Patent ID: 9673321
Date: 2017-06-06
CPC Classifications: H01L

Claim:
1. A pillar-shaped semiconductor device comprising: a semiconductor pillar on a substrate and oriented perpendicular to a surface of the substrate; an impurity region within the semiconductor pillar and containing donor or acceptor atoms; a metal-semiconductor alloy layer in contact with a side surface of the impurity region, and within and around the semiconductor pillar; and two interlayer insulating layers sandwiching the metal-semiconductor alloy layer, wherein at least one of the two interlayer insulating layers is separated from a side surface of the semiconductor pillar, wherein the metal-semiconductor alloy layer includes extension regions in the semiconductor pillar containing metal atoms, semiconductor atoms, and donor or acceptor atoms, where at least some of the donor or acceptor atoms reside in the semiconductor pillar after being pushed out from the metal-semiconductor alloy layer under a heat treatment and into the impurity region of the semiconductor pillar.