CN112309839A

CN112309839A - Preparation method of silicon oxide graph structure based on hot mold photoetching

Info

Publication number: CN112309839A
Application number: CN202011108307.5A
Authority: CN
Inventors: 陈国东; 魏劲松; 王阳; 王璐
Original assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Current assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2021-02-02

Abstract

A silicon oxide pattern structure writing method based on thermal die photoetching is mainly characterized in that the invention performs random pattern writing on a silicon oxide block or a silicon oxide film in the optical element manufacturing and semiconductor industries, so as to achieve the purposes of optical modulation, etching mask or insulating grid preparation. Firstly, depositing a layer of phase-change material film on the surface of a silicon oxide film or a silicon oxide substrate, exposing a designed pattern through a 405nm laser direct writing device, developing a corresponding pattern structure by utilizing ammonium sulfide, and transferring the pattern to the surface of the silicon oxide film or the silicon oxide substrate of the substrate through a plasma etching process to finish the writing of the silicon oxide pattern. The invention is used as a novel preparation method of a micro-nano structure in a silicon-based or silicon oxide-based photoelectronic element.

Description

Preparation method of silicon oxide graph structure based on hot mold photoetching

Technical Field

The invention relates to a preparation method of any micro-nano structure on the surface of silicon oxide, in particular to a preparation technology of the surface structure of the silicon oxide based on laser hot mold photoetching.

Background

In the fields of optical modulation elements, integrated circuit processing and the like, the structure preparation of the surface of a silicon oxide-based material is a one-step key process. Generally, electron beam lithography, projection exposure lithography and other methods are adopted to form a micro-nano structure on the surface of organic photoresist, then a plasma etching technology is utilized to transfer the structure to a substrate material, and then a photoresist solution is utilized to remove the residual photoresist, so that a micro-nano pattern structure is formed on a silicon oxide substrate. The most representative is the preparation of the silicon oxide optical modulation grating, which is to write a complex pattern array on the surface of a photoresist by an exposure method, and transfer a designed pattern to the surface of the silicon oxide by the steps of pre-baking, developing, post-baking, etching and photoresist removing. The traditional preparation method of the silicon oxide structure mainly comprises the steps of spin coating, soft baking, exposure, pre-baking, development, post-baking, etching, photoresist removal and the like, the generation of patterns is realized by adopting organic photoresist and combining methods such as electron beam lithography, projection lithography, direct writing lithography and the like, and the problems of low photoresist transfer ratio, low pattern fidelity, low exposure speed, various process steps and the like are solved.

The silicon oxide preparation method based on the laser thermal mold lithography technology has the advantages of simple process steps, high writing speed, small feature size, relatively high trans-scale writing and transfer ratio and the like as a preparation technology. Has good application prospect in the preparation field of silicon-based structures.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for preparing a silicon oxide pattern structure based on laser hot die lithography.

In order to achieve the purpose, the technical specific solution of the invention is as follows:

a silicon oxide pattern structure writing method based on hot mold photoetching is characterized by comprising the following steps:

a) plating a layer of chalcogenide phase change material film on the silicon oxide substrate or the silicon oxide film by adopting a magnetron sputtering technology, wherein the thickness is h; then, laser direct writing exposure is carried out on the silicon oxide substrate or the silicon oxide film plated with the chalcogenide phase change film by using laser beams with the wavelength of 405 nm; carrying out selective wet etching on the film subjected to the laser exposure by using a developing solution to form a chalcogenide phase change film pattern layer with a micro-nano pattern structure, wherein the depth of the pattern is d, and d is h to form a complete windowing structure;

b) etching the pattern structure of the chalcogenide phase change film to the surface of silicon oxide or the silicon oxide film by plasma etching, and removing residual glue by a degumming solution.

The plasma etching in the step b) comprises the following specific steps:

and placing the completely windowed chalcogenide phase-change film micro-nano graph structure in a reactive ion etching machine or a plasma etching machine, etching and removing silicon oxide exposed on the surface in the atmosphere of fluorine-based gas and argon gas to realize directional etching, and transferring the micro-nano structure from the chalcogenide phase-change film to a silicon oxide substrate.

