Polysilicon emitter BJT access device for PCRAM
AssigneeInternational Business Machines Corporation
InventorsBipin Rajendran, Tak H. Ning, Chung H. Lam
Life of this patent
Estimating the term…
Abstract
A resistive non-volatile memory cell with a bipolar junction transistor (BJT) access device formed in conjunction with the entire memory cell. The memory cell includes a substrate acting as a collector, a semiconductor base layer acting as a base, and a semiconductor emitter layer acting as an emitter. Additionally, metal plugs and the phase change memory element are formed above the BJT access device while the emitter, metal plugs, and phase change memory element are contained within an insulating region. In one embodiment of the invention, a spacer layer is formed and the emitter layer is contained within the protective spacer layer. The spacer layer is contained within the insulating region.
Claims13
A memory array comprising one or more memory cells, at least one of the memory cells comprising:
- a substrate comprised of silicon;
- an insulating region comprising insulating material above the substrate;
- a base layer comprised of silicon above the substrate and contained within the insulating region, the base layer forming a word-line;
- an emitter layer comprised of a semiconductor material above the base layer and contained within the insulating region, the semiconductor material being substantially polycrystalline silicon;
- a plug comprised of conductive material above the emitter layer and contained within the insulating region;
- a phase change element comprised of phase change material above the plug and contained within the insulating region;
- and
- a top electrode layer comprised of conductive material above the phase change element and contained within the insulating region, the top electrode forming a bit-line.
Dependencies are inferred from the claim text.