A target structure for preparing a thin film of a gallium-based compound doped with a metal element

Abstract

The application provides a target structure for preparing a metal element doped gallium-based compound film, and relates to the field of gallium-based compound film preparation. The target structure for preparing the metal element doped gallium-based compound film comprises a target material containing disc and a permanent magnet cover which are stacked from top to bottom, the target material containing disc is used for containing target material, the permanent magnet cover is used for covering a permanent magnet, the opening directions of the target material containing disc and the permanent magnet cover are opposite to each other, and a heat conduction plate is arranged between the target material containing disc and the permanent magnet cover, the target material containing disc comprises a target material tray and a metal block groove, the metal block groove is arranged below the target material tray, and the containing space of the metal block groove is communicated with the containing space of the target material tray. The application has the following advantages: low deposition temperature, large film forming area, no pollution, simple doping process, high growth rate, low preparation cost, and adjustable doping concentration.

Description

Technical Field

[0001] This invention relates to the field of gallium-based compound thin film preparation, and more specifically to a target structure for preparing metal element-doped gallium-based compound thin films. Background Technology

[0002] Gallium-based compounds such as gallium nitride and gallium oxide are wide-bandgap semiconductor materials. Their wide bandgap can effectively reduce the temperature quenching of rare-earth-doped semiconductors. Therefore, gallium-based compounds doped with rare-earth elements are widely used in rare-earth-doped light-emitting devices, optical communications and other related fields. In the preparation of rare-earth-doped GaN thin films, the addition of elements such as Mg and Zn can improve the light-emitting effect of rare-earth elements.

[0003] Gallium nitride (GaN) doped with magnesium or silicon can have its conductivity tuned to achieve p-type and n-type doping. However, current methods for preparing element-doped gallium-based compound films generally employ metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). In MOCVD, rare-earth elements are typically implanted into the film using ion beam technology, which inevitably causes severe lattice damage and introduces numerous defects. MBE involves epitaxial growth on sapphire or silicon substrates at high temperatures (800–1000°C). Furthermore, both methods are extremely expensive.

[0004] Magnetron sputtering is a method for preparing gallium-based compound thin films, enabling film growth at relatively low temperatures and significantly reducing preparation costs. However, using liquid metal targets for sputtering presents challenges in controlling the doping concentration. Therefore, designing a liquid metal target structure that allows for convenient control of metal doping levels, thereby greatly improving research and production efficiency, has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the doping concentration is difficult to control when preparing gallium-based compound thin films doped with metal elements by magnetron sputtering in the prior art, thereby providing a target structure for preparing gallium-based compound thin films doped with metal elements.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a target structure for preparing gallium-based compound thin films doped with metal elements, comprising a target receiving disk and a permanent magnet cover stacked from top to bottom. The target receiving disk is used to receive the target material, and the permanent magnet cover is used to cover the permanent magnet. The opening directions of the target receiving disk and the permanent magnet cover are opposite to each other, and a heat-conducting plate is disposed between the target receiving disk and the permanent magnet cover. The target receiving disk includes a target tray and a metal block groove. The metal block groove is disposed below the target tray, and the receiving space of the metal block groove is connected to the receiving space of the target tray.

[0008] Furthermore, the permanent magnet cover is provided with a cylindrical permanent magnet and an annular permanent magnet, the cylindrical permanent magnet being located in the middle of the permanent magnet cover and at the center of the annular permanent magnet.

[0009] Furthermore, the number of the metal block grooves is at least one, and the metal block grooves are located on the annular sputtering area formed by the annular permanent magnet.

[0010] Furthermore, the inner surface of the target material tray is a smooth spherical surface.

[0011] Furthermore, the target receiving disk and the permanent magnet cover are made of stainless steel; the heat-conducting plate is made of copper.

[0012] Furthermore, the target tray contains a liquid metal gallium target or a gallium-based cryogenic eutectic alloy, and the metal block groove contains a metal block to be doped.

[0013] Furthermore, the gallium-based cryogenic eutectic alloy includes at least one of Ga-Sn alloy, Ga-In alloy, Ga-Bi alloy, Ga-Zn alloy, or Sn-In-Ga alloy;

[0014] The metal block to be doped includes at least one of Er, Yb, Ce, Tb, Eu, Zn, Mg or Ti.

