A surface selective atomic layer deposition method using a pre-bonding method

Abstract

The present invention belongs to the field of optics and semiconductor manufacturing, and relates to the field of optical coating, and specifically to a surface selective atomic layer deposition method using a pre-bonding method. Provide a functional glass element and a bonding auxiliary element, perform surface polishing on the surface to be protected of the functional glass element and the protective surface of the bonding auxiliary element, then bond the surface to be protected and the protective surface, and then perform a pre-bonding treatment until no bubbles are generated at the edge of the bonding surface between the surface to be protected and the protective surface, and then perform atomic layer deposition, and perform debonding after the atomic layer deposition; wherein, the pre-bonding treatment adopts a direct bonding method, and the pressure applied during the direct bonding method is 0.05 to 0.1 MPa. The method provided by the present invention can avoid atomic layer deposition and device contamination, has a low risk of damage, is simple and easy to operate, has low cost, and has good effects.

Description

Technical Field

[0001] The invention belongs to the field of optics and semiconductor manufacturing, relates to the field of optical coating, and specifically relates to a surface selective atomic layer deposition method using a pre-bonding method. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] In the manufacturing process of optical devices and semiconductor devices, in order to achieve miniaturization, multifunctionality and high performance of the devices, it is often necessary to deposit a film layer with special properties on the electrical or optical surface composition, such as a high refractive index, high density, high dielectric constant and other characteristic film layers, which can provide some functionality while encapsulating and protecting the composition. Atomic layer deposition technology has special advantages in the preparation of these film layers. Its high shape retention, high density, and precise and controllable thickness make it the only choice for surface composition coating. However, at the same time, atomic layer deposition technology, as a coating technology for adsorption-type film growth, will grow film layers on all exposed surfaces of optical components or optoelectronic devices. In the conventional sense, atomic layer deposition is a non-selective technology for deposition on all surfaces. In other words, a thin film will also be deposited where a film layer is not needed, that is, a non-deposited surface, and because the film layer has good bonding strength, it is difficult to remove later.

[0004] According to the inventors' research, most of the existing selective atomic layer deposition technologies block or inhibit the growth of the film layer in the area that needs to be protected by coating or adhering protective materials, surface modification, etc. On the one hand, this method of inhibiting the growth of the film layer can only reduce the deposition rate of the film layer, but cannot completely avoid the deposition of the film layer; on the other hand, the surface coating material often needs to be removed in subsequent processes, which increases the risk of device contamination and damage and reduces process efficiency. Summary of the invention

[0005] In order to address the deficiencies of the prior art, the purpose of the present invention is to provide a surface selective atomic layer deposition method using a pre-bonding method, which can avoid atomic layer deposition and device contamination, has a low risk of damage, is simple and easy to operate, has low cost and good effect.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] On the one hand, a surface selective atomic layer deposition method using a pre-bonding method provides a functional glass element and a bonding auxiliary element, performs surface polishing on the surface to be protected of the functional glass element and the protective surface of the bonding auxiliary element, then bonds the surface to be protected and the protective surface, and then performs pre-bonding until no bubbles are generated at the edges of the bonding surfaces of the surface to be protected and the protective surface, and then performs atomic layer deposition, and then performs debonding after the atomic layer deposition; wherein the pre-bonding treatment adopts a direct bonding method, and a pressure of 0.05 to 0.1 MPa is applied during the direct bonding method.

[0008] The present invention adopts a pre-bonding method to effectively protect the surface where no film layer needs to be deposited during the atomic layer deposition film layer process, and re-exposes the non-deposited surface by debonding after the film layer deposition is completed.

[0009] The pre-bonding methods that can be implemented include direct bonding, eutectic bonding and anodic bonding.

[0010] The direct bonding method applies a certain pressure and temperature to the substrate to be bonded so that the bonding surfaces are bonded and a certain bonding strength is generated. However, direct bonding is very sensitive to factors such as the surface flatness, roughness, scratches, and attached particles of the substrate. Direct bonding needs to be implemented under high purification conditions, and the applied pressure and temperature are often high, which can easily cause damage to the substrate.

