CN116885547A - Preparation method of semiconductor microsphere - Google Patents

Abstract

The invention discloses a method for preparing semiconductor microspheres. The preparation method of the semiconductor microspheres includes: applying ink on the surface of the semiconductor substrate using inkjet printing to form ink droplet microspheres; drying the ink droplet microspheres to form glue balls on the surface of the semiconductor substrate ; Etch the surface of the rubber ball and the semiconductor substrate to form semiconductor microspheres on the surface of the semiconductor substrate. The preparation method of the present invention uses inkjet printing technology. By controlling the ink material, the contact angle between the ink and the substrate, the ink volume and other factors, the required rubber balls can be directly obtained without going through the reflow process, thereby reducing the impact of external factors on the process. to the minimum, thereby ensuring the quality of the photoresist microspheres, thereby improving the quality of the final semiconductor microspheres.

Description

A kind of preparation method of semiconductor microspheres

Technical field

The invention belongs to the technical field of semiconductor device manufacturing, and specifically relates to a method for preparing semiconductor microspheres.

Background technique

Microspheres prepared through semiconductor methods have been widely used in lasers, optical communications, optical sensing and other fields. The general preparation process is to use photolithography technology to prepare glue pillars on the substrate material, then heat the glue pillars to form microspheres under the action of thermodynamics, and then prepare microspheres of the substrate material through semiconductor processes such as etching. ball.

The use of this process will be affected by many factors, especially during the reflow process, which has a decisive impact on its morphology. If affected by external factors, it will lead to its ROC (Radius of Curvature), RMS (Root mean square), Conic, etc. The parameters are affected, and this influence affects the photoresist microsphere parameters of the finished product (microsphere lens formed from the base material) through the etching process. Specifically, the microsphere surface is compared with the standard fixed ROC and Conic sphere. The influence deviation can be determined by RMS reacts.

Contents of the invention

The main purpose of the present invention is to provide a method for preparing semiconductor microspheres to overcome the shortcomings in the prior art.

In order to achieve the aforementioned objects of the invention, the technical solutions adopted in the embodiments of the present invention include:

The embodiment of the present invention provides a method for preparing semiconductor microspheres, including:

Use inkjet printing to apply ink on the surface of the semiconductor substrate to form ink droplet microspheres;

Drying the ink droplet microspheres to form glue balls on the surface of the semiconductor substrate;

The glue ball and the surface of the semiconductor substrate are etched to form semiconductor microspheres on the surface of the semiconductor substrate.

Further, the method for preparing semiconductor microspheres specifically includes: adjusting the parameters of the rubber spheres by at least regulating the contact angle between the ink and the surface of the semiconductor substrate and the ink droplet microspheres. The parameters include one or more of the effective area of the rubber ball, radius of curvature, diameter, and degree of surface deviation; wherein, the volume of the ink droplet microsphere is marked as V, the radius of curvature is marked as R, and the volume of the rubber ball is marked as R. The sag height of the rubber ball is marked as h, the bottom diameter of the rubber ball is marked as D, and the contact angle of the rubber ball is marked as α, and they satisfy the following relationship: V=πh^2*(3R-h)/3, α=arcsin (D/2/R),

Further, the method for preparing semiconductor microspheres includes: surface treatment of the semiconductor substrate.

Furthermore, the surface treatment includes using hexamethyldisilazane to perform surface hydrophobization treatment on the semiconductor substrate under conditions of 100°C-150°C for 0.5h-1h, wherein the hexamethyldisilazane The spraying flow rate of nitrogen is 0.1scm-2scm, and the spraying time is 0.5h-1h.

Further, the ink includes photoresist or nanoimprint glue.

Compared with the prior art, the present invention has the following beneficial effects:

The processing method of the present invention uses inkjet printing technology. By controlling the ink material, the contact angle between the ink and the substrate, the ink volume and other factors, the required rubber balls can be directly obtained without going through the reflow process, thereby reducing the impact of external factors on the process. to the minimum, thereby ensuring the quality of the final photoresist microspheres, thereby improving the quality of the final semiconductor microspheres.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments recorded in this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic flow chart of a method for preparing semiconductor microspheres in an embodiment of the present application.

Figure 2 is a schematic flow chart of the preparation method of semiconductor microspheres in the comparative example.

Explanation of reference signs: 1. Semiconductor substrate, 2. Ink, 3. Inkjet printing equipment, 4. Ink droplet microspheres, 5. Glue balls, 6. Semiconductor microspheres, 7. Photoresist, 8. Glue column .