[0015] Furthermore, the diameter of the target structure for preparing the gallium-doped metal-based compound thin film is 76 mm; the height of the target material receiving disk is 18 mm; the height inside the permanent magnet cover is 13 mm; the thickness of the heat-conducting plate is 2 mm; the depth of the target material tray is 10 mm, and the diameter of the opening is 76 mm; the depth of the metal block groove is 6 mm, and the size of the groove opening is 5 mm × 5 mm; the height of the permanent magnet is 10 mm; the diameter of the cylindrical permanent magnet is 22 mm; the inner ring diameter of the annular permanent magnet is 38 mm, and the outer ring diameter is 50 mm; the inner diameter of the permanent magnet cover is 66 mm; the number of metal block grooves is 4, and they are distributed at the 4 vertices of a square, with the distance between the metal block grooves located at the two vertices on the diagonal of the square being 25 mm.

[0016] Secondly, the present invention provides a method for preparing gallium-doped compound thin films by magnetron sputtering, using the target structure described above for preparing gallium-doped compound thin films, the method comprising:

[0017] A liquid gallium target or gallium-based cryogenic eutectic alloy is placed in the target tray, a metal block to be doped is placed in the metal block groove, and a permanent magnet is placed in the permanent magnet cover. Under vacuum conditions, sputtering gas is introduced, or a reaction gas is introduced or not, and the metal element-doped gallium-based compound thin film is deposited on the substrate located at the target tray.

[0018] Furthermore, the sputtering gas is argon, and the reactant gas is one of nitrogen, oxygen, and hydrogen, or a mixture of two of them. The vacuum condition is a background vacuum of 1×10⁻⁶. -4 1×10 -2 Pa.

[0019] Furthermore, the doping concentration is controlled by the number of metal blocks to be doped, with the top of the metal blocks to be doped located inside the target tray.

[0020] The technical solution of this invention has the following advantages:

[0021] This invention provides a target structure for preparing gallium-based compound thin films doped with metal elements. The structure includes a target receiving disk and a permanent magnet cover stacked from top to bottom. The target receiving disk holds the target material, and the permanent magnet cover houses the permanent magnet. The opening directions of the target receiving disk and the permanent magnet cover are opposite to each other, and a heat-conducting plate is disposed between them. The target receiving disk includes a target tray and a metal block groove. The metal block groove is located below the target tray, and its accommodating space is connected to that of the target tray. The target tray holds liquid gallium metal or gallium-based cryogenic eutectic alloy, while the metal block groove is used to insert the metal block to be doped. The permanent magnet cover houses the permanent magnet, and the heat-conducting plate ensures more uniform heating of the target material during sputtering. During magnetron sputtering, a permanent magnet provides a stable magnetic field to confine particle motion, acting on the liquid gallium target / gallium-based cryogenic eutectic alloy and the metal block to be doped, achieving effective doping. This further allows the metal element-doped gallium-based compound thin film to be deposited on the substrate at the target tray alignment. The doping concentration can be controlled by adjusting the number of metal blocks to be doped, thereby enabling the preparation of gallium-based compound thin films with different doping concentrations. This invention has the following advantages: low deposition temperature, large film area, no pollution, simple doping process, high growth rate, low preparation cost, and adjustable doping concentration. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the internal structure of the target structure for preparing gallium-doped metal-based compound thin films provided by the present invention.

[0024] Figure 2 This is a three-dimensional structural diagram of the target structure for preparing gallium-doped metal-based compound thin films provided by the present invention.

[0025] Figure 3 This is a top view of the target structure for preparing gallium-doped metal-based compound thin films provided by the present invention;

[0026] Figure 4 This is a simulation diagram of the magnetic field strength distribution in the target structure.

[0027] Figure label:

[0028] 1-Target material receiving tray; 2-Permanent magnet cover; 3-Heat-conducting plate; 4-Target material tray; 5-Metal block groove; 6-Cylindrical permanent magnet; 7-Ring permanent magnet. Detailed Implementation

[0029] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0030] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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, they should not be construed as limitations on this invention.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] like Figures 1-3 As shown, the present invention provides a target structure for preparing gallium-based compound thin films doped with metal elements, including a target material receiving disk 1 and a permanent magnet cover 2 stacked from top to bottom. The target material receiving disk 1 is used to receive the target material, and the permanent magnet cover 2 is used to cover the permanent magnet. The opening directions of the target material receiving disk 1 and the permanent magnet cover 2 are opposite to each other, and a heat-conducting plate 3 is provided between the target material receiving disk 1 and the permanent magnet cover 2. The target material receiving disk 1 includes a target material tray 4 and a metal block groove 5. The metal block groove 5 is located below the target material tray 4, and the receiving space of the metal block groove 5 is connected to the receiving space of the target material tray 4.

