Ferro Electronic Material Systems has added two-component technology to its patented TruPlane™ family of chemical mechanical planarization (CMP) slurries, which enable high-yield processes for next-generation devices. TruPlane slurries are formulated with an optimized low-defectivity ceria particle and provide high selectivity for shallow trench isolation (STI) fabrication processes.
TruPlane 8272 is performing successfully in high-volume manufacturing of 65 nm technology Flash devices, and Ferro is supplying leading-edge slurries for 45 nm node STI logic devices. New two-component TruPlane 8291 offers comparable polishing performance to single-component TruPlane products.
“Many customers who need our increased CMP performance have existing manufacturing processes built around two-component systems,” said Barry Russell, vice president, Ferro Electronic Material Systems. “Our R&D team responded to supply our new technology in the formulation they prefer.”
Ferro’s optimized ceria solid-state particles have 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. Ferro works closely with each customer to develop formulations specifically for the material stack, feature sizes and densities used on different wafer types.
The new two-component TruPlane 8291 is available as separate concentrated abrasive and additive packages, which allows customers to mix them in different ratios to tune removal rates and selectivity in their own fabrication facilities. The two-component slurry is especially recommended for use as the second step polish in typical two-step STI CMP processes.
TruPlane 8291 has post-etch defectivity levels of approximately 0.014 scratches/cm2 using Tencor 6420 (0.036 using AMAT Orbot), which is comparable to Ferro’s single-component TruPlane slurry and a significant improvement over available market alternatives.
TruPlane 8291 also provides a large over-polish window. Dishing of trench oxide usually increases during the over-polish step, but when using TruPlane 8291 dishing is relatively stable on all features. On a MIT864 test wafer, there is no degradation of the small density features during 30% over-polish, with even the 0% density (4 x 4 mm) structure holding. Dishing is < 250 A for most features, and the difference in over-polishing between the 90% and 10% density features is approximately 170 A. No increase in defectivity levels has been observed after one year of shelf life.
Additional information is available at www.ferro.com