Method for fabrication of a semiconductor device
AssigneeVLSI Technology, Inc.
InventorsXi-Wei Lin, Henry Lee, Ian R. Harvey
Life of this patent
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Abstract
A method for forming a semiconductor structure on an active area mesa with minimal loss of field oxide deposited in isolation trenches adjacent the mesa. The trench insulating material is protected by an etch barrier layer having at least a partial resistance to etchants used in further device processing steps. The barrier layer may also be deposited over the surface of the substrate to protect it from damage during device processing. The barrier layer may be removed by an etchant having a selectivity for the barrier layer over that of the surrounding device elements. Final processing of the device may be completed once the barrier layer is removed.
Claims5
A method for forming a semiconductor structure, comprising:
- defining isolation trenches in a semiconductor substrate to define at least one active area mesa;
- filling the trenches with an insulating material;
- forming a gate electrode on said active area mesa;
- depositing an etch barrier layer over the insulating material;
- depositing a spacer material;
- etching the spacer material with a first etchant having a selectivity for etching the spacer material at a higher rate than the etch barrier layer, thereby forming spacers adjacent the gate electrode;
- and
- etching the etch barrier layer with a second etchant having a selectivity for etching the etch barrier layer at a greater rate than the spacers.
A method of forming a semiconductor structure, comprising:
- etching a semiconductor substrate to form trenches between active area mesas, the active area mesas having a surface;
- depositing an insulating material in the trenches;
- planarizing the surface of the insulating material and the surface of the semiconductor substrate;
- forming a gate electrode on an active area mesa, and oxidizing the exposed surfaces of the gate electrode and substrate, wherein the etch barrier layer is deposited over the oxidized surfaces and the insulating material;
- and
- depositing an etch barrier layer over at least the insulating material, the etch barrier layer protecting the insulating material during further device processing.
Dependencies are inferred from the claim text.