TRITON SYSTEMS, INC. — Department of Defense SBIR Phase I: N231-076

Description

Triton Systems proposes to develop a vacuum-processible, conjugated polymer coating for oriented monolayer conductivity, highly-uniform coverage, and anti-stiction performance. Such a coating is critical to the reliability of advanced Micro-Electromechanical Systems (MEMS) devices that malfunction if their micro-sized features become stuck. Stiction can occur from opposing surfaces being charged, which is particularly concerning in a nuclear environment. Stiction also occurs from the capillary action of narrow gaps holding up moisture encountered during aqueous microfabrication steps or high-humidity environments. The requirements for strategic sensors necessitate special considerations, including minimizing induced stresses from mismatches of coefficients of thermal expansion (CTE), designing the sensor to be robust through strategic radiation environments, preventing parasitic charges from creating erroneous signals, and ensuring that the sensor will be stable over several decades. Other requirements will include robustness of the coating to each of the microfabrication steps subsequent to the SAM formation that might include deep etches or other methods of surface selectivity.  In Phase I, Triton plans to demonstrate a conformal coating for the wafer-level processing of MEMS devices that functions as an anistropically conductive anti-stiction monolayer. Performance will be demonstrated on test devices. The microfabricated monolayer-scale coating has a target resistance between the coating and the silicon substrate of < 100 Ohm and a lateral resistance of > 1 MOhm. The proposed process will allow for functionalization of only silicon and not oxide or metal surfaces while avoiding aqueous steps that cause stiction. The coating must be stable over 30 years in a storage environment. In the Phase I Option period, Triton plans to validate the coating performance on sample MEMS devices and to specify the optimized process design for Phase II transfer and prototyping of the technology at Triton. In Phase II, Triton plans to demonstrate the process for functionalizing MEMS devices with the anisotropically conductive, anti-stiction coating on a batch of at least five wafers. Characterization of the coating will include uniformity of coverage over typical MEMS features, coating selectivity, conductivity, stiction reduction, and thermal sensitivity for sample MEMS devices. The prototypes, test samples, and characterization results will be delivered by the end of Phase II.