Development of silicon wafer packaging technology for deep UV LED

Abstract

This paper reports a deep-ultraviolet LED (deep-UV-LED) package based on silicon MEMS process technology (Si-PKG). The package consists of a cavity formed by silicon crystalline anisotropic etching, through-silicon vias (TSVs) filled with electroplated Cu, bonding metals made of electroplated Ni/AuSn and a quartz lid for hermetic sealing. A deep-UV LED die is directly mounted in the Si-PKG by AuSn eutectic bonding without a submount. It has advantages in terms of size, 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. Based on simulation, further improvement of the optical output is expected by optimizing DUV-LED die mount condition.