Detailed ways

In view of the shortcomings of the existing technology, the inventor of this case was able to propose the technical solution of the present invention after long-term research and extensive practice. The main method is to use inkjet printing technology to directly form microspheres through printing without the need for traditional glue dispersion and exposure. Development, reflow and other processes. The technical solution, its implementation process and principles will be further explained below.

One aspect of the embodiment of the present invention provides a method for preparing semiconductor microspheres, including:

Use inkjet printing to apply ink on the surface of the semiconductor substrate to form ink droplet microspheres;

Drying the ink droplet microspheres to form glue balls on the surface of the semiconductor substrate;

The glue ball and the surface of the semiconductor substrate are etched to form semiconductor microspheres on the surface of the semiconductor substrate.

In some preferred embodiments, the method for preparing semiconductor microspheres specifically includes: adjusting the parameters of the rubber balls by at least regulating the contact angle between the ink and the surface of the semiconductor substrate and the ink droplet microspheres. The parameters of the microsphere include one or more of the effective area of the rubber ball, the radius of curvature, the diameter, and the degree of surface deviation; wherein, the volume of the ink droplet microsphere is recorded as V, and the radius of curvature is recorded as R, so The sag height of the rubber ball is denoted as h, the bottom diameter of the rubber ball is denoted as D, and the contact angle of the rubber ball is denoted as α, and the following relationship is satisfied between them: V=πh^2*(3R-h)/3 ,α=arcsin(D/2/R),

In some preferred embodiments, the method for preparing semiconductor microspheres includes: surface treatment of the semiconductor substrate.

In some more preferred embodiments, the surface treatment includes using hexamethyldisilazane to perform surface hydrophobization treatment on the semiconductor substrate under conditions of 100°C-150°C for 0.5h-1h, wherein, The spraying flow rate of hexamethyldisilazane is 0.1scm-2scm, and the spraying time is 0.5h-1h.

In some preferred embodiments, the ink may include photoresist or nanoimprint glue, but is not limited thereto.

In some preferred embodiments, a plurality of ink droplet microspheres are provided, and the plurality of ink droplet microspheres are distributed in an array on the semiconductor substrate.

In some preferred embodiments, the drying temperature of the ink droplet microspheres is 50°C-100°C.

In some preferred embodiments, the etching process conditions are: etching the rubber ball with an etching reagent at an etching rate of 0.03um/min-3um/min, and etching the semiconductor substrate at an etching rate of 0.1um/min. /min-5um/min etching speed for etching.

In some preferred embodiments, the material of the semiconductor substrate may include any one of silicon wafers, fused quartz, gallium arsenide, etc., but is not limited thereto.

In some more preferred embodiments, the etchant may include carbon tetrafluoride (CF ₄ ), octafluoropropane (C ₃ F ₈ ), trifluoromethane (CHF ₃ ), sulfur hexafluoride (SF ₆ ) and other gases, but are not limited to these.

In some preferred embodiments, the semiconductor microspheres are hemispherical.

The embodiment of the present invention uses inkjet printing technology. By controlling the ink material, the contact angle between the ink and the substrate, the ink volume and other factors, the required rubber balls can be directly obtained without going through the reflow process, thereby reducing the impact of external factors on the process. to the minimum, thereby ensuring the quality of the final product photoresist microspheres, such as the stability of parameters such as ROC (Radius of Curvature), RMS, Conic, diameter, and degree of deviation of the surface shape of the photoresist.

In order to make the above objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Example 1

The preparation method of semiconductor microspheres provided in this embodiment, as shown in Figure 1, includes the following steps:

S1. Select a silicon wafer with a lateral size of 1 inch and a thickness of 500 μm to 1500 μm as the semiconductor substrate 1, and perform surface hydrophobization treatment on the silicon wafer using hexamethyldisilazane at 100°C for 1 hour. Among them, the spraying flow rate of hexamethyldisilazane is 0.1scm, and the spraying time is 1h;

S2. Use AZ4620 photoresist as ink 2, and use inkjet printing equipment 3 to drop ink 2 on the silicon wafer to form ink droplet microspheres 4 distributed in an array;

S3. The ink droplet microsphere 4 is dried at 50°C. After drying, the rubber ball 5 is obtained. The volume of the ink droplet microsphere 4 is denoted as V, the radius of curvature is denoted as R, and the rubber ball 5 is The ball sag height is recorded as h, the bottom diameter of the rubber ball 5 is recorded as D, and the contact angle of the rubber ball 5 is recorded as α, and the following relationship is satisfied between them: V=πh^2*(3R-h)/3, α= arcsin(D/2/R)，

S4. Use CF ₄ to etch the surface of the rubber ball 5 and the semiconductor substrate 1, etching the rubber ball 5 at an etching rate of 0.03um/min, and etching the semiconductor substrate 1 at an etching rate of 0.1um/min. Etching is performed to form hemispherical semiconductor microspheres 6 on the surface of the semiconductor substrate 1 .