[0011] The eutectic bonding method requires the introduction of a medium such as an adhesive film or solder to the bonding substrate, which can achieve higher air density and better air density stability. However, in the manufacture of chip / wafer stacking technology and optical devices, the introduction of bonding media will cause poor device performance.

[0012] Anodic bonding connects the substrate to be bonded to an electrode. Under the action of the electric field, the sodium ions in the glass will drift toward the negative electrode, forming a depletion layer on the glass surface next to the silicon wafer or quartz. The depletion layer carries a negative charge, and the silicon wafer or quartz carries a positive charge. There is a large electrostatic attraction between the silicon wafer or quartz and the glass, which makes the two closely contact and bond. However, anodic bonding has some restrictions on the material of the bonding substrate, which needs to include a glass substrate, and the glass needs to contain alkali metal ions that can drift under the action of the electric field, mainly sodium ions; at the same time, during the bonding process of optical elements, if the thickness of the optical substrate is large, it is often necessary to apply a very high voltage to achieve the required electric field strength, which places high requirements on the power supply equipment.

[0013] The present invention adopts direct bonding method to carry out pre-bonding treatment, which adopts bonding overlapping surface to protect the surface to be protected of the functional glass element, without the need to completely bond the two elements together, that is, the bonding strength is relatively low, and thus the surface flatness, roughness, scratches, attached particles, pressure, temperature and other factors of the substrate are not required to be high. However, studies have shown that when bubbles exist at the edge of the bonding surface after pre-bonding treatment, it is not conducive to the protection of the surface to be protected during atomic layer deposition. The pre-bonding treatment of the present invention to the edge of the bonding surface of the surface to be protected and the protective surface does not produce bubbles, which can effectively prevent the entry of precursor gas, thereby protecting the non-deposition surface growth film layer. At the same time, when performing atomic layer deposition, the heating process before deposition will cause the bonding surface to produce a certain degree of strength, which can further improve the degree of bonding between the surface to be protected and the protective surface, and further effectively prevent the entry of precursor gas. In addition, the direct bonding method is used for pre-bonding treatment, because the bonding strength requirement is relatively low, it is more conducive to debonding, thereby avoiding device damage caused by excessive bonding strength.

[0014] Functional glass elements, the substrate is generally a double-sided polished and parallel flat glass sheet or cylinder, one of the surfaces is deposited with a silicon dioxide film layer by chemical vapor deposition, and then a graphic functional layer is produced by processes such as photolithography, dry etching, and cleaning, and then a film layer of a certain thickness different from the refractive index of the substrate is deposited on this surface by atomic layer deposition technology. The film layer encapsulates the graphic structure to prevent structural contamination or damage; at the same time, due to the difference in refractive index, the spectral transmittance of the surface can be improved. In the atomic layer deposition process, since the growth mode of the film layer is adsorption growth, as long as the surface exposed in the deposition chamber will be deposited with a film layer, so not only the required film layer is deposited on the graphic surface of the functional element, but also the same thickness of the film layer is deposited on the side surface and back of the element. The back of the functional element often needs to be coupled with other optical devices, and does not need to deposit a film layer, and needs to be protected during the deposition process. Therefore, on the other hand, a surface selective atomic layer deposition method using a pre-bonding method is used in the back protection of functional glass elements.

[0015] The beneficial effects of the present invention are:

[0016] The present invention uses a bonding auxiliary element to directly bond the surface of the functional glass element that needs to be protected before atomic layer deposition, until no bubbles are generated at the edge of the bonding surface. At the same time, the heating process before atomic layer deposition will make the bonding surface have a certain degree of strength, which can further improve the degree of bonding between the two surfaces, thereby effectively preventing the entry of precursor gas, thereby protecting the non-deposition surface from growing a film layer. After the deposition is completed and the temperature is lowered, the two bonding surfaces are debonded by applying a load to expose the non-deposition surface again. In this way, the required film layer is deposited on the surface of the functional glass element, and the non-deposition surface can be effectively protected.

