Pillar-shaped semiconductor device having connection material layer for anchoring wiring conductor layer and method for producing the same

A method for producing a pillar-shaped semiconductor device, comprising:

• (a) forming, on a substrate, a semiconductor pillar that stands in a first direction perpendicular to a surface of the substrate;
• (b) forming, so as to surround the semiconductor pillar, a first material layer either inclusive or exclusive of a gate conductor layer, wherein the outermost layer of the first material layer, which is single- or multi-layered, is surrounded by a first insulating layer;
• (c) forming, so as to surround the first material layer, a second insulating layer having an upper surface positioned lower than a top portion of the semiconductor pillar;
• (d) removing a part of the first material layer to expose a side surface of the semiconductor pillar or of the gate conductor layer to form an opening in the first material layer so that a lower end of the opening is positioned as high as the upper surface of the second insulating layer in the first direction;
• (e) forming a connection material layer, which contains a semiconductor atom or a metal atom, such that the connection material layer is in contact with the exposed side surface of the semiconductor pillar or of the gate conductor layer, wherein the connection material layer has an outer circumference extensive in a second direction perpendicular to the first direction beyond an outer circumference of the first material layer, and the connection material layer is formed by a selective deposition method so that the connection material layer is selectively deposited on the exposed side surface of the semiconductor pillar or of the side surface of the gate conductor layer but not deposited on a surface of the first insulating layer or a surface of the second insulating layer;
• and
• (f) forming a wiring conductor layer over the second insulating layer so that the wiring conductor layer at least partially surrounds the connection material layer,
• (g) wherein the connection material layer is formed such that a gap is formed in the opening between an upper surface of the connection material layer and an upper surface of the opening.