BACKGROUND

Embodiments of the present disclosure relate to semiconductor device manufacturing apparatus and method of using the same.

Chemical mechanical polishing (CMP, also known as “chemical mechanical planarization”) is a process of smoothing wafer surface with the combination of chemical etching and free abrasive mechanical polishing. Mechanical grinding alone causes too much surface damage, while wet etching alone cannot attain good planarization. Most chemical reactions are isotropic and etch different crystal planes with different speed. CMP involves both processes at the same time.

In semiconductor fabrication, CMP process is used to planarize oxide, polysilicon, or metal layers (e.g., copper, aluminum, tungsten, etc.) in order to prepare them for the following lithographic step, avoiding depth focus problems during illumination of photosensitive layers. It is the preferred planarization step utilized in deep sub-micron semiconductor device manufacturing.

SUMMARY

Embodiments of apparatus and method for CMP are disclosed herein.

In one example, an apparatus for CMP includes a platen, a slurry supply, and at least one scraping fixture. The platen is configured to rotate a pad thereon about a central axis of the pad. The slurry supply is configured to supply a slurry onto the pad while the pad rotates. The at least one scraping fixture is configured to scrape the slurry off the pad when the slurry travels a distance between the slurry supply and the at least one scraping fixture in a circumferential direction of the pad as the pad rotates.

In another example, an apparatus for CMP includes a platen, a slurry supply, a carrier, and at least one scraping fixture. The platen is configured to rotate a pad thereon about a central axis of the pad. The slurry supply is configured to supply a fresh slurry onto the pad while the pad rotates. The carrier is configured to hold a wafer on the pad while the pad rotates. The fresh slurry flows between the wafer and the pad as the pad rotates and thereby becomes a used slurry. The at least one scraping fixture is configured to scrape the used slurry off the pad while the pad rotates.

In a different example, a method for CMP is disclosed. A pad is rotated about a central axis of the pad. A fresh slurry is supplied onto the pad while the pad rotates. A wafer is held on the pad while the pad rotates. The wafer is polished by the fresh slurry when the fresh slurry flows between the wafer and the pad as the pad rotates, thereby becoming a used slurry. The used slurry is scraped off the pad by a scraping fixture while the pad rotates.

