Investigation on the relationship between dislocation type and the annihilation mechanism of GaN-on-Si

In this work, we have found that there is a clear difference between the annihilation of screw dislocation and edge dislocation, and the density of edge dislocations remains almost unchanged during the growth from AlN to GaN. Through the transmission electron microscope (TEM), the internal mechanism of this phenomenon has been explored in this paper, which can be attributed to the failure of AlGaN buffer layer and AlN insertion layer to block the edge dislocation. The explanation proposed in this paper may provide new ideas to further reduce the dislocations in GaN-on-Si, improving the crystal quality.

Automated summary

This work explores the difference between the annihilation of screw dislocation and edge dislocation, and finds that the density of edge dislocations remains almost unchanged during the growth from AlN to GaN. Through TEM analysis, it is discovered that the failure of AlGaN buffer layer and AlN insertion layer to block edge dislocations contributes to this phenomenon. This explanation may offer new insights for reducing dislocations and improving the crystal quality of GaN-on-Si.