SBIR Phase II: High Performance MOF-Based Storage and Delivery of Electronic Gases

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is in the development of a new hazardous gas storage and delivery system for semiconductor fabrication that will significantly promote worker health and safety benefits at a reduced cost. The new system incorporates a new class of ultra-high performing absorbents, namely Metal-Organic Frameworks (MOFs), that will greatly mitigate the environmental and public health risks by reducing incidents of toxic gas release, chances of equipment damage, and fabrication facility evacuation. Moreover, the use of MOFs enables an increase in the storage capacity while providing savings in ventilation energy, and reducing the risk of leakages over both high pressure mechanical cylinders and sub-atmospheric carbon-based storage. Given the current vast market share of activated carbon cylinders, the higher capacity MOF filled cylinders offer the prospect of substantial decreased in per wafer production costs by minimizing gas cylinder change-outs and fabrication facility downtime. Furthermore, this technology represents the first large scale commercial application for MOFs, thus opening the doors for this promising class of materials for other gas storage applications. This project aims to increase the capacity of gas cylinders for the storage and delivery of highly toxic gases, such as arsine (AsH3), phosphine (PH3), and boron trifluoride (BF3), that are commonly used in semiconductor fabrication. As a safety measure, these highly toxic gases are currently stored at low pressure in activated carbon-filled cylinders. However, the capacity of activated carbon adsorbents is severely limited by their ill-defined internal pore structure. NuMat is developing higher capacity gas cylinders by focusing on the following key technical objectives: 1) Design highly porous, well-defined, crystalline MOF absorbents to be integrated into cylinders, allowing for high capacity storage of these highly toxic gases at sub-atmospheric pressures, 2) Develop industrially relevant MOF scale-up procedures to minimize the cost of production, 3) Maximize the volumetric storage of MOFs in cylinders by developing high density MOF pellets, and 4) Integrate high density MOF pellets into cylinders to displace the lower performing activated carbon filled cylinders currently used this commercial application. Additionally, the technical milestones achieved in this project will help to establish the necessary foundation for incorporating this class of ultra-high performing materials (MOFs) into other gas storage applications.