Low-defect-density thin film material preparation technology

Abstract

The invention provides a low-defect-density thin film material preparation technology, and relates to the technical field of thin film deposition. The thin film deposition device comprises a metal shell, a vacuum cavity, an electrode plate and an ultraviolet lamp, the electrode plate is arranged on the side edge in the deposition area in the movement direction of deposition particles, the ultraviolet lamp emits ultraviolet rays, the ultraviolet rays irradiate the deposition area, light-induced charging is conducted on impurity particles and the deposition particles in the deposition area, and plasma is formed; the electrode plate forms a deflection magnetic field in the deposition area, so that the impurity particles deflect the movement direction of the deposition particles and are deposited on the electrode plate, and the deposition particles are accelerated to hit the substrate. The method solves the problem that impurity particles left in the vacuum cavity in the coating process cause high defects of the prepared film, also solves the problem that the binding force of the film layer of the electron beam evaporation coating is not enough, and is suitable for preparing the high-purity low-defect film in different environments.

Description

Technical Field

[0001] This invention relates to the field of thin film deposition technology, and in particular to a technique for preparing thin film materials with low defect density. Background Technology

[0002] Electron beam evaporation coating technology is widely used in the coating of optical devices, electronic components and other devices due to its advantages such as high deposition rate, wide range of target materials and high precision.

[0003] Due to continuous deposition, instrument aging, and insufficient vacuum, some impurity particles may remain inside the vacuum chamber. These impurity particles will deposit onto the substrate during subsequent deposition processes, creating nodules or defects within the film, thus affecting the purity and uniformity of the prepared film. Meanwhile, although electron beam evaporation deposition has a series of advantages, the energy of the deposited particles is relatively low, resulting in poor film adhesion after deposition onto the substrate. This leads to insufficient film density and a tendency for the film to detach.

[0004] Currently, common methods for dealing with residual impurity particles inside the vacuum chamber, such as ultrasonic cleaning and post-deposition vacuuming, suffer from low efficiency and cumbersome operation. Furthermore, there is currently no good solution for the adhesion problem of thin films prepared by electron beam evaporation deposition. Therefore, solving the problems of residual impurity particles inside the vacuum chamber and poor film adhesion during deposition is of great significance for preparing low-defect, high-performance thin films. Summary of the Invention

[0005] In view of this, the present invention proposes a low defect density thin film material preparation technology, which solves the problems of impurity contamination and insufficient film adhesion during the coating process by using ultraviolet light photocharging and electric field screening to accelerate charged particles.

[0006] The technical solution of the present invention is achieved as follows:

[0007] In a first aspect, the present invention provides a thin film deposition apparatus with low defect density, comprising a metal housing and a vacuum chamber, wherein:

[0008] The metal outer shell is a sealed vacuum chamber, which contains an electron beam system, a workpiece holder, a target, a substrate, an electrode plate, and an ultraviolet lamp.

[0009] A target is placed on the electron beam system, and a substrate is placed on the workpiece holder. The area between the target and the substrate is a deposition area. The electron beam system emits an electron beam onto the surface of the target, causing the target to evaporate and deposit particles into the deposition area, which then strike the substrate to form a thin film.

[0010] The electrode plate is positioned on the side of the deposition zone along the direction of particle movement. The ultraviolet lamp emits ultraviolet light, which irradiates the deposition zone and photocharges the impurity particles and deposition particles in the deposition zone to form plasma. The electrode plate forms a deflection magnetic field in the deposition zone, which deflects the impurity particles in the direction of particle movement and deposits them onto the electrode plate, thereby accelerating the deposition particles to hit the substrate.

[0011] Based on the above technical solutions, preferably, the angle between the electrode plate and the plane of the substrate is 30° to 90°.

[0012] More preferably, the angle between the electrode plate and the plane of the substrate is 60° to 70°.

[0013] Based on the above technical solutions, preferably, the height of the electrode plate along the direction of deposition particle movement is 20% to 80% of the height of the deposition zone.

[0014] More preferably, the height of the electrode plate along the direction of particle movement is 50% to 70% of the height of the deposition zone.

