No abstract

No abstract

In Fan-out Wafer Level Packaging (FOWLP) processes, redistribution layer (RDL) line width reduction is a key challenge to expand the FOWLP market to multi-chip interconnections, including interconnections between SoC and DRAM, split-die connection of FPGA, and interconnections between image sensors and SoC. Next generation FOWLP requires 1.0 μm RDL and future FOWLP is targeting 0.8 μm RDL. To meet these requirements, Canon has developed new projection optics with a high NA and wide-field that is best suited for sub-micron FOWLP. These projection optics are a new option for FPA-5520iV steppers, offering NA 0.24 imaging and a 52 × 34 mm exposure field. FPA-5520iV steppers with NA 0.24 provide excellent 0.8 μm resolution performance throughout all imaging fields thanks to Canon's wave-front aberration based projection optics manufacturing methods and on-axis optical tilt focus sensor.

Canon has developed the world's first stepper with the shot shape compensator called "SSC", which inde pendently controls x and y magnification of shots on a wafer. This SSC function enables steppers to achieve overlay accuracy equivalent to scanners. The most suita ble application of this function is back side illumination (BST) image sensors, which has large distortion on wafers because of bonding and thinning processes. In this paper, we will provide the detailed descriptions along with the exposure results using our new solutions.