PROCESS OF FORMING SEED LAYER IN VERTICAL TRENCH/VIA

摘要

In a process of forming a seed layer, particularly in a vertical trench or via, a semiconductor substrate having a dielectric structure and a hard mask structure thereon is provided. An opening is formed in the hard mask structure, and a trench or via is formed in the dielectric structure in communication with the opening, wherein an area of the opening is greater than that of an entrance of the trench or via. A seed layer is then deposited in the trench or via through the opening, and then subjected to a reflow process.

主权项

1. A process of forming a seed layer, comprising:
providing a semiconductor substrate having a dielectric structure and a hard mask structure thereon, an opening being formed in the hard mask structure, a trench or via being formed in the dielectric structure in communication with the opening, and an area of the opening being greater than that of an entrance of the trench or via; depositing a seed layer in the trench or via through the opening; and reflowing the seed layer, wherein the hard mask structure includes:
a silicon oxynitride (SiON) layer formed over the semiconductor substrate;a titanium (Ti) layer overlying the SiON layer; anda titanium nitride (TiN) layer overlying the Ti layer, wherein the opening is formed in the hard mask structure by:
partially removing the SiON layer, the Ti layer and the TiN layer to form a trench-defining opening; andperforming a pull back procedure to partially remove the TiN layer and the Ti layer of the hard mask structure in the trench-defining opening after completing the formation of the trench or via, thereby forming the opening having the area thereof greater than that of the entrance of the trench or via and rendering a rounded corner of the TiN layer while retaining a sham corner of the SiON layer in the opening.