Programmable memory devices comprising tungsten, and methods of forming programmable memory devices comprising tungsten

A programmable memory device supported by a semiconductor substrate and comprising:

• a floating gate over the substrate;
• a dielectric material over the floating gate;
• a mass consisting essentially of W over the dielectric material;
• the mass comprising a pair of opposing sidewalls;
• and
• a pair of sidewall spacers along the opposing sidewalls of the mass;
• the sidewall spacers comprising first layer consisting essentially of one or more nitride compounds and a second layer different from the first layer.

A programmable memory device supported by a semiconductor substrate and comprising:

• a floating gate over the substrate;
• a dielectric material over the floating gate;
• a first layer consisting essentially of WNx over the dielectric material;
• a mass consisting essentially of W over the first layer;
• a second layer consisting essentially of one or more nitride compounds over the mass;
• the mass, first layer and second layer being comprised by a stack having a pair of opposing sidewalls;
• and
• a pair of sidewall spacers along and physically against the opposing sidewalls of the stack;
• the sidewall spacers comprising a first portion consisting essentially of one or more nitride compounds and a second portion different from the first portion.

A method of making a programmable memory device, comprising:

• forming at least one floating gate layer over a semiconductor substrate;
• forming a dielectric material over the at least one floating gate layer;
• forming a mass consisting essentially of W over the dielectric material, the mass having a pair of opposing sidewalls;
• forming a first layer over the mass and along the sidewalls of the mass;
• forming a second layer over the first layer, the second layer extending over the mass and along the sidewalls of the mass and having a different composition than the first layer;
• and
• anisotropically etching the first and second layers to form sidewall spacers extending along the sidewalls of the mass and comprising the first and second layers.

A method of making a programmable memory device, comprising:

• forming a floating gate mass over a semiconductor substrate;
• forming a dielectric material over the floating gate mass;
• forming a first layer consisting essentially of W over the dielectric material;
• forming a second layer consisting essentially of one or more nitride compounds over the layer consisting essentially of W;
• forming a first gate pattern by etching through the first and second layers;
• the first gate pattern having sidewalls extending along the etched layers;
• forming sidewall spacers along the sidewalls;
• and
• while the sidewall spacers are along the sidewalls, forming a second gate pattern by etching through the dielectric material and the floating gate mass;
• the first and second gate patterns being together incorporated into a programmable memory device.

A method of making a programmable memory device, comprising:

• forming a stack over a semiconductor substrate;
• the stack comprising in ascending order from the substrate a floating gate mass, a dielectric material, a first layer comprising non-oxidized silicon, a second layer consisting essentially of WNx, a third layer consisting essentially of W, a fourth layer consisting essentially of one or more nitride compounds, and a fifth layer comprising non-oxidized silicon;
• forming a first gate pattern by etching through the second, third, fourth and fifth layers;
• the etching terminating partway through the first layer to leave a remaining portion of the first layer that is not etched;
• the first gate pattern having sidewalls extending along the etched layers;
• forming sidewall spacers along the sidewalls;
• and
• while the sidewall spacers are along the sidewalls, forming a second gate pattern by etching through the dielectric material, the floating gate mass and the remaining portion of the first layer;
• the first and second gate patterns being together incorporated into a programmable memory device.