CVD diamond hard disk substrate structure

Abstract

The utility model provides a CVD diamond hard disk substrate structure which comprises a base layer, a buffer transition layer is deposited on the surface of the top of the base layer through magnetron sputtering, a CVD diamond layer is arranged on the top of the buffer transition layer, a nano-structure modified layer is arranged on the top of the CVD diamond layer, and the nano-structure modified layer is arranged on the surface of the top of the base layer. A heat dissipation enhancement layer is welded to the bottom of the substrate layer through laser; according to the CVD diamond hard disk substrate structure, the buffer transition layer provides chemical compatibility with the base layer, the diamond nanorods reduce the actual contact area, and the friction coefficient is reduced from 0.2 to 0.05; the adsorption capacity of lubricating oil is enhanced, and the retention time of a perfluoropolyether lubricating film is prolonged by 3 times; the heat dissipation enhancement layer reduces the read-write hot spot temperature; a covalent bond is formed by the perfluoropolyether lubricating film, the fluorine-containing group and a surface hydroxyl group (-OH) of the CVD diamond layer; the contact angle is increased from 80 degrees to 110 degrees, and water vapor adsorption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor storage technology, specifically to a CVD diamond hard disk substrate structure. Background Technology

[0002] Traditional hard drive substrates mostly use aluminum alloy or glass substrates, which have the following drawbacks:

[0003] Insufficient wear resistance: When the magnetic head's flight altitude is reduced to 1nm, the wear life of traditional materials is only about 106 start-stop cycles;

[0004] Poor thermal conductivity: Heat generated during reading and writing causes disk deformation, affecting track positioning accuracy.

[0005] Therefore, it is necessary to design a CVD diamond hard disk substrate structure. Utility Model Content

[0006] The present invention aims to solve the problems mentioned in the background art by providing a CVD diamond hard disk substrate structure.

[0007] The specific technical solution is as follows:

[0008] A CVD diamond hard disk substrate structure includes a base layer, a buffer transition layer deposited on the top surface of the base layer by magnetron sputtering, a CVD diamond layer on top of the buffer transition layer, a nanostructure modification layer on top of the CVD diamond layer, and a heat dissipation enhancement layer laser-welded to the bottom of the base layer.

[0009] As a preferred embodiment of this utility model, the buffer transition layer is a gradient SiC / CrN composite film with a thickness of 5-10 μm and a hardness gradient of HV1000-HV2500.

[0010] As a preferred embodiment of this utility model, the CVD diamond layer is disposed on top of the buffer transition layer using the hot-wire CVD method.

[0011] As a preferred embodiment of this utility model, the CVD diamond layer has a thickness of 3-5 μm and a surface roughness Ra≤0.1 nm.

[0012] As a preferred embodiment of this utility model, the nanostructure modified layer includes a perfluoropolyether lubricating film and diamond nanopillars arranged in an array. The height of the diamond nanopillars is 50-100 nm, the spacing is 200-300 nm, and the thickness of the perfluoropolyether lubricating film is 2-5 nm.

[0013] As a preferred embodiment of this utility model, the heat dissipation enhancement layer is a graphene thermal conductive sheet with a thermal conductivity greater than 1500 W / (m·K).

[0014] This utility model has the following beneficial effects:

[0015] Buffer transition layer:

[0016] The SiC layer (inner layer) provides chemical compatibility with the substrate 100;

[0017] The CrN layer (outer layer) matches the coefficient of thermal expansion of diamond;

[0018] Technical effect: Adhesion force > 50 N / cm, effectively inhibiting the peeling of CVD diamond layer.

[0019] (2) Nanoscale surface texture design

[0020] Diamond nanopillars:

[0021] By reducing the actual contact area (contact rate <10%), the coefficient of friction decreases from 0.2 to 0.05;

[0022] Enhanced lubricant adsorption capacity; perfluoropolyether lubricating film 420 retains its properties for 3 times longer.

[0023] Technical effect: The start-stop life of the magnetic head is increased to 5×10 6 More than once.

[0024] (3) Composite heat dissipation system

[0025] The heat dissipation enhancement layer is a graphene thermal conductive sheet:

[0026] Reduce the temperature of the read / write hotspot from 85℃ to 55℃;

[0027] Thermal response time reduced to 0.1ms;

[0028] Technical benefits: Disk thermal deformation is less than 5nm, and magnetic track positioning accuracy is improved by 20%.

[0029] (4) Surface chemical modification

[0030] Perfluoropolyether lubricating film:

[0031] The fluorinated groups of the perfluoropolyether lubricating film form covalent bonds with the surface hydroxyl groups (-OH) of the CVD diamond layer;

[0032] The contact angle was increased from 80° to 110°, reducing water vapor adsorption;

[0033] Technical effect: The probability of Stiction failure is reduced to below 0.01%. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the CVD diamond hard disk substrate structure provided in an embodiment of the present invention.

[0035] In the picture:

[0036] 100, Base layer; 200, Buffer transition layer; 300, CVD diamond layer; 400, Nanostructure modified layer; 410, Diamond nanopillars; 420, Perfluoropolyether lubricating film; 500, Heat dissipation enhancement layer 。 Detailed Implementation

[0037] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0038] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of this utility model, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0039] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0040] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] Example 1

[0042] like Figure 1The present invention provides a CVD diamond hard disk substrate structure, including a base layer 100, a buffer transition layer 200 deposited on the top surface of the base layer 100 by magnetron sputtering, a CVD diamond layer 300 on the top of the buffer transition layer 200, a nanostructure modification layer 400 on the top of the CVD diamond layer 300, and a heat dissipation enhancement layer 500 laser-welded to the bottom of the base layer 100.

[0043] The buffer transition layer 200 is a gradient SiC / CrN composite film with a thickness of 5-10 μm and a hardness gradient of HV1000-HV2500.

[0044] The CVD diamond layer 300 is applied on top of the buffer transition layer 200 using a hot-wire CVD method.

[0045] The CVD diamond layer 300 has a thickness of 3-5 μm and a surface roughness Ra≤0.1 nm.

[0046] The nanostructure modified layer 400 includes a perfluoropolyether lubricating film 420 and diamond nanopillars 410 arranged in an array. The height of the diamond nanopillars 410 is 50-100 nm and the spacing is 200-300 nm. The thickness of the perfluoropolyether lubricating film 420 is 2-5 nm.

[0047] The heat dissipation enhancement layer 500 is a graphene thermal conductive sheet with a thermal conductivity >1500W / (m·K).

[0048] This CVD diamond hard disk substrate structure:

[0049] (1) Gradient interface structure optimization

[0050] Buffer transition layer 200:

[0051] The SiC layer (inner layer) provides chemical compatibility with the substrate 100;

[0052] The CrN layer (outer layer) matches the coefficient of thermal expansion of diamond;

[0053] Technical effect: Adhesion force > 50 N / cm, effectively inhibiting the peeling of CVD diamond layer 300.

[0054] (2) Nanoscale surface texture design

[0055] Diamond nanopillars 410:

[0056] By reducing the actual contact area (contact rate <10%), the coefficient of friction decreases from 0.2 to 0.05;

[0057] Enhanced lubricant adsorption capacity; perfluoropolyether lubricating film 420 retains its properties for 3 times longer.

[0058] Technical effect: The start-stop life of the magnetic head is increased to 5×10 6 More than once.

[0059] (3) Composite heat dissipation system

[0060] The heat dissipation enhancement layer 500 is a graphene thermal conductive sheet:

[0061] Reduce the temperature of the read / write hotspot from 85℃ to 55℃;

[0062] Thermal response time reduced to 0.1ms;

[0063] Technical benefits: Disk thermal deformation is less than 5nm, and magnetic track positioning accuracy is improved by 20%.

[0064] (4) Surface chemical modification

[0065] Perfluoropolyether lubricating film 420:

[0066] Fluorine-containing groups form covalent bonds with the surface hydroxyl groups (-OH) of the CVD diamond layer 300;

[0067] The contact angle was increased from 80° to 110°, reducing water vapor adsorption;

[0068] Technical effect: The probability of Stiction failure is reduced to below 0.01%.

[0069] The fabrication process of this CVD diamond hard disk substrate structure:

[0070] Substrate 100 pretreatment: Substrate 100 is anodized to form a microporous structure (pore size 50-100nm);

[0071] Preparation of buffer transition layer 200: DC magnetron sputtering deposition of SiC (power 500W, Ar flow rate 30sccm) → medium frequency sputtering of CrN (power 800W, N2 flow rate 15sccm);

[0072] Growth of CVD diamond layer 300: hot filament CVD process (filament temperature 2200℃, CH4 concentration 0.5%, growth pressure 30kPa);

[0073] Fabrication of nanostructure modified layer 400: Electron beam lithography + RIE etching (CF4 / O2 = 4:1, power 100W) to form diamond nanopillars 410;

[0074] Grafting of perfluoropolyether lubricating film 420: The substrate is placed in PFPE vapor (120°C, 1000 ppm) -3 Process in Pa) for 2 hours.

[0075] This CVD diamond hard disk substrate structure:

[0076] Increased storage density: Supports head flight altitude down to 0.8nm, with areal density exceeding 5Tb / in 2 ;

[0077] Enhanced reliability: Mean time between failures (MTBF) increased from 1.2 × 10⁻⁶. 6 Hours increased to 2.5×10 6 Hour;

[0078] Environmental adaptability: The operating temperature range is extended to -40℃ to +85℃, and the humidity tolerance is improved to 95%RH.

[0079] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A CVD diamond hard disk substrate structure, characterised in that, The substrate layer (100) is provided with a buffer transition layer (200) on the top surface by magnetron sputtering deposition, the top of the buffer transition layer (200) is provided with a CVD diamond layer (300), the top of the CVD diamond layer (300) is provided with a nano-structure modification layer (400), and the bottom of the substrate layer (100) is provided with a heat dissipation enhancement layer (500) by laser welding.

2. The CVD diamond hard disk substrate structure of claim 1, wherein, The buffer transition layer (200) is a gradient SiC / CrN composite film with a thickness of 5-10 microns and a hardness gradient of HV1000-HV2500.

3. The CVD diamond hard disk substrate structure of claim 2, wherein, The CVD diamond layer (300) is arranged on the top of the buffer transition layer (200) by using a hot wire CVD method.

4. The CVD diamond hard disk substrate structure of claim 3, wherein, The CVD diamond layer (300) has a thickness of 3-5 microns and a surface roughness Ra≤0.1 nm.

5. The CVD diamond hard disk substrate structure of claim 1, wherein, The nano-structure modification layer (400) comprises a perfluoropolyether lubricating film (420) and diamond nano-pillars (410) arranged in an array, the diamond nano-pillars (410) have a height of 50-100 nm and a spacing of 200-300 nm, and the perfluoropolyether lubricating film (420) has a thickness of 2-5 nm.

6. The CVD diamond hard disk substrate structure of claim 2, wherein, The heat dissipation enhancement layer (500) is a graphene heat conduction sheet with a thermal conductivity of >1500 W / (m·K).

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