High-temperature-resistant ion beam coating target positioning device

Abstract

The application discloses a high-temperature-resistant ion beam coating target material positioning device, which comprises a target material support, three groups of elastic compression structures are symmetrically and equidistantly arranged on the upper end of the target material support in the circumferential direction, and the elastic compression structure comprises a compression ring, a target material, a water-cooled plate and a bottom plate. The application has the beneficial effects that: the uniform distribution of the compression force on the contact surface of the target material and the back plate is realized, the contact thermal resistance is reduced, and the heat dissipation efficiency is improved; the self-adaptive compensation capacity of thermal expansion is provided, so that the target material can always keep good contact with the back plate under the condition of temperature change; the occupation of the fixed mechanism to the effective sputtering area of the target material is minimized, and the utilization rate of the target material is improved; the structure design is simple and reliable, the target material can be quickly installed and replaced, the equipment downtime maintenance time is shortened, and the long-term use reliability of the device in the high-temperature and plasma environment is improved.

Description

Technical Field

[0001] This invention relates to the field of ion beam sputtering technology, specifically to a high-temperature ion beam coating target positioning device. Background Technology

[0002] In ion beam sputtering systems, the target material is the core consumable material for sputtering, and its installation and fixing method directly affects the stability of the coating process, the film quality, and the utilization rate of the target material. Planar sputtering targets are one of the most common types of sputtering targets in industrial applications. They are usually fixed to a copper backing plate by bonding or mechanical clamping. The backing plate supports the target and removes a large amount of heat generated by the target during sputtering through cooling water circulation. Therefore, the contact quality between the target and the backing plate is crucial. Poor contact will lead to local overheating, causing a series of problems such as target cracking, delamination, and uneven sputtering rate.

[0003] 1. Adhesive fixing method: The target material is bonded to the backplate using conductive and thermally conductive adhesive. This method is mature, but it has the following problems: 1. The adhesive layer is prone to aging and failure at high temperatures, causing the target material to fall off; 2. The adhesive layer increases thermal resistance and reduces the heat transfer efficiency between the target material and the backplate; 3. The entire target material needs to be replaced after it is consumed, resulting in low material utilization; 4. Adhesive residue contaminates the vacuum chamber; 5. The entire assembly needs to be disassembled when replacing the target material, resulting in a long maintenance cycle.

[0004] Second: Direct bolt tightening method: The method of drilling screw holes on the target surface and fixing the target directly to the back plate with bolts has the following problems: 1. The bolts occupy the effective sputtering area of ​​the target, reducing the material utilization rate; 2. Stress concentration occurs around the bolt holes, which can easily form grooves during sputtering, resulting in uneven etching; 3. The bolt material is different from the target material, which may cause abnormal discharge in the plasma environment; 4. Disassembly and assembly are cumbersome and replacement is inefficient.

[0005] Three: Clamp-type fixing method: Applying clamping force to the target material using clamps has the following problems: 1. The clamping force is concentrated at the edge of the target material, and the clamping force in the central area is insufficient; 2. The target material is subjected to uneven force in the circumference, which is prone to eccentric displacement; 3. The structure is complex and requires a large installation space.

[0006] Therefore, it is evident that existing planar target fixation technologies generally suffer from the following problems: 1. Uneven distribution of clamping force: Regardless of whether the bolt is used to directly clamp the pressure plate, it is difficult to achieve a uniform distribution of contact pressure between the target material and the back plate, which leads to an increase in local contact thermal resistance and affects the heat dissipation effect; 2. Insufficient thermal expansion compensation: The target material undergoes thermal expansion due to the temperature rise during sputtering. Most existing fixing methods lack an effective thermal expansion compensation mechanism, resulting in gaps between the target material and the backing plate or warping of the target material. 3. Low target utilization: The fixing mechanism occupies the effective area of ​​the target surface, reducing the sputterable area; 4. Low assembly and disassembly efficiency: The existing structural design is complex, and the replacement of the target material is cumbersome, which increases the downtime for equipment maintenance. 5. Insufficient long-term reliability: Elastic elements or adhesive layers are prone to failure under long-term high-temperature plasma environment, and the clamping force gradually decreases. Summary of the Invention

[0007] The purpose of this invention is to provide a high-temperature resistant ion beam coating target positioning device to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature ion beam coating target positioning device, comprising a target support, wherein three sets of elastic clamping structures are equidistantly and symmetrically arranged on the upper end of the target support in the circumferential direction, and the elastic clamping structure comprises a pressure ring, a target, a water-cooling plate and a base plate.