[0017] The selective atomic layer deposition method provided by the present invention does not require high cleanliness of the target surface during bonding. Even if bubbles are generated during bonding, it does not affect the barrier effect on the entry of the precursor. It is only necessary to prevent bubbles from being generated at the edge of the bonding surface. At the same time, since the requirements for factors such as surface flatness, roughness, scratches, and attached particles are not high, the generated bubbles will reduce the bonding strength of the entire surface, which is beneficial to the debonding process at the end of deposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 A schematic structural diagram of bubbles that do not meet the requirements when the back side of the functional glass element of Example 1 of the present invention is protected;

[0020] Figure 2 A schematic structural diagram of bubbles that do not meet the requirements when the back side of the functional glass element of Example 1 of the present invention is protected;

[0021] Figure 3 A schematic diagram of the structure of bubbles that meet the requirements when the back side of the functional glass element of Example 1 of the present invention is protected;

[0022] Among them, 1. functional glass components, 2. bonding auxiliary components, 3. bubbles. DETAILED DESCRIPTION

[0023] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0025] In view of the problems of low deposition rate, difficulty in avoiding film deposition, device contamination, device damage and the like in the existing selective atomic layer deposition technology, the present invention proposes a surface selective atomic layer deposition method using a pre-bonding method.

[0026] A typical embodiment of the present invention provides a surface selective atomic layer deposition method using a pre-bonding method, providing a functional glass element and a bonding auxiliary element, performing surface polishing on the surface to be protected of the functional glass element and the protective surface of the bonding auxiliary element, then bonding the surface to be protected and the protective surface, and then performing pre-bonding treatment until no bubbles are generated at the bonding edge of the surface to be protected and the protective surface, and then performing atomic layer deposition, and debonding after the atomic layer deposition; wherein the pre-bonding treatment adopts a direct bonding method, and a pressure of 0.05 to 0.1 MPa is applied during the direct bonding method.

[0027] In some embodiments, before atomic layer deposition, the surface to be protected and the protective surface are wiped with water. Wiping with water can make the surface to be protected and the protective surface moist, which is convenient for lamination. At the same time, several bubbles will be formed during pre-bonding, which will reduce the final bonding strength and reduce the difficulty of debonding.

[0028] The higher the temperature of atomic layer deposition, the higher the bonding strength. In order to avoid excessively high bonding strength and increase the difficulty of debonding, in some embodiments, the temperature of atomic layer deposition is 150-250°C.

[0029] In some embodiments, plasma assistance is performed during the atomic layer deposition process, and the deposition rate can be increased by plasma assistance, thereby effectively controlling the growth of bonding strength.

[0030] In some embodiments, the functional glass element is a sheet-like structure, and the bonding auxiliary element is a columnar structure.

[0031] In some embodiments, the upper surface of the functional glass element is formed by chemical vapor deposition of a silicon dioxide film layer, and then photolithography, dry etching, and cleaning are performed to produce a graphic functional layer, and then the lower surface of the functional glass element is used as the surface to be protected.

[0032] In some embodiments, before debonding, the bonding strength between the surface to be protected and the protection surface is less than 3 MPa. The debonding can be achieved by pulling or shearing load without damaging the surface.

[0033] In some embodiments, when debonding, the edge is first debonded and desorbed by tensile load, and then the entire surface is completely debonded and desorbed. This method is to first desorb a part of the bonding area, so that the bonding surface is reduced, and the overall bonding strength is reduced, which is conducive to debonding and avoids damage to the sheet-like functional glass element. At this time, the temperature can be carried out at room temperature. The room temperature described in the present invention refers to the indoor ambient temperature, which is generally 15 to 30°C.

[0034] In some embodiments, during debonding, the temperature is 50-150° C. An increase in temperature is beneficial to the dissociation of the bonding surface.

[0035] Another embodiment of the present invention provides an application of the surface selective atomic layer deposition method using the pre-bonding method in the back protection of a functional glass element.

