A domestic research team has developed core micro light-emitting diode (LED) display technology with ultra-high resolution that can be used in artificial intelligence (AI) and Extended Reality (XR) devices. The process technology precisely bonds micro LEDs on silicon-based circuits and can be applied to next-generation Augmented Reality (AR) glasses, Virtual Reality (VR) headsets, and high-density semiconductor packaging.
The Electronics and Telecommunications Research Institute (ETRI) said on the 11th it developed a 2,500 PPI (pixels per inch) class LEDOS (Light Emitting Diode on Silicon) display and an ultra-precision laser bonding technology to implement it. The research results were unveiled at the recent Society for Information Display (SID) Display Week 2026 and won the micro LED field "People's Choice Award."
LEDOS is an ultra-compact display that directly integrates micro LEDs on a silicon complementary metal-oxide semiconductor (CMOS) circuit. Because XR devices must render images close to the eye and integrate many pixels in a small area, high resolution, high brightness, and low power consumption are crucial.
The ETRI team secured a process technology that can precisely connect about 920,000 micro contacts arranged at 10 μm (micrometer, one-millionth of a meter) intervals in a single step. This requires connecting more contacts at tighter pitch than HBM4 used in AI Semiconductor.
Existing ultra-fine bonding processes faced issues such as substrate warpage during high-temperature treatment, generation of fine contaminants, and misalignment of bonding positions. In particular, when bonding hundreds of thousands of contacts at once as with micro LEDs, even small errors can lead to Production yield loss.
The team reduced these issues by applying the new material "SITRAB" developed by ETRI. SITRAB suppresses the formation of fume-type fine contaminants generated during the laser process. It also enables a room-temperature stage-based process, reducing substrate deformation from thermal expansion and alignment errors.
Through this, the team reliably bonded gallium nitride–based micro LED chips on silicon CMOS circuits and implemented a 2,500 PPI–class LEDOS display.
The results were published in May in the international journal Microsystems & Nanoengineering. The SITRAB material technology was transferred to a domestic materials corporations, and the related process equipment is being verified on mass-production lines at a domestic semiconductor back-end process specialist corporations.
ETRI plans to continue developing full-color RGB (red, green, blue) implementation, ultra-low-power driving, and large-area technologies. It also aims to expand cooperation with domestic materials, equipment, and packaging corporations to strengthen the foundation for commercialization in next-generation displays and advanced packaging.