Influence of the B doping concentration on phase transition and properties of Be-B films grown by magnetron sputtering

Highlights: • The grains in Be-B films were refined and the crystalline columnar growth was weakened with increasing the B doping concentration. • The crystalline-amorphous transition point of Be-B films was about 11 at.%~12 at.% B dopant. • The addition of B was acted as the nucleation agent in heterogeneous nucleation to favor production of crystal nucleus and inhibit the grain growth. • The tensile stress-compressive stress transition of Be-B films was accorded with the grain boundary eliminating model. the Be-B films with B doping concentration in range of 0~20at.% were prepared by magnetron sputtering. The phase transition, density, electrical resistance and inner stress were investigated by XRD, SEM, TEM, balance, four-point probe and laser interferometer, respectively. The results suggested that the Be-B films gradually transformed from crystalline phase into amorphous phase, the grains in film were refined and the crystalline columnar growth was weakened with increasing the B doping concentration, the crystalline-amorphous transition point was about 10 at.%~12 at.% B. The density of Be-B films increased from 1.76 g/cm³ to 2.07 g/cm³ and the square resistance increased from 72.9Ω/sq to 140.8Ω/sq with increasing the B dopant due to the higher B content and its bad conductivity. Meanwhile, the inner stress of Be-B film transformed from tensile stress to compressive stress and the tensile stress-compressive stress transition point was near to the crystalline-amorphous transition point.