[0036] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0037] Example 1

[0038] A titanium oxide film layer is deposited on the surface of the functional glass element pattern, with a pre-deposition thickness of 500nm. The surface of the titanium oxide film to be deposited is the upper surface, and the pattern is a periodic slit structure with a period of 700nm, a ridge width of 300nm, a slit width of 400nm, and a depth of 400nm. The substrate material is a K9 optical glass sheet with a diameter of 30mm and a thickness of 0.4mm. The lower surface is a non-deposited surface, which has been polished and is the protective surface of the bonding surface. The bonding auxiliary element is a cylindrical K9 glass with a diameter of 26mm and a height of 8mm. The surface to be bonded has been polished.

[0039] At room temperature, a pressure load of 0.07 MPa is applied to directly bond the surface to be bonded of the bonding auxiliary element 2 to the non-deposition surface of the functional glass element 1. When the bubbles 3 generated by bonding are at the edge of the bonding auxiliary element, such as Figures 1-2 As shown, a tensile load of 0.02 MPa is applied to release the bond and then rebond until the bubble 3 generated by the bond is no longer generated at the edge; if the bubble 3 is generated during bonding, but the bubble 3 is not at the edge of the bonding auxiliary element, as shown in FIG. Figure 3 As shown, the next step of deposition can be carried out directly.

[0040] The pre-bonded components were placed in the chamber of the atomic layer deposition equipment, and titanium oxide films were deposited at 200°C. After the deposition was completed and cooled to room temperature, they were taken out. The two components were fixed with a tool on a tensile load machine. When the tensile load was applied to 1.5MPa, the bonding surfaces of the two components were disengaged again, completing the debonding process.

[0041] There is no damage to the surface after debonding. XPS detection of element distribution on the non-deposited surface shows no titanium infiltration. That is, this method protects the non-deposited surface well during the atomic layer deposition process, so that it is not contaminated by the deposited film layer and no subsequent treatment is required for removal.

[0042] Example 2

[0043] A titanium oxide film layer is deposited on the patterned surface of the functional glass element, with a pre-deposition thickness of 500nm. The surface of the titanium oxide film to be deposited is the upper surface, and the pattern is a periodic slit structure with a period of 700nm, a ridge width of 300nm, a slit width of 400nm, and a depth of 400nm. The substrate material is a K9 optical glass sheet with a diameter of 30mm and a thickness of 0.4mm. The lower surface is a non-deposited surface, which is polished to serve as a protective surface for the bonding surface. The bonding auxiliary element is a cylindrical K9 glass with a diameter of 26mm and a height of 8mm. The surface to be bonded is polished. The protective surface to be bonded of the functional glass element and the surface to be bonded of the bonding auxiliary element are both wiped with a wet dust-free cloth to make the surface to be bonded fully wet.

[0044] At room temperature, the surface to be bonded of the bonding auxiliary element is directly bonded to the non-deposition surface of the functional glass element (applying a pressure load of 0.05 MPa) until bubbles generated by the bonding are no longer generated at the edge, and then the next step of deposition can be carried out directly.

[0045] The pre-bonded components were placed in the chamber of the atomic layer deposition equipment, and titanium oxide films were deposited at 200°C. After the deposition was completed and cooled to room temperature, they were taken out. The two components were fixed with a tool on a tensile load machine. When the tensile load was applied to 1.1 MPa, the bonding surfaces of the two components were disengaged again, completing the debonding process.

[0046] The surface after debonding is not damaged, and the element distribution of the non-deposited surface is detected by XPS, and no titanium element has penetrated, that is, this method protects the non-deposited surface well during the atomic layer deposition process, so that it is not contaminated by the deposited film layer, and no subsequent treatment is required for removal. This embodiment is compared with embodiment 1 to illustrate that after wetting the surface to be bonded, it is not only easier to bond; but also easier to generate bubbles, which reduces the bonding strength.

