Low resistive and low dislocation GaN wafer produced by OVPE method

Estimation of Shockley–Read–Hall Lifetime in Homoepitaxial n‐GaN on Low‐Dislocation‐Density GaN Substrates Prepared by Hydride Vapor Phase Epitaxy and Maskless 3D

“…We found a positive correlation between N dis and R on (symbols in Figure 5) [33] and discussed how such correlation under high-level injection conditions arise in relation to photon recycling. [30,31,55,[58][59][60][61][62] Namely, photon emission occurs in direct transition-type GaN by the recombination of electron-hole pairs at forward-biased conditions. The valence electrons are excited to the neutral Mg acceptors by the absorption of photons.…”

“…A record high breakdown voltage of 5 kV has been achieved in combination with a low on-resistance R on of 1.25 mΩ cm 2 at a forward voltage V F of 5 V. [14] The quality of substrates has also been improved. [22][23][24][25][26][27][28][29][30][31][32] For example, low-dislocation-density (N dis ≤ 4 Â 10 5 cm À2 ) GaN substrates became available via hydride vapor phase epitaxy (HVPE) and a maskless 3D (M-3D) method. [32] To suppress propagation of dislocations from the seed crystal, the M-3D method avoids c-plane growth; namely, the initial 3D growth is followed by 2D growth in which growth temperature and partial pressures of gallium chloride and ammonia are changed.…”

Extreme reduction of on-resistance in vertical GaN p–n diodes by low dislocation density and high carrier concentration GaN wafers fabricated using oxide vapor phase epitaxy method

“…Figure 3 shows the relationship between the depth of the MOVPE-GaN layer to the OVPE-GaN wafer and the impurity concentrations. 26) The detection elements were oxygen, hydrogen, carbon, and silicon, with lower detection limits of 6.0 × 10 15 atoms cm −3 , 2.0 × 10 16 atoms cm −3 , 2.0 × 10 15 atoms cm −3 , and 7.0 × 10 14 atoms cm −3 , respectively. The average concentrations of oxygen, hydrogen, and silicon in the MOVPE-GaN layer at depths of 1.0-7.0 μm were below the detection limit, and the concentration of carbon was 8.1 × 10 15 atoms cm −3 .…”

Impact on on-resistance of p-n junction diodes by using heavily Ge-doped GaN substrate

“…In recent years, it has become possible to manufacture high-quality GaN substrates, and as a result of active efforts to improve the substrate quality, low threading dislocation density (TDD) in the range of 10 5 cm −2 or less has been achieved. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Vertical structure devices made on the highquality substrates have made it possible to realize devices with superiority in terms of power conversion efficiency and chip size efficiency. 2,[28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] A p-n junction diode as a basic minority-carrier device is suitable for the evaluation of semiconductor materials.…”