Three-dimensional memory device with high mobility channels and nickel aluminum silicide or germanide drain contacts and method of making the same

A memory device comprising:

• a strained single-crystalline silicon layer;
• an alternating stack of insulating layers and electrically conductive layers located over the strained single-crystalline silicon layer;
• a memory opening vertically extending through the alternating stack;
• a memory opening fill structure located in the memory opening and comprising an epitaxial silicon-containing pedestal channel portion in epitaxial alignment with the strained single-crystalline silicon layer, a vertical semiconductor channel, a vertical stack of memory elements located adjacent to the vertical semiconductor channel at levels of the electrically conductive layers, and a drain region;
• and
• a single-crystalline silicon-germanium compound semiconductor layer,
• wherein:
• the strained single-crystalline silicon layer is located on and in epitaxial alignment with the single-crystalline silicon-germanium compound semiconductor layer;
• the strained single-crystalline silicon layer and the epitaxial silicon-containing pedestal channel portion have a doping of a first conductivity type;
• a source region having a doping of a second conductivity type opposite to the first conductivity type is in contact with the strained single-crystalline silicon layer and is located outside the memory opening;
• and
• the source region comprises:
• a lower source portion comprising a doped single-crystalline silicon-germanium compound semiconductor material having a doping of the second conductivity type;
• and
• an upper source portion comprising a doped single-crystalline strained silicon material and having a doping of the second conductivity type.

A memory device comprising:

• a strained single-crystalline silicon layer;
• an alternating stack of insulating layers and electrically conductive layers located over the strained single-crystalline silicon layer;
• a memory opening vertically extending through the alternating stack;
• and
• a memory opening fill structure located in the memory opening and comprising an epitaxial silicon-containing pedestal channel portion in epitaxial alignment with the strained single-crystalline silicon layer, a vertical semiconductor channel, a vertical stack of memory elements located adjacent to the vertical semiconductor channel at levels of the electrically conductive layers, and a drain region;
• wherein:
• the single-crystalline silicon-germanium compound semiconductor layer has a variable in-plane lattice constant that increases monotonically with a vertical distance from the substrate single-crystalline silicon layer;
• and
• a dislocation density decreases with the vertical distance from the substrate single-crystalline silicon layer within an upper region of the single-crystalline silicon-germanium compound semiconductor layer.

A memory device comprising:

• a strained single-crystalline silicon layer;
• an alternating stack of insulating layers and electrically conductive layers located over the strained single-crystalline silicon layer;
• a memory opening vertically extending through the alternating stack;
• and
• a memory opening fill structure located in the memory opening and comprising an epitaxial silicon-containing pedestal channel portion in epitaxial alignment with the strained single-crystalline silicon layer, a vertical semiconductor channel, a vertical stack of memory elements located adjacent to the vertical semiconductor channel at levels of the electrically conductive layers, and a drain region;
• wherein the drain region comprises:
• a semiconductor drain portion including a doped silicon-containing semiconductor material and contacting an end portion of the vertical semiconductor channel;
• and
• a nickel-aluminum-semiconductor alloy drain portion comprising silicon.