Influence of Si Doping on Dislocations and Mechanical Properties of GaAs Crystals Grown by Modified Vertical Bridgman Method

Abstract

GaAs crystals are important III–V compound semiconductor materials and the bandgap and quantum efficiency can be optimized by doping. However, the doping may bring some problems to the crystal growth. In this paper, Si‐doped GaAs crystals are grown by the modified vertical Bridgman method and the influence of Si doping on dislocations and mechanical properties are discussed. It is found that a proper amount of Si doping significantly reduces the dislocation density of GaAs crystals. The mechanical properties of (100), (110), (111), and (511) planes are measured, and the results show that the mechanical properties of Si‐doped GaAs crystals have obvious anisotropy. The (111) plane has the strongest mechanical properties among them. The Vickers hardness, fracture toughness, nanoindentation hardness, and elastic modulus of the (111) plane are 6.05 GPa, 0.69 MPa m1/2, 10.82 GPa, 138.7 GPa, respectively. Moreover, Si doping can improve the mechanical properties of GaAs crystals.