This chapter reviews concept of Molecular Layer Deposition (MLD), and describes selective wire growth for location and orientation control of polymer/molecular wires, which can be combined with MLD. The concept of MLD utilizing repulsive and attractive electrostatic force between source molecules for one-sided growth. In conventional carrier gas–type MLD equipment, gas injection into a chamber and gas removal from the chamber are necessary for molecular gas switching, resulting in an increase in processing time. The domain-isolated MLD using three kinds of source molecules, terephthalaldehyde, p-Phenylenediamine, and oxalic dihydrazide. The polymer wire alignment is favorable for enhancing second-order or third-order optical nonlinearities of the optical waveguides. Selectively-aligned polymer wire growth techniques will provide a wide range of device structures. Experimental demonstration of electric-field-assisted growth was performed for polyamic acid by using pyromellitic dianhydride and 2,4-diaminonitrobenzene. For head-to-tail growth, special molecules are necessary to carry out experimental demonstrations.