Method for manufacturing electronic component

1. A method for manufacturing an electronic component, in which a substrate including at least first and second layers is etched to form a structure, comprising:

a first etching step of etching the substrate from the first layer side;

a mask formation step of forming a mask on the second layer side of the substrate; and

a second etching step of etching, using the mask, the substrate from the second layer side,

wherein at the first etching step, a portion of the structure formed of the first layer is formed as a pre-structure having a larger shape than a final shape,

at the mask formation step, a mask corresponding to the final shape is formed on the second layer side of the substrate in the pre-structure as viewed in a thickness direction of the substrate, and

at the second etching step, the second layer and the pre-structure are, using the mask corresponding to the final shape, etched to form the final shape.

2. The method of claim 1 , wherein

the structure includes a first structure formed of the first and second layers,

at the first etching step, a portion of the first structure formed of the first layer is formed as a first pre-structure having a larger shape than a final shape,

at the mask formation step, a first mask corresponding to the final shape of the first structure is formed on the second layer side of the substrate in the first pre-structure as viewed in the thickness direction of the substrate, and

at the second etching step, the second layer and the first pre-structure are, using the first mask, etched to form the final shape of the first structure.

3. The method of claim 2 , wherein

the structure includes a second structure not including the first layer and formed of the second layer,

at the first etching step, a portion of the first layer facing the second structure is etched to form a recess at the first layer,

at the mask formation step, a second mask corresponding to a final shape of the second structure is formed on the second layer side of the substrate in the recess as viewed in the thickness direction of the substrate, and

at the second etching step, the second layer is, using the second mask, etched to form the final shape of the second structure.

4. The method of claim 3 , wherein

at the mask formation step, the first and second masks are formed using a photomask defining a positional relationship between the first and second masks.

5. The method of claim 2 , wherein

the electronic component includes a base, a movable portion configured to move on the base, and a connection portion configured to elastically connect between the movable portion and the base, and

the connection portion includes the first structure.

6. The method of claim 1 , wherein

the structure includes a third structure not including the second layer and formed of the first layer,

at the first etching step, a portion of the third structure formed of the first layer is formed as a third pre-structure having a larger shape than a final shape,

at the mask formation step, a third mask corresponding to the final shape of the third structure is formed on the second layer side of the substrate in the third pre-structure as viewed in the thickness direction of the substrate, and

at the second etching step, the second layer and the third pre-structure are, using the third mask, etched to form the final shape of the third structure.

7. The method of claim 6 , wherein

the substrate includes a third layer provided between the first and second layers, and at the second etching step,

the second and third layers are, using the third mask, etched such that a portion of the third layer on the third pre-structure is formed into a shape corresponding to the final shape of the third structure, and then,

the third mask is detached, and the third pre-structure is, using a portion of the third layer remaining on the third pre-structure, etched to form the final shape of the third structure.

8. The method of claim 7 , wherein

the structure includes a first structure formed of the first and second layers,

at the first etching step, a portion of the first structure formed of the first layer is formed as a first pre-structure having a larger shape than a final shape,

at the mask formation step, a first mask corresponding to the final shape of the first structure is formed on the second layer side of the substrate in the first pre-structure as viewed in the thickness direction of the substrate,

the first mask includes a lower mask formed on the second layer, and an upper mask formed on the lower mask,

at the second etching step,

the second and third layers are, using the upper mask of the first mask and the third mask, etched such that a portion of the first structure formed of the second and third layers is formed into a final shape thereof and that a portion of the second and third layers on the third pre-structure is formed into a shape corresponding to the final shape of the third structure, and then,

the upper mask of the first mask and the third mask are detached, and a portion of the second layer on the third pre-structure and the third pre-structure are, using the lower mask of the first mask and a portion of the third layer remaining on the third structure, etched to form the final shape of the first structure and the final shape of the third structure.

9. The method of claim 8 , wherein

at the mask formation step, the first and third masks are formed using a photomask defining a positional relationship between the first and third masks.

10. The method of claim 6 , wherein

the electronic component includes a first comb electrode with a plurality of electrode fingers, and a second comb electrode with a plurality of electrode fingers, the electrode fingers of the first and second comb electrodes being alternately arranged,

the first comb electrode includes a second structure not including the first layer and formed of the second layer, and

the second comb electrode includes the third structure.