CN102153046A - Method for preparing semi-cylindrical micro-groove by combining two-time film deposition and dry-wet method - Google Patents

Abstract

The invention discloses a method for preparing semi-cylindrical micro-grooves by combining two film depositions, dry etching and wet etching. The main steps are: preparing a masking film layer with a nanometer slit structure on a quartz substrate; through the slit, using a hydrofluoric acid buffer solution to perform isotropic corrosion on the quartz substrate to obtain a semi-cylindrical fine groove. This method does not require expensive equipment such as electron beams and ion beams to prepare slits with a width ranging from 100 nanometers to 500 nanometers. By controlling the conditions of wet etching, the diameter width ranges from 500 nanometers to 2.5 microns, and the depth range is Semi-cylindrical fine grooves from 250nm to 1.25um.

Description

A method for preparing semi-cylindrical fine grooves by combining two film depositions and dry-wet methods

technical field

The invention relates to a method for preparing a semi-cylindrical micro-groove, in particular to a method for preparing a semi-cylindrical micro-groove by utilizing two film depositions, dry etching and wet etching.

technical background

Micro-nano components, especially micro-nano optical components, have great application potential in scientific research, military, civilian and other fields. Semi-cylindrical micro-grooves are the basis for preparing micro-nano optical elements with complex structures. The preparation of micron and submicron semi-cylindrical micro-grooves is a difficult research point. Semi-cylindrical micro-grooves have broad application prospects, for example, in super-resolution imaging, SPP nanolithography and other aspects.

The preparation method of semi-cylindrical grooves is gray-scale exposure etching, which uses the difference in the exposure dose of photoresist in different areas to make the structural pattern in the exposed area reach the required shape, and then transfers the pattern to the substrate by dry etching. on the bottom. Such as gray-scale mask lithography, moving mask lithography, etc., these methods are suitable for processing semi-cylindrical groove structures with a diameter of more than 3 microns, and their disadvantage is that it is difficult to prepare structures with smaller feature sizes. Some SPP devices require a semi-cylindrical fine trench structure with a diameter of hundreds of nanometers. Although direct writing equipment such as electron beams and ion beams can produce patterns of this size, they are expensive and the processing area is only on the order of microns, which is difficult to meet the needs of practical applications. This method only needs to use conventional thin film deposition technology, photolithography technology, dry etching technology and wet etching technology to prepare a masking film layer with a slit structure with a width of 100 nanometers to 500 nanometers and a wide range of diameters. Semi-cylindrical fine grooves ranging from 500 nanometers to 2.5 microns and depths ranging from 250 nanometers to 1.25 microns. The semi-cylindrical groove prepared by this method is not much different in size from the semi-cylindrical groove prepared by conventional thin film deposition technology, photolithography technology, and wet etching technology, but the edge of the groove should be smooth and flat a lot of.

Contents of the invention

The technical problem to be solved in the present invention is to propose a method for preparing semi-cylindrical micro-grooves by using two film depositions, dry etching and wet etching in view of the limitations of existing microfabrication. Only need to use conventional thin film deposition technology, photolithography technology, dry etching technology and wet etching technology, you can prepare a semi-cylindrical shape with a diameter and width ranging from 500 nanometers to 2.5 microns and a depth ranging from 250 nanometers to 1.25 microns. micro grooves.

The technical solution adopted by the present invention to solve its technical problems is: a method for preparing semi-cylindrical micro-fine grooves by utilizing two film depositions, dry etching and wet etching, as shown in Figure 1, the steps are as follows:

(1) Using magnetron sputtering technology or vapor deposition technology to deposit a film layer on a quartz substrate, and coat photoresist on the film layer; the thickness of the quartz substrate is 200 to 2000 microns, and the thickness of the film layer is 20-300 nanometers, the thickness of the photoresist is 100-2000 nanometers;

(2) Using photolithography technology to prepare a pattern structure with a period of more than 20 microns and a width of 10 microns or more on the photoresist;

(3) Utilize the photoresist pattern prepared by said step (2) as a mask, dry etching is anisotropic, and wet etching isotropic characteristics, first utilize dry etching to remove no photoresist for masking The film layer, and then use the etching solution to laterally etch the film layer below the edge of the photoresist pattern to form an air gap with a width of 100-500 nanometers;

(4) Depositing a film layer of the same material again on the structure surface obtained after the step (3), removing the photoresist to obtain a slit corresponding to the width of the air gap;

(5) With the film layer deposited in the step (1) and the step (4) as a mask, through the slit, the substrate is etched isotropically with the substrate etching solution to obtain a diameter width ranging from 500 nanometers to 2.5 microns, semi-cylindrical microgrooves with a depth ranging from 250 nanometers to 1.25 microns.