[0034] The target tray 4 holds the liquid gallium target or gallium-based cryogenic eutectic alloy, while the metal block groove 5 is used to insert the metal block to be doped. The permanent magnet cover 2 is used to cover the permanent magnet, and the heat-conducting plate 3 is used to make the target material heat up more evenly during sputtering. During magnetron sputtering, the permanent magnet provides a stable magnetic field to constrain particle motion, acting on the liquid gallium target / gallium-based cryogenic eutectic alloy and the metal block to be doped, achieving effective doping and further depositing the metal element-doped gallium-based compound thin film onto the substrate at the alignment point of the target tray 4. By adjusting the number of metal blocks to be doped, the doping concentration can be controlled, thereby enabling the preparation of gallium-based compound thin films with different doping concentrations.

[0035] The target structure provided by this invention can be used to prepare gallium-based compound thin films doped with metal elements, such as gallium nitride, gallium oxide, gallium oxynitride, indium gallium nitride, indium gallium oxide, tin gallium oxide, bismuth gallium oxide, zinc gallium oxide, etc.

[0036] As an optional embodiment of the present invention, the permanent magnet cover 2 is provided with a cylindrical permanent magnet 6 and an annular permanent magnet 7. The cylindrical permanent magnet 6 is located in the middle of the permanent magnet cover 2 and is located at the center of the annular permanent magnet 7.

[0037] As an optional embodiment of the present invention, the number of metal block grooves 5 is at least one, and the metal block grooves 5 are located on the annular sputtering area formed by the annular permanent magnet 7. Preferably, the number of metal block grooves 5 is four and they are distributed at the four vertices of a square. It should be noted that the number of metal block grooves 5 can be adjusted as needed, and the number of metal blocks placed affects the doping concentration.

[0038] like Figure 4 As shown in the figure, the magnetic field strength distribution in the target structure was obtained through simulation. It can be clearly seen from the figure that the magnetic field strength is the largest at the sputtering ring where sputtering occurs. The location of the metal block groove 5 is selected at the sputtering ring to achieve the most effective doping.

[0039] As an optional embodiment of the present invention, the inner surface of the target tray 4 is a smooth spherical surface. Gallium and gallium-based cryogenic eutectic alloys are liquid at room temperature. Considering the surface tension factor, in order to make the sputtering surface flat and improve the sputtering effect, the target tray 4 adopts a concave design, approximately dish-shaped, such as a smooth spherical surface formed by the concave edge of the target receiving disk 1.

[0040] As an optional embodiment of the present invention, the target receiving disk 1 and the permanent magnet cover 2 are made of stainless steel (such as 304 stainless steel); the heat-conducting plate 3 is made of copper plate.

[0041] As an optional embodiment of the present invention, the target tray 4 contains a liquid gallium target or a gallium-based cryogenic eutectic alloy, and the metal block tank 5 contains a metal block to be doped. Optionally, the gallium-based cryogenic eutectic alloy includes at least one of Ga-Sn alloy, Ga-In alloy, Ga-Bi alloy, Ga-Zn alloy, or Sn-In-Ga alloy; the metal block to be doped includes at least one of Er, Yb, Ce, Tb, Eu, Zn, Mg, or Ti.

[0042] Clearly, the height of the doped metal block inserted into the metal block tank 5 affects the doping effect: only when its height is higher than the gallium liquid level will its upper surface be bombarded by particles, achieving effective doping. Therefore, if no doping is needed, removing the metal block or adding gallium until it completely submerges the metal block will achieve zero doping. Users can design metal blocks of different specifications according to their needs to control the smallest unit of proportional doping amount variation, and can quickly set multiple sets of doping concentrations.

