阅读说明：本技术 一种硅光学薄膜的制备方法 (Preparation method of silicon optical film ) 是由 朱民稷 于 2020-04-15 设计创作，主要内容包括：本发明公开了一种硅光学薄膜的制备方法,采用单晶硅作为镀膜材料,采用物理气相沉积法制备的硅光学薄膜；本发明制备的硅光学薄膜能够大幅提高光学薄膜的折射率,可实现较少层数的光学薄膜替代现有较多层的光学薄膜,大幅减小光学器件的厚度,进而有效降低红外光学薄膜器件的制作成本。(The invention discloses a preparation method of a silicon optical film, which adopts monocrystalline silicon as a coating material and adopts a physical vapor deposition method to prepare the silicon optical film; the silicon optical film prepared by the invention can greatly improve the refractive index of the optical film, can realize that the optical film with fewer layers replaces the existing optical film with more layers, greatly reduces the thickness of an optical device, and further effectively reduces the manufacturing cost of the infrared optical film device.)

1. A preparation method of a silicon optical film is characterized in that monocrystalline silicon is used as a coating material, and a physical vapor deposition method is adopted to prepare the silicon optical film.

2. The method of claim 1, wherein the silicon optical thin film is prepared by a vacuum evaporation process.

3. The method of manufacturing a silicon optical film according to claim 2, comprising the steps of:

s1, preparing a coating material, weighing monocrystalline silicon, putting the monocrystalline silicon into a crucible of an electron gun, and placing a substrate to be coated at a specified position of a workpiece rack;

s2, preparing before coating, starting a vacuum pumping system, and vacuumizing a vacuum chamber; starting a substrate baking system and a cold trap, wherein the substrate baking system heats the substrate, and the cold trap traps water vapor in the vacuum chamber;

s4, premelting, when the vacuum degree in the vacuum chamber reaches a first preset value, adjusting the electron gun to a first preset beam current value, and enabling the electron gun to emit a first electron beam to irradiate the monocrystalline silicon in the crucible;

s5, evaporating to form a film, when the vacuum degree in the vacuum chamber reaches a second preset value, increasing the power of the electron gun to a second preset beam current value, irradiating the monocrystalline silicon in the crucible by the second electron beam emitted by the electron gun, evaporating the monocrystalline silicon, and controlling the gaseous monocrystalline silicon to deposit on the surface of the substrate at a preset deposition rate by the quartz crystal controller;

and S6, taking a piece, finishing film coating, closing the substrate baking system and the vacuum pumping system, recovering the low-temperature cold trap in the vacuum chamber to normal temperature after a certain time, and inflating the vacuum chamber to normal pressure to obtain the piece, thereby finishing the film coating of the substrate.

4. The method of claim 3, wherein the crucible of the electron gun is a water-cooled multi-cavity crucible.

5. The method as claimed in claim 3, wherein the substrate temperature is in the range of 180-220 ℃.

6. The method for producing a silicon optical thin film according to claim 3, wherein the first predetermined value is 1 x 10^-3Pa; the second predetermined value is 8 x 10^-4Pa。

7. The method of claim 3, wherein the electron beam spot diameter is in the range of 0.5 mm.

8. The method of claim 3, wherein the deposition rate is 0.2 to 0.3 nm/s.

9. The method as claimed in claim 3, wherein the first predetermined beam current value is in the range of 150-200 mA; the second predetermined beam current value is 200-300 mA.

Technical Field

The invention relates to the technical field of optical thin films, in particular to a preparation method of a silicon optical thin film.

Background

Monocrystalline silicon is an indispensable basic material in modern science and technology, and televisions, computers, refrigerators, telephones, automobiles and the like used in daily life cannot be separated from monocrystalline silicon materials. The photoelectric conversion efficiency of the monocrystalline silicon is high and reaches about 17%, so that the monocrystalline silicon is widely applied to solar cells. In the infrared region with a wavelength of about 1100nm, the refractive index of monocrystalline silicon is about 3.54, and monocrystalline silicon begins to be transparent (its k value is less than 0.5), so that monocrystalline silicon is also commonly used as a substrate material of "photoelectric elements" in the photoelectric industry. However, single crystal silicon has not been widely used in the field of preparing optical thin film materials, and the main reason for the non-wide application is that the problem of the preparation method of the silicon optical thin film is not solved well.

