Method of improving the bondability between Au wires and Cu bonding pads
First Claim
1. A method of improving the bondability between Au wires and copper (Cu) pads used in semiconductor manufacturing process, comprises forming a Cu bonding pad on the top level of the metallization;
- chemical mechanical polishing (CMP) said Cu bonding pad;
etching back said Cu bonding pad;
depositing a barrier layer over said Cu bonding pad; and
depositing AlCu or Al over said barrier layer to cover said Cu bonding pads;
0 Assignments
0 Petitions
Accused Products
Abstract
Cu, for its rather low resistivity, will be widely used in sub-quarter micron meter ULSI devices. However, it is well known that Cu is easy to be corroded as exposed in air. In packaging of chips the bonding pads making of Cu will thus oxides. In addition, the reaction between Au-ball and Cu pads is very poor. On the other hand, a native AlOx layer, about 3-4 nm in thickness, will form as Al exposes in air; the formed layer is inert and is capable of protecting Al from corrosion. Furthermore, the reaction between Au-ball and Al was very well. Therefore, with the methods of the present invention, Al or AlCu as a glue and protection layer is implemented on Cu bonding pads for successful Au wiring.
-
Citations
14 Claims
-
1. A method of improving the bondability between Au wires and copper (Cu) pads used in semiconductor manufacturing process, comprises
forming a Cu bonding pad on the top level of the metallization; -
chemical mechanical polishing (CMP) said Cu bonding pad;
etching back said Cu bonding pad;
depositing a barrier layer over said Cu bonding pad; and
depositing AlCu or Al over said barrier layer to cover said Cu bonding pads;
- View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of improving the bondability between Au wires and Cu pads, used in semiconductor manufacturing process, comprises
etching a passivation layer to expose the underlying Cu bonding pads of the top level metallization; -
depositing a tungsten (W) barrier layer upon said Cu bonding pads; and
depositing a Al layer on said W barrier layer. - View Dependent Claims (8, 9, 10, 11, 12, 14)
-
-
13. A method of improving the bondability between Au wires and Cu pads used in semiconductor processing, comprises
forming a Cu bonding pad upon the top level metal; -
depositing a passivation layer over Cu bonding pad of the top level metallization;
etching said passivation layer to expose said underlying Cu bonding pad through a contact window;
depositing blanket aluminum (Al) on top of said barrier layer;
performing Al CMP to remove Al on top of said passivation layer and leave Al only on the bonding pad of said contact window;
-
Specification