Sputtering film forming controllable doping process and coating device

Abstract

The invention provides a controllable doping process for sputtering film formation and a film coating device, and relates to the technical field of semiconductor film coating. The sputtering film-forming controllable doping process comprises the following steps: placing a substrate and a target material in a vacuum chamber; inert gas and process gas are injected into the vacuum chamber; discharging to the vacuum chamber to ionize the inert gas; and introducing a gas with an organic metal compound into the vacuum chamber to carry out a doping reaction so as to prepare a compound doped film layer containing corresponding metal on the surface of the substrate. Therefore, the organic metal compound gas with different concentrations is introduced to react with the process gas to generate the metal compound, so that the doping concentration of the metal compound on the thin film is adjusted, the controllability of the doping concentration of the film layer is effectively improved, the film layer deposition of a multi-layer structure can be realized, and more and higher process requirements can be met.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor coating technology, and in particular to a sputtering film-forming controllable doping process and a coating device. Background Art

[0002] The film-forming process of sputtering equipment is a process in which the atoms or molecules near the solid surface gain enough kinetic energy to break away from the solid surface by bombarding the solid surface with particles of specific energy. The main method of doping the sputtered film layer is to dope the elements to be doped at a fixed concentration during the production process of the target material. However, the film layer generated by the target material not only has a very small adjustable range of doping concentration of the doped elements, but also makes it difficult to complete the multi-layer film deposition process. Summary of the invention

[0003] The present invention provides a sputtering film-forming controllable doping process and a film coating device, which can adjust the doping concentration of the doping element in the film layer by adjusting the gas flow rate of the doping element, so as to adapt to more and higher process requirements.

[0004] The embodiments of the present invention can be implemented as follows:

[0005] In a first aspect, the present invention provides a sputtering film-forming controllable doping process, comprising:

[0006] placing the substrate and the target in a vacuum chamber;

[0007] injecting an inert gas and a process gas into the vacuum chamber;

[0008] discharging electricity into the vacuum chamber to ionize the noble gas;

[0009] A gas containing an organic metal compound is introduced into the vacuum chamber to perform a doping reaction, so as to prepare a film layer doped with a compound containing a corresponding metal on the surface of the substrate.

[0010] In the above embodiment, the substrate and the target material are first placed in a vacuum chamber, and the pressure in the vacuum chamber is adjusted to a preset pressure by a vacuum pump to prepare for the sputtering process and the doping process. The inert gas can be argon (Ar) which has very stable chemical properties and is not easy to react chemically with other substances, which helps to maintain the purity and controllability of the sputtering process. The process gas can be oxygen (O2); by starting the RF power supply to apply RF voltage to the target material, a plasma region is formed between the target material and the substrate, in which the inert gas is ionized, and the generated high-energy particles bombard the target material, so that the atoms on its surface are sputtered out and deposited on the substrate, thereby forming the required thin film on the surface of the substrate; in the process of sputtering film formation, an organic metal compound gas is introduced into the vacuum chamber, so that the organic metal compound gas generates metal compounds with the process gas in the plasma atmosphere, and the generated compounds move to the substrate and complete doping on the film. Therefore, the doping concentration of the metal compound on the film can be adjusted by introducing organic metal compound gases of different concentrations and reacting with the process gas to generate metal compounds, which effectively improves the controllability of the doping concentration of the film layer, and can also realize the deposition of multi-layer structure films, so that it can adapt to more and higher process requirements.

[0011] The beneficial effects of the sputtering film-forming controllable doping process and the coating device provided by the embodiments of the present invention include: by introducing organic metal compound gas into the vacuum chamber, the organic metal compound gas generates compounds with the process gas under the plasma atmosphere, and the generated compounds move to the substrate and complete the doping on the thin film. Therefore, the doping concentration of the organic metal compound on the thin film can be adjusted by introducing organic metal compound gas and process gas of different concentrations, which effectively improves the controllability of the doping concentration of the film layer, and can also realize the deposition of multi-layer structured film layers, thereby being able to adapt to more and higher process requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 A schematic structural diagram of a film coating device provided in an embodiment of the present invention;

[0014] Figure 2 A flow chart of the sputtering film-forming controllable doping process provided in an embodiment of the present invention.

