The New Battlefield, On-Silicon Display

OLED on-silicon (OLEDoS) shows displays show content through the self-emission of OLED pixels. OLEDoS can be relatively thin and light, with power consumption potentially lower than that of LCoS displays. There are several variations of OLEDoS to achieve full color display, including White OLED (WOLEDoS) and red, blue, green (RGB) OLEDoS. Currently only WOLEDoS is available in the market.

LED on-silicon (LEDoS) displays show the content through the self-emission of LED pixels. Like OLEDoS, LEDoS can be thin and light, with power consumption lower than both LCoS and OLEDoS. Variations of LEDoS for full color display, include the Color-converted (CC) LEDoS, RGB LEDoS, Stacked RGB LEDoS, and Color Tunable RGB LEDoS. Currently only CC LEDoS is available in the market.

Substrate shift from glass/plastic to silicon wafer

The manufacturing process for on-silicon display differs from the conventional flat panel display (FPD) industry. 

Traditionally, FPD suppliers have produced display panels primarily on glass substrates, which provide a flat surface for fabricating TFT circuits with resolutions below 1000 PPI. These glass substrates are purchased in large mother glass sizes from sheet suppliers.

Since 2014, FPD display suppliers have begun using polyimide substrates for flexible OLED displays. Unlike glass, polyimide substrates are supplied in liquid form, which the panel manufacturers then turn into thins during production.

On-silicon displays, however, require silicon wafer (Si-Wafer) substrates for circuit fabrication. Unfortunately, most FPD suppliers lack the proper facilities to produce Si-wafer substrates or to fabricate the circuits on them as their focus has historically been on manufacturing displays with glass or polyimide substrates (typically under 1000 PPI).

While FPD suppliers are equipped for patterning LC, OLED or LED on various substrates, they rely on partnerships with semiconductor partners to design and fabricate the on-silicon substrates. Generally, the bill of materials (BOM) cost of silicon wafers accounts for more than 50% of an on-silicon display. This highlights the importance of designing and fabricating silicon wafers for these displays.

However, due to the relatively small market size of on-silicon displays, the demand is limited and considered sporadic for semiconductor manufacturers meaning the initiative largely lies with these companies. 

Competition in the on-silicon display industry

Over the past decade, the Head-Mounted Display (HMD) market has seen limited growth. It seems unlikely that it will grow at the same rate as the smartwatch market by 2031, as HMDs currently don’t perform as well smartphones or offer the same level of comfort and ease of use as smartwatches. However, despite this, the market is diversifying in terms of performance and price ranges. In essence, the HMD display market is evolving, even with modest demand. 

AR brands generally prioritize high-brightness and lightweight designs over high-resolution and full-color, as the purpose of AR devices is to display simple information like text or icons in outdoor environments. On the other hand, VR brands focus more on high-resolution and full-color, as VR devices are designed to display multi-media content such as games or movies in dark room settings.

Given these differences, it is not a wise strategy for a panel makers to invest heavily in manufacturing all types of on-silicon displays independently. Instead, panel makers should focus on forming strategic partnerships with key suppliers of on-silicon display technology, such as design houses and Si-wafer foundries. Securing major customers is also crucial for ensuring long-term business sustainability.

Recently, many HMD brands have begun developing their own on-silicon displays through exclusive partnerships with display suppliers. This trend suggests that brands are aiming to develop specialized display products tailored to their needs, building technical barriers to protect themselves from competitors. As a result, the industry is likely to become polarized between the companies with vertically integrated supply chains, and those without.

Furthermore, the on-silicon market will rapidly diversify with high-performance products produced by exclusive suppliers and normal-performance products by non-exclusive suppliers. This shift will make the on-silicon display market a competitive battlefield with the survival of companies depending on their ability to secure and develop key technologies.