We report on an over 50% reduction in polarization field strength in c-axis oriented InGaN multi-quantum wells (MQW) by applying quaternary AlGaInN barrier layers with better polarization matching to InGaN than GaN barriers. With the reduction in polarization fields, a strong blue-shift in photoluminescence is observed in agreement with theoretical expectation and simulations. By gracing incidence x-ray diffraction measurements, we demonstrate that partial relaxation already occurs for GaN/InGaN MQWs. As a consequence, the requirement of higher In-content layers for green light emission is in conflict with increasing strain leading to lattice relaxation.

We investigated the emission wavelength uniformity of 200-mm GaN-on-Si based blue light-emitting diode (LED) wafer grown by metalorganic vapor phase epitaxy (MOVPE). The larger the Si substrate diameter becomes, the more difficult to obtain uniform distribution of the emission wavelength because of the larger bow during growth, resulting in larger on-wafer inhomogeneity in growth temperature. Owing to the GaN-on-Si buffer strain management, optimized gas flow condition, and precise control of temperature balance in a reactor, we have achieved high thickness and crystal quality uniformity over the 200-mm GaN-on-Si based blue LED wafer. As a result, excellent blue photoluminescence emission wavelength uniformity from the InGaN-multi-quantum wells can be demonstrated on a 200-mm wafer with a standard deviation of 2.53 nm (0.57%). Less wavelengths binning with these highly uniform emission over the 200-mm wafer show the capability of sustainable cost reduction in LED fabrication based on GaN-on-Si technology.

We report on the on-wafer device characteristics of 150 and 200 mm GaN-on-Si-based blue LED wafers grown by metalorganic chemical vapor deposition on Si(111) substrates with electroluminescence at 447 nm. Excellent uniformity was achieved with standard deviations of 3.9% for the electroluminescence intensity, 0.6–0.8% for the peak wavelength and 1.3% for the forward voltage. The high uniformity confirms the viability of the GaN-on-Si technology on large-diameter substrates for next-generation LED manufacturing. The reverse bias current leakage mechanism is also investigated to provide an insight into improving device reliability.

This work presents a HEM technology which is developed for fast on-waf of 150mm epitaxial GaN-on-Si material. The te for extraction of key device and GaN-based m Information on wafer homogeneity can be o maps. This technology is suitable and ess different MOCVD growth conditions on de short time and, hence, significantly accele development towards the desired material qua high power electronic products.

We propose and demonstrate an efficient approach to extract key parameters of GaN‐based 2DEG heterostructures grown on conducting Silicon substrates. The methodology enables an electrical feedback on different epitaxial design or MOCVD growth conditions in a very short‐time frame by means of vertical capacitance–voltage (C–V) measurement on simple gate‐metal top‐electrodes, which are evaporated through a shadow mask. Key parameters such as sheet charge carrier density of the 2DEG‐channel, (AlGaN) barrier thickness between 2DEG and top‐electrode and threshold voltage of 2DEG depletion can be extracted with minimum effort. All respective parameters can be logged across the entire wafer without the need for a sophisticated device process and reveal the lateral (in‐) homogeneity of the wafer material. In addition, this method can be used to mimic the gate‐module of metal–insulator–semiconductor (MIS)‐HEMTs and, therefore, to study different charge‐related properties of the dielectric‐GaN interface or the dielectric layer itself.