Preferably, the chalcogenide phase change thin film is AgInSbTe or Ge₂Sb₂Te₅。

Preferably, the fluorine-based gas is CHF₃。

Preferably, in the step a), the developing solution is an aqueous solution of ammonium sulfide, and the concentration of the developing solution is 17%.

Preferably, in the step b), the degumming solution is a 4:1 mixed aqueous solution of ammonium ceric nitrate (with the concentration of 10% -20%) and nitric acid (with the concentration of 5% -10%), the degumming temperature is 35-45 ℃, and the degumming time is 20-40 min.

Compared with the prior art, the invention has the following technical effects:

1) the AgInSbTe chalcogenide phase-change thin film material is used as an inorganic photoresist, due to the thermal threshold and the thermal diffusion effect of the material, any size of inscription smaller than the size of a light shift and larger than the size of the light shift can be realized, and the micro-nano structure of the AgInSbTe thin film is successfully transferred to the surface of a silicon-based material, so that a silicon-based optical element is formed;

2) the laser hot mold photoetching technology is adopted, the operation is simple, and the preparation steps are simple.

Drawings

FIG. 1 is a schematic flow chart of a method for preparing a silicon oxide pattern structure based on hot mold lithography according to the present invention;

FIG. 2 is an AgInSbTe patterned layer of the method for preparing a silicon oxide patterned structure based on thermal die lithography;

FIG. 3 is a silicon dioxide pattern layer of a method for preparing a silicon oxide pattern structure based on hot mold lithography according to the present invention;

Detailed Description

The present invention is further illustrated by the following examples and figures, but should not be construed as being limited thereby.

As shown in fig. 1, the method for preparing a silicon oxide surface structure based on laser thermal mold lithography comprises the steps of:

a) plating a layer of AgInSbTe sulfur series phase change material film on a silicon oxide crystal or silicon oxide film substrate by adopting a magnetron sputtering technology, wherein the thickness of the film is about 300 nm;

b) performing laser direct writing exposure on the silicon oxide substrate plated with the AgInSbTe chalcogenide phase change film by adopting a laser beam with the wavelength of 405nm, wherein an exposed area is of a crystalline structure, and an unexposed area is in a deposition state;

c) carrying out selective wet etching on the film subjected to the laser exposure by using a developing solution, wherein the developing temperature is 23 ℃, and the developing time is 4min, so as to form an AgInSbTe graph layer with a micro-nano graph structure, and representing the height of the micro-nano graph structure to be 300nm by using an atomic force microscope, as shown in FIG. 2;

d) etching the AgInSbTe graph structure to the surface of the silicon oxide by the formed micro-nano structure through plasma etching, wherein the Ar gas flow is 10sccm, and CHF is adopted₃The gas flow is 200sccm, the RF power is 630W, the DC bias is 200W, the etching pressure is 2.0pa, and the etching time is 6 min;

e) and (3) putting the etched silicon oxide surface structure into a degumming solution, removing the AgInSbTe film on the silicon oxide surface which is not completely etched under the action of heating and ultrasound, wherein the degumming time is 30min, and then carrying out morphology characterization by adopting an atomic force microscope and a scanning electron microscope, wherein the height is 1.2um, and the line width is 2um as shown in figure 3.

Claims

1. A silicon oxide pattern structure writing method based on hot mold photoetching is characterized by comprising the following steps:

2. The method for writing a silicon oxide pattern structure by thermal mold lithography according to claim 1, wherein the plasma etching in step b) comprises the following specific steps:

3. The method as claimed in claim 2, wherein the chalcogenide phase-change film is AgInSbTe or Ge₂Sb₂Te₅。

4. The method for patterning a silicon oxide pattern according to claim 2, wherein the fluorine-based gas is CHF₃。

5. The method according to claim 1, wherein said developing solution in step a) is an aqueous solution of ammonium sulfide with a concentration of 17%.

6. The method according to claim 1, wherein the photoresist removing solution in step b) is a 4:1 mixed aqueous solution of ammonium ceric nitrate (10% -20%) and nitric acid (5% -10%), the photoresist removing temperature is 35-45 deg.C, and the photoresist removing time is 20-40 min.