[0015] Icons: 10 - coating device; 100 - chamber; 110 - air inlet; 120 - anode mounting; 130 - cathode mounting; 200 - ionization mechanism; 210 - matching device; 220 - RF power supply; 300 - vacuum pump; 400 - insulating part; 500 - plasma; 11 - substrate; 12 - target material. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0019] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0021] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0022] The film-forming process of sputtering equipment is a process in which particles (ions or neutral atoms, molecules) with specific energy bombard the solid surface so that the atoms or molecules near the solid surface obtain sufficient kinetic energy and thus detach from the solid surface. This process has unique advantages, making it an important thin film preparation technology. Since the discovery of the sputtering phenomenon, sputtering coating technology has undergone long-term research and development and has gradually become a key thin film preparation method. At present, sputtering coating technology is widely used in the industrial field, involving many industries such as decoration, microelectronics, optics, machinery, and solar cells.

[0023] The main method for doping sputtered films is to dope the required elements at a fixed concentration during the target material manufacturing process. However, the film layer generated by the target material not only has a very small adjustable range of the doping concentration of the doped elements, but also makes it difficult to complete the multi-layer film deposition process.

[0024] Based on the problems existing in the prior art, an embodiment of the present invention provides a controllable doping process for sputtering film forming, which is applied to the sputtering film forming process. The doping process can adjust the doping concentration of the doping elements in the film layer by adjusting the gas flow rate of the doping elements, so as to adapt to more and higher process requirements.

[0025] In order to implement the sputtering film-forming controllable doping process provided by the embodiment of the present invention, please refer to Figure 1 The present invention also provides a coating device 10 , including a chamber 100 , an ionization mechanism 200 and a vacuum pump 300 .

[0026] Among them, the side wall of the cavity 100 is provided with an air inlet 110, and the air inlet 110 is used to introduce gas; the interior of the cavity 100 is also provided with a relative anode mounting member 120 and a cathode mounting member 130, the anode mounting member 120 is used to support the substrate 11, and the cathode mounting member 130 is used to install the target material 12, the ionization mechanism 200 is connected to the cathode mounting member 130, and the vacuum pump 300 is connected to the cavity 100.

[0027] In the present embodiment, the interior of the cavity 100 is a vacuum chamber, and the through-hole vacuum pump 300 can make the interior of the cavity 100 be in a low pressure or vacuum environment.

[0028] The ionization mechanism 200 includes a matching device 210 and a radio frequency power supply 220 connected to each other. The matching device 210 is also connected to the cathode mounting member 130 inside the cavity 100. It is worth mentioning that an insulating member 400 is provided at the connection between the matching device 210 and the cavity 100 to isolate the cavity 100 and the wires connected to the matching device 210.

[0029] Therefore, when the target material 12 is mounted on the cathode mounting member 130 and the substrate 11 is mounted on the anode mounting member 120, the RF power supply 220 is started, and an inert gas, a process gas, etc. are introduced through the gas inlet 110 to generate a plasma 500 between the target material 12 and the substrate 11, and the sputtering film forming process and the doping process are completed to form a film layer of the doping element with a preset doping concentration on the surface of the substrate 11.

[0030] It should be noted that the ionization mechanism 200 may also include other types of devices, for example, radio frequency sputtering, direct current sputtering, magnetron sputtering, etc., which are not specifically limited here. For the convenience of description, radio frequency sputtering is used for description below.

[0031] For details, see Figure 2 , the sputtering film-forming controllable doping process includes the following steps:

[0032] Step S100 , placing the substrate 11 and the target 12 in a vacuum chamber.

[0033] In this embodiment, the substrate 11 and the target material 12 are first placed in a vacuum chamber, and the pressure in the vacuum chamber is adjusted to a preset pressure by a vacuum pump 300 to prepare for the sputtering process and the doping process.

[0034] Step S200: injecting inert gas and process gas into the vacuum chamber.

[0035] In this embodiment, the inert gas can be argon (Ar) which has very stable chemical properties and is not easy to react chemically with other substances, which helps to maintain the purity and controllability of the sputtering process. Of course, the inert gas can also be other gases, such as neon (Ne), helium (He), etc., which can be selected according to actual process requirements and are not specifically limited here; the process gas can be oxygen (O2). Of course, the process gas can also be other gases, such as nitrogen (N2), ammonia (NH3), etc., which can be selected according to the elements that need to be doped and are not specifically limited here.

