PROCESS FOR MANUFACTURING DIFFRACTION BINARY OPTICAL ELEMENTS WITH PHASE CONTRAST

摘要

The invention relates to a process for manufacturing a diffraction optical element functioning on the basis of two-level phase contrast. According to the invention, the process consists of thermally growing a layer (2) of silicon dioxide on a silicon wafer (1), followed by spreading a positive-type photoresist layer (3) by depositing a layer with a thickness of 1 ... 3 mium by centrifugation at a rotary speed of 1, 000 ... 5, 000 rpm, applying a heat treatment for 40 ... 50 min, at a temperature of 80 ... 90A C, then the exposure to UV radiation through a chrome mask (4) and development taken place and, applying another heat treatment for 40 ... 50 min, at a temperature of 80 ... 90A C, etching the silicon dioxide layer through the photoresist windows for 1.5 ... 2.0 min, removing the photoresist remained in the acetone solution, evaluating the sizes of etched windows by means of an electronic microscope in order to determine the thickness of a metallic layer (5) exhibiting good reflective properties for the wavelength for the operation of the diffraction optical element and finally correspondingly depositing the metallic layer (5) by means of an electronic beam deposition apparatus which ensures the controlled growth of non-etched areas dimensions up to the desired values.