A new inexpensive, quick-drying polymer that could lead to dramatic cost savings and efficiency gains in semiconductor manufacturing and computer chip packaging has been developed by researchers at Rensselaer Polytechnic Institute and Polyset Company. The new material called polyset epoxy siloxane (PES), allows enhanced performance and cost savings for conventional photolithography processes, and should also enable a new generation of lower-cost, on-chip nano imprinting lithography technology. With this new material, chip manufacturers will be able to trim several steps from their production and packaging processes, and in turn realize a cost savings.
The widely adopted technique of photolithography involves using a mix of light and chemicals to generate intricate micro and nano-scale patterns on tiny areas of silicon. As part of the process, a thin polymer film - called a redistribution layer, and crucial to the effectiveness of device - is deposited onto the silicon wafer, in order to ease the signal propagation delay and to protect the chip from different environmental and mechanical factors. The new PES material developed is one such thin polymer film, and it offers several advantages over the incumbent materials typically used in the semiconductor manufacturing industry. In addition, their new PES material can also be used as a thin polymer film for ultraviolet (UV) on-chip nano imprinting lithography technology, which is still in the early phases of development. The consistency of using PES in conventional technology, and then continuing to use PES while academia and industry test and gradually migrate to the next generation of devices, should help ease the transition.
PES cures, or dries and hardens, at 165 degrees Celsius, about 35% cooler than the other two materials. The need for less heat should translate directly into lower overhead costs for manufacturers, Lu said. Another advantage of PES is its low water uptake rate of less than 0.2%, less than the other materials. Additionally, PES adheres well to copper and can easily be made less brittle if needed. All of these attributes make PES a promising candidate for redistribution layer application and UV imprint lithography.
Along with photolithography and on-chip nano imprinting lithography, PES holds the potential for applications in other optical devices, flat-panel display, biotechnology devices, and micro electromechanical systems.