CN102214492B - Method for manufacturing concave X-ray focusing small hole - Google Patents

Abstract

The invention discloses a method for manufacturing a concave X-ray focusing pinhole, which comprises the following steps: manufacturing a substrate; coating photoresist on a substrate, and photoetching the photoresist by using electron beams with different doses to form a photoresist pattern with a cylindrical convex surface at the center; electroplating a gold layer on the formed photoresist pattern; etching from the back of the substrate until penetrating through the substrate; and removing the photoresist to form a concave X-ray focusing aperture. The method for manufacturing the concave X-ray focusing pinhole provided by the invention is a method which has the advantages of simple process, low manufacturing cost, high production efficiency and higher uniformity of HSQ process, and can finish the manufacturing of the concave X-ray focusing pinhole.

Description

A Method for Making Concave X-ray Focusing Hole

technical field

The invention relates to the technical field of manufacturing diffractive optical elements, in particular to a method for manufacturing concave X-ray focusing holes.

Background technique

X-rays are difficult to focus due to their short wavelength and strong transmission. In the past, zone plates or photon sieves were often used to focus, and such zone plates or photon sieves were often planar. The concave type can focus better due to the focusing characteristics of its surface, but it is difficult to manufacture due to the concave surface characteristics of its surface.

Contents of the invention

(1) Technical problems to be solved

In view of this, the main purpose of the present invention is to provide a method for manufacturing a concave X-ray focusing hole, so as to reduce the difficulty of manufacturing the concave surface.

(2) Technical solution

To achieve the above object, the present invention provides a method for making a concave X-ray focusing hole, the method comprising:

making substrates;

Coating photoresist on the substrate, and photoetching the photoresist with electron beams of different doses to form a photoresist pattern with a cylindrical convex surface in the center;

Electroplating a gold layer on the formed photoresist pattern;

Etching from the backside of the substrate, through to the substrate; and

Remove the glue to form a concave X-ray focusing hole.

In the above scheme, the step of making the substrate includes: spin-coating a polyimide film on the front side of a smooth silicon wafer, and then using wet etching to etch away the silicon from the back of the silicon wafer to form a hollow polyimide film; A chromium/gold layer is evaporated on a polyimide film by electron beam evaporation to form a substrate. In the chromium/gold layer, the thickness of chromium is 5nm, and the thickness of gold is 10nm.

In the above scheme, the step of coating photoresist on the substrate, photoetching the photoresist with electron beams of different doses, and forming a photoresist pattern with a cylindrical convex surface in the center includes: coating the chromium/ Electron beam photoresist with a thickness of 600nm was spin-coated on the gold layer, and baked in an oven to dry it; then the photoresist was photoetched with different doses of electron beams. The surrounding dose is gradually increased until the dose is completely removed; after exposure, a developer is used for development, and finally a photoresist pattern with a cylindrical convex surface is formed on the silicon wafer, and the photoresist pattern is from the middle to The surrounding area is gradually lowered, and the unphotographed ring in the middle forms a cylindrical glue column.

In the above scheme, in the step of electroplating a gold layer on the formed photoresist pattern, the method of electroplating is used to form a gold layer on the photoresist, and gold is gradually deposited on the photoresist pattern, slowly from the surrounding Diffusion in the middle until it is flush with the photoresist.

In the above scheme, the step of etching from the back of the substrate until penetrating the substrate includes: etching the polyimide from the back of the substrate, and continuing to etch until the chromium/ The gold layer is completely etched away.

In the above scheme, the step of removing the glue to form the concave X-ray focusing small hole includes: placing the substrate in the glue removing solution to remove the photoresist to form a concave gold film, and the unphotoresisted glue in the middle of the gold film The column forms a circular small hole to complete the production of the concave X-ray focusing small hole.

(3) Beneficial effects

As can be seen from the foregoing technical solutions, the present invention has the following beneficial effects:

1. The method for making concave X-ray focusing pinholes provided by the present invention is a method of simple process, low manufacturing cost, high production efficiency, and can provide a higher uniformity HSQ process, which can complete the concave surface. Focus on pinhole making.

2. In the method for making concave X-ray focusing holes provided by the present invention, the HSQ glue used has a very high resolution, and the HSQ process can greatly improve the accuracy rate and ensure the uniformity of the concave surface, thus having a wider range of applications. Application prospects.

3. The method for producing concave X-ray focusing holes provided by the present invention can efficiently produce concave focusing holes. Compared with flat holes, the concave focusing holes have stronger focusing effect, has a greater application prospect.

Description of drawings

Fig. 1 is the flow chart of the method for making the concave X-ray focusing pinhole provided by the present invention;

2 is a schematic diagram of electron beam exposure of a substrate substrate according to an embodiment of the present invention;

Figure 3 is a schematic diagram of the relationship between residual glue and dosage;

Figure 4 is a schematic diagram of the image after development;

Fig. 5 is the schematic diagram of figure after electroplating, and yellow is gold layer;

Fig. 6 is a schematic diagram of the final concave focusing aperture.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The method for manufacturing the concave X-ray focusing hole provided by the invention adopts the sensitivity of the HSQ process to electron beams to make the concave X-ray focusing hole. As shown in Figure 1, Figure 1 is a flow chart of a method for manufacturing a concave X-ray focusing pinhole provided by the present invention, the method includes:

Step 1: making the substrate;

Step 2: apply photoresist on the substrate, and use different doses of electron beams to photoresist the photoresist to form a photoresist pattern with a cylindrical convex surface in the center;

Step 3: electroplating a gold layer on the formed photoresist pattern;

Step 4: Etching from the back of the substrate until penetrating the substrate; and

Step 5: Remove glue to form concave X-ray focusing holes.