Example 2

The preparation method of semiconductor microspheres provided in this embodiment, as shown in Figure 1, includes the following steps:

S1. Select a silicon wafer with a lateral size of 20 inches and a thickness of 1500 μm as the semiconductor substrate 1, and perform surface hydrophobization treatment on the silicon wafer using hexamethyldisilazane at 150°C for 0.5h, where , the spraying flow rate of hexamethyldisilazane is 2scm, and the spraying time is 0.5h;

S2. Use AZ4620 photoresist as ink 2, and use inkjet printing equipment 3 to drop ink 2 on the silicon wafer to form ink droplet microspheres 4 distributed in an array;

S3. The ink droplet microsphere 4 is dried at 100°C. After drying, the rubber ball 5 is obtained. The volume of the ink droplet microsphere 4 is denoted as V, the radius of curvature is denoted as R, and the rubber ball 5 is The ball sag height is recorded as h, the bottom diameter of the rubber ball 5 is recorded as D, and the contact angle of the rubber ball 5 is recorded as α, and the following relationship is satisfied between them: V=πh^2*(3R-h)/3, α= arcsin(D/2/R)，

S4. Use C ₃ F ₈ or CHF ₃ to etch the surface of the rubber ball 5 and the semiconductor substrate 1 , etching the rubber ball 5 at an etching rate of 3um/min, and etching the semiconductor substrate 1 at an etching rate of 5um/min. The etching is performed at an etching speed to form hemispherical semiconductor microspheres 6 on the surface of the semiconductor substrate 1 .

Example 3

The preparation method of semiconductor microspheres provided in this embodiment, as shown in Figure 1, includes the following steps:

S1. Select a silicon wafer with a lateral size of 10 inches and a thickness of 1000 μm as the semiconductor substrate 1, and perform surface hydrophobization treatment on the silicon wafer using hexamethyldisilazane at 120°C for 0.8h, where , the spraying flow rate of hexamethyldisilazane is 1scm, and the spraying time is 0.8h;

S2. Use AZ4620 photoresist as ink 2, and use inkjet printing equipment 3 to drop ink 2 on the silicon wafer to form ink droplet microspheres 4 distributed in an array;

S3. The ink droplet microsphere 4 is dried at 75°C. After drying, the rubber ball 5 is obtained. The volume of the ink droplet microsphere 4 is denoted as V, the radius of curvature is denoted as R, and the rubber ball 5 is The ball sag height is recorded as h, the bottom diameter of the rubber ball 5 is recorded as D, and the contact angle of the rubber ball 5 is recorded as α, and the following relationship is satisfied between them: V=πh^2*(3R-h)/3, α= arcsin(D/2/R)，

S4. Use SF ₆ to etch the surface of the rubber ball 5 and the semiconductor substrate 1, etching the rubber ball 5 at an etching rate of 2um/min, and etching the semiconductor substrate 1 at an etching rate of 3um/min. , so that hemispherical semiconductor microspheres 6 are formed on the surface of the semiconductor substrate 1 .

Comparative ratio

The preparation method of semiconductor microspheres provided in this comparative example, as shown in Figure 2, includes the following steps:

S1. Select a silicon wafer with a lateral size of 10 inches and a thickness of 1000 μm as the semiconductor substrate 1, and perform surface hydrophobization treatment on the silicon wafer using hexamethyldisilazane at 120°C for 0.8h, where , the spraying flow rate of hexamethyldisilazane is lscm, and the spraying time is 0.8h;

S2. Use a coating machine to evenly coat a layer of AZ4620 photoresist 7 with a thickness of 4um on the surface of the semiconductor substrate 1;

S3. Use a photolithography machine to expose the substrate 1 coated with the photoresist 7. After the exposure, the substrate 1 is put into the developer. In the area of the semiconductor substrate 1 that is illuminated by UV light, the photoresist 7 is being developed. Dissolve in the liquid, exposing the underlying substrate, the area on the semiconductor substrate 1 that is not irradiated with UV light, and the photoresist 7 remains to form a glue column 8 on the surface of the semiconductor substrate 1;

S4. Make the glue column 8 form the glue ball 5 under the action of thermodynamics by heating and refluxing;

S5. Etch the surface of the rubber ball 5 and the base semiconductor substrate 1 to form hemispherical semiconductor microspheres 6 on the surface of the semiconductor substrate 1.

