Method of trench isolation using spacers to form isolation trenches with protected corners
AssigneeMicron Technology, Inc.
InventorsPierre C. Fazan, Martin C. Roberts, Gurtej S. Sandhu
Life of this patent
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Abstract
A trench for isolating active devices on a semiconductor substrate, formed by creating a trench which has a peripheral edge, and disposing an isolating material in the trench. The isolating material extends over the peripheral edge of the trench, thereby covering at least a portion of the substrate surrounding the trench, and substantially limiting leakage of the active devices disposed on the substrate.
Claims12
A process of forming an isolation structure on a semiconductor substrate, comprising steps of:
- providing a semiconductor substrate;
- forming at least one trench in said semiconductor substrate, said trench having a peripheral edge;
- disposing an electrically insulating material in said trench, said material extending over said peripheral edge of said trench and covering at least a portion of said substrate beyond said trench;
- and
- etching said electrically insulating material including at least a portion thereof extending over said peripheral edge to form said isolation structure with a dome-shaped cap over said trench.
A process of forming an isolation structure for a semiconductor substrate comprising steps of:
- providing a semiconductor substrate within which to form said isolation structure;
- forming a groove in said semiconductor substrate;
- conformally layering said substrate with a first layer, said first layer lining said groove;
- providing a second layer over said substrate, said second layer patterned with an opening over said groove;
- disposing electrically insulating material over said substrate masked by said second layer;
- planarizing said electrically insulating material to expose said second layer;
- after said step of planarizing, removing said second layer and leaving a portion of said electrically insulating material protruding beyond a surface plane of said substrate;
- conformally layering a third layer over said substrate and said protruding portion of said electrically insulating material;
- selectively removing portions of said third layer to define spacers adjacent sidewalls of said protruding portion of said electrically insulating material, said spacers including a portion extending over said substrate outside a peripheral edge of said groove;
- and
- etching said electrically insulating material and said spacers to from said isolation structure with a rounded cap over said groove.
A process of forming an isolation region for a semiconductor substrate comprising steps of:
- forming a groove in a semiconductor substrate;
- providing a mask layer over said substrate, said mask layer having an opening over said groove;
- disposing electrically insulating material conformably over said substrate masked by said mask layer;
- removing said mask layer while leaving a portion of said electrically insulating material in said groove and protruding away from, beyond a surface plane of, said substrate;
- forming spacers adjacent sidewalls of said protruding portion of said electrically insulating material;
- and
- etching said electrically insulating material and said spacers to provide said electrically insulating material and said spacers with a dome-shaped cap over said groove.
Dependencies are inferred from the claim text.