Presentation Abstract

Why is it so difficult to ramp-up volume manufacturing of microLED microdisplay with decent yield and cost?

Tight pitch integration of compound semiconductor with advanced node CMOS like in microLED displays requires a full wafer level monolithic approach. Dedicated microLED display fabs are hereby an unlikely solution since older generation fabs used for compound semiconductor (e.g. 4”-6”) do not have the capability and precision while Si-CMOS fabs (e.g. 200mm/300mm) require a very large CAPEX that during the slow AR market ramp up would be under-utilized for several years. Process and tool compatibility to existing CMOS foundries is therefore a must.

At pitches below 5um, the CMOS bonding is at the center and cannot be considered as an afterthought of a great LED process. In this presentation we discuss different option for CMOS integration, color generation and how they influence cost effective volume manufacturing.

Finally, we present an update on MICLEDI 300mm foundry integration approach implemented using standard volume manufacturing equipment with a similar integration scheme as is done for 3D-stacked backside illuminated imager (BSI). This includes the realization of wafer level optics for beam-shaping.

Dr. Soeren Steudel, MICLEDI Microdisplay BV, CTO & Co-founder