Method to form upward pointing p-i-n diodes having large and uniform current

A method for forming a monolithic three dimensional memory array, the method comprising:

• a) monolithically forming a first memory level above a substrate by:
• i) forming a first plurality of rail-shaped conductors above the substrate;
• ii) forming a bottom heavily doped p-type region of deposited semiconductor material above the first rail-shaped conductors;
• iii) forming a middle intrinsic or lightly doped region of deposited semiconductor material above the bottom heavily doped p-type semiconductor, wherein the deposited semiconductor material is silicon, germanium, or a silicon-germanium alloy;
• iv) patterning and etching the bottom heavily doped p-type region and the middle intrinsic or lightly doped region to form a first plurality of pillars;
• v) forming a top heavily doped region doped with arsenic;
• vi) annealing to crystallize the semiconductor material, where some portion of the semiconductor material was amorphous as deposited and is in contact with a silicide, germanide, or silicide-germanide after the annealing step;
• and
• vii) forming a second plurality of rail-shaped conductors above the middle intrinsic or lightly doped region, wherein the first memory level comprises a first plurality of memory cells, each first memory cell comprising a portion of one of the first rail-shaped conductors, one of a first plurality of pillars, and a portion of one of the second conductors,
• wherein each of the first pillars comprises a p-i-n diode comprising a bottom heavily doped p-type region, a middle intrinsic or lightly doped region, and a top heavily doped n-type region formed by the doping step, and
• b) monolithically forming a second memory level above the first memory level.