A phase change memory may be formed which is amenable to multilevel programming. The phase change material may be formed with a lateral extent which does not exceed the lateral extent of an underlying heater. As a result, the possibility of current bypassing the amorphous phase change material in the reset state is reduced, reducing the programming current that is necessary to prevent this situation. In addition, a more controllable multilevel phase change memory may be formed in some embodiments.

A resistive random-access memory device formed on a semiconductor substrate includes a first interlayer dielectric formed over the semiconductor substrate and includes a first via. A chemical-mechanical-polishing stop layer is formed over the interlayer dielectric. A lower metal layer formed in the first via has a top surface extending above a top surface of the chemical-mechanical-polishing stop layer. A dielectric layer is formed over the chemical-mechanical-polishing stop layer and is in electrical contact with the lower metal layer. A barrier metal layer is formed over the dielectric layer. Edges of the dielectric layer and the first barrier metal layer extend beyond outer edges of the first via. A second interlayer dielectric layer including a second via is formed over the dielectric layer. An upper metal layer formed in the second via in electrical contact with the barrier metal layer.

An insulating film and another insulating film are formed over a semiconductor substrate in that order to cover first, second, and third gate electrodes. The another insulating film is etched back to form sidewall spacers over side surfaces of the insulating film. Then, the sidewall spacers over the side surfaces of the insulating films corresponding to the sidewalls of the first and second gate electrodes are removed to leave the sidewall spacers over the side surfaces of the insulating film corresponding to the sidewalls of the third gate electrode. Then, the sidewall spacers and the insulating films are etched back, so that the sidewall spacers are formed of the insulating film over the sidewalls of the first, second, and third gate electrodes.

A resistive random-access memory device formed on a semiconductor substrate includes a first interlayer dielectric formed over the semiconductor substrate and includes a first via. A chemical-mechanical-polishing stop layer is formed over the interlayer dielectric. A lower metal layer formed in the first via has a top surface extending above a top surface of the chemical-mechanical-polishing stop layer. A dielectric layer is formed over the chemical-mechanical-polishing stop layer and is in electrical contact with the lower metal layer. A barrier metal layer is formed over the dielectric layer. Edges of the dielectric layer and the first barrier metal layer extend beyond outer edges of the first via. A second interlayer dielectric layer including a second via is formed over the dielectric layer. An upper metal layer formed in the second via in electrical contact with the barrier metal layer.

A resistive random-access memory device formed on a semiconductor substrate includes an interlayer dielectric formed over the semiconductor substrate and includes a first via. A chemical-mechanical-polishing stop layer is formed over the interlayer dielectric. A lower metal layer formed in the first via presents a substantially planar top surface. A dielectric layer is formed over the chemical-mechanical-polishing stop layer and is in electrical contact with the lower metal layer. A barrier metal layer is formed over the dielectric layer. Edges of the dielectric layer and the first barrier metal layer form an aligned stack having edges extending beyond outer edges of the first via. A dielectric barrier layer including a second via is formed over the aligned stack and at least a portion of the chemical-mechanical-polishing stop layer. An upper metal layer formed in the second via in electrical contact with the barrier metal layer.

A resistive random-access memory device formed on a semiconductor substrate includes an interlayer dielectric formed over the semiconductor substrate and includes a first via. A chemical-mechanical-polishing stop layer is formed over the interlayer dielectric. A lower metal layer formed in the first via presents a substantially planar top surface. A dielectric layer is formed over the chemical-mechanical-polishing stop layer and is in electrical contact with the lower metal layer. A barrier metal layer is formed over the dielectric layer. Edges of the dielectric layer and the first barrier metal layer form an aligned stack having edges extending beyond outer edges of the first via. A dielectric barrier layer including a second via is formed over the aligned stack and at least a portion of the chemical-mechanical-polishing stop layer. An upper metal layer formed in the second via in electrical contact with the barrier metal layer.

An insulating film and another insulating film are formed over a semiconductor substrate in that order to cover first, second, and third gate electrodes. The another insulating film is etched back to form sidewall spacers over side surfaces of the insulating film. Then, the sidewall spacers over the side surfaces of the insulating films corresponding to the sidewalls of the first and second gate electrodes are removed to leave the sidewall spacers over the side surfaces of the insulating film corresponding to the sidewalls of the third gate electrode. Then, the sidewall spacers and the insulating films are etched back, so that the sidewall spacers are formed of the insulating film over the sidewalls of the first, second, and third gate electrodes.

A layout arrangement for a resistive random access memory cell includes an active area, a polysilicon row address line over the active region, a metal column address line running orthogonal to the row address line and having an active region contact portion extending over the active region and having a contact to the active region. A metal output line runs parallel to the column address line over the active region. A first cell contact region intersects with the output line and has a contact to the active region. A first metal cell contact region forms an intersection with the first cell contact region. A first resistive random access memory device is formed at the intersection of the first cell contact region and the output line. A second resistive random access memory device is formed at the intersection of the first cell contact region and the first cell contact region.

An insulating film and another insulating film are formed over a semiconductor substrate in that order to cover first, second, and third gate electrodes. The another insulating film is etched back to form sidewall spacers over side surfaces of the insulating film. Then, the sidewall spacers over the side surfaces of the insulating films corresponding to the sidewalls of the first and second gate electrodes are removed to leave the sidewall spacers over the side surfaces of the insulating film corresponding to the sidewalls of the third gate electrode. Then, the sidewall spacers and the insulating films are etched back, so that the sidewall spacers are formed of the insulating film over the sidewalls of the first, second, and third gate electrodes.

An insulating film and another insulating film are formed over a semiconductor substrate in that order to cover first, second, and third gate electrodes. The another insulating film is etched back to form sidewall spacers over side surfaces of the insulating film. Then, the sidewall spacers over the side surfaces of the insulating films corresponding to the sidewalls of the first and second gate electrodes are removed to leave the sidewall spacers over the side surfaces of the insulating film corresponding to the sidewalls of the third gate electrode. Then, the sidewall spacers and the insulating films are etched back, so that the sidewall spacers are formed of the insulating film over the sidewalls of the first, second, and third gate electrodes.