Other

Chartered Semiconductor Manufacturing Ltd (corporation)

Silicon Manufacturing Partners, Pte, Ltd.

Chartered Semiconductor Manuf. Ltd.

Ser Wee Quek

Charles Lin

Arun Kumar Nanda

Jimmy Lo(Yuk Ting)

A polishing pad conditioner used in the removal of slurry and semiconductor thin film build-up in the polishing pad in a chemical and mechanical polishing (CMP) process used to planarize a semiconductor wafer surface. The conditioner is pressed against the polishing pad, often while de-ionized water is applied, to remove the material build-up. The conditioner of the present invention has a convex lower surface covered by diamond crystals that are bonded to the underside of the nickel alloy conditioner. Typically, the difference between the center and the edge of the conditioning surface will range from a minimum of about 0.2 mm (very slightly convex) to a maximum of the entire thickness of the conditioning surface (more convex). The convex shape reduces the friction between the pad and conditioner and allows the slurry to reach the center of the conditioner. This more uniformly conditions the pad surface which yields more uniformly polished wafers and also increases pad life. Brazing is used to form a molecular bond between the abrasive diamond crystals and the nickel alloy conditioner. This bond is not attacked by the low pH slurry used in CMP, eliminating the problem where diamond crystals separate from the conditioner causing scratches on the wafer surface.

Rounded surface for the pad conditioner using high temperature brazing

The invention teaches an in-site roller dresser that allows for the profile of the polishing pad to be monitored while the roller is dressed or refurbished. This eliminates the need for destructive testing of the polishing pad. The in-site roller dresser at the same time eliminates the need for machine downtime for polishing pad profile determination since the polishing pad profile is dynamically tested and monitored during polishing operations. In conventional arrangements, the dresser is a disk, in the arrangement of the present invention the dresser is a roller type that can rotate around its axis in either direction. A sensor is provided with the diamond dresser that monitors the surface or profile of the polishing pad. Based on the data obtained by the sensor, the diamond dresser can be adjusted which directly controls the polishing pad refurbishing action provided by the dresser.

In-site roller dresser

An apparatus for removably positioning a semiconductor wafer for polishing. The apparatus including a rotating member with a major lower surface having a plurality of recesses each with a conduit path radially leading to a smaller circular pattern of portholes disposed near the center of the rotating member, the recesses are arranged in concentric segments. A nozzle plate covers the major lower surface defining a plurality of chambers therebetween. The nozzle plate includes a radial pattern of gas dispensing orifices which are aligned centrally relative to each chamber. A preset regulated gas pressure communicates with each orifice pattern to exert an opposing force against a force urging the article against the polishing pad. At least two of the orifice patterns have gas pressures adjusted independently from one another so that independent pressure control creates varying forces to be exerted against the back side of the wafer.

Variable pressure plate CMP carrier

Double or multiple unit polishing heads are used thereby negating the negative effects that irregularities in the surface of the polishing pad have on the polishing results obtained. Adjacent double or multiple unit polishing heads rotate in opposite directions thereby eliminating the effects of microscopic directions in the surface of the polishing pads.

Double polishing head

An improved and new substrate carrier head for use in a CMP apparatus is described. The new substrate carrier head has a substrate retaining ring with embedded intersecting channels in the outer face. The embedded intersecting channels improve the circulation of polishing slurry to and from the polished substrate and polishing byproducts away from the polished substrate and thereby improve the polishing uniformity on the substrate.

Growing community of inventors

Singapore, Singapore

Ser Wee Quek