Microwave enhanced wet anisotropic etching of silicon utilizing a memory effect of KOH activation - a remote E2MSi process

摘要

A new method of the microwave enhanced fast wet anisotropic etching of the monocrystalline silicon has been presented. In the method, weak aqueous solutions of KOH were activated and heated by microwave irradiation in the resonator. After irradiation, highly reactive, warm etchant flowed from resonator to the reaction chamber in which silicon substrates were etched. It has been shown that fast etching of silicon may be obtained by few seconds after irradiation. It has been documented that significant changes of the irradiated solution remain by minutes after irradiation. It was assumed that observed unique properties of microwave irradiated solution were induced by change of water structure. This has been confirmed by infrared (IR) spectroscopy measurements. This is possible that new etching method reported here may be applied for deep silicon micromachninig. Further-more, memory effects reported here seem to be valid for all of the aqueous solutions and may have negative effects on the environment as well as may generate several negative biohazardous effects. (C) 2004 Elsevier B.V. All rights reserved.