The PHENIX experiment at RHIC has measured single electrons at mid-rapidity(|y|<0.35) and single muons at forward and backward rapidities(1.2<|y|<2.2) for p+p and d+Au collisions at $\sqrt{s_{NN}}=200\ GeV$. The inclusive lepton spectra exhibit an excess over lepton yields resulting from light hadron decays. Light hadrons are independently measured, yielding information concerning their production over a wide kinematic range. The excess is attributed to the semileptonic decay of charm and bottom hadrons. Perturbative QCD and the parton model are applicable to heavy quark production in p+p collisions. For d+Au collisions, departures from naive $N_{coll}$(number of collisions) scaling may be caused by initial state effects such as gluon saturation. As a function of $p_{T}$ and rapidity, we compare the excess leptons with predictions for heavy quark production calculated using next-to-leading-order pQCD, and we investigate the scaling property for d+Au collisions.