The redistribution of Be during growth of GaInP layers by gas source molecular beam epitaxy has been studied using secondary ion mass spectrometry for the first time. Apparent Be diffusion occurs at doping level over 4×1019 cm−3 at growth temperature of 500°C. At lower temperature the Be diffusion profile exhibits a significant increase of Be concentration and reduced diffusion. In contrast to Zn behavior in metalorganic vapor-phase epitaxy, no enhancement of Be redistribution in both GaInP and GaAs is observed by nearby highly n-type doped layers. Based on these results, a p+–n+ GaInP tunnel diode with a high conductance of 15 mA/cm2 at 1.7 mV has been achieved.