Three-dimensional semiconductor device having vertical channel extending through horizontal layer structure and method of fabricating same

A method of manufacturing a three-dimensional (3D) semiconductor device comprising one or more cells each comprising a gate structure and a channel, the method comprising:

• providing a horizontal layer structure above a crystalline substrate;
• forming an opening that extends vertically through the horizontal layer structure to the crystalline substrate;
• lining an inside vertical surface of the opening with a gate stack;
• lining the inside vertical surface of the opening having the gate stack lined thereon and a horizontal surface at a bottom of the opening with a sacrificial material layer;
• filling the opening, having the inside vertical and the horizontal surface thereof lined with the sacrificial material layer, with a filling material;
• after filling the opening with the filling material, removing parts of the sacrificial material layer to form a recess positioned laterally between the gate stack and the filling material and extending vertically down from a top of the opening to the crystalline substrate;
• and
• forming the channel by epitaxially growing, directly on a bottom horizontal surface of the recess comprising an exposed surface of the crystalline substrate, a channel material vertically upwards from the crystalline substrate.