Study on the Homogeneities of SI-GaAs Polished Wafers

Semi insulating GaAs polished wafers with high homogeneity in PL mapping are essential materials for large power microwave devices and large scale ultra high speed digital IC.The factors of affecting uniformities of SI GaAs wafers have been researched.It have been found that the dislocation density has some effect on both macro and micro homogeneities of electric resistivity as well as PL mapping uniformity while AB EPD and polishing process have more influence on the uniformity in PL mapping,and the AB EPD depends on heat treatment of the ingots.The results were explained.