Method of making an insulator for electrical structures

A method for insulating a gate comprising:

• providing a gate stack projecting from a gate oxide layer upon a semiconductor substrate, said gate stack having first and second opposing lateral sides and a top surface;
• forming a layer of primary material over said top surface of said gate stack and over said first and second opposing lateral sides of said gate stack;
• forming a layer of secondary material over said layer of primary material and said layer of secondary material;
• performing a spacer etch of said layer of secondary material to form a first spacer and a second spacer respectively upon each portion of the layer of primary material that is on the first and second lateral sides of the gate stack;
• etching said layer of primary material with an etch that is selective to said gate stack and to said layer of secondary material to form adjacent each of the first and second opposing lateral sides of the gate stack:
• a first portion of the layer of primary material that is remote from the semiconductor substrate and that secures the first spacer to the gate stack;
• a second portion of the layer of primary material that is remote from the semiconductor substrate and that secures the second spacer to the gate stack;
• forming a cover layer extending continuously upon and over the gate stack, the first spacer, the second spacer, and the gate oxide layer to form, adjacent to each of the first and second lateral sides of the gate stack, a plurality of closed voids each filled with an ambient gas and situated between the layer of primary material, the layer of secondary material, and the gate stack.

A method for forming an insulated structure comprising:

• providing a structure projecting from a semiconductor substrate, said structure having opposing first and second lateral sides;
• forming a layer of primary material over said structure, said layer of primary material having a top surface that is remote from said semiconductor substrate;
• forming a layer of secondary material over said layer of primary material;
• removing a portion of said layer of secondary material to expose said top surface of said layer of primary material;
• removing a portion of said layer of primary material to form, adjacent to each of the first and second lateral sides of the structure, a recess between the layer of secondary material and one of the opposing first and second lateral sides of said structure, each said recess having an opening remote from said semiconductor substrate;
• forming a closing layer extending continuously upon and over said opening of each said recess to form, adjacent to each of the first and second lateral sides of the structure, a plurality of closed empty spaces situated between the closing layer and the semiconductor substrate.

A method for forming a closed void comprising:

• providing a structure projecting from a semiconductor substrate, said structure having opposing first and second lateral sides;
• forming a layer of primary material over said structure having a top surface remote from said semiconductor substrate;
• forming a layer of secondary material over said layer of primary material;
• performing a spacer etch of said layer of secondary material to form therefrom a spacer upon the layer of primary material;
• etching said portion of said layer of primary material with an etch that is selective to said structure and said layer of secondary material to form a recess adjacent to each of the first and second lateral sides of the structure, each said recess being situated between the spacer and the structure and having an opening remote from said semiconductor substrate;
• forming a cover layer extending continuously upon and over said opening of each said recess without filling each said recess with said cover layer so as to form, adjacent to each of the first and second lateral sides of the structure, a plurality of closed voids filled with an ambient gas.

A method for making an insulated structure comprising:

• forming a gate layer upon a gate oxide layer situated upon a silicon base layer, said gate layer being adjacent to an electrically active region within said silicon base layer, said gate layer having opposing first and second lateral sides;
• forming a layer of primary material over said gate layer;
• forming a layer of secondary material over said layer of primary material;
• selectively removing a portion of said layer of secondary material to create, adjacent to each of the first and second lateral sides of the each layer, a spacer that is attached to the gate layer by the layer of primary material;
• etching a portion of said layer of primary material situated between each of the spacers and the gate layer to form thereat a recess having an opening thereto remote from said silicon base layer;
• forming cover layer extending continuously upon and over the opening to each of the recesses, wherein a plurality of closed empty spaces is situated adjacent to each of the first and second lateral sides of the gate layer between the cover layer and the silicon base layer.

