Method for reducing and homogenising the thickness of a semiconductor layer on the surface of an electrically insulating material

摘要

Reducing and homogenizing the thickness of a semiconductor layer which lies on surface of an electrically insulating material, involves exposing to and etching of the surface of semiconductor layer by the action of an etchant whose redox potential is adjusted as a function of the material and the desired final thickness of semiconductor layer, so that the material erosion per unit time on surface of semiconductor layer due to the etchant becomes less as the thickness of semiconductor layer decreases and is only 0-10% of the final thickness per second when a target thickness is reached. Reducing and homogenizing the thickness of a semiconductor layer which lies on the surface of an electrically insulating material, involves exposing to and etching of the surface of the semiconductor layer by the action of an etchant whose redox potential is adjusted as a function of the material and the desired final thickness of the semiconductor layer, so that the material erosion per unit time on the surface of the semiconductor layer due to the etchant becomes less as the thickness of the semiconductor layer decreases and is only from 0 to 10% of the final thickness per second when a target thickness is reached. The method is carried out without the action of light or the application of an external electrical voltage. The redox potential of the etchant is adjusted via the composition of the etchant; via the choice of the constituents of the etchant; or adjusted via the concentrations of the constituents of the etchant.