[0036] In step S300 , discharge is applied to the vacuum chamber to ionize the inert gas.

[0037] In this embodiment, the RF power supply 220 is started to apply an RF voltage to the target material 12, so that a plasma 500 region is formed between the target material 12 and the substrate 11. In this region, the inert gas is ionized, and the generated high-energy particles bombard the target material 12, causing the atoms on its surface to be sputtered out and deposited on the substrate 11, thereby forming a desired thin film on the surface of the substrate 11.

[0038] In step S400 , a gas containing an organic metal compound is introduced into a vacuum chamber to perform a doping reaction, so as to prepare a film layer doped with a compound containing a corresponding metal on the surface of the substrate 11 .

[0039] First of all, it should be noted that the doping process can be carried out simultaneously with the sputtering process, before or after the sputtering process, or during the sputtering film forming process. The timing of the doping process can be selected according to the actual film forming effect, and no specific limitation is made here.

[0040] In this embodiment, during the sputtering film forming process, an organic metal compound gas is introduced into the vacuum chamber, so that the organic metal compound gas generates a compound with the process gas in the atmosphere of the plasma 500, and the generated compound moves to the substrate 11 and completes the doping on the thin film. Therefore, the doping concentration of the metal-containing compound generated on the thin film can be adjusted by introducing organic metal compound gases and process gases of different concentrations, which effectively improves the controllability of the doping concentration of the film layer, and can also realize the deposition of a multi-layer structure film layer, thereby being able to adapt to more and higher process requirements.

[0041] It is worth mentioning that the gas with an organometallic compound is the vapor of an organometallic compound, which is a class of compounds with organic ligands and metal centers that can exist in the form of a gas. The vapor of the organometallic compound is reacted with the process gas to generate a compound containing the corresponding metal in the organometallic compound and dope it into the film layer.

[0042] Furthermore, step S200 also includes the following sub-steps:

[0043] Sub-step S210, injecting an inert gas into the vacuum chamber at a first flow rate;

[0044] In sub-step S220, a process gas is injected into the vacuum chamber at a second flow rate, where the process gas includes oxygen.

[0045] In this embodiment, since the inert gas is mainly used as a sputtering gas to bombard the target material 12 so that the atoms or molecules of the target material 12 are sputtered out and deposited on the substrate to form a thin film, the argon gas flow rate is usually determined based on factors such as the sputtering power, the type of target material 12, and the substrate area. The deposition rate can be increased by setting a higher argon gas flow rate.

[0046] The oxygen flow rate determines the oxygen content of the film, which in turn affects the structure and properties of the film. For example, for metal oxide films, adjustment of the oxygen flow rate will affect the crystallinity and electrical properties of the film. Therefore, the oxygen flow rate is usually relatively small to control the degree of oxidation of the film.

[0047] Therefore, in this embodiment, the first flow rate is greater than or equal to the second flow rate.

[0048] In detail, the ratio of the first flow rate to the second flow rate is n:1, where 1≤n≤50.

[0049] The ratio of the inert gas to the process gas flow is also very important, that is, in this embodiment, the ratio of the argon to oxygen flow is also very important. For example, in the preparation process of metal oxides, the ratio of the oxygen flow to the argon flow needs to be appropriately adjusted to obtain the desired film composition and performance. The specific ratio can be optimized based on the experimental results and the target film properties, and the optimal flow ratio can be determined through multiple experiments.

[0050] In this embodiment, the ratio of the first flow rate to the second flow rate is 3-5:1, the sputtering effect is good and the quality of the prepared thin film is good.

[0051] Furthermore, step S200 also includes the following sub-steps:

[0052] Sub-step S230, adjusting the pressure in the vacuum chamber to a preset pressure, the preset pressure being 0.1 Pa to 1.0 Pa;

[0053] In sub-step S240 , the substrate 11 is driven to reciprocate in the vacuum chamber at a preset moving speed, wherein the preset moving speed is 5 mm / s to 15 mm / s.

[0054] In this embodiment, the pressure in the vacuum chamber is adjusted to a preset pressure so that the sputtering process and the doping process can proceed smoothly. In addition, during the sputtering process and the doping process, the substrate 11 is moved back and forth in the vacuum chamber so that the deposition of the thin film on various positions on the surface of the substrate 11 is more uniform, ensuring that all exposed surfaces can obtain good film coverage and the film thickness can reach the thickness required by the process.

