The forward domain growth in polar direction has been investigated on the example of the formation of isolated wedge-shaped domains and arrays of domains on lithium niobate nonpolar cuts under an electric field of a scanning probe microscope. Domain growth occurs due to the generation of steps and motion of charged kinks along charged domain walls (CDWs). A simulation of field spatial distribution showed that the generation of steps near a domain vertex is mainly caused by the effect of external field, whereas the forward growth is due to the kink motion in the field induced by neighboring kinks. Scanning by a probe tip with an applied voltage leads to the self-assembled formation of domain arrays with domain length alternation: doubling, quadrupling, and chaotic behavior under the action of the depolarizing fields formed by three neighboring domains.