The invention provides a
silicon through hole
etching method and belongs to the field of
micro nano machining of micro electro mechanical systems, and the method can be used for solving the problems that the side wall of a substrate generates ripples, a
photoresist can be easily damaged and
metal pollution is caused when an existing Bosch process and a
metal mask are utilized to carry out deep
silicon etching. The method provided by the invention comprises a pattern preparation step, an
etching step, a culture slice adding step, a penetrating step and a
photoresist removing step. In the etching step,
processing is stopped after circulative and alternative etching is finished, so that the
photoresist is cooled and the protective action of the photoresist is prevented from being reduced; then circulative etching is carried out again; passivating gas is added into etching gas; and the etching gas is added into the passivating gas for improving the smoothness of the side wall. In the culture slice adding step, a
silicon wafer is adhered to the upper surface of a culture slice,thus preventing silicon
wafer fracture and equipment damage after etching penetration. The method provided by the invention has the advantages that the process is simple and the etching speed is quick; the photoresist utilized as the
mask can be easily removed after being etched, and
metal pollution is avoided; the verticality of the side wall of a through hole is easily controlled; the smoothness of the side wall is improved; and the ripples on the side wall are eliminated.