Polishing device for manufacturing ultrathin monocrystal diamond substrate

Abstract

The polishing device comprises a base, a two-dimensional driving mechanism is installed above the base through a support and drives a vertical electric cylinder to move forwards, backwards, leftwards and rightwards, a pressure sensor is installed at the lower end of a telescopic shaft of the vertical electric cylinder, and the two-dimensional driving mechanism drives the vertical electric cylinder to move forwards, backwards, leftwards and rightwards. A mounting plate is mounted at the bottom of the pressure sensor, and a detachable composite buffering polishing head is mounted at the bottom of the mounting plate. Mixed liquid nozzles are mounted on the left side and the right side of the composite buffer polishing head; according to the polishing device for manufacturing the ultrathin single crystal diamond substrate, chemical and mechanical cooperative polishing and flexible buffering compensation are achieved, a rectangular hole of the mounting frame allows the polishing head to move slightly, local stress concentration is eliminated, polishing uniformity is improved, the green manufacturing characteristic is achieved, modular maintenance is achieved, the detachable composite buffering polishing head and a bolt are designed to be replaced quickly, and maintenance is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to baby supplies technical field, concretely relates to a kind of polishing device of manufacturing ultrathin single crystal diamond substrate. BACKGROUND

[0002] Ultrathin single crystal diamond substrate (thickness≤50μm) as the core carrier of third-generation semiconductor material, in high-power electronic devices, quantum computing chip and deep ultraviolet optical element etc. Field has irreplaceable application value.The surface quality directly influences device performance, and traditional polishing process faces multiple technical bottlenecks:

[0003] Ultrathin single crystal diamond substrate is easy to produce subsurface damage under polishing pressure.The microcrack extension caused by local stress concentration cannot be avoided by traditional rigid polishing head (such as cast iron disc).

[0004] Chemical mechanical polishing (CMP) commonly used acidic slurry (such as SiO2 suspension+NaOH) can leave fluoride, resulting in the decline of substrate surface hydrophilicity.Extra 30 minutes ultrasonic cleaning is needed after traditional CMP process, and residual ion concentration>10 -9 Magnitude, affect device reliability.

[0005] In view of this status quo, a kind of polishing device of manufacturing ultrathin single crystal diamond substrate is designed. INVENTION CONTENTS

[0006] The utility model provides a kind of polishing device of manufacturing ultrathin single crystal diamond substrate to solve the problem raised in the background art for the purpose of solving the problem raised in the above background art.

[0007] The specific technical solutions are as follows:

[0008] A kind of polishing device of manufacturing ultrathin single crystal diamond substrate, including base, the top of the base is installed with two-dimensional drive mechanism by support, the top middle part of the base is installed with vacuum adsorption workbench, the two-dimensional drive mechanism drives vertical electric cylinder to move back and forth and left and right, the lower end of the telescopic shaft of vertical electric cylinder is installed with pressure sensor, the bottom of the pressure sensor is installed with mounting plate, the bottom of the mounting plate is installed with detachable composite buffer polishing head;

[0009] The left and right sides of the composite buffer polishing head are installed with mixed liquid spray head;

[0010] It further includes liquid supply system for the mixed liquid spray head.

[0011] As a preferred scheme of the utility model, the composite buffering polishing head comprises, from top to bottom, a rubber layer and a gradient hardness polyurethane pad, the composite buffering polishing head is installed inside the mounting frame, and the mounting frame is installed at the bottom of the mounting plate.

[0012] As a preferred scheme of the utility model, the gradient hardness polyurethane pad and the mounting frame are connected through bolts, and rectangular holes for the bolts to move up and down are formed in the left and right side walls of the mounting frame.

[0013] As a preferred scheme of the utility model, the liquid supply system comprises a liquid supply tank and a feed pump, supercritical CO2 and hydrogen peroxide solution are mixed in the inside of the liquid supply tank, and the feed pump delivers the mixed liquid in the inside of the liquid supply tank to the mixed liquid spray head through a corrugated pipe.

[0014] As a preferred scheme of the utility model, double-wavelength pulse lasers are installed on the outside of the mixed liquid spray head.

