The invention provides a preparation method of a thick
silicon backplane for an MEMS
differential pressure chip. The preparation method comprises the following steps: carrying out wet
etching on a through hole of a single-sided polished
silicon wafer and a double-sided polished
silicon wafer, temporarily bonding with
quartz glass, and removing a
mask on a single-side polished surface; the single-face polished silicon
wafer and the double-face polished silicon wafer are subjected to de-bonding, cleaning, activation and silicon-silicon bonding with the
quartz glass respectively; and annealing and cleaning after silicon-silicon bonding, and removing the
mask and cleaning after annealing. Through the wet
etching method, the
processing of the silicon backboard through hole is realized, and the problems of silicon wafer
fracture risk and particulate matter residue in the hole in mechanical drilling and
laser drilling are avoided; by adopting a mode of temporarily bonding
quartz glass with a single-sided polished silicon wafer and a double-sided polished silicon wafer, single-side
mask removal of the single-sided polished silicon wafer and the double-sided polished silicon wafer is realized; thickness superposition of the silicon
backplane is realized by adopting a silicon-silicon bonding mode. And meanwhile, the strength of the thick silicon back plate is enhanced by adopting an annealing technology, and an
effective solution is provided for preparation of the thick silicon back plate.