Copper growth to continue
The long awaited transition to copper interconnects for memory devices skyrocketed in 2009, and will impact nearly every sector of the semiconductor equipment market into 2011, according to the report 300mm/Copper/Low-K Convergence: Timing, Trends, Issues, Market Analysis, recently published by The Information Network (www.theinformationnet.com). a New Tripoli, PA-based market research company.
In late 2006. Micron Technology became the first DRAM vendor to produce commodity DRAM with copper, rather than traditional aluminum, interconnect. Elpida followed a year later. The adoption of copper in memory devices is currently under way, and all memory suppliers, led by Samsung, spent huge sums of money upgrading as many of their lines as they could to copper and this change had an important impact on purchases of copper deposition equipment and materials in 2009.
"While the overall semiconductor equipment market decreased more than 40% in 2009, equipment directly tied to the copper interconnect part of semiconductor manufacturing decreased only 8.7%, noted Dr. Robert N. Castellano, President of The Information Network.
The impact of this transition on processing equipment was most obvious in equipment used with traditional aluminum interconnects. For example, the high-density plasma CVD sector (HDPCVD), which is used for depositing undoped (USG) and doped (PSG and FSG) films saw revenues drop 72% in 2009. A drop in Metal Etch equipment revenues registered a similar drop.
The integration of copper into memory devices presents a different set of challenges than the long-established logic processes. DRAM and Flash, which comprise the majority of the memory applications, exhibit high aspect ratios, small CD sizes, and critical sensitivity to line resistance.
The growth of the PVD market was strong for the deposition of the copper barrier metal, which is typically a bi-layer of Ta/TaN, or TiN. However, the transition to memory presents challenges. As feature size continues to shrink, a thinner barrier metal is required to maximize copper volume in the damascene structure and maintain effective resistivity. Ultra-thin barrier metals must achieve optimum step coverage, density, and morphology in high aspect ratio trenches and vias.
"The transition to copper greatly impacted the Chemical Mechanical Planarization (CMP) slurry and pad business," added Dr. Castellano. "Eventually this huge ramp in copper transitioning will stabilize and these consumables will again track the overall CMP and semiconductor equipment markets."
