Method of manufacturing a semiconductor device
AssigneeNEC Corporation
InventorTatsuro Inoue
Life of this patent
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Abstract
In a method of manufacturing a semiconductor device, a first sacrifice oxide film is formed on a substrate. Next, a second sacrifice oxide film is formed on the substrate by etching the first sacrifice oxide film to a predetermined depth in a first etching process. Herein, the second sacrifice oxide film is thinner than the first sacrifice oxide film. Subsequently, the second sacrifice oxide film is completely removed from a surface of the substrate in a second etching process so as to expose the surface of the substrate. Finally, an oxide film is formed on the exposed surface of the substrate.
Claims15
A method of manufacturing a semiconductor device having a substrate, comprising the steps of:
- forming a first sacrifice oxide film on said substrate;
- forming a second sacrifice oxide film on said substrate by etching said first sacrifice oxide film to a predetermined depth in a first etching process, said second sacrifice oxide film being thinner than said first sacrifice oxide film;
- completely removing said second sacrifice oxide film from a surface of said substrate in a second etching process so as to expose the surface of said substrate;
- and
- forming an oxide film on the exposed surface of said substrate.
A method of manufacturing a semiconductor memory device which has a memory cell region and a peripheral region adjacent to said memory cell region on a substrate, comprising the steps of:
- forming sacrifice oxide films on said memory cell region and said peripheral region, respectively;
- forming a resist mask on the sacrifice oxide film on the peripheral region;
- etching the sacrifice oxide film on said memory cell region to a predetermined depth by the use of said resist mask so as to remain a thin film on said active region;
- removing the resist mask on the peripheral region in order to remain the sacrifice oxide film on the peripheral region;
- completely removing the thin film on the memory cell region so as to expose a surface of the substrate;
- and
- forming a tunnel oxide film on the exposed surface of the substrate.
A method of manufacturing a semiconductor memory device which has an internal region and an external region adjacent to said internal region on a substrate, comprising the steps of:
- forming first oxide films on said internal region and said external region, respectively;
- forming a first gate electrode and a resist mask on the first oxide film on said external region;
- etching the first oxide film on said internal region to a predetermined depth by the use of said resist mask so as to remain a thin film on said internal region;
- removing the resist mask on said external region;
- completely removing the thin film on the internal region in order to expose a surface of the substrate;
- forming a second gate oxide film on the exposed surface of the substrate on the internal region;
- and
- forming a second gate electrode on said second gate oxide film.
Dependencies are inferred from the claim text.