Method of producing semiconductor element and nonvolatile semiconductor memory produced by this method
AssigneeOki Electric Industry Co., Ltd.
InventorToshio Nagata
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Abstract
As the first method, provided is using Tetraethyl Orthosilicate Si(OC2H5)4 at the process temperature of 650° C.±5° C. as film forming material, to decrease crystal defects occurring during deposition. As the second method, provided is annealing in sparse oxygen gas atmosphere after deposition, to mend crystal defects occurred during deposition. As the third method, provided is keeping initial temperature of CVD device in the temperature (about 400° C.) in which natural oxidation of deposition starting surface is prevented and production circumstance of semiconductor element is not deteriorated, then, heating up to CVD temperature (about 750° C. or about 650° C.), to deposit oxide.
Claims20
A method of producing a semiconductor element comprising:
- a process of forming the first oxide film on a semiconductor substrate, a process of forming a semiconductor film and a oxidation stopping film on the first oxide film,
- a process of forming an opening by patterning the oxidation stopping film,
- a process of forming an insulating local oxide film by local oxidation of the surface of the semiconductor film exposed through the opening,
- a process of removing the oxidation stopping film,
- a process of forming a floating gate with the semiconductor film remained under the local oxide film by selective etching of the semiconductor film masked with the local oxide film,
- a process of cleaning the semiconductor substrate, and
- a process of forming the second oxide film covering the floating gate by low pressured chemical vapor deposition with tetra-ethyl ortho-silicate as a material of film forming;
- wherein
- the film forming condition in the process of forming the second oxide film is that the temperature range is 650° C.±10° C. where the uniformity of the surface of the semiconductor film is kept and a thin film less than 200 Å is formed in a stable condition.
A method of producing a semiconductor element comprising:
- a process of forming the first oxide film on a semiconductor substrate,
- a process of forming a semiconductor film and a oxidation stopping film on the first oxide film,
- a process of forming an opening by patterning the oxidation stopping film,
- a process of forming an insulating local oxide film by local oxidation of the surface of the semiconductor film exposed through the opening,
- a process of removing the oxidation stopping film,
- a process of forming a floating gate with the semiconductor film remained under the local oxide film by selective etching of the semiconductor film masked with the local oxide film,
- a process of cleaning the semiconductor substrate, and
- a process of forming the second oxide film covering the floating gate by low pressured chemical vapor deposition, and
- a process of annealing the second oxide film in a sparse oxygen atmosphere.
A method of producing a semiconductor element comprising:
- a process of forming the first oxide film on a semiconductor substrate,
- a process of forming a semiconductor film and a oxidation stopping film on the first oxide film,
- a process of forming an opening by patterning the oxidation stopping film,
- a process of forming an insulating local oxide film by local oxidation of the surface of the semiconductor film exposed through the opening,
- a process of removing the oxidation stopping film,
- a process of forming a floating gate with the semiconductor film remained under the local oxide film by selective etching of the semiconductor film masked with the local oxide film,
- a process of cleaning the semiconductor substrate, and
- a process of transferring the silicon substrate with the floating gate to a chemical vapor deposition device where the initial temperature is kept in the range where the surface of the floating gate is able to be restrained and the production circumstance is not ruined,
- a process of heating up the chemical vapor deposition device from the initial temperature to the chemical vapor deposition temperature, and
- a process of forming the second oxide film covering the floating gate by low pressured chemical vapor deposition.
Dependencies are inferred from the claim text.