Memory Cell with Separate Read and Program Paths

A phase change memory cell, the memory cell being part of a phase change memory device, comprising:

• a bit line, a read word line and a program word line;
• the read device having first and second read terminals, the second read terminal connected to the read word line;
• a program device having first and second program terminals, the second program terminal connected to the program word line;
• a phase change element comprising a phase change region between first and second phase change element terminals, at least the phase change region of the phase change element comprising a phase change material the electrical resistance of which can be changed by the application of heat;
• the first phase change element terminal connected to the first read terminal and the second phase change element terminal connected to the bit line;
• a heat emitting element comprising first and second spaced apart heat emitting element terminals and a heat emitting region between the first and second heat emitting element terminals;
• the heat emitting region being in a heat-transmitting relationship with the phase change region;
• and
• the first heat emitting element terminal connected to the first program terminal and the second heat emitting element terminal connected to the bit line.

A method for programming a memory cell, the memory cell being part of a memory device, the memory cell of the type comprising:

• a memory element comprising a memory region between first and second memory element terminals, at least the memory region of the memory element comprising a memory material having an electrical property that can be changed by the application of energy;
• an energy emitting element comprising first and second spaced apart energy emitting element terminals and an energy emitting region between the first and second energy emitting element terminals;
• the energy region being in an energy-transmitting relationship with the memory region, the method comprising:
• changing the electrical property state of the memory region by passing a first electrical current between the first and second energy emitting element terminals thereby transmitting energy from the energy emitting region to the memory region;
• sensing the electrical property state of the memory material element by passing a second electrical current between the first and second memory element terminals.