Method for producing semiconductor device and semiconductor device

A method for producing a semiconductor device, comprising:

• a first insulating-layer-forming and removing step of forming a first insulating layer over a semiconductor substrate and removing the first insulating layer of a predetermined region on the semiconductor substrate to form an insulating-layer-removed region or
• a second insulating-layer-forming and removing step of removing, in a thickness direction of the semiconductor substrate, a portion of the semiconductor substrate around the predetermined region, and forming a first insulating layer in a semiconductor-substrate-removed region from which the portion of the semiconductor substrate has been removed;
• a first-semiconductor-layer-forming step of forming a first semiconductor layer containing a donor impurity or an acceptor impurity on the semiconductor substrate so as to cover at least the predetermined region;
• a conductor-layer-forming step of forming a conductor layer on the first semiconductor layer;
• a shaping step of shaping the conductor layer and the first semiconductor layer into predetermined shapes;
• a second-insulating-layer-forming step of forming a second insulating layer so as to cover the conductor layer and the first semiconductor layer that have been formed into the predetermined shapes;
• a planarizing step of planarizing a surface of the second insulating layer;
• a bonding step of bonding a substrate to the planarized surface of the second insulating layer;
• a thinning step of thinning the semiconductor substrate to a predetermined thickness;
• a pillar-shaped-semiconductor-forming step of forming, from the semiconductor substrate, a pillar-shaped semiconductor having a pillar-shaped structure on the first semiconductor layer;
• and
• a circuit-element-forming step of forming a circuit element in the pillar-shaped semiconductor,
• the method further comprising, at least after the first-semiconductor-layer-forming step, a first-semiconductor-region-forming step of forming a first semiconductor region in the pillar-shaped semiconductor through diffusion of the impurity from the first semiconductor layer containing the donor impurity or the acceptor impurity.