Low k dielectric insulator and method of forming semiconductor circuit structures

A semiconductor structure comprising:

• a layer of semiconductor material having an upper surface;
• a device formed along the upper surface;
• an interconnect structure, providing electrical contact to the device, including a plurality of metallization levels each level comprising conductive elements;
• and
• at least one dielectric layer positioned to provide electrical isolation between portions of the conductive elements, the dielectric layer comprising:
• oxygen;
• at least 25 percent atomic silicon;
• 5 to 15 atomic percent hydrogen;
• and carbon, characterized by a refractive index less than 1.45 for light at a wavelength between 633 nm and 673 nm.

A semiconductor structure comprising:

• a first upper level of interconnect having at least one conductive element formed over a semiconductor layer;
• at least one lower level of interconnect having at least one conductive element formed between the semiconductor layer and the first upper level;
• a first insulative material comprising:
• oxygen;
• at least 25 percent silicon;
• and at least 5 atomic percent hydrogen;
• and carbon, combined in a porous layer and having a density less than 2 g/cc, positioned to electrically isolate the conductive element of the first upper level from the conductive element of the lower level.

A semiconductor structure comprising:

• an upper interconnect level having a conductive element formed over a semiconductor layer;
• at least one lower interconnect level having a conductive element formed between the semiconductor layer and the first upper interconnect level;
• and
• a first insulative material comprising:
• at least 25 percent silicon;
• at least 50 atomic percent oxygen;
• 5 to 15 percent hydrogen;
• and carbon, characterized by a wet etch ratio relative to thermally grown silicon dioxide between 4:1 and 20:1 in an etchant comprising dilute HF,
• said first insulative material positioned to isolate the conductive element of the upper level from the conductive element of the lower level.

A semiconductor structure comprising:

• a upper level of interconnect members formed over a semiconductor layer;
• at least one lower level of interconnect members formed between the semiconductor layer and the first upper level;
• a porous layer of insulative material comprising:
• oxygen;
• at least 25 atomic percent silicon;
• and 5 to 15 atomic percent hydrogen;
• and carbon, having a Young's modulus less than 45 GPa, said porous layer positioned to electrically isolate members of the first upper level from members of the lower level.

A semiconductor structure comprising

• an upper level of interconnect members formed over a semiconductor layer;
• at least one lower level of interconnect members formed between the semiconductor layer and first upper level;
• and
• a layer of insulative material comprising:
• oxygen;
• at least 25 atomic percent silicon;
• and 5 to 15 percent hydrogen;
• and carbon, having a continual distribution of voids throughout the majority of the layer volume.