Switch array circuit and system using programmable via structures with phase change materials

A switch unit array comprising:

• a plurality of programmable via structures, each programmable via structure including at least two phase change material vias that are both directly contacting a heating element, said programmable via structure farther including a first terminal in contact with a first portion of said heating element, a second terminal in contact with a second portion of said heating element, a third terminal in contact with one of said at least two programmable vias, and a fourth terminal in contact with another one of said at least two programmable vias;
• a first circuit block in contact with one of said third and fourth terminals;
• a second circuit block in contact with the third or fourth terminal not contacting said first circuit block;
• a source region of a first field effect transistor in contact with one of said first and second terminals;
• and a drain region of a second field effect transistor in contact with the first or second terminal that is not contacting said source region of said first field effect transistor.

A method comprising:

• providing a structure including:
• at least one programmable via structure including at least two phase change material vias that are both directly contacting a heating element, said programmable via structure further including a first terminal in contact with a first portion of said heating element, a second terminal in contact with a second portion of said heating element, a third terminal in contact with one of said at least two programmable vias, and a fourth terminal in contact with another one of said at least two programmable vias;
• a first circuit block in contact with one of said third and fourth terminals;
• a second circuit block in contact with the third or fourth terminal not contacting said first circuit block;
• a source region of a first field effect transistor in contact with one of said first and second terminals, a drain region of said first field effect transistor in contact with a bit line, and a gate of said first field effect transistor in contact with a write line;
• and
• a drain region of a second field effect transistor in contact with the first or second terminal that is not contacting said source region of said first field effect transistor, said second transistor further including a source region in contact to ground, and a gate of said first field effect transistor is in contact with said write line;
• and
• applying a current pulse through said bit line wherein said current pulse passes through said heating element and changes an initial state of the at least two phase change materials to a secondary state.