Modern photoelectric elements (optical elements) cannot be separated from optical films, the optical films in China are no longer single-layer optical films in the sixty and seventy years of the past, and the processable wavelength range is only visible light; the multilayer optical film includes a few layers, a dozen layers, and a dozen to a hundred layers, and the wavelength range of the optical film is from ultraviolet light, visible light to middle infrared light. Multilayer optical films are typically composed of alternating layers of 2 to 3 different refractive indices to achieve a wide variety of optical and even electrical properties, such as anti-reflection, high reflectivity, splitting, cut-off, conductivity, radiation protection, etc.

Silicon has two allotropes of crystalline state and amorphous state, and crystalline state silicon is divided into monocrystalline silicon and polycrystalline silicon, which have diamond crystal lattices, are hard and brittle, have metallic luster, can conduct electricity and heat, and have the melting point of 1410 ℃ and the boiling point of 2355 ℃. At high temperature, the chemical properties of silicon are very active and are easy to react with oxygen, nitrogen, sulfur and the like; silicon has good thermal conductivity and is not easy to vaporize and evaporate, so that the silicon optical film is difficult to prepare.

Disclosure of Invention

The invention aims to provide a preparation method of a silicon optical film, which greatly improves the refractive index of the optical film in a near infrared region and effectively reduces the extinction coefficient of the optical film.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the invention provides a preparation method of a silicon optical film, which adopts monocrystalline silicon as a coating material and adopts a physical vapor deposition method to prepare the silicon optical film.

The further scheme of the scheme is that the silicon optical film is prepared by adopting a vacuum evaporation process.

The scheme further comprises the following steps:

s1, preparing a coating material, weighing monocrystalline silicon, putting the monocrystalline silicon into a crucible of an electron gun, and putting a coated substrate at a specified position;

s2, preparing a coating environment, starting a vacuum pumping system, and vacuumizing a vacuum chamber; starting a substrate baking system and a cold trap, wherein the substrate baking system heats the substrate, and the cold trap traps water vapor in the vacuum chamber;

s4, premelting, when the vacuum degree in the vacuum chamber reaches a first preset value, increasing the power of the electron gun to a first preset beam current value, and enabling the electron gun to emit a first electron beam to irradiate the monocrystalline silicon in the crucible;

s5, evaporating to form a film, when the vacuum degree in the vacuum chamber reaches a second preset value, increasing the power of the electron gun to a second preset beam current value, irradiating the monocrystalline silicon in the crucible by the electron gun to evaporate the monocrystalline silicon, and controlling the gaseous monocrystalline silicon to deposit on the surface of the substrate at a preset deposition rate by the quartz crystal controller;

and S6, taking a piece, finishing film coating, closing the substrate baking system and the vacuum pumping system, recovering the low-temperature cold trap in the vacuum chamber to normal temperature after a certain time, and inflating the vacuum chamber to normal pressure to obtain the piece, thereby finishing the film coating of the substrate.

In a further scheme of the scheme, the crucible is a water direct cooling type multi-cavity crucible.

The scheme is further characterized in that the temperature range of the substrate is 180-220 ℃.

In a further aspect of the foregoing, the first predetermined value is 1 x 10^-3Pa; the second predetermined value is 8 x 10^-4Pa。

In a further aspect of the above, the electron beam spot diameter range is 0.5 mm.

In a further aspect of the above, the deposition rate is 0.2-0.3 nm/s.

The scheme is further characterized in that the first preset beam current value range is 150-; the second predetermined beam current value is 200-300mA

Compared with the prior art, the technical scheme of the invention has the following advantages and beneficial effects: the invention relates to a preparation method of a silicon optical film, which adopts monocrystalline silicon as a coating material and adopts a physical vapor deposition method to prepare the optical film; the silicon optical film can greatly improve the refractive index of the optical film and effectively reduce the extinction coefficient of the optical film, can realize that the optical film with fewer layers replaces the existing optical film with more layers, greatly reduces the thickness of an optical device and reduces the cost of an infrared optical film original piece.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely in the following embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terms "comprises" and "comprising," and any variations thereof, in the description and claims of this invention, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In the following examples, K9 glass was used as the substrate for coating.