Two important observed substorm growth phase phenomena are modeled: the formation of a near-Earth (∣X∣ ~ 8 RE) thin cross-tail current sheet, as well as the equatorward shift of the ionospheric Birkeland currents. Our study is performed by solving the 3D force-balance equation with realistic boundary conditions and pressure distributions. The obtained cross-tail current sheet has large current density (Jφ ~ 10 nA/m2) and a half-thickness in the north-south direction of ~1 RE, while plasma ¿ is very high (¿ ~ 40) in the current sheet region. The Region-1 and Region-2 Birkeland currents, formed on closed field lines due to pressure gradients, move equatorward and become more intense (J∥max ~ 3 ¿A/m2) compared to quiet times. The results agree with growth phase observations. We also find that the cross-tail current sheet maps into the ionosphere in the transition region between the Region-1 and Region-2 currents.