In situ growth of oxide and silicon layers
AssigneeASM America, Inc.
InventorsArmand Ferro, Ivo Raaijmakers, Derrick Foster
Life of this patent
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Abstract
A single-wafer, chemical vapor deposition reactor is provided with hydrogen and silicon source gas suitable for epitaxial silicon deposition, as well as a safe mixture of oxygen in a non-reactive gas. Methods are provided for forming oxide and silicon layers within the sane chamber. In particular, a sacrificial oxidation is performed, followed by a hydrogen bake to sublime the oxide and leave a clean substrate. Epitaxial deposition can follow in situ. A protective oxide can also be formed over the epitaxial layer within the same chamber, preventing contamination of the critical epitaxial layer. Alternatively, the oxide layer can serve as the gate dielectric, and a polysilicon gate layer can be formed in situ over the oxide.
Claims15
A method of processing semiconductor substrates, comprising forming an epitaxial layer containing silicon by thermal chemical vapor deposition in a single substrate, cold wall chemical vapor deposition chamber and forming an oxide layer directly over the epitaxial layer within the chamber by exposing the epitaxial layer to an oxidant source gas from a container having a level of oxygen that is non-explosive in the presence of any amount of hydrogen under operating conditions of the method, wherein all reactants are flowed substantially horizontally through the chamber to a substrate, wherein a horizontal flow is substantially unidirectional.
A method of fabricating integrated circuits on a semiconductor substrate, the method comprising:
- loading the substrate into a chemical vapor deposition processing chamber specifically designed to process one substrate at a time;
- depositing an epitaxial silicon layer by thermal chemical vapor deposition on at least part of the substrate within the chamber;
- exposing the epitaxial layer to an oxidant source gas from an oxidant source containing inert gas and less than about 5% O2 gas by volume to grow a thermal oxide layer over the epitaxial silicon layer within the chamber to form a transistor gate oxide while radiantly heating the substrate through radiation-transparent walls of the chamber;
- and
- depositing a polysilicon gate electrode layer over the thermal oxide layer within the chamber.
A method of processing semiconductor substrates, comprising:
- forming an epitaxial layer containing silicon by thermal chemical vapor deposition in a single substrate, cold wall chemical vapor deposition chamber,
- forming an oxide layer directly over the epitaxial layer within the chamber by exposing the epitaxial layer to an oxidant source gas;
- and
- cleaning an oxidized residue of a silane in the chamber by introducing an etchant containing fluorine into the chamber.
Dependencies are inferred from the claim text.