Diffractive optical component making method

Abstract

The present invention provides a method for manufacturing a diffractive optical element capable of manufacturing a diffractive optical element with high precision and improving diffraction efficiency. Using a mask, a series of processes of exposing, developing, forming a resist pattern and etching the resist pattern on the substrate (1) coated with the resist (2) are repeated to manufacture a periodic Step-shaped diffractive optical element. In the first process, a pattern having the same width as the step width is formed, and in subsequent processes, the pattern width is increased. In the case of manufacturing a diffractive optical element with a 7-step stepped shape, when the step difference is D, in the first process, the second, fourth, and sixth-level parts are etched at a depth D, and in the second process, The 9th level part is etched with a depth of 2D. In the third process, the 5th, 6th, and 7th level parts are etched with a depth of 2D. In the fourth process, the 3rd, 4th, 5th, and 6th level are etched with a depth of 2D. , Level 7 parts are etched.

Description

technical field [0001] The present invention relates to a method of manufacturing a diffractive optical element having a stepped shape. Background technique [0002] In recent years, there has been an increasing demand for diffractive optical elements that control the traveling direction and phase of light based on periodic fine shapes. There are various shapes of diffractive optical elements. Among them, a diffractive optical element with a zigzag cross section has a high logical diffraction effect. In fact, a stepped diffractive optical element similar to the zigzag shape is easy to manufacture and is widely used. Generally, as a method of manufacturing a diffractive optical element having a stepped shape, there is a method described in the following Non-Patent Document 1, which uses m (m is a natural number) masks to repeatedly expose, A series of processes of developing and etching, manufacturing 2 m class diffractive optical elements. For example, in the case of an 8...

AI Technical Summary

Problems solved by technology

In this way, in the conventional manufacturing method, a stepped shape with a size different from the design value may be formed, or a protrusion may be generated at the edge, so there is a problem of causing a decrease in diffraction efficiency.

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