Abstract: Provided is a method including at least the thermal treatment step of thermally treating a SOI substrate having a first silicon layer at a first temperature that the diffusion flow rate of an interstitial silicon atom in a silicon single crystal is higher than the diffusion flow rate of an interstitial oxygen atom and the processing step of processing the SOI substrate after the thermal treatment step to obtain a displacement enlarging mechanism.

Abstract: This piezoelectric element includes a lower electrode formed on a substrate, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the piezoelectric layer. The upper electrode includes a first upper electrode layer made of a metal oxide including an amorphous portion at least at a boundary with the piezoelectric layer and a second upper electrode layer formed on the first upper electrode layer.

Abstract: Provided is a method including at least the thermal treatment step of thermally treating a SOI substrate having a first silicon layer at a first temperature that the diffusion flow rate of an interstitial silicon atom in a silicon single crystal is higher than the diffusion flow rate of an interstitial oxygen atom and the processing step of processing the SOI substrate after the thermal treatment step to obtain a displacement enlarging mechanism.

Abstract: A mirror device includes a frame body, a mirror configured to tilt about a Y-axis with respect to the frame body, a fixed inner comb electrode including a plurality of electrode fingers arranged in the arrangement direction along the Y-axis and provided at the frame body, and a movable inner comb electrode including a plurality of electrode fingers arranged in the arrangement direction and provided at the mirror, the electrodes fingers of the fixed inner comb electrode and the movable inner comb electrode being alternately arranged. The mirror includes a mirror body and an extension extending from the mirror body. Some of the electrode fingers of the movable inner comb electrode are provided at the mirror body, and another electrode fingers of the movable inner comb electrode are provided at the extension.

Abstract: This piezoelectric element includes a lower electrode formed on a substrate, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the piezoelectric layer. The upper electrode includes a first upper electrode layer made of a metal oxide including an amorphous portion at least at a boundary with the piezoelectric layer and a second upper electrode layer formed on the first upper electrode layer.

Abstract: At the first etching step of etching an SOI substrate from a first silicon layer side, a portion of a first structure formed of the first silicon layer is formed as a pre-structure having a larger shape than a final shape. At the mask formation step of forming a final mask on a second silicon layer side of the SOI substrate, a first mask corresponding to the final shape of the first structure is formed in the pre-structure. At the second etching step of etching the SOI substrate from the second silicon layer side, the second silicon layer and the pre-structure are, using the first mask, etched to form the final shape of the first structure.

Abstract: A mirror device includes a frame body, a mirror configured to tilt about a Y-axis with respect to the frame body, a fixed inner comb electrode including a plurality of electrode fingers arranged in the arrangement direction along the Y-axis and provided at the frame body, and a movable inner comb electrode including a plurality of electrode fingers arranged in the arrangement direction and provided at the mirror, the electrodes fingers of the fixed inner comb electrode and the movable inner comb electrode being alternately arranged. The mirror includes a mirror body and an extension extending from the mirror body. Some of the electrode fingers of the movable inner comb electrode are provided at the mirror body, and another electrode fingers of the movable inner comb electrode are provided at the extension.

Abstract: At the first etching step of etching an SOI substrate from a first silicon layer side, a portion of a first structure formed of the first silicon layer is formed as a pre-structure having a larger shape than a final shape. At the mask formation step of forming a final mask on a second silicon layer side of the SOI substrate, a first mask corresponding to the final shape of the first structure is formed in the pre-structure. At the second etching step of etching the SOI substrate from the second silicon layer side, the second silicon layer and the pre-structure are, using the first mask, etched to form the final shape of the first structure.