Method for determination of resistivity of N-type silicon epitaxial layer
AssigneeShin-Etsu Handotai Co., Ltd.
InventorsKiyoshi Mitani, Shigenori Saisu
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Abstract
A method for the determination of the resistivity of an n-type epitaxial layer formed on a silicon substrate is disclosed. This invention resides in either directly determining the true resistivity of a sample by preparing this sample without a natural oxide film which is responsible for the change with the passage of time or indirectly determining the true resistivity of a sample by intentionally forming on the sample a natural oxide film so stable to defy the change with the passage of time and measuring resistivity of this sample.
Claims7
A method for determination of resistivity of an n-type epitaxial layer formed on a silicon substrate characterized by;
- subjecting the surface of said n-type epitaxial layer to hydrogen termination;
- keeping said n-type epitaxial layer in a hydrogen terminal state;
- and
- four point probe method measuring sheet resistance of said surface;
- and
- wherein determination of said resistivity of said n-type silicon epitaxial layer is accomplished by the steps of;
- growing said n-type epitaxial layer on a silicon substrate;
- displacing an inner gas of an epitaxial growth reactor with hydrogen gas and cooling said silicon substrate to a temperature below 400.degree. C. thereby effecting said hydrogen termination of the surface of said n-type epitaxial layer;
- subsequently displacing said hydrogen gas in said epitaxial growth reactor with an inert gas;
- simultaneously cooling said silicon substrate to normal room temperature;
- removing said cooled silicon substrate from said epitaxial growth reactor;
- and
- four point probe method measuring sheet resistance of said n-type epitaxial layer.
A method for determination of resistivity of an n-type epitaxial layer formed on a silicon substrate characterized by the steps of:
- finding changes of resistivity with passage of time with respect to n-type epitaxial layers possessing varying magnitudes of resistivity,
- treating the surface of an n-type epitaxial layer on a silicon substrate subjected to determination of resistivity with a chemical solution thereby forming a stable oxide film on said surface,
- rinsing the treated surface of said n-type epitaxial layer,
- drying the wet n-type epitaxial layer,
- four point probe method measuring sheet resistance thereby obtaining resistivity after a change with passage of time;
- and obtaining true resistivity based on magnitude of resistance in combination with a ratio of change in resistivity with passage of time.
Dependencies are inferred from the claim text.