The invention relates to a production method for an MEMS
air mass flow meter with a back cavity structure. The method comprises the steps of forming composite
dielectric film on a surface of a siliconwafer; preparing a
metal thermistor thin film pattern through utilization of an exfoliation method; growing a
protection layer on the surface of
metal thermistor thin film; carrying out high temperature annealing; removing the
protection layer on a bonding pad and exposing a
metal layer of the bonding pad; carrying out photoetching on the back of the
silicon wafer, and carrying out
dry etching, thereby forming the back cavity structure; and
cutting and splitting chips, thereby finishing
processing the chips. According to the method, after photoetching, development and
plasma glue
extrusion steps are carried out, a deionized
water washing step is imported, so residual impurities on the surface of the
wafer can be effectively removed after the
plasma washing is carried out, the adhesion ofthe metal film on the
dielectric film is ensured, and the metal film is prevented from falling off. According to the method, through utilization of a back
dry etching technology, a back cavity is realized, and a corrosive effect of corrosive liquid in wet
etching for a front pattern structure can be effectively prevented.