[0015] As a preferred scheme of the utility model, the two-dimensional driving mechanism comprises a horizontal plate, a horizontal electric cylinder is fixedly installed at the middle of the right side of the horizontal plate, a horizontal T-shaped plate is slidably installed in the inside of the horizontal plate, and the horizontal electric cylinder drives the horizontal T-shaped plate to move left and right;

[0016] A vertical plate is installed at the bottom of the horizontal T-shaped plate through bolts, a vertical electric cylinder is installed at the middle of the rear end of the vertical plate, a vertical T-shaped plate is slidably installed in the inside of the vertical plate, and the vertical electric cylinder drives the vertical T-shaped plate to move forward and backward;

[0017] The vertical electric cylinder is installed at the bottom of the vertical T-shaped plate through bolts.

[0018] As a preferred scheme of the utility model, at least two telescopic rods are equidistantly installed between the mounting plate and the vertical T-shaped plate, and the telescopic rod is provided with an outer tube and an inner rod.

[0019] The utility model has the following beneficial effects:

[0020] The polishing device for manufacturing ultra-thin single-crystal diamond substrates,

[0021] Chemical and mechanical cooperative polishing, supercritical CO2 and hydrogen peroxide mixed liquid cooperate with double-wavelength lasers, material removal efficiency is significantly improved, and surface quality is optimized.

[0022] Flexible buffering compensation: the rectangular holes of the mounting frame allow the polishing head to be slightly displaced, local stress concentration is eliminated, and polishing uniformity is improved.

[0023] Green manufacturing characteristics: supercritical CO2 waste liquid is zero discharged.

[0024] Modular maintenance: detachable composite buffer polishing head and bolt quick change design, convenient maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A front view of a polishing device for manufacturing an ultrathin single crystal diamond substrate according to an embodiment of the present application is provided.

[0026] Figure 2 For Figure 1 An enlarged view of A in the figure.

[0027] Figure 3 A structure diagram of a mounting frame according to an embodiment of the present application is provided.

[0028] Figure 4 A structure diagram of a two-dimensional driving mechanism according to an embodiment of the present application is provided.

[0029] Figure 5 An exploded structure diagram of a two-dimensional driving mechanism according to an embodiment of the present application is provided.

[0030] In the figure:

[0031] 100, base; 110, support; 120, vacuum adsorption workbench; 200, two-dimensional driving mechanism; 201, horizontal plate; 202, horizontal electric cylinder; 203, horizontal T-shaped plate; 210, longitudinal plate; 211, longitudinal electric cylinder; 220, longitudinal T-shaped plate; 221, telescopic rod; 300, vertical electric cylinder; 310, pressure sensor; 400, mounting plate; 410, mounting frame; 411, bolt; 412, rectangular hole; 420, composite buffer polishing head; 421, gradient hardness polyurethane pad; 422, rubber layer; 430, mixed liquid spray head; 431, liquid supply tank; 432, feeding pump; 440, dual-wavelength pulse laser. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be further described below in combination with the drawings and through specific embodiments.

[0033] Among them, the drawings are only used for example explanation, and the representation is only a schematic diagram, not a real object diagram, and cannot be understood as a limitation of the present patent; in order to better illustrate the embodiments of the present application, some components of the drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some known structures and their descriptions in the drawings can be omitted.

[0034] The same or similar reference signs in the drawings of the embodiments of the present utility model correspond to the same or similar components; in the description of the present utility model, it is understood that, if the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or position relationship shown in the drawings, it is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore the terms describing the position relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present patent, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0035] In the description of the present utility model, unless explicitly specified and limited, if the terms "connection" and the like indicate the connection relationship between components, the term should be understood in a broad sense, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two components or the interaction relationship between two components. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0036] Embodiment one

[0037] As Figures 1-5 The polishing device for manufacturing ultra-thin single crystal diamond substrate provided by the embodiment of the present utility model includes a base 100, a two-dimensional driving mechanism 200 is installed above the base 100 through a support 110, a vacuum adsorption workbench 120 is installed at the top middle part of the base 100, the two-dimensional driving mechanism 200 drives a vertical electric cylinder 300 to move forward and backward and left and right, a pressure sensor 310 is installed at the lower end of the telescopic shaft of the vertical electric cylinder 300, an installation plate 400 is installed at the bottom of the pressure sensor 310, and a detachable composite buffer polishing head 420 is installed at the bottom of the installation plate 400; a mixed liquid spray head 430 is installed at the left and right sides of the composite buffer polishing head 420; and the polishing device further includes a liquid supply system for supplying liquid to the mixed liquid spray head 430.

[0038] The vacuum adsorption workbench 120 can firmly adsorb the ultra-thin single crystal diamond substrate, prevent the substrate from moving during polishing, and ensure the polishing precision;

[0039] The pressure sensor 310 can monitor the pressure in real time during polishing, facilitate the adjustment of the polishing pressure, and avoid damaging the substrate due to excessive pressure or poor polishing effect due to insufficient pressure;

[0040] The composite buffer polishing head 420 is detachable, which facilitates the replacement of the worn polishing head, improves the applicability and maintenance convenience of the device;

[0041] The mixed liquid spray head 430 and the liquid supply system can provide the required mixed liquid for the polishing process, and play a role in lubrication, cooling and auxiliary polishing.

[0042] The composite cushion polishing head 420 includes a rubber layer 422 and a gradient hardness polyurethane pad 421 from top to bottom, and is installed in the inside of the mounting frame 410 installed on the bottom of the mounting plate 400; the rubber layer 422 has an elastic cushioning effect, which can reduce the vibration and impact force generated during polishing, and avoid damage to the ultra-thin single crystal diamond substrate.

[0043] The gradient hardness polyurethane pad 421 can provide different hardness supports according to the polishing requirements, adapt to different polishing stages and process requirements, and improve the polishing effect and quality; the mounting frame 410 is used to fix the composite cushion polishing head 420 to ensure its stability.

[0044] The gradient hardness polyurethane pad 421 and the mounting frame 410 are connected through the bolts 411, and the left and right side walls of the mounting frame 410 are provided with rectangular holes 412 for the up and down movement of the bolts 411. The bolt 411 connection mode makes the gradient hardness polyurethane pad 421 firmly installed, which is convenient for disassembly and replacement.

[0045] The rectangular hole 412 allows the bolt 411 to move up and down, so that the gradient hardness polyurethane pad 421 can have a certain buffer and displacement space when subjected to pressure, further enhancing the buffering effect and protecting the substrate.

[0046] The liquid supply system includes a liquid supply tank 431 and a feed pump 432, the inside of the liquid supply tank 431 is mixed with supercritical CO2 and hydrogen peroxide solution, and the feed pump 432 delivers the mixed liquid in the inside of the liquid supply tank 431 to the mixed liquid spray head 430 through the corrugated pipe. The supercritical CO2 has good solubility and diffusivity, and the hydrogen peroxide has oxidizing property, and the mixed liquid of the two can play a better chemical auxiliary role in the polishing process, such as removing surface impurities and improving the polishing surface quality.

[0047] The outside of the mixed liquid spray head 430 is provided with a double-wavelength pulse laser 440, which can generate laser of specific wavelength and pulse, and assist in processing the surface of the ultra-thin single crystal diamond substrate, such as improving the surface microstructure and improving the polishing efficiency and quality.

[0048] The two-dimensional driving mechanism 200 includes a transverse plate 201, a transverse electric cylinder 202 fixedly installed at the middle of the right side of the transverse plate 201, a transverse T-shaped plate 203 slidingly installed at the inside of the transverse plate 201, the transverse electric cylinder 202 driving the transverse T-shaped plate 203 to move left and right, a longitudinal plate 210 bolted to the bottom of the transverse T-shaped plate 203, a longitudinal electric cylinder 211 installed at the middle of the rear end of the longitudinal plate 210, a longitudinal T-shaped plate 220 slidingly installed at the inside of the longitudinal plate 210, the longitudinal electric cylinder 211 driving the longitudinal T-shaped plate 220 to move forward and backward, and a vertical electric cylinder 300 bolted to the bottom of the longitudinal T-shaped plate 220, the transverse electric cylinder 202 and the transverse T-shaped plate 203 cooperating to realize the left and right movement of the composite buffer polishing head 420, the longitudinal electric cylinder 211 and the longitudinal T-shaped plate 220 cooperating to realize the forward and backward movement, and the movement of the electric cylinder being accurately controlled to enable the composite buffer polishing head 420 to accurately reach a specified position in a two-dimensional plane, thereby improving the polishing precision and flexibility.

