15:45 〜 16:00
▼ [23p-C200-9] Micro-LED sidewall damage compensation by the hydrogen plasma passivation
キーワード：InGaN LEDs, Micro-LEDs, Non-radiative recombination
III-nitride-based micro-light-emitting diodes (μLEDs) are gaining attraction as a base technology for the next generation of high-resolution displays, primarily for VR and AR applications. However, it was shown that with reducing device size, μLEDs are experiencing a significant decrease in efficiency[1]. One of the main reasons for that is the sidewall damage introduced during the chip patterning using plasma dry etching[2]. In this work, we demonstrate the application of the hydrogen plasma treatment to compensate for etching damage by suppressing the current injection into the sidewall region. Hydrogen plasma can deactivate dopants in the LED’s p-side, increasing the resistivity of GaN:Mg up to 10 times[3]. We apply hydrogen passivation to the device’s sidewall, which results in an approximately 1.5 μm-thick passivated region along the LED chip’s perimeter. Figure 1 demonstrates a direct observation of the passivation effect captured by the optical microscope.
With current injection being suppressed in the damaged sidewall region, the probability of non-radiative recombination of charge carriers decreases. Therefore, device efficiency improves. We have investigated the effect of hydrogen passivation on LEDs of different sizes. Up to 2.6 times increase in the green μLEDs’ wall-plug efficiency was reached, as shown in Fig. 2, along with a 10-fold decrease in the reverse leakage current.
With current injection being suppressed in the damaged sidewall region, the probability of non-radiative recombination of charge carriers decreases. Therefore, device efficiency improves. We have investigated the effect of hydrogen passivation on LEDs of different sizes. Up to 2.6 times increase in the green μLEDs’ wall-plug efficiency was reached, as shown in Fig. 2, along with a 10-fold decrease in the reverse leakage current.