[0009] In a further optimization, the lower end of the target support is provided with a magnetofluid pipe connected thereto, and the lower end of the magnetofluid pipe away from the target support is provided with a driving component.

[0010] In a further optimized configuration, the magnetohydrodynamic pipeline is provided with a cooling water outlet and a cooling water inlet on both sides of the upper end near the target support.

[0011] In a further optimized configuration, the target material is placed on the upper end of the water-cooled plate, and multiple equally spaced water channels are formed on the end face of the water-cooled plate.

[0012] In a further optimized configuration, the outer edge of the pressure ring is provided with multiple sets of tension components at equal intervals in the circumferential direction.

[0013] In a further optimized configuration, the tension assembly consists of a fixing screw and a tension spring fixedly disposed on the outer edge of the pressure ring and the base plate, wherein the tension spring is a disc spring.

[0014] In a further optimization, thermally conductive silicone grease is filled between the water-cooled plate and the target material.

[0015] In a further optimized configuration, the base plate is provided with an outlet and an inlet on both sides near the bottom of the target support.

[0016] Furthermore, the base plate is provided with a positioning pin in the middle, and the positioning pin corresponds to the positioning hole opened in the middle of the target material. Beneficial effects

[0017] The high-temperature ion beam coating target positioning device provided by this invention uses multiple elastic clamping units evenly distributed along the circumference of the target, combined with an adjustable preload mechanism, to achieve uniform distribution of clamping force on the contact surface between the target and the backplate. Compared with traditional bolt clamping or pressure plate clamping methods, the uniformity of contact pressure is improved by more than 50%, effectively reducing local contact thermal resistance and increasing the target heat dissipation efficiency by 30%. Through a triple compensation mechanism of radial compensation gap, circumferential floating connection, and central positioning sliding, the target can still maintain good uniform adhesion to the backplate under sputtering temperature rise (200~400℃). Experimental verification shows that the target warpage deformation is reduced by 60%, and the risk of target cracking due to thermal expansion is significantly reduced. The elastic clamping units only act on the very narrow edge of the target. The area (5-8mm wide) and the central positioning structure are lower than the target surface, so they do not occupy the effective sputtering area of ​​the target. Compared with the bolt fixing method (bolts occupy 5% of the area) and the elastic pressure plate method (pressure plate covers 10% of the area), the effective sputtering area utilization rate is increased by 8%-12%. The split clamping frame and modular clamping unit design shortens the target replacement time from 30-60 minutes in the traditional method to 10-15 minutes, significantly reducing equipment downtime for maintenance and improving production efficiency. The disc spring combination, as an elastic element, has the characteristics of good fatigue resistance and small force attenuation. It is stable in long-term high-temperature environment. Experiments show that after 1000 thermal cycles, the clamping force attenuation does not exceed 10%, which is a connection method (adhesive layer aging failure). Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is an exploded view of the overall structure of the present invention; Figure 3 This is a comparative table illustrating the overall benefits of the present invention. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments. Example

[0020] like Figure 1-2 As shown, a high-temperature ion beam coating target positioning device includes a target support 8. The upper end of the target support 8 is provided with three sets of elastic clamping structures at equal intervals and symmetrically in the circumferential direction. The elastic clamping structure includes a pressure ring 6, a target 4, a water-cooled plate 3, and a base plate 5.

[0021] In this embodiment, the lower end of the target support 8 is provided with a magnetic fluid pipe 1 connected thereto, and the lower end of the magnetic fluid pipe 1 away from the target support 8 is provided with a driving component.

[0022] The magnetohydrodynamic pipe 1 is provided with a cooling water outlet 3 and a cooling water inlet 2 on both sides of the upper end near the target support 8.

[0023] The target material 4 is placed on the upper end of the water-cooled plate 3, and multiple equally spaced water channels are opened on the end face of the water-cooled plate 3.

[0024] Multiple sets of tension components are provided at equal intervals in the circumferential direction along the outer edge of the pressure ring 6.

[0025] The tension assembly consists of a fixing screw fixed to the outer edge of the pressure ring 6 and the base plate 5, and a tension spring 7, which is a disc spring.

[0026] Thermally conductive silicone grease 11 is filled between the water-cooled plate 3 and the target material 4.

[0027] The bottom plate 5 is provided with an outlet 9 and an inlet 10 on both sides near the bottom of the target support 8.

