Method of making integrated circuits
AssigneeGeneral Electric Company
InventorDale M. Brown
Life of this patent
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Abstract
A method of forming in a substrate of monocrystalline silicon semiconductor material having a major surface, a plurality of islands of silicon each including an active region of the substrate adjacent the major surface and surrounded by a body of silicon dioxide separating the islands from the substrate is described.
Claims19
A method of forming, in a substrate of monocrystalline silicon semiconductor material having a major surface, an island of silicon including an active region of said substrate adjacent said major surface and surrounded by a body of silicon dioxide separating said island from said substrate comprising:
- providing said substrate of monocrystalline silicon semiconductor material having said major surface and including said active region of said substrate adjacent said major surface thereof,
- providing an oxidation-resistant and etch-resistant masking layer overlying and in registry with said active region,
- patterning said substrate using said masking layer to form a mesa the top of which is said active region,
- forming a film of an oxidation-resistant material on the sides of said mesa,
- heating said substrate in an oxidizing atmosphere to a temperature and for a time to cause silicon dioxide to be grown in a direction generally perpendicular to said major surface of said substrate and laterally underneath said mesa from the sides thereof to form a first region of silicon dioxide surrounding said mesa and a second region of silicon dioxide underneath said mesa, whereby said mesa is converted into an island surrounded by said first region of silicon dioxide and separated from said substrate by said second region of silicon dioxide,
- removing said masking layer to expose said major surface of said island.
A method of forming in a substrate of monocrystalline silicon semiconductor material having a major surface, a plurality of islands of silicon each including an active region of said substrate adjacent said major surface and surrounded by a body of silicon dioxide separating said islands from said substrate comprising:
- providing said substrate of monocrystalline silicon semiconductor material having said major surface and including a plurality of active regions of said substrate each adjacent said major surface thereof,
- providing an oxidation-resistant and etch-resistant masking layer including a plurality of retained portions each overlying and in registry with a respective one of said active regions,
- patterning said substrate using said masking layer to form a plurality of mesas, the top of each of which is a respective active region,
- forming a film of an oxidation resistant material on the sides of each of said mesas,
- heating said substrate in an oxidizing atmosphere to a temperature and for a time to cause silicon dioxide to be grown in a direction generally perpendicular to the major surface of said substrate and laterally underneath each of said mesas from the sides thereof to form a first region of silicon dioxide surrounding each of said mesas and a second region of silicon dioxide underneath each of said mesas, whereby each of said mesas is converted into a respective island surrounded by a respective first region of silicon dioxide and separated from said substrate by a respective second region of silicon dioxide,
- removing said masking layer to expose the major surface of each of said islands.
Dependencies are inferred from the claim text.