Abstract: Undoped, S-doped and Fe-doped 4 inch diameter (100) InP single crystals with average dislocation etch pit density less than 5000 cm-2 have been grown by using high pressure vertical temperature gradient Freeze (VGF) method.A multiple points X-ray double crystal diffraction measurement across the 4 inch wafer indicates a full width at half maximum (FWHM) around 30 arcsec with uniform distribution of the rocking curves.Due to the low temperature gradient during the VGF growth process, the possibility of twin generation is quite high compared to that of liquid encapsulated growth process (LEC).However, the orientation of the crystal main body is still (100) direction after the twin formation on the VGF-InP crystal ingots.In this case, a large quantity of (100) single crystal wafers with diameter of 2 inch, 3 inch and 4 inch can be sliced from the ingot.Since the effective segregation coefficient is very low for Fe, polycrystal growth caused by composition super cooling of Fe-doped InP VGF is found frequently.The single crystal yield of the Fe-InP VGF growth can be increased significantly by strictly control the Fe doping quantity and the temperature gradient.Electrical property, dislocation density and its distribution, lattice perfection of the VGF-InP single crystals have been investigated.

Key words: Undoped, S-doped and Fe-doped 4 inch diameter (100) InP single crystals with average dislocation etch pit density less than 5000 cm-2 have been grown by using high pressure vertical temperature gradient Freeze (VGF) method.A multiple points X-ray double crystal diffraction measurement across the 4 inch wafer indicates a full width at half maximum (FWHM) around 30 arcsec with uniform distribution of the rocking curves.Due to the low temperature gradient during the VGF growth process, the possibility of twin generation is quite high compared to that of liquid encapsulated growth process (LEC).However, the orientation of the crystal main body is still (100) direction after the twin formation on the VGF-InP crystal ingots.In this case, a large quantity of (100) single crystal wafers with diameter of 2 inch, 3 inch and 4 inch can be sliced from the ingot.Since the effective segregation coefficient is very low for Fe, polycrystal growth caused by composition super cooling of Fe-doped InP VGF is found frequently.The single crystal yield of the Fe-InP VGF growth can be increased significantly by strictly control the Fe doping quantity and the temperature gradient.Electrical property, dislocation density and its distribution, lattice perfection of the VGF-InP single crystals have been investigated.