A method for making an insulated structure comprising:

• forming a gate layer upon a gate oxide layer situated upon a silicon base layer, said gate layer being adjacent to an electrically active region within said silicon base layer, said gate layer having opposing first and second lateral sides;
• forming a layer of primary material over said gate layer;
• forming a layer of secondary material over said layer of primary material;
• selectively removing a portion of said layer of secondary material to create, adjacent to each of the first and second lateral sides of the gate layer, a spacer that is attached to the gate layer through the layer of primary material;
• forming a patterned layer of photoresist upon each said spacer to expose the layer of primary material extending above the structure;
• etching a portion of said layer of primary material situated between each said spacer and the gate layer to form a recess having an opening thereto remote from said silicon base layer;
• forming cover layer extending continuously upon and over the opening to each said recess, wherein, adjacent to each of the first and second lateral sides of the gate layer, a plurality of closed empty spaces is situated between the cover layer and the silicon base layer.

A method for making an insulated structure comprising:

• providing a polysilicon gate stack projecting above a silicon base layer, said polysilicon gate stack being located adjacent to an electrically active region within said silicon base layer, said polysilicon gate layer having opposing first and second lateral sides;
• forming a layer of silicon nitride over said gate stack, said layer of silicon nitride having a thickness of about 100 Å to about 150 Å;
• forming a layer of a secondary material over said layer of silicon nitride;
• spacer etching said layer of secondary material using a process that is selective to silicon nitride, said spacer etch forming, adjacent to each of the opposing first and second lateral sides of the polysilicon gate stack, a spacer upon the layer of silicon nitride;
• selectively etching a portion of said layer of silicon nitride utilizing an anisotropic dry etch process that is selective to said layer of secondary material to form a recess defined in part between each of the opposing first and second lateral sides of said polysilicon gate stack and each said spacer, each said recess having an opening remote from said semiconductor substrate;
• forming a silicon dioxide layer extending continuously upon and over said polysilicon gate stack and said opening of each said recess to cover said opening of each said recess and form, adjacent to each of the first and second lateral sides of the polysilicon gate stack, a plurality of closed voids filled with an ambient gas.

A method for isolating an electrically active area comprising:

• providing a structure projecting from a substrate;
• forming a layer of primary material over said structure;
• forming a layer of secondary material over said layer of primary material;
• removing a portion of said layer of secondary material that extends above the structure;
• forming a recess having an opening remote from said substrate by:
• forming a mask patterned to expose the structure and the layer of primary material adjacent thereto;
• and
• exposing a surface on said substrate adjacent to said structure by removing the layer of primary material adjacent to the structure with a first etch process that is selective to said layer of secondary material and to the structure, wherein the recess is defined by:
• a sidewall of said structure;
• said layer of secondary material;
• and
• said substrate;
• removing the mask and the structure;
• forming a closing layer extending continuously upon and over said opening of said recess without substantially filling said recess, whereby the opening to the recess is closed and a closed void is thereby formed within said recess.

A method of forming a semiconductor device, the method comprising:

• forming a substrate having an electrically conductive raised feature projecting therefrom, the electrically conductive raised feature having opposing first and second lateral sides;
• forming, adjacent to each of the opposing first and second lateral sides of the electrically conductive raised feature, a spacer projecting from the semiconductor substrate;
• and
• forming a cover layer continuously upon each said spacer and the electrically conductive raised feature, wherein the cover layer with each said spacer and the semiconductor substrate define, adjacent to each of the first and second lateral sides of the structure, a plurality of closed voids.

A method of forming a semiconductor device, the method comprising:

• providing a semiconductor substrate having an active area therein and having a silicon dioxide layer thereon;
• forming a gate stack projecting from the silicon dioxide layer adjacent to said active area and having a sidewall, the gate stack having opposing first and second lateral sides;
• forming an insulative spacer on each of the opposing first and second lateral sides of said gate stack;
• forming a cover disposed continuously upon the gate stack and each said insulative spacer, wherein the opposing first and second lateral sides of the gate stack, the cover, and each said spacer form, adjacent to each of the first and second lateral sides of the structure, a plurality of closed voids.

