Development of Silicon Wafer Packaging Technology for Deep UV LED

This paper reports a deep-UV LED package based on silicon MEMS process technology. The package (Si-PKG) consists of a cavity formed by silicon crystalline anisotropic etching, through-silicon vias (TSV) filled with electroplated Cu, bonding metals made of electroplated Ni/AuSn and a quartz lid for hermetic sealing. A deep-UV LED chip is directly mounted in the Si-PKG by AuSn eutectic bonding. It has advantages in terms of heat dissipation, light utilization efficiency, productivity and cost over conventional AlN ceramic packages. We confirmed a light output of 30 mW and effective reflection on Si (111) cavity slopes in the Si-PKG. Further improvement of the optical output is expected.