Process for making a silicon-on-insulator ledge by implanting ions from silicon source

A process comprising:

• patterning a substrate, wherein the substrate includes a protective layer;
• first etching a recess in the substrate to a recess first bottom;
• growing a dielectric film upon exposed semiconductive material of the substrate;
• second etching in the recess to a recess second bottom;
• forming a deep implantation region in the recess second bottom;
• and
• third etching a lateral cavity at the recess second bottom, wherein the third etching is selective to the deep implantation region wherein forming a deep implantation region at the level of the recess second bottom is carried out before first etching.

A process comprising:

• patterning a substrate, wherein the substrate includes a protective layer;
• first etching a recess in the substrate to a recess first bottom;
• growing a dielectric film upon exposed semiconductive material of the substrate;
• second etching in the recess to a recess second bottom;
• forming a deep implantation region in the recess second bottom;
• third etching a lateral cavity at the recess second bottom, wherein the third etching is selective to the deer implantation region;
• forming a shallow implantation region in the substrate at a level of the recess first bottom;
• and either preceded or followed by
• forming the deep implantation region in the substrate at a level of the recess second bottom.

A process of forming an active area, comprising:

• patterning a substrate, wherein the substrate includes a protective layer;
• first etching a recess in the substrate to a recess first bottom;
• growing a dielectric film upon exposed semiconductive material of the substrate;
• second etching in the recess to a recess second bottom;
• from a silicon source, forming a deep implantation region at a level of the recess second bottom;
• and
• third etching a lateral cavity at the recess second bottom, wherein the third etching is selective to the deep implantation region, and wherein the third etching partially isolates an active area in the substrate at a level above the recess first bottom.

A process comprising:

• forming a pad oxide layer over a substrate;
• forming a protective layer over the pad oxide layer;
• first etching a recess in the substrate to a recess first bottom and a recess first wall;
• growing a nitride dielectric film upon exposed semiconductive material of the substrate;
• second etching in the recess to a recess second bottom and a recess second wall, and that is selective to the nitride dielectric film disposed on the recess first wall, wherein the recess second wall is substantially coplanar to the nitride dielectric film;
• forming deep implantation region at a level of the recess second bottom, wherein forming a deep implantation region at a level of the recess second bottom includes implanting material that is substantially identical to the material of the substrate;
• and
• third etching a lateral cavity at the recess second bottom, wherein the third etching is an isotropic etch selected from tetramethyl ammonium hydroxide and potassium hydroxide, and wherein the third etching is selective to the deep implantation region and the nitride film.

A process comprising:

• forming a pad oxide layer over a substrate;
• forming a protective layer over the pad oxide layer;
• first etching a recess in the substrate to a recess first bottom and a recess first wall;
• growing a nitride dielectric film upon exposed semiconductive material of the substrate;
• second etching in the recess to a recess second bottom and a recess second wall, and that is selective to the nitride dielectric film disposed on the recess first wall, wherein the recess second wall is substantially coplanar to the nitride dielectric film;
• forming a deep implantation region at a level of the recess second bottom;
• and
• third etching a lateral cavity at the recess second bottom, wherein the third etching is an isotropic etch selected from tetramethyl ammonium hydroxide and potassium hydroxide, and wherein the third etching is selective to the deep implantation region and the nitride film;
• annealing the substrate under conditions to repair semiconductive material of the deep implantation region;
• forming an oxidation in the lateral cavity;
• covering the lateral cavity with a spacer under conditions to leave at least a portion of the lateral cavity void;
• filling the recess;
• and
• planarizing the substrate to expose the protective layer.

A process of forming an active area, comprising:

• forming a deep implantation region in a semiconductive substrate below a top surface of the substrate, wherein the deep implantation region is amorphous;
• isotropically etching the substrate at the deep implantation region under conditions that are selective to the deep implantation region, and that form a lateral cavity that partially isolates an active area in the semiconductive substrate between the lateral cavity and the top surface;
• and
• forming a shallow implantation region in the substrate that is above the deep implantation region.

A process of forming an active area, comprising:

• forming a deep implantation region in a semiconductive substrate below a top surface of the substrate, wherein the deep implantation region is amorphous;
• isotropically etching the substrate at the deep implantation region under conditions that are selective to the deep implantation region, and that form a lateral cavity that partially isolates an active area in the semiconductive substrate between the lateral cavity and the top surface;
• forming a shallow implantation region above the deep implantation region;
• first etching a recess in the substrate to a recess first bottom and a recess first wall and that removes a portion of the shallow implantation region;
• growing a dielectric film upon exposed semiconductive material of the substrate;
• and
• second etching in the recess to a recess second bottom, the deep implantation region, and that leaves a portion of the dielectric film on the recess first wall.

A process of forming a storage device, comprising:

• patterning a substrate, wherein the substrate includes a protective layer;
• first etching a recess in the substrate to a recess first bottom;
• growing a dielectric film upon exposed semiconductive material of the substrate;
• second etching in the recess to a recess second bottom;
• from a silicon source, forming a deep implantation region in the recess second bottom;
• third etching a lateral cavity at the recess second bottom, wherein the third etching is selective to the deep implantation region, and wherein the third etching partially isolates an active area above the lateral cavity;
• optionally oxidizing the lateral cavity;
• removing the dielectric film;
• forming a spacer that covers the lateral cavity;
• filling the recess;
• and
• forming a storage device above the active area.

A method of assembling an electrical device comprising:

• from a silicon source, forming a deep implantation region in a semiconductive substrate below a top surface of the substrate, wherein the deep implantation region is amorphous;
• isotropically etching the substrate at the deep implantation region under conditions that are selective to the deep implantation region, and that form a lateral cavity that partially isolates an active area in the semiconductive substrate between the lateral cavity and the top surface;
• and
• forming at least one junction in the active area.