[0028] The base plate 5 has a positioning pin in the middle, and the positioning pin corresponds to the positioning hole opened in the middle of the target material 4.

[0029] The method for fixing the planar target material, Step 1: Place the target on the backplate and achieve precise alignment between the target and the backplate through the central positioning structure; Step 2: Close the clamping frame so that the clamping heads of the multiple elastic clamping units abut against the edge of the target material; Step 3: Adjust the clamping force adjustment mechanism of each elastic clamping unit one by one to make the pre-compression of each clamping unit reach the set value, so as to achieve uniform clamping between the target material and the back plate. Step 4: Lock all clamping force adjustment mechanisms to complete target fixation; Step 5: During the operation of the target material, the thermal expansion compensation structure adaptively compensates for the thermal expansion deformation of the target material to maintain the uniform adhesion between the target material and the backing plate.

[0030] Operating parameters: 1. Sputtering power density: 5 W / cm²; 2. Maximum target temperature: 250℃; 3. Cooling water flow rate: 8 L / min; 4. Thermal expansion calculation: ΔL = 23.6×10⁻ 6 × 300 × 230 = 1.63mm < Δr = 1.5mm (In actual design, 1.5mm is taken on both radial sides, and the displacement on one side is within the allowable range).

[0031] Effect verification: 1. The thermal resistance between the target and the backplate is reduced by approximately 35% (the temperature difference measured by the infrared thermal imager is reduced); 2. The effective sputtering area utilization rate of the target is approximately 97.5%; 3. The target replacement time is approximately 12 minutes; 4. After 500 hours of continuous operation, the clamping force decreases by less than 5%, and there is no loosening.

[0032] Fixing large-size circular planar target: Application scenario: 200mm diameter, 12mm thickness titanium target material for tool coating magnetron sputtering systems.

[0033] Device configuration adjustment: 1. Elastic clamping units: 12 units, evenly spaced along the circumference of the target (one every 30°); 2. Disc springs: 3 disc springs stacked and connected (to increase load-bearing capacity); 3. Single disc spring stiffness K ≈ 540 N / mm; 4. Equivalent stiffness after parallel connection K_eq = 3 × 540 = 1620 N / mm; 5. Pre-compression δ = 0.5mm; 6. Unit clamping force F = 1620 × 0.5 = 810 N; 7. Total clamping force F_total = 12 × 810 = 9720 N; 8. Clamping frame: Overall circular ring, open on one side (closed by fastening bolts); 9. Radial compensation gap: Δr = 0.8mm (titanium has a relatively small coefficient of thermal expansion); 10. Calculation of thermal expansion: ΔL = 8.6 × 10⁻ 6 × 200 × 300 = 0.516mm < Δr = 0.8mm.

[0034] Effect verification: 1. Large-size target material exhibits excellent uniformity of contact pressure distribution (pressure-sensitive paper test, pressure deviation <±15%); 2. Target material utilization rate is approximately 98% (positioning pins and clamping heads do not occupy sputtering area); 3. Clamping force attenuation is <8% after 500 thermal cycles. Quickly change scenes: For batch replacement of sputtering targets in semiconductor production lines, the replacement time must be less than 10 minutes. Configuration optimization: 1. The clamping frame adopts a hinge quick-release design, which can be opened and closed with one hand; 2. The preload of all elastic clamping units is set by a uniform preload amount (factory calibration), eliminating the need for individual adjustment; 3. Edge structure assists in positioning, automatically adsorbing and centering when the target material approaches.

[0035] Replacement process: 1. Open the clamping frame buckle → 5 seconds; 2. Remove the old target material → 10 seconds; 3. Place the new target (magnetic-assisted automatic centering) → 15 seconds; 4. Close the clamping frame buckle → 5 seconds; 5. Visually confirm the seal status for 5 seconds; 6. Total: Approximately 35 seconds (total < 5 minutes).

[0036] A radial compensation gap (Δr) is reserved between the clamping head and the guide sleeve. When the target material expands due to heat, the clamping head can slide freely in the radial direction, avoiding warping stress caused by the restricted expansion of the target material.

[0037] Clamping force calculation The clamping force F provided by a single elastic clamping unit can be calculated using the following formula: F = n × K × δ in: 1. n is the number of disc springs (when connected in series); 2. K is the stiffness of a single disc spring (N / mm); 3. δ represents the pre-compression amount (mm).

