Method for forming a planarization structure
AssigneeSTMicroelectronics (Crolles 2) SAS
InventorLoic Gaben
Life of this patent
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Abstract
A planarization structure is formed with a planar upper face enclosing a relief projecting from a planar substrate. The process used deposits a layer of a first material over the reliefs and then forms a layer of a second material with a planar upper face. This second material may be etched selectively with respect to the first material. The second layer is processed so that the protuberances of the first material are uncovered. A planarizing is then performed on the first material as far as the layer of the second material by selective chemical-mechanical polishing with respect to the second material.
Claims20
A method for forming a planarization structure having a planar upper face enclosing reliefs projecting from a planar upper face of a substrate, comprising the following steps:
- a) depositing a layer of a first material over the reliefs and substrate to be in physical contact with tops of the reliefs and areas of the substrate between the reliefs;
- b) forming a layer of a second material which can be etched selectively with respect to the first material, said layer of the second material having a planar upper face;
- c) selectively isotropically etching only a part of a thickness of the layer of the second material until protuberances of the first material over said reliefs are uncovered;
- and
- d) planarizing the first material as far as the layer of the second material by selective chemical-mechanical polishing with respect to the second material.
A method for forming a planarization structure having a planar upper face enclosing reliefs projecting from a planar upper face of a substrate, comprising the following steps:
- a) depositing a layer of a first material over the reliefs and substrate to be in physical contact with apices of the reliefs and areas of the substrate between the reliefs;
- b) forming a layer of a second material different from the first material, said layer of the second material having a planar upper face at a level above the apices of the reliefs but below apices of protuberances of the first material over said reliefs;
- c) depositing a further layer of the first material over the layer of the second material and said protuberances;
- and
- d) planarizing the protuberances of the first material at least to the planar upper face of the second material.
Dependencies are inferred from the claim text.