Methods of forming semiconductor circuit constructions and capacitor constructions

A method of forming a semiconductor circuit construction, comprising forming a material which comprises QxRySz (B);

• wherein Q is a single element selected from the group consisting of tantalum and tungsten;
• R is a single element selected from the group consisting of tungsten, aluminum and silicon;
• S is a single element of oxygen;
• and B is boron;
• and provided that R is not the same element as Q.

A method of forming a semiconductor circuit construction, comprising forming a material which comprises QxRySz (B);

• wherein Q is a single element that is a refractory metal;
• R is a single element selected from the group consisting of tungsten and aluminum;
• S is a single element selected from the group consisting of nitrogen and oxygen;
• and B is boron;
• provided that R is not the same element as Q.

A method of forming a capacitor construction, comprising:

• forming an insulative material layer over a substrate;
• forming a polysilicon interconnect extending through the insulative material and to an electrical node;
• forming a first diffusion barrier layer against the polysilicon interconnect, the first barrier layer comprising QxRySz;
• wherein Q is a single element that is a refractory metal;
• R is a single element selected from the group consisting of tungsten, aluminum and silicon;
• and S is a single element selected from the group consisting of nitrogen and oxygen;
• and provided that R is not the same element as Q;
• exposing the first barrier layer to a nitrogen-containing plasma;
• forming a first capacitor electrode separated from the polysilicon interconnect by the first barrier layer;
• forming a dielectric layer proximate the first electrode;
• and
• forming a second capacitor electrode separated from the first electrode by the dielectric layer.