[0015] If the electrode plate voltage is too high, the deposited ions will be excessively deflected and will not be deposited on the substrate; if the electrode plate voltage is too low, charged impurity particles will not be adsorbed onto the electrode plate. It is necessary to select the appropriate electrode plate voltage and power according to the target material so that the deflection electric field has the effect of screening particles.

[0016] Based on the above technical solutions, preferably, the distance between the ultraviolet lamp and the deposition zone is 10cm to 50cm.

[0017] By adopting the above technical solution, the ultraviolet lamp emits ultraviolet light into the sedimentation area, so that the entire sedimentation area is completely covered by ultraviolet light.

[0018] Based on the above technical solutions, preferably, the target material is made of SiO2 or TiO2. x The electrode plate is made of one or more of the following materials: copper, aluminum, tungsten, molybdenum, and stainless steel; the working substance of the ultraviolet lamp is one or more of the following: mercury vapor, metal halide, and xenon.

[0019] The present invention also provides a thin film deposition method with low defect density, which uses the above-mentioned apparatus to evacuate the vacuum chamber;

[0020] Rotate the workpiece holder;

[0021] An electron beam system emits an electron beam onto the surface of a target material;

[0022] The target material evaporates deposited particles into the deposition area;

[0023] Ultraviolet lamps emit ultraviolet light into the deposition zone, causing impurity particles and deposition particles to become charged and form plasma;

[0024] The electrode plate generates a deflection electric field in the deposition area, causing charged impurity particles to be deflected and adsorbed onto the electrode plate, screening out deposited ions, and accelerating the deposited ions to be deposited onto the substrate to form a thin film.

[0025] Based on the above technical solutions, the preferred method is to evacuate the vacuum chamber to 5*10. -4 Pa or above.

[0026] Based on the above technical solutions, preferably, the rotational speed of the workpiece holder is 5 to 30 r / min.

[0027] The present invention has the following advantages over the prior art:

[0028] 1. Ultraviolet light is emitted by an ultraviolet lamp to charge impurity particles and deposited particles in the deposition zone. The charging process does not require the introduction of a complex electromagnetic field, and the equipment is relatively simple. At the same time, no other pollution is introduced during the entire charging process, which improves the purity of the film. The ultraviolet irradiation range covers the entire deposition zone, ensuring that all particles in the deposition zone are charged to form plasma, which improves the uniformity of charging.

[0029] 2. The electrode plate generates a deflection electric field in the deposition area, which on the one hand filters particles and adsorbs impurity particles onto the electrode plate, and on the other hand increases the kinetic energy of the deposited ions, making the film layer formed after deposition on the substrate more tightly bonded. The equipment is highly functional and further improves the deposition rate. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a schematic diagram showing the relative positions of the electrode plate and the target material in this invention.

[0033] Figure 3 This is a schematic diagram illustrating the movement of deposited particles and impurity particles according to the present invention;

[0034] Figure 4 This is a diagram of the ultraviolet lamp irradiation area of ​​the present invention;

[0035] Figure 5 This is a cross-sectional schematic diagram of the present invention;

[0036] Figure 6 This is a schematic diagram of the process of the present invention;

[0037] In the figure, the metal casing is 7, the electron beam system is 6, the workpiece holder is 1, the target material is 5, the substrate is 2, the electrode plate is 3, and the ultraviolet lamp is 4. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1

[0040] like Figures 1-5 As shown, this embodiment discloses a thin film deposition apparatus with low defect density, including a metal shell 7, inside which is a sealed vacuum chamber 2, and an electron beam system 6 and a workpiece holder 1 are arranged inside the vacuum chamber 2.

[0041] A target 5 is placed on the electron beam system 6, and a substrate 2 is placed on the workpiece holder 1. The area between the target 5 and the substrate 2 is the deposition area 7.

[0042] Electron beam system 6 emits an electron beam onto the surface of target 5, causing the target to evaporate and deposit particles into deposition area 7, which then strike the substrate 2 to form a thin film.