[0043] As an optional embodiment of the present invention, the diameter of the target structure for preparing the gallium-based compound thin film doped with metal elements is 76 mm; the height of the target material receiving disk 1 is 18 mm; the height inside the permanent magnet cover 2 is 13 mm; the thickness of the heat-conducting plate 3 is 2 mm; the depth of the target material tray 4 is 10 mm, and the diameter of the opening is 76 mm; the depth of the metal block groove 5 is 6 mm, and the size of the groove opening is 5 mm × 5 mm; the height of the permanent magnet is 10 mm; the diameter of the cylindrical permanent magnet 6 is 22 mm; the inner ring diameter of the annular permanent magnet 7 is 38 mm, and the outer ring diameter is 50 mm; the inner diameter of the permanent magnet cover 2 is 66 mm; there are 4 metal block grooves 5, which are distributed at the 4 vertices of a square, and the distance between the two metal block grooves 5 located at the two vertices on the diagonal of the square is 25 mm.

[0044] This invention also provides a method for preparing gallium-doped metal-based compound thin films by magnetron sputtering, using the target structure described above for preparing gallium-doped metal-based compound thin films, the method comprising:

[0045] Liquid metal gallium target or gallium-based cryogenic eutectic alloy is placed in target tray 4, metal block to be doped is placed in metal block tank 5, permanent magnet is placed in permanent magnet cover 2, sputtering gas is introduced under vacuum conditions, and reaction gas may or may not be introduced, and metal element doped gallium-based compound thin film is deposited on substrate located at the target tray 4.

[0046] As an optional embodiment of the present invention, the sputtering gas is argon, and the reaction gas is one of nitrogen, oxygen, and hydrogen, or a mixture of two of them.

[0047] As an optional embodiment of the present invention, the vacuum condition is a background vacuum of 1×10⁻⁶. -4 1×10 -2 Pa.

[0048] As an optional embodiment of the present invention, the doping concentration is controlled by the number of metal blocks to be doped, with the top of the metal blocks to be doped located inside the target tray 4.

[0049] The following embodiments all adopt the following... Figures 1-3 The target structure shown was prepared by magnetron sputtering.

[0050] Example 1

[0051] Preparation of Er-doped gallium nitride thin films:

[0052] Background vacuum 1×10 -4 1×10 -2Under the condition of Pa, argon is used as the sputtering gas, nitrogen as the reactant gas, and liquid gallium is added as the sputtering target. One Er metal block is inserted into the metal block groove, and the sputtering doping amount is marked as mat.%. Correspondingly, if two Er blocks are inserted, the doping amount can be marked as 2m at.%. And so on. By controlling the number of inserted Er blocks, the doping amount of rare earth elements can be controlled proportionally to obtain gallium nitride thin films with different rare earth doping concentrations.

[0053] Example 2

[0054] Preparation of Er-doped gallium oxide thin films:

[0055] Background vacuum 1×10 -4 1×10 -2 Under the condition of Pa, argon is used as the sputtering gas, oxygen is used as the reactant gas, and liquid gallium is added as the sputtering target. An Er metal block is inserted into the metal block groove, and the sputtering doping amount is marked as mat.%. Correspondingly, if two Er blocks are inserted, the doping amount can be marked as 2 at.%. Similar to Example 1, gallium oxide thin films with different rare earth doping concentrations can be obtained.

[0056] Example 3

[0057] Preparation of Er-Yb co-doped gallium nitride thin films:

[0058] Background vacuum 1×10 -4 1×10 -2 Under the condition of Pa, argon (sputtering gas) and nitrogen (reacting gas) are mixed in a ratio of 1:3 and introduced into the atmosphere. Liquid gallium is added as the sputtering target. One piece of erbium metal and three pieces of ytterbium metal are inserted into four metal block grooves to obtain a gallium nitride thin film co-doped with Er:Yb = 1:3.

[0059] Example 4

[0060] Preparation of Er-Yb co-doped indium gallium nitride thin films:

[0061] Background vacuum 1×10 -4 1×10 -2 Under the condition of Pa, argon (sputtering gas) and nitrogen (reacting gas) are mixed in a ratio of 1:3 and introduced into the atmosphere. Liquid metal Ga-In is added as the sputtering target. One piece of erbium metal and three pieces of ytterbium metal are inserted into four metal block slots to obtain a gallium indium nitride thin film co-doped with Er:Yb = 1:3.

