The invention discloses a wet chemical
etching method for preparing large-area and flexible ultra-thin
monocrystalline silicon wafers, and belongs to the field of
semiconductor technology. According to the method,
acetone,
anhydrous ethanol, deionized water and
hydrofluoric acid are adopted to treat a N(100) double-side-polished
monocrystalline silicon wafer in advance, so that the surface of the
silicon surface is cleaned.
Potassium hydroxide, isopropanol and deionized water are uniformly mixed to prepare a
reducer and the
reducer is preheated in a water-bath. After that, the
silicon wafer is well fixed and dipped in the
reducer by a clamp. In this way, an ultra-thin
wafer of a desired thickness can be obtained through controlling the reaction time and the
reaction temperature, The surface of the
silicon wafer is bright, flat, smooth and free of any obvious
thinning defect, and appears the mirror-surface result. According to the technical scheme of the invention, the
thinning process of silicon wafers is simplified by adopting the single-
step method, and the characteristics of the wet
etching technique in the low-temperature and normal-pressure condition are maintained.
Silicon wafers with the thickness thereof smaller than 10 mm are obtained for the first time. Meanwhile, the application range of the wet
silicon etching technique is expanded. Therefore, the method provides a novel idea and a novel technical means for the
thinning process of silicon wafers.