[0043] The device disclosed in this embodiment also includes an electrode plate 3 and an ultraviolet lamp 4;

[0044] Two electrode plates 3 are set on both sides of the deposition zone 7 along the direction of the movement of the deposited particles. The ultraviolet lamp 4 irradiates the deposition zone 7, photo-charges the impurity particles and deposited particles in the deposition zone 7, and forms plasma. The electrode plates 3 form a deflection magnetic field in the deposition zone 7, which deflects the impurity particles in the direction of the movement of the deposited particles, and accelerates the deposited particles to hit the substrate 2.

[0045] In the device disclosed in this embodiment, the angle between the plane of the electrode plate 8 and the plane of the substrate 2 is 30° to 90°; more preferably, it is 60° to 75°.

[0046] In the apparatus disclosed in this embodiment, the height of the electrode plate 3 along the direction of the deposition particle movement is 20% to 80% of the height of the deposition zone 7; more preferably, it is 50% to 70%.

[0047] In the apparatus disclosed in this embodiment, the distance between the ultraviolet lamp 4 and the deposition zone 7 is 10cm to 50cm.

[0048] In the device disclosed in this embodiment, the target material 5 is made of SiO2 or TiO2. x The electrode plate 3 is made of one or more of the following materials: copper, aluminum, tungsten, molybdenum and stainless steel; the working substance of the ultraviolet lamp 4 is one or more of the following materials: mercury vapor, metal halide and xenon.

[0049] Application Examples 1-5 illustrate low-defect-density thin film deposition methods using the apparatus described in Example 1, such as... Figure 5 As shown, the details are as follows.

[0050] Application Example 1

[0051] This application example discloses a thin film deposition method with low defect density, using 40g of high-purity SiO2 particles as the target material, and evacuating the vacuum chamber 2 to 5*10. -4 Pa, preheat vacuum chamber 2, mover 1 drives substrate 2 to rotate at 10 r / min, energize electrode plate 3 and ultraviolet lamp 4, turn on electron beam system 6 to emit electron beam to target surface, causing target to evaporate deposited particles to deposition zone 7. Under the irradiation of ultraviolet lamp 4, SiO2 deposited particles and impurity particles in deposition zone are photocharged. Electrode plate 3 forms deflection magnetic field in deposition zone 7, causing impurity particles to deflect the direction of movement of deposited particles, causing deposited particles to accelerate and hit substrate 2 to form a thin film. When the film reaches a suitable thickness, turn off ultraviolet lamp and electrode plate, open vacuum chamber door and take out sample.

[0052] In this embodiment, the working substance of the ultraviolet lamp is mercury vapor, the ultraviolet wavelength is 254nm, and the ultraviolet lamp is 30cm away from the deposition area.

[0053] The electrode plate used in this embodiment is made of aluminum metal, the angle between the electrode plate and the plane of the target is 30°, and the vertical height of the electrode plate accounts for 20% of the deposition area.

[0054] Application Example 2

[0055] This application example discloses a thin film deposition method with low defect density. The difference from application example 1 is that the angle between the electrode plate and the plane of the target material is 45°, and the vertical height of the electrode plate accounts for 40% of the deposition area.

[0056] Application Example 3

[0057] This application example discloses a thin film deposition method with low defect density. The difference from Application Example 1 is that the angle between the electrode plate and the plane of the target material is 60°, and the vertical height of the electrode plate accounts for 50% of the deposition area.

[0058] Application Example 4

[0059] This application example discloses a thin film deposition method with low defect density. The difference from Application Example 1 is that the angle between the electrode plate and the plane of the target material is 70°, and the vertical height of the electrode plate accounts for 60% of the deposition area.

[0060] Application Example 5

[0061] This application example discloses a thin film deposition method with low defect density. The difference from Application Example 1 is that the angle between the electrode plate and the plane of the target material is 90°, and the vertical height of the electrode plate accounts for 80% of the deposition area.

[0062] Comparative Example

[0063] This comparative example discloses a thin film deposition method with low defect density. The difference from Application Examples 1-5 is that the apparatus used does not include an electrode plate and an ultraviolet lamp.

[0064] Using 40g of high-purity SiO2 particles as the target material, the vacuum chamber was evacuated to a vacuum level of 5*10. -4 Pa, preheat the vacuum chamber, the moving workpiece holder drives the substrate to rotate at a speed of 10 r / min, turn on the electron beam system to emit an electron beam to the target surface, causing the target to evaporate and deposit particles into the deposition area, so that the deposited particles hit the substrate to form a thin film. When the film reaches a suitable thickness, turn off the ultraviolet lamp and electrode plate, open the vacuum chamber door, and take out the sample.