The film layer in the step (1) is a metal, silicon or organic film layer, and the film layer will play a masking role in the subsequent wet etching process of quartz.

In the step (3), the instrument used for dry etching is IBE, the etching time is 3 to 10 minutes, the etching solution is a chromium removal solution, the temperature is 20 to 30° C., and the time for wet etching the chromium layer is 1 ~6 minutes.

When performing wet etching on the substrate in the step (5), it is necessary to continuously stir the substrate etching solution. The etching solution is hydrofluoric acid buffer solution, the temperature is 20-30° C., and the time for wet etching the quartz substrate is 6-35 minutes.

In the step (5), the advantage of the present invention compared with the prior art is that the present invention only needs to adopt conventional thin film deposition technology, photolithography technology, dry etching and wet etching technology to prepare the diameter Semi-cylindrical fine grooves with a width ranging from 500 nm to 2.5 microns and a depth ranging from 250 nm to 1.25 microns; only conventional thin film deposition technology, photolithography technology, dry etching and wet etching technology can be used to greatly Reduce the preparation cost of semi-cylindrical micro-grooves; the invention can be processed in a large area, and the distribution area of the prepared semi-cylindrical groove microstructure can reach up to hundreds of square centimeters; it provides a precise processing method for micro-nano components. , Novel, convenient and efficient processing methods.

Description of drawings

Fig. 1 is the flowchart of the inventive method;

Fig. 2 is in the embodiment 1 of the present invention, the sectional structure schematic diagram after chromium plating film and coating photoresist on the quartz substrate surface;

3 is a schematic cross-sectional structure diagram of a wide-line pattern produced by conventional photolithography equipment in Embodiment 1 of the present invention;

4 is a schematic cross-sectional structure diagram of the chromium film not masked by the photoresist after dry etching in Example 1 of the present invention;

5 is a schematic cross-sectional structure diagram of a microstructure pattern obtained after using a chromium-removing solution to laterally etch away the chromium film layer below the edge of the photoresist pattern in Example 1 of the present invention;

Fig. 6 is a schematic cross-sectional structure obtained after depositing a chromium layer for the second time on the structure shown in Fig. 5 in Example 1 of the present invention;

Fig. 7 is in the embodiment 1 of the present invention, adopts the sectional structure schematic diagram obtained after removing surface photoresist by LIFT OFF process;

Fig. 8 is a schematic cross-sectional structure diagram of a semi-cylindrical fine groove obtained by placing the structure in Fig. 7 in a hydrofluoric acid buffer solution for isotropic etching in Example 1 of the present invention;

9 is a schematic cross-sectional structure diagram of a semi-cylindrical fine groove obtained by removing the chromium film in Example 1 of the present invention.

In the figure: 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

The right figure in Fig. 10 is a semi-cylindrical fine groove prepared by the present invention. The picture on the left is a semi-cylindrical fine groove prepared by two layers of film deposition, wet etching, and no dry etching. The line structure in the trench in the figure is a mask pattern etched by FIB.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. But the following examples are only limited to explain the present invention, and the protection scope of the present invention should include the whole content of claim, and promptly can realize the whole content of claim of the present invention to those skilled in the art through following embodiment.

Embodiment 1, make the semi-cylindrical fine groove of 700 nanometers in diameter, the making process is as follows:

(1) Select a quartz plate with a thickness of 360 microns as the substrate; use magnetron sputtering technology to deposit a layer of 100 nanometers thick metal chromium layer on the surface of the substrate, and coat AR-P3100 with a thickness of 1.1 microns on the chromium film Photoresist, as shown in Figure 2, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

(2) Through exposure, development, and die hardening, a line structure with a period of 30 microns and a line width of 10 microns is prepared on the photoresist, as shown in Figure 3, 1 represents the substrate material quartz; 2 represents the chromium film material ; 3 represents photoresist AR-P3100.