A method of forming a gate structure, the method comprising:

• forming a gate stack projecting from a gate oxide layer upon a semiconductor substrate, said gate stack having first and second opposing lateral sides;
• forming a first spacer and a second spacer respectively attached to said first and second opposing lateral sides of said gate stack, respectively, by first and second portions of a layer of primary material;
• and
• forming a cover layer extending continuously upon the gate stack, the first spacer, the second spacer, and the gate oxide layer so as to define:
• a first closed and ambient gas filled void located between the gate oxide and the first spacer;
• a second closed and ambient gas filled void located between the gate oxide and the second spacer;
• a third closed and ambient gas filled void located between the gate stack and the first spacer;
• and
• a fourth closed void situated between the gate stack and the second spacer.

A method of forming a gate structure, the method comprising:

• forming a gate stack projecting from a gate oxide layer upon a semiconductor substrate, said gate stack having first and second opposing lateral sides and a top surface therebetween;
• forming a first spacer and a second spacer that are:
• separated from and adjacent to, respectively, said first and second opposing lateral sides of said gate stack;
• and
• situated upon, respectively, first and second portions of a layer of primary material that is upon the gate oxide;
• forming a cover layer extending continuously upon:
• the first spacer;
• the top surface of the gate stack;
• and
• the second spacer;
• wherein, adjacent to each of the first and second opposing lateral sides of the gate stack, a plurality of closed voids each filled with ambient gas is situated between the gate oxide and the cover layer.

A void formation method comprising:

• providing a structure projecting from a semiconductor substrate, said structure having first and second opposing lateral sidewalls;
• forming a layer of primary material over said structured, said layer of primary material having a top surface remote from said semiconductor substrate;
• forming a layer of secondary material composed of an electrically conductive material over said layer of primary material;
• forming, adjacent to each of the first and second opposing lateral sides of the structure, a plurality of closed voids each situated between the layer of secondary material and one of the first and second opposing lateral sides of said structure by:
• forming a patterned layer of photoresist upon said layer of secondary material to expose said structure and a portion of said layer of primary material extending above the structure;
• forming, adjacent to each of the first and second opposing lateral sides of the structure, a recess having an opening remote from said semiconductor substrate and defined in part by the one of the first and second opposing lateral sides of said structure and said layer of secondary material;
• and
• forming a cover layer composed of a dielectric material over said opening of said recess without filling any of said recesses with said cover layer.

A void formation method comprising:

• providing a structure projecting from a semiconductor substrate, said structure having first and second opposing lateral sides;
• forming a layer of primary material over said structure having a top surface remote from said semiconductor substrate;
• forming a layer of secondary material over said layer of primary material;
• forming, adjacent to each of the first and second opposing lateral sides of the structure, a plurality of closed voids each situated between the layer of secondary material and one of the first and second opposing lateral sides of said structure by:
• forming a patterned layer of photoresist upon said layer of secondary material to expose said structure and a portion of said layer of primary material extending above the structure;
• forming, adjacent to each of the first and second opposing lateral sides of the structure, a recess having an opening remote from said semiconductor substrate and defined in part by one of the first and second opposing lateral sides of said structure and said layer of secondary material;
• and
• forming a cover layer, composed of a material selected from the group consisting of silicon nitride, silicon dioxide, and polysilicon, over said opening of each said recess without filling and of said recesses with said cover layer.

A method of making an electrically insulated structure, the method comprising:

• providing an electrically conductive structure projecting from substrate and having two opposing sides;
• forming a plurality of dielectric structures each projecting from one of the two opposing sides of the electrically conductive structure;
• and
• forming a dielectric layer over the electrically conductive structure, the plurality of dielectric structures, and the substrate such that a plurality of separate closed voids are formed between the electrically conductive structure and each said dielectric structure.