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Product Briefing Outline: Ferro Electronic Material Systems has formulated patented high selectivity shallow trench isolation (STI) CMP slurries with an optimized low defectivity ceria particle that enable high-yield processes for next-generation devices.  ‘TruPlane™ 8272' is performing successfully in high-volume manufacturing of 65nm technology Flash devices, according to the company.

Problem: Traditional silica-based products are unsuitable below 90nm due to their inability to meet more rigorous performance and defectivity targets demanded by small feature sizes. The use of a ceria-based single-component high selectivity STI CMP slurry can enable the required slurry performance and reduce over-polish effects for devices at the 65nm node and below.  

Solution: Ferro has optimized its ceria manufacturing process to produce second-generation solid-state particles with a surface chemistry that, when formulated with additives, provides the desired oxide removal rates tailored for each customer's process with consistent, extremely low defectivity, according to the company.  TruPlane 8272 has a claimed post-etch defectivity level of approximately 0.014 scratches/cm2 using a Tencor 6420 (0.036 using AMAT Orbot), which is 1.5 to 3 times better than the first-generation slurry and a significant improvement over available market alternatives, according to the company. TruPlane 8272 is designed to provide a large over-polish window.  Dishing of trench oxide usually increases during the over-polish step, but when using TruPlane 8272 dishing is relatively stable on all features.  On a MIT864 test wafer, there is no degradation of the small density features during 30 percent over-polish, with even the 0 percent density (4x4 mm) structure holding.  Dishing is < 250Å for most features, and the difference in over-polishing between the 90 percent and 10 percent density features is around 170Å.  No increase in defectivity levels has been observed after one year of shelf life, according to Ferro.  Various aspects of the slurry formulation can be optimized to specific customer requirements for the material stack, feature sizes and densities, and wafer type.

Applications: High selectivity STI CMP slurry

Platform: A ceria-based single-component slurry with various aspects of the slurry formulation being optimized to specific customer requirements for the material stack, feature sizes and densities, and wafer type.

Availability: June 2007 onwards.

New TruPlane™ 8272 from Ferro Electronic Material Systems provides a large over-polish window by stopping on nitride without inducing dishing of FOX.

Within-wafer ranges for both nitride and FOX are relatively stable through the large over-polish window of TruPlane™ 8272 from Ferro Electronic Material Systems.