A plasma etching method for large-diameter optical components

Abstract

The invention discloses a plasma etching method for large-diameter optical components. The method draws on the radio frequency anomalous glow discharge method in the radio frequency magnetron sputtering coating technology, and can form high-density and large-area plasma. The directional movement of the orthogonal magnetic field can drive the plasma to produce directional movement, and realize the processing of the optical element surface by line and surface. The introduction of active gas is ionized and excited, and the flow conductance field generated by the inherent gas distributor of the vacuum system is used to guide the free radicals to act on the surface of the workpiece, which will also improve the etching efficiency of the material. And through the parameters of the radio frequency electric field (such as power, etc.), the parameters of the magnetic field (such as the small changes of each magnetic pole, including the equilibrium and non-equilibrium modes and the speed of the directional movement of the magnetic poles, etc.), and gas-related parameters (including the type of gas, flow rate and Pressure, etc.), the type, density and distribution of plasma can be precisely regulated, and high-efficiency large-area plasma polishing of the surface of optical components is realized.

Description

technical field [0001] The invention relates to the technical field of plasma etching processing of optical elements and semiconductor materials, in particular to a plasma etching method for large-diameter optical elements. Background technique [0002] With the expansion of the size and aperture of optical components and the expansion of materials, it also brings a series of new challenges and problems, mainly in the following aspects, one is that the processing aperture reaches the meter level, and the "inertial confinement nuclear fusion" optical engineering Nearly 1,000 pieces of aspherical optical elements with a side length of 430×430mm are required. The largest optical element diameter in the Shenguang III high-power laser device can reach 630mm. The objective lens of the tactical laser weapon needs a Φ460mm aspherical optical lens, and the space detection system needs 900mm. For the above aspherical optical lenses, in 2018, Chinese scientists successfully developed a...

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Problems solved by technology

However, it has been found in specific engineering practice that although PACE technology has extremely high work efficiency in eliminating defect layers on the surface and subsurface of components, due to the limitation of the size of the plasma generator electrode and the problem of plasma uniformity, this technology It is not yet possible to process medium and large aperture optical components

Atmospheric pressure plasma method can use computer control technology to process non-destructive processing of large-aperture optical components from point to point in the atmospheric environment. Unstable, unable to achieve deterministic removal of materials, and the secondary adsorption of products after chemical reactions on the surface of optical components will greatly affect the surface quality of components, reduce processing efficiency, and need to be assisted by other conformal processing methods for secondary adsorption Deposits are removed, thereby prolonging the processing cycle, resulting in an increase in time and economic costs

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