Flat trench insulation structure production used in electronic devices comprises forming oxide intermediate layer, first hard material layer, etch stop layer and second hard material layer on substrate and further treating

摘要

Production of a flat trench insulation structure comprises preparing a substrate (200); forming an oxide intermediate layer (202), a first hard material layer (204), an etch stop layer (206) and a second hard material layer (208) on the substrate; patterning the second hard material layer, the etch stop layer, the first material layer and the oxide intermediate layer to form a trench in the substrate; simultaneously carrying out a relief process on the first hard material layer and removing the second hard material layer; depositing an insulating material in the trench and over the etch stop layer to form an insulating layer; removing the insulating layer and the etch stop layer above the first hard material layer; and removing the first hard material and the oxide intermediate layer. Preferred Features: The hard material layers are made from silicon nitride. The relief process involves using hydrofluoric acid and ethylene glycol.