Abstract :
The effect of Al incorporation on the AlGaN growth by metalorganic chemical vapor deposition is investigated. With the increase of
trimethylalluminum (TMAl) flux, the crystal quality becomes worse, and the epilayer surface becomes rougher. An interesting phenomenon is that
the growth rate of AlGaN decrease with increasing TMAl flux, which is opposite to the AlN growth rate dependence on the TMAl flux. All these
effects are attributed to the different properties of Al atoms due to the higher bond strength of Al–N compared with Ga–N, which lead to lower
surface mobility and stronger competitive ability of Al atoms during the growth. The enhancement of the surface mobility of Al is especially
important for improving the quality of AlGaN.
