Electrical conductivity across InP and GaAs wafer-bonded structures with miscut substrates

Low temperature direct bonding of InP and GaAs wafer combinations using an (NH4)2S treatment are investigated for the effect of out of plane misorientation on interface electrical conductivity. The Seager-Pike model is applied to the zero-bias conductance across a range of temperatures, revealing an increase in potential barrier height across all wafer combinations as the degree of surface misorientation is increased above 4°. This demonstrates that out-of-plane misorientation is a crucial parameter for direct-bonded homo and hetero structures where interface resistivity must be minimized, such as multijunction solar cells.