Phase-change memory device with tapered thermal transfer layer

A method of forming a memory device, the method comprising:

• forming a first electrode, a second electrode, and a heater structure laterally spaced between the first electrode and the second electrode;
• depositing a thermal transfer layer over the first electrode, the second electrode, and the heater structure;
• etching the thermal transfer layer to form a first thermal transfer structure over the heater structure and spaced from the first and second electrodes, the first thermal transfer structure comprising a first tapered portion, a second tapered portion, and a lateral portion extending from the first tapered portion to the second tapered portion;
• and
• depositing a phase-change layer on the first electrode, the first tapered portion of the first thermal transfer structure, the lateral portion of the first thermal transfer structure, the second tapered portion of the first thermal transfer structure, and the second electrode.

A method of forming a memory device, the method comprising:

• forming a first electrode, a second electrode, and a heater layer, wherein a first portion of a first dielectric layer is laterally between the first electrode and the heater layer, and wherein a second portion of the first dielectric layer is laterally between the second electrode and the heater layer;
• depositing a thermal transfer layer on the first electrode, the first portion of the first dielectric layer, the heater layer, the second portion of the first dielectric layer, and the second electrode;
• forming a masking layer over the thermal transfer layer;
• etching the thermal transfer layer and the masking layer to remove the thermal transfer layer from the first electrode and the second electrode, wherein a lateral portion of the thermal transfer layer remains on the heater layer, wherein a first tapered portion of the thermal transfer layer remains on the first portion of the first dielectric layer, and wherein a second tapered portion of the thermal transfer layer remains on the second portion of the first dielectric layer;
• and
• depositing a phase-change layer on the first electrode, the first portion of the first dielectric layer, the first tapered portion of the thermal transfer layer, the lateral portion of the thermal transfer layer, the second tapered portion of the thermal transfer layer, the second portion of the first dielectric layer, and the second electrode,
• wherein the phase-change layer has a first thickness over the first tapered portion of the thermal transfer layer and a second thickness over the lateral portion of the thermal transfer layer, and wherein a difference between the first thickness and the second thickness is less than 20% of an average of the first thickness and the second thickness.