[0055] Furthermore, step S400 also includes the following sub-steps:

[0056] In sub-step S410, the vapor of the organometallic compound is carried into the vacuum chamber by using an inert gas as a carrier.

[0057] In this embodiment, in order to facilitate the controllable vapor of the organic metal compound and avoid contamination caused by other gases entering the vacuum chamber, an inert gas consistent with that introduced in the sputtering process is used to bring the vapor of the organic metal compound into the vacuum chamber through the inert gas.

[0058] Furthermore, sub-step S410 further includes the following steps:

[0059] Sub-step S411, adjusting the flow rates of the inert gas and the vapor of the organometallic compound to adjust the doping concentration.

[0060] In this embodiment, the flow rate of the inert gas is adjusted to correspondingly adjust the flow rate of the vapor of the organic metal compound, thereby adjusting the doping concentration of the thin film on the substrate 11 .

[0061] Sub-step S412, adjusting the flow rate of the process gas to adjust the doping concentration.

[0062] In this embodiment, since the vapor of the organic metal compound will generate compounds with the process gas, and the generated compounds will eventually move to the substrate 11 and complete doping on the film, the doping concentration of the film on the substrate 11 can also be adjusted by adjusting the flow rate of the process gas.

[0063] It can be understood that sub-step S411 and sub-step 412 can be performed one by one, one after the other, or simultaneously, and no specific limitation is made here.

[0064] Furthermore, step S410 also includes the following sub-steps:

[0065] heating the organometallic compound to a predetermined temperature to generate vapor of the organometallic compound;

[0066] The inert gas is made to carry the vapor of the organometallic compound into the vacuum chamber at a third flow rate. For example, the third flow rate may be less than or equal to the second flow rate.

[0067] In this embodiment, during the doping process, only a small flow rate of inert gas is needed to carry the vapor of the organic metal compound into the vacuum chamber. Therefore, the third flow rate is usually made smaller than the second flow rate. It can also avoid that the inert gas flow rate is too large, causing a large change in the gas flow ratio of the inert gas to the process gas, and avoiding affecting the normal progress of the sputtering process.

[0068] In detail, the ratio of the second flow rate to the third flow rate is m:1, where 1≤m≤50.

[0069] For example, in this embodiment, the ratio of the second flow rate to the third flow rate is 4-6:1, the doping effect is good and the quality of the prepared thin film is good.

[0070] In summary, the embodiment of the present invention provides a sputtering film-forming controllable doping process and a coating device 10. Taking the nickel oxide process performed by a PVD device of model SC-VT-300 as an example, a nickel oxide film layer and a copper-doped nickel oxide film layer are deposited by a radio frequency sputtering device through the device. The target material 12 is a nickel oxide target material 12. First, Ar with a gas flow rate of 200 sccm and O2 with a gas flow rate of 50 sccm are introduced into the vacuum chamber. The radio frequency power supply 220 is started at a power of 550 W to deposit the NiOx film layer. At the same time, the pressure in the vacuum chamber is set to 0.35 Pa, so that the base The substrate 11 is displaced at a moving speed of 9 mm / s, and a film layer with a thickness of up to 20 nm can be formed on the substrate 11 after 4 round trips; and if doping is required, the vapor of the organic copper organometallic compound (such as Cu(dmamb)2, the temperature of the organic metal compound is 80°C) is carried into the vacuum chamber 100 with a gas flow rate of 10 sccmAr as a carrier gas for doping reaction, so that the vapor of the organic copper organometallic compound generates CuO in the atmosphere of the plasma 500, and finally the CuO moves to the surface of the substrate 11 to complete the copper doping in the NiOx film layer. It is worth mentioning that the doping concentration can be adjusted by changing the amount of source vapor carried in and the flow rate of oxygen to adjust the doping concentration in the film layer; after experimental verification, the above process can increase the efficiency of the prepared perovskite cell with a copper-doped nickel oxide film layer from 15.78% to 18.51%.