[0038] Taking a typical planar target (300mm×100mm×10mm, weighing approximately 15kg) as an example, the total clamping force required between the target and the backing plate is generally the target contact pressure P × contact area A. Assuming the target contact pressure P = 0.1~0.3 MPa and the contact area A ≈ 30000 mm², the total clamping force F_total = 3000~9000 N.

[0039] If eight elastic clamping units are evenly distributed, the clamping force of each unit, F_unit, is 375~1125 N. Selected disc spring parameters are: outer diameter D = 31mm, inner diameter d = 16.2mm, thickness t = 1.75mm, and single-piece stiffness K ≈ 240 N / mm. The clamping force requirement can be met by adjusting the pre-compression δ = 2~5mm.

[0040] The temperature rise of the target material during sputtering can reach 200~400°C, and the corresponding thermal expansion ΔL can be estimated by the following formula: ΔL = α × L × ΔT; in: 1. α is the coefficient of linear expansion of the target material (e.g., for an aluminum target, α ≈ 23.6 × 10⁻). 6 / °C, titanium target α ≈ 8.6×10⁻ 6 / °C); 2. L represents the characteristic dimension of the target material (mm). 3. ΔT is the temperature rise (°C). Taking a 300mm aluminum target with a temperature rise of 300°C as an example: 1. ΔL = 23.6 × 10⁻ 6 × 300 × 300 = 2.124 mm Thermal expansion compensation is achieved through the following structure: Radial compensation: A radial clearance Δr is reserved between the guide sleeve and the clamping head of each elastic clamping unit, so that the clamping head can move freely radially as the target material expands; Circumferential compensation: By adding thermal grease and cooling the target backplate, and using a floating connection method (such as elongated hole connection) between the clamping frame and the backplate, the target material as a whole is allowed to have a small amount of free expansion space in the circumferential direction. Through the aforementioned multi-directional compensation mechanism, the target material will not be subjected to additional constraint stress during thermal expansion and will always maintain uniform contact with the backing plate.

[0041] Quick-installation and quick-disassembly design To enable rapid target replacement, the present invention has been optimized in the following aspects: 1. The elastic clamping unit adopts a modular design, and each unit can be independently disassembled and replaced for easy maintenance; 2. The center positioning structure is equipped with a guide cone surface, which automatically guides the centering of the target material during installation, reducing the installation and adjustment time; 3. The clamping frame adopts a split design (such as a two-part type or a hinged type), and the target material can be directly removed after opening without having to loosen all the clamping units one by one.

[0042] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-temperature ion beam coating target positioning device, characterized in that: The target support (8) includes three sets of elastic clamping structures equidistantly and symmetrically arranged on the upper end of the target support (8) in the circumferential direction. The elastic clamping structures include a pressure ring (6), a target (4), a water-cooled plate (3), and a base plate (5).

2. The high-temperature ion beam coating target positioning device according to claim 1, characterized in that: The lower end of the target support (8) is provided with a magnetic fluid pipe (1) connected thereto, and the lower end of the magnetic fluid pipe (1) away from the target support (8) is provided with a driving component.

3. The high-temperature ion beam coating target positioning device according to claim 2, characterized in that: The magnetohydrodynamic pipe (1) is provided with a cooling water outlet (3) and a cooling water inlet (2) on both sides of the upper end near the target support (8).

4. The high-temperature ion beam coating target positioning device according to claim 1, characterized in that: The target material (4) is placed on the upper end of the water-cooled plate (3), and multiple equally spaced water channels are opened on the end face of the water-cooled plate (3).

5. The high-temperature ion beam coating target positioning device according to claim 1, characterized in that: The outer edge of the pressure ring (6) is provided with multiple sets of tension components at equal intervals in the circumferential direction.

6. The high-temperature ion beam coating target positioning device according to claim 5, characterized in that: The tension assembly consists of a fixing screw and a tension spring (7) fixedly installed on the outer edge of the pressure ring (6) and the base plate (5). The tension spring (7) is a butterfly spring.

7. The high-temperature ion beam coating target positioning device according to claim 1, characterized in that: Thermally conductive silicone grease (11) is filled between the water-cooled plate (3) and the target material (4).

8. The high-temperature ion beam coating target positioning device according to claim 1, characterized in that: The bottom plate (5) is provided with an outlet (9) and an inlet (10) on both sides near the bottom of the target support (8).

9. The high-temperature ion beam coating target positioning device according to claim 1, characterized in that: The base plate (5) is provided with a positioning pin in the middle, and the positioning pin corresponds to the positioning hole opened in the middle of the target material (4).

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