Overlay improvements using a novel high-order distortion correction system for NIL high-volume manufacturing

Nanoimprint lithography manufacturing equipment utilizes a patterning technology that involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. The technology faithfully reproduces patterns with a higher resolution and greater uniformity compared to those produced by photolithography equipment. Additionally, as this technology does not require an array of wide-diameter lenses and the expensive light sources necessary for advanced photolithography equipment, NIL equipment achieves a simpler, more compact design, allowing for multiple units to be clustered together for increased productivity. In this paper, we review the advancements in the wafer imprinting system. To address high volume manufacturing concerns, an FPA-1200NZ2C four-station cluster tool is used in order to meet throughput and cost of ownership requirements (CoO). Throughputs of up to 90 wafers per hour were achieved by applying a multi-field dispense method. Mask like of up to 81 lots, using a contact test mask were demonstrated. The status of the tool overlay is discussed. Application of a High Order Distortion Correction (HODC) system to the existing magnification actuator has enabled correction of high order distortion terms up to K30. A mix and match overlay of 3.4 nm has been demonstrated and a single machine overlay across the wafer was 2.5nm.