Based on the method for manufacturing a concave X-ray focusing hole shown in FIG. 1 , FIGS. 2 to 6 show a process flow chart for manufacturing a concave X-ray focusing hole according to an embodiment of the present invention.

As shown in Figure 2, the polyimide film is spin-coated on the front side of the smooth silicon wafer, and then the silicon is etched away from the back side of the silicon wafer by wet etching to form a hollow polyimide film. Evaporate a chromium Cr/gold Au layer on the polyimide film on the front side of the silicon wafer by electron beam evaporation, wherein the thickness of Cr is 5nm, and the thickness of Au is 10nm, and then spin-coat the chromium Cr/gold Au layer with electron beam The photoresist HSQ is about 600nm, baked in an oven to dry it; then use electron beams for photolithography, and the dose of electron beams during photolithography is a concentric ring with a middle dose of 0 and a surrounding dose that gradually increases until it is completely removed dosage. As shown in Figure 3, it is the curve of dose and residual photoresist. As the dose increases, the photoresist residue gradually decreases.

As shown in Figure 4, after the exposure, the developer is used for development, and the photoresist pattern formed on the silicon wafer is finally a hillside pattern that decreases from the middle to the periphery, and the unphotographed ring in the middle forms a glue column.

After that, gold is electroplated on the photoresist pattern of the substrate, and due to the good uniformity of electroplating, gold is gradually deposited on the substrate, slowly diffused from the surrounding to the middle, until it is flush with the photoresist , as shown in Figure 5.

Etch the polyimide from the back of the silicon wafer, and continue to etch until the chromium/gold layer in the window area is completely etched away, and then place the substrate in a stripping solution to remove the photoresist HSQ, thereby forming The final pattern formed by gold is shown in FIG. 6 . The unphotographed glue column in the middle forms a circular small hole, which completes the production of the concave X-ray focusing small hole. The small hole is coated with a metal chromium film and a layer of gold film on a silicon wafer with a diameter of 2 inches. A concave hole is formed in the center of the metal film.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. a method of making concave-surface X-ray focusing pinhole is characterized in that, the method comprises:

Make substrate;

Resist coating on substrate carries out photoetching with the electron beam of various dose to this photoresist, and the formation center has the photoetching offset plate figure of the convex surface of cylinder;

In the photoetching offset plate figure that the forms Gold plated Layer that powers on;

Carry out etching from the back side of substrate, until penetrate substrate; And

The formation concave-surface X-ray focusing pinhole removes photoresist.

2. the method for making concave-surface X-ray focusing pinhole according to claim 1 is characterized in that, the step of described making substrate comprises:

Then positive spin-on polyimide film at smooth silicon chip uses wet etching from silicon chip back side silicon to be eroded, and forms the Kapton of hollow out;

Adopt electron beam evaporation method to evaporate chromium/gold layer at Kapton, form substrate.

3. the method for making concave-surface X-ray focusing pinhole according to claim 2 is characterized in that, in described chromium/gold layer, the thickness of chromium is 5nm, and the thickness of gold is 10nm.

4. the method for making concave-surface X-ray focusing pinhole according to claim 1, it is characterized in that, described on substrate resist coating, with the electron beam of various dose this photoresist is carried out photoetching, the step of photoetching offset plate figure that the formation center has the convex surface of cylinder comprises:

Spin coating thickness is the electron beam resist of 600nm on the chromium of substrate/gold layer, and baking makes its drying in baking oven; Then adopt the electron beam of various dose that this photoresist is carried out photoetching, the dosage of electron beam be in the middle of dosage be the donut that dosage increases gradually around 0, until reach the dosage of removing fully; After exposure, use developer solution to develop, the formation center has the photoetching offset plate figure of the convex surface of cylinder on the final silicon chip, and this photoetching offset plate figure reduces towards periphery gradually from the centre, and the annulus of photoetching does not form a cylindrical glue post in the centre.

5. the method for making concave-surface X-ray focusing pinhole according to claim 1, it is characterized in that, described photoetching offset plate figure forming powers in the step of Gold plated Layer, to adopt electric plating method to form the gold layer at photoresist, gold depositing on the photoetching offset plate figure gradually, by spreading to the centre slowly on every side, until flush with photoresist.

6. the method for making concave-surface X-ray focusing pinhole according to claim 2 is characterized in that, etching is carried out at the described back side from substrate, until penetrate the step of substrate, comprising:

From the back side of substrate polyimide is carried out etching, and continue etching until the chromium of window area/gold layer is etched away fully.

7. the method for making concave-surface X-ray focusing pinhole according to claim 1 is characterized in that, described removing photoresist forms the step of concave-surface X-ray focusing pinhole, comprising:

Place the liquid that removes photoresist to remove photoresist substrate, form the golden film of concave surface, the middle not circular aperture of glue cylindricality of photoetching of this gold film is finished the making of concave-surface X-ray focusing pinhole.

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