[0047] Example 3

[0048] A titanium oxide film layer is deposited on the surface of the functional glass element pattern, with a pre-deposition thickness of 500nm. The surface of the titanium oxide film to be deposited is the upper surface, and the pattern is a periodic slit structure with a period of 700nm, a ridge width of 300nm, a slit width of 400nm, and a depth of 400nm. The substrate material is a K9 optical glass sheet with a diameter of 30mm and a thickness of 0.4mm. The lower surface is a non-deposited surface, which has been polished and is the protective surface of the bonding surface. The bonding auxiliary element is a cylindrical K9 glass with a diameter of 26mm and a height of 8mm. The surface to be bonded has been polished.

[0049] At room temperature, the surface to be bonded of the bonding auxiliary element is directly bonded to the non-deposition surface of the functional glass element (applying a pressure load of 0.1 MPa) until bubbles generated by the bonding are no longer generated at the edge, and then the next step of deposition can be carried out directly.

[0050] The pre-bonded components were placed in the chamber of the atomic layer deposition equipment, and titanium oxide films were deposited at 250°C. After the deposition was completed, the components were taken out after cooling to room temperature. The two components were fixed with a fixture on the tensile load machine, and a tensile load of 1.2MPa was used to first debond and desorb the edges, and then a tensile load of 1.0MPa was used to completely debond and desorb the entire surface, completing the debonding process.

[0051] The surface after debonding is not damaged, and the element distribution of the non-deposited surface is detected by XPS, and no titanium element has penetrated, that is, this method protects the non-deposited surface well during the atomic layer deposition process, so that it is not contaminated by the deposited film layer, and no subsequent treatment is required for removal. This embodiment is compared with Example 1 to illustrate that when the bonding strength is high, a part of the bonding area can be desorbed first to reduce the bonding surface and reduce the overall bonding strength, which is conducive to debonding and avoids damage to the sheet-like functional glass element.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A surface selective atomic layer deposition method using a pre-bonding method, characterized in that, A functional glass element and a bonding auxiliary element are provided, and the surface to be protected of the functional glass element and the protective surface of the bonding auxiliary element are polished, and then the surface to be protected and the protective surface are bonded together, and then a pre-bonding treatment is performed until no bubbles are generated at the bonding edge of the surface to be protected and the protective surface, and then atomic layer deposition is performed, and debonding is performed after the atomic layer deposition; wherein the pre-bonding treatment adopts a direct bonding method, and a pressure of 0.05 to 0.1 MPa is applied during the direct bonding method; Before atomic layer deposition, the surface to be protected and the protection surface are wiped with water; The temperature of atomic layer deposition is 150-250°C.

2. The surface selective atomic layer deposition method using the pre-bonding method as claimed in claim 1, characterized in that: Plasma assistance is performed during the atomic layer deposition process.

3. The surface selective atomic layer deposition method using a pre-bonding method as claimed in claim 1, characterized in that: The functional glass element is a sheet-like structure, and the bonding auxiliary element is a columnar structure.

4. The surface selective atomic layer deposition method using a pre-bonding method as claimed in claim 1, characterized in that: The upper surface of the functional glass element is deposited with a silicon dioxide film layer by chemical vapor deposition, and then a graphic functional layer is produced by photolithography, dry etching, and cleaning, and then the lower surface of the functional glass element is used as the surface to be protected.

5. The surface selective atomic layer deposition method using a pre-bonding method as claimed in claim 1, characterized in that: Before debonding, the bonding strength between the surface to be protected and the protection surface is less than 3 MPa.

6. The surface selective atomic layer deposition method using a pre-bonding method as claimed in claim 1, characterized in that: During debonding, tensile load is used to first debond and desorb the edges, and then completely debond and desorb the entire surface.

7. The surface selective atomic layer deposition method using a pre-bonding method as claimed in claim 1, characterized in that: When debonding, the temperature is 50 to 150°C.

8. Use of the surface selective atomic layer deposition method using a pre-bonding method as claimed in any one of claims 1 to 7 in back side protection of a functional glass element.

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