substrate;
• and
• removing the substrate pattern.

A method for forming contact formations on a semiconductor substrate comprising:

• preparing a pattern on said semiconductor substrate to provide at least an exposed conductive portion, the semiconductor substrate having at least one integrated circuit formed therein and the at least one exposed conductive portion being electrically connected to the at least one integrated circuit;
• placing said semiconductor substrate in a first electrolytic solution, the first electrolytic solution including a plurality of metallic ions;
• applying a voltage across the electrolytic solution and the at least one conductive portion of the substrate while the semiconductor substrate is within the first electrolytic solution to cause a portion of the plurality of metallic ions to be reduced to metal and deposited on the at least one conductive portion;
• placing said semiconductor substrate in a second electrolytic solution, the second electrolytic solution including said plurality of metallic ions and an accelerator, the accelerator comprising at least one of bis-(sodium sulfopropyl)-disulfide and 3-mercapto-1-propanesulfonic acid-sodium salt;
• applying a voltage across the electrolytic solution and the at least one conductive portion of the substrate while the semiconductor substrate is within the second electrolytic solution to cause the a portion of the plurality of metallic ions to be reduced to metal and deposited on the at least one conductive portion to form at least one contact formation on the at least one conductive portion,
• wherein the contact formation on the conductive portion is characterized as conductive bumps for connecting portions of the substrate to a package substrate;
• and
• removing the substrate pattern.