Low-temperature metal-induced crystallization of silicon-germanium films

A method for forming a first memory level comprising a plurality of first memory cells, the method comprising:

• depositing a film of a silicon-germanium alloy at a temperature below about 490 degrees C.;
• depositing a layer of a metal catalyst selected from the group consisting of nickel and aluminum, the metal catalyst in contact with the silicon-germanium film;
• crystallizing the silicon-germanium alloy film at a temperature not exceeding about 490 degrees C.;
• and
• forming the first memory cells, wherein each memory cell comprises a portion of the silicon-germanium alloy film.

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

• a) monolithically forming a first memory level above a substrate by a method comprising:
• i) depositing an amorphous film of a silicon-germanium alloy;
• ii) depositing a metal catalyst in contact with the silicon-germanium alloy film, the metal catalyst selected from the group consisting of nickel and aluminum;
• iii) annealing to crystallize the silicon-germanium alloy film, wherein during the steps of depositing and annealing the silicon-germanium alloy film, the temperature does not exceed about 490 degrees C.;
• iv) forming a first plurality of memory cells, each memory cell comprising a portion of the silicon-germanium alloy film, the first memory level comprising the first plurality of memory cells;
• and
• b) monolithically forming a second memory level above the first memory level.