MEMS device manufacturing method, MEMS device, and shutter apparatus using the same

A MEMS device manufacturing method comprising:

• at least
• a substrate preparation step of preparing a substrate having a silicon layer whose precipitated oxide density is equal to or less than 5×105/cm2 and whose stacking fault density is equal to or greater than 1×104/cm2;
• and
• a thermal treatment step of thermally treating the substrate at a first temperature that a diffusion flow rate of an interstitial silicon atom in a silicon single crystal is higher than a diffusion flow rate of an interstitial oxygen atom, wherein
• at a step performed after the thermal treatment step, a temperature applied to the silicon layer is equal to or lower than a second temperature that the diffusion flow rate of the interstitial oxygen atom in the silicon single crystal is higher than the diffusion flow rate of the interstitial silicon atom and precipitated oxide contained in the silicon layer does not substantially grow,
• the first temperature is higher than 1000° C. and the second temperature is lower than 1000° C., and
• the method further comprises a processing step of processing the substrate after the thermal treatment step to obtain a MEMS device.