Unlocking the full Potential of Lithography for Advanced Packaging

Abstract

Abstract Advanced Packaging technologies and applications are developing rapidly in order to support the ever increasing demand for integrating functionality in small and thin devices with low power consumption, high bandwidth, low latency- all at low cost of ownership. Lithography is the key enabling technology for developing and manufacturing such devices. Advanced Packaging processes, in particular Fan-Out, drive towards redistribution patterns with smallest feature sizes of a few micron today and towards 1 micron in the future. These feature sizes must be realized in production processes with multiple layers stacked on top of each other which need to be accurately aligned. In order to meet economic boundary conditions, routine operation on 300 mm wafers (possibly strongly warped) is required with high throughput. Kulicke & Soffa Liteq B.V. developed together with key partners, a novel Lithography system which is focused specifically to meet the challenging requirements of Advanced Packaging, both for current and future applications. The high quality optics used is capable to project the optimally sized reticle field with lowest possible aberrations on the wafer. The system includes Reticle Masking blades (REMA), which delivers high flexibility and high speed for multi-pattern jobs. The magnification of the optics is adjustable for optimal intra-field overlay performance. The reticle is illuminated by a high power UV laser. This novel setup creates many advantages for imaging, Cost of Ownership and throughput. The illumination and projection optics is combined with modern mechatronics to handle warped wafers with minimal overhead times. The design has a strong focus on contamination control. Wafer Edge Processing functions are integrated in the system to support the use of state-of-the-art plating processes. The modularity of the system architecture makes it possible to extend functionality and performance into the future. In this paper we will introduce the novel LITEQ 500 projection stepper, present imaging results and demonstrate the flexibility and high throughput potential of reticle masking for complex multi-pattern jobs.