Nanosized filamentary carbon structures (CNTs) nucleating over a catalyzed surface may be grown in an up-right direction reaching a second surface, spaced from the first surface, without the need of applying any external voltage source bias. The growth process may be inherently self-stopping, upon reaching a significant population of grown CNTs on the second surface. A gap between the two surfaces may be defined for CNT devices being simultaneously fabricated by common integrated circuit integration techniques. The process includes finding that for separation gaps of up to a hundred or more nanometers, a difference between the respective work functions of the materials delimiting the gap space, for example, different metallic materials or a doped semiconductor of different dopant concentration or type, may produce an electric field intensity orienting the growth of nucleated CNTs from the surface of one of the materials toward the surface of the other material.