MICROPHONE MANUFACTURING METHOD
First Claim
1. A microphone manufacturing method comprising the steps of:
- forming an etching protective film on a surface of a semiconductor substrate, and then opening an etching window through said etching protective film;
forming a sacrifice layer in said etching window as well as on an upper face of said etching protective film, with at least one portion thereof being connected to each other;
forming a vibration film above said sacrifice layer;
starting an etching process on said sacrifice layer from a portion that is sandwiched by said vibration film and said etching protective film and located apart from said etching window, by using an etchant to which said etching protective film is resistant, so that said etching window is opened; and
crystal anisotropically etching said semiconductor substrate from said etching window by using said etchant to which said etching protective film is resistant so that a cavity is formed on the surface side of said semiconductor substrate.
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Accused Products
Abstract
A sacrifice layer 36 is exposed through a chemical charging port 31 so that the sacrifice layer 36 and sacrifice layer 35 are etched and removed by an etchant introduced from the chemical charging port 31. Since the surface of an Si substrate 22 is exposed to an etching window 34 corresponding to the removed portion of the sacrifice layer 35, the Si substrate 22 is crystal anisotropically etched below the etching window 34 to form a cavity 23. In contrast, in a space corresponding to the etched and removed portion of the sacrifice layer 36, since the surface of the Si substrate 22 is covered with a protective film 32, the Si substrate 22 is not etched to form a bent hole 26 therein. The cavity can be formed in the semiconductor substrate by an etching process from the surface side. Moreover, a bent hole having a great acoustic resistance can be easily formed.
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Citations
9 Claims
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1. A microphone manufacturing method comprising the steps of:
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forming an etching protective film on a surface of a semiconductor substrate, and then opening an etching window through said etching protective film; forming a sacrifice layer in said etching window as well as on an upper face of said etching protective film, with at least one portion thereof being connected to each other; forming a vibration film above said sacrifice layer; starting an etching process on said sacrifice layer from a portion that is sandwiched by said vibration film and said etching protective film and located apart from said etching window, by using an etchant to which said etching protective film is resistant, so that said etching window is opened; and crystal anisotropically etching said semiconductor substrate from said etching window by using said etchant to which said etching protective film is resistant so that a cavity is formed on the surface side of said semiconductor substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification