摘要 |
An anisotropic etching method and apparatus is disclosed, by which the anisotropic etching of a wafer surface can be stably performed, the generation of mu pyramids generated on the etched surface of a semiconductor wafer can be reduced, and the etching depth can be uniform. Therefore, during the anisotropic etching, a replenishing etchant which compensates for the evaporation of a component from the surface of the anisotropic etchant is continuously supplied by an amount corresponding to the amount of the component evaporated. An anisotropic etching apparatus is also disclosed, by which the etchant is not contaminated, the evaporated component of the etchant does not catch fire, the composition of the etchant does not change and the characteristics of the anisotropic etching are stabilized, the generation of mu pyramids can be suppressed, and the etching depth is uniform over the wafer surface. In the apparatus, when a circulating pump is operated, a heating medium in a heating medium jacket is drawn into a heating medium circulating passage, and then is heated by a heating device in the middle of the passage and returned to the jacket. The anisotropic etchant in the anisotropic etching vessel is heated by the heat of the returned heating medium.
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