[0049] At least two telescopic rods 221 are equidistantly installed between the mounting plate 400 and the longitudinal T-shaped plate 220, the telescopic rod 221 being provided with an outer tube and an inner rod, the telescopic rod 221 being able to play a guiding and buffering role in the vertical direction, thereby ensuring the stability of the movement of the mounting plate 400 and the composite buffer polishing head 420 in the vertical direction, preventing shaking or deviation, and further improving the polishing quality.

[0050] Workflow:

[0051] Substrate fixation and initial positioning:

[0052] The vacuum adsorption workbench 120 is started to adsorb the ultra-thin single-crystal diamond substrate to a specified position through negative pressure.

[0053] Polishing head two-dimensional path planning:

[0054] The two-dimensional driving mechanism 200 moves the composite buffer polishing head 420 to an initial polishing position through the coordinated movement of the transverse electric cylinder 202 and the longitudinal electric cylinder 211.

[0055] Technical effect: XY axis positioning accuracy of ±5 μm is realized, and the polishing path of the entire area of the substrate is covered.

[0056] Mixed liquid pretreatment and delivery

[0057] The liquid supply system delivers the supercritical CO2 and hydrogen peroxide mixed liquid to the mixed liquid spray head 430 through the corrugated pipe.

[0058] Technical effect: The mixed liquid is uniformly sprayed on the surface of the substrate to form a chemical auxiliary polishing environment.

[0059] Laser-assisted surface activation:

[0060] Dual-wavelength pulsed laser 440 synchronously emits laser beams to pre-treat the area of the substrate to be polished.

[0061] Technical effect: surface microstructure optimization, significantly improved material removal efficiency.

[0062] Dynamic control of polishing pressure:

[0063] The vertical electric cylinder 300 presses the composite buffer polishing head 420 to contact the substrate, and the pressure sensor 310 feeds back real-time pressure data.

[0064] Technical effect: maintain the polishing pressure in the range of 5-15N, and avoid substrate damage.

[0065] Gradient hardness polishing operation:

[0066] The gradient hardness polyurethane pad 421 has adaptive hardness according to the polishing stage, and the rubber layer 422 buffers mechanical stress.

[0067] Technical effect: hardness≥80ShoreA in rough polishing stage (material removal), hardness≤60ShoreA in fine polishing stage (improve smoothness).

[0068] Dynamic compensation of buffer structure:

[0069] The rectangular hole 412 of the mounting frame 410 allows the bolt 411 to move slightly with the change of the polishing head pressure.

[0070] Technical effect: eliminate local stress concentration between the polishing head and the substrate, surface roughness Ra≤0.5nm.

[0071] Multi-axis linkage precision machining:

[0072] The two-dimensional driving mechanism 200 drives the polishing head to move along the preset trajectory at a feed speed of 0.1mm / s, and the telescopic rod 221 maintains vertical stability.

[0073] Technical effect: realize non-uniform surface polishing, and processing consistency reaches±0.05μm.

[0074] Polishing waste liquid recycling treatment:

[0075] Supercritical CO2 carries polishing debris through the vacuum adsorption system for recycling, and hydrogen peroxide is decomposed into harmless products.

[0076] In summary: the polishing device for manufacturing ultra-thin single crystal diamond substrates,

[0077] Chemical and mechanical polishing, supercritical CO2 and hydrogen peroxide mixed solution cooperate with dual-wavelength laser, material removal efficiency is significantly improved, surface quality is optimized.

[0078] Flexible buffer compensation: the rectangular hole 412 of the mounting frame 410 allows the slight displacement of the polishing head, eliminates local stress concentration, and improves polishing uniformity.

[0079] Green manufacturing characteristics: supercritical CO2 waste liquid zero discharge.

[0080] Modular maintenance: detachable composite buffer polishing head 420 and bolt 411 quick change design for easy maintenance.

[0081] It should be noted that the vacuum adsorption workbench 120 and the operating system involved in the present scheme are prior art, which will not be described here.

[0082] The above is only the preferred embodiment of the present application, and does not limit the implementation and protection scope of the present application. For those skilled in the art, it should be realized that any equivalent replacement and obvious change made by applying the content of the present application description and drawings should be included in the protection scope of the present application.

Claims

1. A polishing device for manufacturing ultra-thin monocrystalline diamond substrates, comprising a base (100), a two-dimensional driving mechanism (200) is installed above the base (100) through a support (110), a vacuum adsorption workbench (120) is installed in the middle of the top of the base (100), characterized in that, The two-dimensional driving mechanism (200) drives the vertical electric cylinder (300) to move forward and backward and left and right, the lower end of the telescopic shaft of the vertical electric cylinder (300) is provided with a pressure sensor (310), the bottom of the pressure sensor (310) is provided with a mounting plate (400), and the bottom of the mounting plate (400) is provided with a detachable composite buffer polishing head (420). The left and right sides of the composite buffer polishing head (420) are provided with mixed liquid nozzles (430). The liquid supply system for supplying liquid to the mixed liquid nozzles (430) is further included.

2. The polishing apparatus for manufacturing an ultrathin single crystal diamond substrate according to claim 1, wherein The composite buffer polishing head (420) sequentially comprises a rubber layer (422) and a gradient hardness polyurethane pad (421) from top to bottom, the composite buffer polishing head (420) is mounted in the inside of a mounting frame (410), and the mounting frame (410) is mounted at the bottom of the mounting plate (400).

3. The polishing apparatus for manufacturing an ultrathin single crystal diamond substrate according to claim 2, wherein The gradient hardness polyurethane pad (421) and the mounting frame (410) are connected through bolts (411), and the left and right side walls of the mounting frame (410) are each provided with a rectangular hole (412) for the up-and-down movement of the bolts (411).

4. The polishing apparatus for manufacturing an ultrathin single-crystal diamond substrate according to claim 3, wherein The liquid supply system comprises a liquid supply tank (431) and a feed pump (432), the inside of the liquid supply tank (431) is mixed with supercritical CO2 and hydrogen peroxide solution, and the feed pump (432) delivers the mixed liquid in the inside of the liquid supply tank (431) to the mixed liquid nozzles (430) through a bellows.

5. The polishing apparatus for manufacturing an ultrathin single-crystal diamond substrate according to claim 1, wherein The outside of the mixed liquid nozzles (430) is each provided with a dual-wavelength pulse laser (440).

6. The polishing apparatus for manufacturing an ultrathin single-crystal diamond substrate according to claim 1, wherein The two-dimensional driving mechanism (200) comprises a transverse plate (201), the right middle part of the transverse plate (201) is fixedly provided with a transverse electric cylinder (202), the inside of the transverse plate (201) is slidably provided with a transverse T-shaped plate (203), and the transverse electric cylinder (202) drives the transverse T-shaped plate (203) to move left and right. The bottom of the transverse T-shaped plate (203) is provided with a longitudinal plate (210) through bolts, the middle part of the rear end of the longitudinal plate (210) is provided with a longitudinal electric cylinder (211), the inside of the longitudinal plate (210) is slidably provided with a longitudinal T-shaped plate (220), and the longitudinal electric cylinder (211) drives the longitudinal T-shaped plate (220) to move forward and backward. The vertical electric cylinder (300) is mounted at the bottom of the longitudinal T-shaped plate (220) through bolts.

7. The polishing apparatus for manufacturing an ultrathin single crystal diamond substrate according to claim 6, wherein At least two telescopic rods (221) are mounted at equal distances between the mounting plate (400) and the longitudinal T-shaped plate (220), and the telescopic rod (221) is provided with an outer tube sleeve and an inner rod.

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