[0071] Similarly, a PVD device can also be used to make a tin oxide film layer for the upright battery. The target material 12 is a tin oxide target material 12. First, Ar with a gas flow rate of 200 sccm and O2 with a gas flow rate of 50 sccm are introduced into the vacuum chamber, and the RF power supply 220 is started at a power of 500 W to deposit the SnOx film layer. At the same time, the pressure in the vacuum chamber is set to 0.35 Pa, and the substrate 11 is displaced at a moving speed of 9 mm / s. After 4 round trips, a film layer with a thickness of 28 nm can be formed on the substrate 11. Experimental verification shows that the film layer mobility is about 7 cm2 / v·s. If doping is required, A with a gas flow rate of 10 sccm is used. r is used as a carrier gas to carry the vapor of an organic niobium organometallic compound (such as TBTDENb, the temperature of the organic metal compound is 80°C) into a vacuum chamber for a doping reaction, or Ar with a gas flow rate of 10sccm is used as a carrier gas to carry the vapor of an organic molybdenum organometallic compound (such as BTBMM, the temperature of the organic metal compound is 70°C) into a vacuum chamber for a doping reaction, so as to prepare a doped tin oxide film layer. Experimental verification shows that the film layer mobility can be increased to about 50cm2 / v·s, and the efficiency of a 300*300cm upright perovskite cell is increased from 13.85% to 16.24%.

[0072] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A sputtering film-forming controllable doping process, characterized in that: include: placing the substrate and the target in a vacuum chamber; injecting an inert gas and a process gas into the vacuum chamber; discharging electricity into the vacuum chamber to ionize the noble gas; A gas containing an organic metal compound is introduced into the vacuum chamber to perform a doping reaction, so as to prepare a film layer doped with a compound containing a corresponding metal on the surface of the substrate.

2. The sputtering film-forming controllable doping process according to claim 1, characterized in that: The gas containing the organometallic compound is vapor of the organometallic compound, and the step of passing the gas containing the organometallic compound into the vacuum chamber for the doping reaction further comprises: The inert gas is used as a carrier to carry the vapor of the organic metal compound into the vacuum chamber.

3. The sputtering film-forming controllable doping process according to claim 2, characterized in that: The sputtering film-forming controllable doping process also includes: The flow rates of the inert gas and the vapor of the organic metal compound are adjusted to adjust the doping concentration.

4. The sputtering film-forming controllable doping process according to any one of claims 1 to 3, characterized in that: The sputtering film-forming controllable doping process also includes: The flow rate of the process gas is adjusted to adjust the doping concentration.

5. The sputtering film-forming controllable doping process according to claim 2, characterized in that: The injecting of inert gas and process gas into the vacuum chamber comprises: injecting the inert gas into the vacuum chamber at a first flow rate; injecting the process gas into the vacuum chamber at a second flow rate, wherein the process gas includes oxygen; Wherein, the first flow rate is greater than or equal to the second flow rate.

6. The sputtering film-forming controllable doping process according to claim 5, characterized in that: The ratio of the first flow rate to the second flow rate is n:1, where 1≤n≤50.

7. The sputtering film-forming controllable doping process according to claim 5, characterized in that: The step of introducing the gas containing the organic metal compound into the vacuum chamber to perform the doping reaction comprises: heating the organometallic compound to a predetermined temperature to generate vapor of the organometallic compound; The inert gas is caused to carry the vapor of the organometallic compound into the vacuum chamber at a third flow rate.

8. The sputtering film-forming controllable doping process according to claim 7, characterized in that: The ratio of the second flow rate to the third flow rate is m:1, where 1≤m≤50.

9. The sputtering film-forming controllable doping process according to claim 1, characterized in that: The step of discharging the vacuum chamber to ionize the inert gas further comprises: Adjusting the pressure in the vacuum chamber to a preset pressure, wherein the preset pressure is 0.1 Pa to 1.0 Pa; The substrate is driven to reciprocate in the vacuum chamber at a preset moving speed, wherein the preset moving speed is 5 mm / s to 15 mm / s.

10. A film coating device for implementing the sputtering film-forming controllable doping process according to any one of claims 1 to 9, characterized in that: The coating device comprises a chamber, an ionization mechanism and a vacuum pump; The side wall of the cavity is provided with an air inlet, and the air inlet is used to introduce inert gas, process gas and gas with organic metal compounds; the interior of the cavity is also provided with relative anode mounting parts and cathode mounting parts, the anode mounting part is used to support the substrate, the cathode mounting part is used to install the target material, and the ionization mechanism is connected to the cathode mounting part; the vacuum pump is connected to the cavity to form the vacuum chamber in the cavity.

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