Compare the semiconductor microspheres formed by the processing methods of Example 3 and Comparative Example. The comparison results are as follows:

Radius of Curvature ROC diameter Conic RMS Example 3 3330um 400um 0 23nm Comparative ratio 3330um 400um 0 42nm

Note: RMS refers to the difference from the standard ROC 3300um, diameter 400um, Conic 0 smooth spherical surface. The mean square error of the difference is 40nm, which is used to represent the degree of deviation from the standard spherical surface. If the film is made of ROC or If the Conic is shifted, the mean square error from the standard spherical surface will be larger.

As can be seen from the above table, by testing semiconductor microspheres prepared by different methods, the mean square error between the semiconductor microspheres of the embodiments and the standard spherical surface is significantly smaller than that of the comparative example. This method can significantly improve the quality of the semiconductor microspheres.

In addition, the inventor of the present case also conducted experiments with other raw materials, process operations, and process conditions mentioned in this specification with reference to the aforementioned embodiments, and achieved relatively ideal results.

Although the present invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions and/or additions may be made and the substance thereof may be used without departing from the spirit and scope of the invention. Elements of the described embodiments may be replaced with effective ones. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Furthermore, unless specifically stated, any use of the terms first, second, etc. does not imply any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another element.

Claims (10)

1. The preparation method of the semiconductor microsphere is characterized by comprising the following steps:

applying ink to the surface of the semiconductor substrate by using an ink jet printing mode to form ink droplet microspheres;

drying the ink droplet microspheres to form glue balls on the surface of the semiconductor substrate;

and etching the glue ball and the surface of the semiconductor substrate so as to form the semiconductor microsphere on the semiconductor substrate.

2. The method for preparing semiconductor microspheres according to claim 1, comprising the following steps: adjusting parameters of the rubber ball at least by adjusting and controlling the contact angle of the ink and the surface of the semiconductor substrate and the ink drop microsphere, wherein the parameters of the microsphere comprise one or more of the effective area, the radius of curvature, the diameter and the surface deviation degree of the rubber ball; the volume of the ink droplet microsphere is marked as V, the curvature radius is marked as R, the rubber ball sagittal height of the rubber ball is marked as h, the bottom diameter of the rubber ball is marked as D, the contact angle of the rubber ball is marked as alpha, and the following relation is satisfied: v=pi h 2 (3R-h)/3, a=arcsin (D/2/R),

3. the method for producing a semiconductor microsphere according to claim 1, comprising: and carrying out surface treatment on the semiconductor substrate.

4. A method of producing semiconductor microspheres according to claim 3, wherein: the surface treatment comprises carrying out surface hydrophobization treatment on the semiconductor substrate by using hexamethyldisilazane at the temperature of 100-150 ℃ for 0.5-1 h, wherein the spraying flow of the hexamethyldisilazane is 0.1-2 scm, and the spraying time is 0.5-1 h.

5. The method for producing a semiconductor microsphere according to claim 1, wherein: the ink comprises photoresist or nanoimprint glue.

6. The method for producing a semiconductor microsphere according to claim 1, wherein: the ink droplet microspheres are arranged in a plurality, and the ink droplet microspheres are distributed on the semiconductor substrate in an array mode.

7. The method for producing a semiconductor microsphere according to claim 1, wherein: the drying temperature of the ink droplet microsphere is 50-100 ℃.

8. The method for preparing semiconductor microspheres according to claim 1, wherein the etching process conditions are as follows: and etching the rubber ball at an etching speed of 0.03um/min-3um/min by using an etching reagent, and etching the semiconductor substrate at an etching speed of 0.1um/min-5 um/min.

9. The method for producing a semiconductor microsphere according to claim 1, wherein: the semiconductor substrate is made of any one of silicon wafer, fused quartz or gallium arsenide.

10. The method for producing a semiconductor microsphere according to claim 1, wherein: the semiconductor microsphere is hemispherical.