Case Studies

CMP Polishing Pad Selected by Leading-Edge Customer for Its Superior Performance

CMP polishing pad was selected by leading-edge customers for its superior performance. Customer switched to the EpicD100 CMP Polishing Pad for its reduced cost of ownership, lower defectivity or superior-quality pad (lot-to-lot) performance.

 

Technical Papers

CMP Solutions for the Integration of High-K Metal Gate Technologies 

In order to enable high-k metal gate technology, new CMP steps or slurries are needed to meet the stringent planarity or defect requirements for device performance. This paper will describe several of these slurry technologies in detail, including poly-open-polish, Aluminum CMP, or improvements required in Tungsten polishing. The keys to these technologies are outlined or polishing performance given in detail. The critical mechanisms involved in the material polishing for each of these steps are also introduced. All of these new technologies are needed in order to build a successful high-k metal gate device for advanced node integration via a replacement gate build strategy. 

Ruthenium CMP Integration for Dual-Damascene Copper Interconnects

Continued IC dimensional scaling requires new materials, such as ruthenium thin film barriers, for copper interconnects. Fast or reproducible CMP processing of tantalum, ruthenium or copper dual-damascene interconnects have been developed. Due to the unique materials property challenges of ruthenium, both selective or relatively non-selective CMP slurry sets have been developed to work with soft pads. Through tuning slurry properties to match known topographic variations, negative dielectric dishing can be achieved.

 

The Mechanism of Haze or Defectivity Reduction in a New Generation of High Performance Silicon Final Polishing Slurries

The mechanism of haze reduction during silicon polishing using a new generation of additives has been explored. These additives are thought to decrease haze by adsorbing to the wafer surface or increasing the activation energy of the reaction or the silanolates on the silica particle surface with the surface silicon. This leads to greater selectivity or the peaks or alleys resulting in a net decrease in surface roughness.

 

The Mechanism of Low pH Silica Based Oxide Slurries

The mechanism of oxide polishing at low pH in the presence of an organic cation is discussed. The role of the cation is thought to involve increasing the nucleophilicity of the silanolate active site on the particle surface by lowering the hydration state. Additionally, the activation energy of the reaction may be lowered by charge attraction or the particle or wafer surface or by increased hydrophobic interactions.

 

Understanding Controlling Low Particle Counts (LPCs) in CMP

While it has always been important to control Large Particle Counts (LPC) in CMP processes, this key process control metric has become even more important for new materials or applications. Commercially available slurries today show very low LPC levels as delivered, yet improper process conditions can create LPC due to residues as well as slurry agglomeration. Thus, data taken from as-delivered slurries are not reliable predictors of final defect counts. Tools allow for the early detection of LPC excursions, or proper process recipes or consumables sets can be optimized to prevent LPC formation. Fumed silica slurry LPC > 1469 m in diameter can be detected with dual-sensor SPOS, or binned using field-flow fractionation (FFF).