(3) Using the photoresist pattern as a mask, the characteristics of dry anisotropy and wet etching isotropy, first use IBE dry etching to remove the 100 nanometer thick metal chromium layer that is not masked by photoresist, etch The time is about 4 minutes, as shown in Figure 4. Etching away the metal chromium layer below the edge of the photoresist line pattern by using an etching solution. The etching solution is a chromium-removing solution, the etching temperature is 23° C., and the time for wet etching the chromium layer is about 2 minutes. The width of the obtained air gap is 150 nanometers, as shown in FIG. 5 . In Figures 4 and 5, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

(4) A chromium film is deposited again on the surface of the structure after dry etching and wet etching, as shown in FIG. 6 . Remove the photoresist and the chromium film attached to the photoresist in the second chrome plating to obtain a chromium film slit with the same width as the air gap of 150 nm, as shown in FIG. 7 . In Figure 6, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100; in Figure 7, 1 represents the substrate material quartz; 2 represents the chromium film material.

(5) Through the slit of the chromium film, the substrate is isotropically etched with hydrofluoric acid buffer solution at a temperature of 23° C., and the wet etching time of quartz is 7 minutes, as shown in FIG. 8 . The remaining masking film layer was removed with a chrome removal solution to obtain a semi-cylindrical fine groove with a diameter of 700 nm and a depth of 350 nm, as shown in FIG. 9 . In Figure 8, 1 represents the substrate material quartz; 2 represents the chromium film material. 1 in Fig. 9 represents the substrate material quartz.

Embodiment 2, making a semi-cylindrical fine groove with a diameter of 1 micron nanometer, the manufacturing process is as follows:

(1) Select a quartz plate with a thickness of 1000 microns as the substrate; use magnetron sputtering technology to deposit a layer of 150 nanometers thick metal chromium layer on the surface of the substrate, and coat AR-P3100 with a thickness of 1.1 microns on the chromium film Photoresist, as shown in Figure 2, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

(2) Through exposure, development, and die hardening, a line structure with a period of 30 microns and a line width of 10 microns is prepared on the photoresist, as shown in Figure 3, 1 represents the substrate material quartz; 2 represents the chromium film material ; 3 represents photoresist AR-P3100.

(3) Using the photoresist pattern as a mask, the characteristics of dry anisotropy and wet etching isotropy, first use IBE dry etching to remove the 150 nanometer thick metal chromium layer that is not masked by photoresist, etch The time is about 5 minutes and 30 seconds, as shown in Figure 4. Etching away the metal chromium layer below the edge of the photoresist line pattern by using an etching solution. The etching solution is a chromium-removing solution, the etching temperature is 23° C., and the wet etching time of the chromium layer is about 3 minutes and 30 seconds. The width of the obtained air gap is 250 nanometers, as shown in FIG. 5 . In Figures 4 and 5, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

(4) A chromium film is deposited again on the surface of the structure after dry etching and wet etching, as shown in FIG. 6 . Remove the photoresist and the chromium film attached to the photoresist in the second chrome plating to obtain a chromium film slit with the same width as the air gap of 250 nm, as shown in FIG. 7 . In Figure 6, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100; in Figure 7, 1 represents the substrate material quartz; 2 represents the chromium film material.

(5) Through the slit, the substrate is isotropically etched with hydrofluoric acid buffer solution at a temperature of 23° C., and the wet etching time for quartz is about 10 minutes and 30 seconds, as shown in FIG. 8 . The remaining masking film layer was removed with a chrome removal solution to obtain a semi-cylindrical fine groove with a diameter of 1 micron and a depth of 500 nm, as shown in FIG. 9 . In Figure 8, 1 represents the substrate material quartz; 2 represents the chromium film material. 1 in Fig. 9 represents the substrate material quartz.

The right figure in FIG. 10 is a scanning electron microscope image of a semi-cylindrical groove with a diameter width of about 1 micron and a depth of about 500 nanometers prepared by the process of Example 2. The picture on the left is a semi-cylindrical fine groove prepared by two layers of film deposition, wet etching, and no dry etching. The line structure in the trench in the figure is a mask pattern etched by FIB.

Embodiment 3, making a semi-cylindrical fine groove with a diameter of 2 microns, the manufacturing process is as follows:

(1) Select a quartz plate with a thickness of 1000 microns as the substrate; use magnetron sputtering technology to deposit a layer of 200 nanometers thick metal chromium layer on the surface of the substrate, and coat AR-P3100 with a thickness of 1.1 microns on the chromium film Photoresist, as shown in Figure 2, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

(2) Through exposure, development, and die hardening, a line structure with a period of 30 microns and a line width of 10 microns is prepared on the photoresist, as shown in Figure 3, 1 represents the substrate material quartz; 2 represents the chromium film material ; 3 represents photoresist AR-P3100.

