Wafer fabrication

A method of producing a radical species which can carry out a chemical reaction adjacent the surface of a substrate, comprising:

• mounting a substrate in a sealed chamber at a target position therein with a surface region of the substrate oriented in a selected direction;
• introducing a first vaporous chemical to the chamber with the first vaporous chemical flowing toward the surface region of the substrate;
• generating a first radical species from the first vaporous chemical at a position in the chamber intermediate the place of introduction of the vaporous chemical and the surface region of the substrate without producing significant amounts of ionized species with the first radical species flowing toward the surface region of the substrate;
• and
• evacuating the chamber at a rate sufficient for maintaining a pressure within the chamber of 10.sup.-7 Torr or below during the introduction of the first vaporous chemical.

A method of cleaning a surface of a substrate to remove one or more solids from a surface thereof, comprising:

• generating a neutral activated chemical species without generating a substantial quantity of ionized activated species at a pressure of no more than about 0.1 Torr within a sealed evacuatable chamber;
• flowing the neutral activated chemical species against the surface, the neutral activated chemical species being selected to react with and convert at least one of the solids to a vaporous species;
• and
• evacuating the chamber at an evacuatiion rate sufficient to maintain the pressure therein at .ltoreq.10.sup.-7 Torr during the flowing until a desired quantity of the solid has been removed by vaporization.

A method of etching into a surface of a substrate, comprising:

• generating a neutral activated chemical species without generating a substantial quantity of ionized activated species at a pressure of no more than about 0.1 Torr within a sealed evacuatable chamber;
• flowing the neutral activated chemical species against the surface, the neutral activated chemical species being selected to react with and convert the surface to a vaporous species until a desired quantity of the surface has been removed by vaporization;
• and
• evacuating the chamber at an evacuation rate sufficient to maintain the pressure therein at .ltoreq.10.sup.-7 Torr during the flowing until a desired quantity of the surface has been removed by vaporization.

A method of depositing a chemical species adjacent a surface region of a substrate, comprising:

• mounting a substrate in a sealed chamber at a target position therein with the surface region of the substrate oriented in a selected direction;
• introducing a first vaporous chemical to the chamber with the first vaporous chemical flowing toward the surface region of the substrate;
• generating a first radical species from the first vaporous chemical at a position in the chamber intermediate the place of introduction of the vaporous chemical and the surface region of the substrate without producing significant amounts of ionized species with the first radical species flowing toward the surface region of the substrate;
• evacuating the chamber at a rate sufficient for maintaining a pressure within the chamber of 10.sup.-7 Torr or below during the introduction of the first vaporous chemical;
• introducing a second vaporous chemical to the chamber intermediate the position of generation of the first radical species and the surface region of the substrate with the second vaporous chemical flowing toward the surface region of the substrate, the second vaporous chemical being selected to react with the first radical species such that substantially all of the second vaporous chemical reacts with the first radical species to produce a second radical species flowing toward the surface region of the substrate, the second radical species, on contacting the surface region of the substrate, depositing the chemical species adjacent the surface region of the substrate.