Successful growth of in_xGa_1-xAs (x > 0.18) single bulk crystal directly on GaAs seed crystal with preferential orientation

We attempted to utilize a GaAs single crystal with preferential orientation as a seed to obtain an InGaAs single bulk crystal. The preferential orientation of the InGaAs bulk crystal was determined as [110] in a preliminary experiment to utilize multiple seed crystals with random orientations. By subsequent zone growth of InGaAs on GaAs(110), an Is_xGa_1-xAs (x > 0.18) single bulk crystal with a diameter of 15mm and a length of 13mm was successfully obtained on the seed without a compositionally graded InGaAs layer. The large lattice mismatch between GaAs and InGaAs was likely to be accommodated by an array of thin columnar grains at the interface.