LED manufacturing issues concerning gallium nitride-on-silicon (GaN-on-Si) technology and wafer scale up challenges

We demonstrated the growth of blue LED structures grown on 4-inch and 8-inch Si (111) substrates. GaN layers that have low threading dislocation density (TDD) of 1.6×10⁸/cm², which is comparable to state of the art in GaN on sapphire, can be obtained on 4-inch Si substrate by using a new TDD reduction technology using a silicon nitride (SiN) interlayer. A dependence of LED device performance on threading dislocation density was studied by using 4-inch Si substrate. A LED manufacturing technology has been developed by using 8-inch Si towards mass production technology. The light output power representing a median performance exceeded 641 mW at 350 mA, which was comparable to state-of-the-art LED.