Taiwan Semiconductor Manufacturing Comp. Ltd.

Cheng-Wei Lee

Kun-Ming Huang

Ding-Jeng Yu

A method for forming aluminum bumps by first sputter aluminum and then chemical mechanical polishing to remove excess aluminum is disclosed. In the method, a pre-processed electronic substrate which has a plurality of I/O pads formed on top is first provided. An insulating material layer such as SiO , Si N , SOG or polyimide is then deposited on the pads to a thickness that is essentially the thickness of the aluminum bumps to be formed. A plurality of openings with one on each of the plurality of I/O pads is then photolithographically formed, followed by a sputtering deposition to fill the plurality of openings with a metal that includes aluminum. A chemical mechanical polishing technique is then used to remove the excess aluminum so that a top surface of the aluminum bump is flush with the top surface of the insulating material layer, followed by the final step of removing at least partially a thickness of the insulating material layer by a wet etch process.

Method for forming aluminum bumps by sputtering and chemical mechanical polishing

A new method is provided for the creation of an aluminum bump on a surface of a semiconductor device. A patterned layer of aluminum overlying a substrate is created, the patterned layer of aluminum is the layer of aluminum over which a contact bump is to be created. A layer of passivation is deposited, a first layer of photoresist is deposited for the creation of an opening in the layer of passivation that partially exposed the surface of the patterned layer of aluminum. This patterned first layer of photoresist remains in place, a layer of aluminum is sputter deposited, a second layer of photoresist is deposited which is patterned and etched for the creation of the aluminum bump overlying the patterned layer of aluminum. The aluminum solder bump is created by etching the deposited layer of aluminum. After the solder bump has been created, the patterned first and the second layers of photoresist are removed in one processing step, leaving in place the solder bump.

Process improvement for the creation of aluminum contact bumps

A method for forming aluminum bumps that has significantly reduced processing steps than the conventional method is disclosed. The method utilizes a chemical vapor deposition technique for the selective deposition of aluminum into an opening for forming the bump and then a wet etch process for removing a polyimide layer that functioned both as a photoresist layer for providing an opening in a passivation layer and as a support for a via hole during the selective aluminum deposition process. The thickness of the passivation layer and the polyimide layer formed on top of the metal I/O pad is important since it determines the height of the aluminum bump formed.

Growing community of inventors

Hsin-Chu, Taiwan

Cheng-Wei Lee