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Information and Communication Technologies
Over the past decade, high-luminosity microdisplays have been developed for new applications like virtual reality systems. The displays use gallium nitride (GaN) LEDs, already widely used in lighting and known for their excellent yields. An article covering a decade of GaN microdisplay research published in the Journal of SID won the Best Paper 2017 award at SID's Display Week 2018. The award will help raise Leti's profile as a leader in GaN microdisplay research.
In 2017, the literature discussed microdisplays of just a few pixels. Back then, the main challenge to microdisplay fabrication was assembling a LED matrix with an active CMOS matrix—an integrated circuit whose role is to run each LED individually. At the time, hybridization and monolithic fabrication were the main two techniques used.
Leti then developed microtube hybridization, which entails placing metal microtubes on the active matrix. The microtubes fit onto metal bumps deposited onto each LED. The LED and CMOS matrices are then assembled by pressing them together at ambient temperature. A few months after the article was published, the process was used to fabricate a microdisplay with an unrivalled resolution of 874 x 500 pixels with a pitch of 10 microns. The microdisplay was presented at Display Week 2017.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.