A process for preparing the air-tight MEMS device includes such steps as Si-Si bonding between the silicon wafer containing MEMS chip and the silicon wafer containing cavity pattern to form the lower cavity of MEMS device, thinning the back of the Si wafer containing cavity pattern, etching the back of the Si wafer containing MEMS chip, and anode bonding between Si glass and the back of the Si wafer containing MEMS chip to form the upper cavity of MEMS device. The resultant device has the Si/Si/glass structure. |