(3) Using the photoresist pattern as a mask, the characteristics of dry anisotropy and wet etching isotropy, first use IBE dry etching to remove the 200 nanometer thick metal chromium layer that is not masked by photoresist, etch The time is about 8 minutes, as shown in Figure 4. Etching away the metal chromium layer below the edge of the photoresist line pattern by using an etching solution. The etching solution is a chromium-removing solution, the etching temperature is 23° C., and the time for wet etching the chromium layer is 5 minutes and 30 seconds. The width of the obtained air gap is 400 nanometers, as shown in FIG. 5 . In Figures 4 and 5, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100.

(4) A chromium film is deposited again on the surface of the structure after dry etching and wet etching, as shown in FIG. 6 . Remove the photoresist and the chromium film attached to the photoresist in the second chrome plating to obtain a slit with the same width as the air gap of 400 nm, as shown in FIG. 7 . In Figure 6, 1 represents the substrate material quartz; 2 represents the chromium film material; 3 represents the photoresist AR-P3100. In Fig. 7, 1 represents the substrate material quartz; 2 represents the chromium film material.

(5) Through the slit, the substrate is isotropically etched with hydrofluoric acid buffer solution at a temperature of 23° C., and the wet etching time of quartz is 30 minutes, as shown in FIG. 8 . The remaining masking film layer was removed with a chrome removal solution to obtain semi-cylindrical fine grooves with a diameter of 2 microns in width and a depth of 1 micron, as shown in FIG. 9 . In Figure 8, 1 represents the substrate material quartz; 2 represents the chromium film material. 1 in Fig. 9 represents the substrate material quartz.

Claims (5)

1. a kind of film deposition that utilizes twice, dry etching and wet etching prepare the method for semi-cylindrical fine groove, and its feature step is as follows: (1) Use magnetron sputtering technology or vapor deposition technology to deposit a film layer on a quartz substrate, and coat photoresist on the film layer. The thickness of the quartz substrate is 200 to 2000 microns, and the thickness of the film layer is 20-300 nanometers, the thickness of the photoresist is 100-2000 nanometers; (2) Using photolithography technology to prepare a pattern structure with a period of more than 20 microns and a width of 10 microns or more on the photoresist; (3) Utilize the photoresist pattern that described step (2) makes to cover, dry etching is anisotropic, the characteristics of wet etching isotropy, first utilize dry etching to get rid of not masked by photoresist The film layer, and then use the etching solution to laterally etch the film layer below the edge of the photoresist pattern to form an air gap with a width of 100-500 nanometers; (4) Depositing a film layer of the same material on the structure surface obtained after the step (3), and removing the photoresist to obtain a film layer slit corresponding to the width of the air gap; (5) Using the film layer deposited in the step (1) and the step (4) as a mask, through the slit of the film layer, the substrate is isotropically etched with the substrate etching solution to obtain a diameter width range of 500 Semi-cylindrical fine grooves ranging from nanometers to 2.5 microns and depths ranging from 250 nanometers to 1.25 microns. 2. a kind of utilizing twice film deposition according to claim 1, dry etching and wet etching prepare the method for semicylindrical fine groove, it is characterized in that: the film layer in described step (1) It is a metal, silicon or organic film layer, which will play a masking role in the subsequent wet etching process of quartz. 3. A kind of film deposition according to claim 1, the method of dry etching and wet etching to prepare semi-cylindrical fine grooves, is characterized in that: in described step (3), dry method The instrument used for etching is IBE, the etching time is 3-10 minutes, the etching solution is chromium-removing solution, the temperature is 20-30° C., and the time for wet etching the chromium layer is 1-6 minutes. 4. a kind of film deposition that utilizes twice according to claim 1, dry etching and wet etching prepare the method for semicylindrical fine groove, it is characterized in that: the lining in described step (5) When the substrate is wet-etched, it is necessary to continuously stir the substrate etching solution. 5. A kind of film deposition that utilizes twice according to claim 1, dry etching and wet etching prepare the method for semi-cylindrical fine groove, it is characterized in that: in described step (5), described The etchant is hydrofluoric acid buffer solution, the temperature is 20-30° C., and the time for wet etching the quartz substrate is 6-35 minutes.

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