Memory arrays having confined phase change material structures laterally surrounded with silicon nitride

The memory array, comprising:

• heater structures over an array of electrical nodes;
• the heater structures being in one-to-one correspondence with the electrical nodes;
• the array having rows extending along a first direction and having columns extending along a second direction substantially orthogonal to the first direction;
• wordlines being under the electrical nodes and extending along the first direction;
• confined phase change material structures over the heater structures and in one-to-one correspondence with the heater structures;
• bitlines across the confined phase change material structures, with the bitlines extending along the second direction;
• conductive material caps between and contacting the bitlines and the confined phase change material structures;
• the confined phase change material structures having lateral peripheries of phase change material;
• and
• wherein:
• the array has x-direction axes extending through the confined phase change material structures along the first direction and has y-direction axes extending through the confined phase change material structures along the second direction;
• the confined phase change material structures and conductive material caps are spaced from one another along the x-direction axes by first insulative material regions comprising a first oxide-containing material having a first pair of opposing vertical sidewalls sandwiched between first nitride-containing materials that extend vertically along an entirety of the first pair of opposing vertical sidewalls;
• the confined phase change material structures and conductive material caps are spaced from on another along the y-direction axes by second insulative material regions comprising a second oxide-containing material having a second pair of opposing vertically extending sidewalls sandwiched between second nitride-containing materials that extend vertically along an entirety of the second pair of opposing vertically extending sidewalls;
• the first and second nitride-containing materials are silicon nitride;
• and
• the lateral peripheries of the confined phase change material structures, the conductive material caps and the heater structures are entirely laterally surrounded by the first and second nitride-containing materials.