[0062] Example 5

[0063] Preparation of Er-doped gallium nitride thin films with added Mg:

[0064] Background vacuum 1×10 -4 1×10-2 Under the condition of Pa, argon (sputtering gas) and nitrogen (reacting gas) are mixed in a ratio of 1:3 and introduced, liquid gallium is added as a sputtering target, and three erbium metals and one magnesium metal are inserted into four metal block grooves to prepare Mg-doped Er-GaN thin films.

[0065] Example 6

[0066] Preparation of zinc gallium oxide thin films:

[0067] Background vacuum 1×10 -4 ~1×10 -2 Under the condition of Pa, argon (sputtering gas) and oxygen (reacting gas) are mixed in a 1:3 ratio and introduced, liquid gallium is added as the sputtering target, and four zinc metal blocks are inserted into four metal block grooves to obtain ZnGaO thin films.

[0068] Example 7

[0069] Preparation of Er-doped zinc gallium oxide thin films:

[0070] Background vacuum 1×10 -4 ~1×10 -2 Under the condition of Pa, argon (sputtering gas) and oxygen (reacting gas) are mixed in a 1:3 ratio and introduced, liquid gallium is added as the sputtering target, and two zinc metal blocks and two erbium metal blocks are inserted into four metal block slots to obtain ZnGaO thin films.

[0071] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A target structure for preparing gallium-doped metal-based compound thin films, characterized in that, The device includes a target receiving disk and a permanent magnet cover stacked from top to bottom. The target receiving disk is used to receive the target material, and the permanent magnet cover is used to cover the permanent magnet. The opening directions of the target receiving disk and the permanent magnet cover are opposite to each other, and a heat-conducting plate is provided between the target receiving disk and the permanent magnet cover. The target receiving disk includes a target tray and a metal block groove. The metal block groove is located below the target tray, and the receiving space of the metal block groove is connected to the receiving space of the target tray. The permanent magnet cover contains a cylindrical permanent magnet and an annular permanent magnet. The cylindrical permanent magnet is located in the middle of the permanent magnet cover and at the center of the annular permanent magnet. There is at least one metal block groove, which is located on the annular sputtering area formed by the annular permanent magnet. The target tray contains liquid gallium metal target or gallium-based cryogenic eutectic alloy, and the metal block groove contains a metal block to be doped. The height of the metal block is higher than the height of the gallium liquid surface.

2. The target structure for preparing gallium-doped metal-based compound thin films according to claim 1, characterized in that, The inner surface of the target material tray is a smooth spherical surface.

3. The target structure for preparing gallium-doped metal-based compound thin films according to claim 1, characterized in that, The target material receiving disk and the permanent magnet cover are made of stainless steel; the heat-conducting plate is made of copper.

4. The target structure for preparing gallium-doped metal-based compound thin films according to claim 1, characterized in that, The gallium-based cryogenic eutectic alloy includes at least one of Ga-Sn alloy, Ga-In alloy, Ga-Bi alloy, Ga-Zn alloy, or Sn-In-Ga alloy; The metal block to be doped includes at least one of Er, Yb, Ce, Tb, Eu, Zn, Mg or Ti.

5. A method for preparing gallium-doped compound thin films by magnetron sputtering, characterized in that, The method for preparing gallium-doped metal-based compound thin films using the target structure described in any one of claims 1 to 4 includes: A liquid gallium target or gallium-based cryogenic eutectic alloy is placed in the target tray, a metal block to be doped is placed in the metal block groove, and a permanent magnet is placed in the permanent magnet cover. Under vacuum conditions, sputtering gas is introduced, or a reaction gas is introduced or not, and the metal element-doped gallium-based compound thin film is deposited on the substrate located at the target tray.

6. The method for preparing gallium-doped compound thin films by magnetron sputtering according to claim 5, characterized in that, The sputtering gas is argon, and the reactant gas is one of nitrogen, oxygen, and hydrogen, or a mixture of two of them; the vacuum condition is a base vacuum of 1×10⁻⁶. -4 ~1×10 -2 Pa.

7. The method for preparing gallium-doped compound thin films by magnetron sputtering according to claim 5, characterized in that, The doping concentration is controlled by the number of metal blocks to be doped, with the top of the metal blocks to be doped located inside the target tray.

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