Method of forming a roughened surface capacitor with two etching steps
First Claim
1. A method of manufacturing a semiconductor device having a capacitor constituted by a lower electrode, an upper electrode, and a dielectric film arranged between said lower and upper electrodes, wherein said lower electrode is formed by comprising:
- the step of forming a polysilicon film containing a Group V element as an impurity;
the first etching step of forming an uneven portion on a surface of said polysilicon film; and
the second etching step of forming an uneven portion on the surface of said polysilicon film, and the second etching step having an etch rate whose impurity concentration dependency is different from an impurity concentration dependency of an etch rate of the first etching step,thereby forming the uneven portion on the surface of said polysilicon film.
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Abstract
In a method of manufacturing a semiconductor device having a capacitor constituted by a lower electrode, an upper electrode, and a dielectric film arranged between the lower and upper electrodes, a polysilicon film containing a Group V element as an impurity is formed. The first etching step of forming an uneven portion on a surface of the polysilicon film is performed. The second etching step of forming an uneven portion on the surface of the polysilicon film is performed. The second etching step has an etch rate whose impurity concentration dependency is different from an impurity concentration dependency of an etch rate of the first etching step, thereby forming the uneven portion on the surface of the polysilicon film.
103 Citations
9 Claims
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1. A method of manufacturing a semiconductor device having a capacitor constituted by a lower electrode, an upper electrode, and a dielectric film arranged between said lower and upper electrodes, wherein said lower electrode is formed by comprising:
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the step of forming a polysilicon film containing a Group V element as an impurity; the first etching step of forming an uneven portion on a surface of said polysilicon film; and the second etching step of forming an uneven portion on the surface of said polysilicon film, and the second etching step having an etch rate whose impurity concentration dependency is different from an impurity concentration dependency of an etch rate of the first etching step, thereby forming the uneven portion on the surface of said polysilicon film. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification