Photoreflectance measurements of indium content in semi-insulating indium-alloyed GaAs bulk substrates

We report the use of rooni-Lemperature photorefleetance measuremenLs to deLenitine radial arid axial nonuniformity of low levels of indium in 3-inch diameter semi-insulaLing GaAs bulk materials grown by the liquid-encapsulaLed Cochralski method. These resulLs were compared with umc. Types of inhomogeneities are discussed in Lerms of indium segregation and the shape of the solid and liquid interface during crystal growth.