Ultra-low-pressure pressure core with stress buffer grooves and preparation method of ultra-low-pressure pressure core

The invention relates to the technical field of pressure cores, and particularly discloses an ultra-low pressure core with stress buffer slots and a preparation method thereof, the ultra-low pressure core comprises a core main body and a substrate connected to the bottom of the core main body; the core main body comprises a silicon wafer supporting substrate and a customized SOI wafer, the customized SOI wafer is provided with a cavity, the customized SOI wafer is provided with a sensitive film suspended on the cavity, and the sensitive film is provided with a four-petal beam film structure which is formed by etching and has a concave edge; the edge of the four-petal beam film structure is provided with a piezoresistive area, and the side of the sensitive film is provided with a lead area. Air holes are formed in the middle of the silicon wafer supporting substrate, and buffer grooves are formed in the bottom of the silicon wafer supporting substrate; according to the invention, the design of the four-petal b