[0065] The purity and density of the films prepared in corresponding use cases 1 to 5 and the comparative examples were tested, and the test results are shown in Table 1.

[0066] Table 1

[0067]

[0068]

[0069] As can be seen from Examples 1-5, the comparative examples, and Table 1, the purity of the film prepared by the technical solution of this application reaches 6N (99.9999%), which is higher than that of the comparative example (5N (99.999%)); the density of the film prepared by the technical solution of this application reaches 2.23 g / cm³. 3 The adhesion strength of the film prepared by the technical solution of this application is more than 10% higher than that of the comparative example; the adhesion strength of the film is more than 24.5N, which is much higher than that of the comparative example of 20.0N.

[0070] Furthermore, the films prepared in Application Examples 3-4 have a higher density than those in other application examples. It can be seen that in the technical solution of this application, when the angle between the plane where the electrode plate 8 and the substrate 2 are located is 60° to 70°, and the height of the electrode plate 3 is 50% to 70% of the height of the deposition region 7, the prepared film has a higher density, better adhesion, and better overall performance.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A thin film deposition apparatus with low defect density, characterized in that, Includes a metal outer shell and a vacuum chamber, wherein: The metal outer shell is a sealed vacuum chamber, which contains an electron beam system, a workpiece holder, a target, a substrate, an electrode plate, and an ultraviolet lamp. A target is placed on the electron beam system, and a substrate is placed on the workpiece holder. The area between the target and the substrate is a deposition area. The electron beam system emits an electron beam onto the surface of the target, causing the target to evaporate and deposit particles into the deposition area, which then strike the substrate to form a thin film. The electrode plate is positioned on the side of the deposition zone along the direction of particle movement. The ultraviolet lamp emits ultraviolet light, which irradiates the deposition zone and photocharges the impurity particles and deposition particles in the deposition zone to form plasma. The electrode plate forms a deflection magnetic field in the deposition zone, which deflects the impurity particles in the direction of particle movement and deposits them onto the electrode plate, thereby accelerating the deposition particles to hit the substrate.

2. The apparatus as described in claim 1, characterized in that: The angle between the electrode plate and the plane of the substrate is 30° to 90°.

3. The apparatus as described in claim 2, characterized in that: The angle between the electrode plate and the plane of the substrate is 60° to 70°.

4. The apparatus as claimed in claim 1, characterized in that: Along the direction of particle movement, the height of the electrode plate is 20% to 80% of the height of the deposition zone.

5. The apparatus as described in claim 4, characterized in that: Along the direction of particle movement, the height of the electrode plate is 50% to 70% of the height of the deposition zone.

6. The apparatus as claimed in claim 1, characterized in that: The distance between the ultraviolet lamp and the deposition zone is 10cm to 50cm.

7. The apparatus as claimed in claim 1, characterized in that: The target material is made of SiO2 and TiO2. x The electrode plate is made of one or more of the following materials: copper, aluminum, tungsten, molybdenum, and stainless steel; the working substance of the ultraviolet lamp is one or more of the following: mercury vapor, metal halide, and xenon.

8. A method for thin film deposition with low defect density, characterized in that: Using any one of the devices described in claims 1 to 7, a vacuum is drawn from the vacuum chamber; Rotate the workpiece holder; An electron beam system emits an electron beam onto the surface of a target material; The target material evaporates deposited particles into the deposition area; Ultraviolet lamps emit ultraviolet light into the deposition zone, causing impurity particles and deposition particles to become charged and form plasma; The electrode plate generates a deflection electric field in the deposition area, causing charged impurity particles to be deflected and adsorbed onto the electrode plate, screening out deposited ions, and accelerating the deposited ions to be deposited onto the substrate to form a thin film.

9. The method as described in claim 8, characterized in that: Evacuate the vacuum chamber to 5*10 -4 Pa or above.

10. The method as described in claim 8, characterized in that: The rotational speed of the workpiece holder is 5 to 30 r / min.

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