Method for preparing molybdenum disulfide film with assistance of segmented oxygen

Abstract

The invention discloses a method for preparing a molybdenum disulfide film through segmented oxygen assistance, and belongs to the technical field of semiconductor material preparation. According to the method, oxygen is introduced in the initial stage of molybdenum disulfide growth, molybdenum disulfide is selectively etched by adjusting oxygen flow, pressure and oxidation time, defective crystal grains are etched away, and high-quality molybdenum disulfide crystal grains are left as nucleation points for subsequent growth; oxygen is introduced in the end stage of molybdenum disulfide growth, the oxidation reaction degree of oxygen and molybdenum disulfide is controlled by adjusting the oxygen flow, the passivation temperature and the passivation time, and the sulfur vacancy defect is passivated. The segmented oxygen-assisted chemical vapor deposition method is beneficial to preparation of the high-quality molybdenum disulfide thin film, and is expected to promote further application of the molybdenum disulfide thin film in electrical and photoelectric devices.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor material preparation, and in particular relates to a method for preparing a molybdenum disulfide film with the assistance of segmented oxygen. Background Art

[0002] Two-dimensional transition metal dichalcogenides (TMDCs) are a class of layered materials that are connected by covalent bonds within the plane and interact with each other by van der Waals forces. Molybdenum disulfide (MoS2), as one of the earliest TMDCs studied, is considered a hot candidate for the next generation of semiconductor materials due to its unique electrical properties. Therefore, the preparation of MoS2 thin films has important research significance in both basic research and practical applications.

[0003] MoS2 thin films prepared by chemical vapor deposition (CVD) are considered promising for application in the field of electronic and optoelectronic devices due to their large area and high quality. However, the MoS2 thin films prepared by CVD still have defects such as sulfur vacancies, which will significantly affect their electrical and optoelectronic properties. Therefore, the controllable preparation of high-quality MoS2 thin films is still a scientific issue worth exploring. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing molybdenum disulfide thin films with the assistance of segmented oxygen, on this basis, obtain high-quality MoS2 thin films, and further promote their application in electronic and optoelectronic devices.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for preparing a molybdenum disulfide film with the aid of segmented oxygen comprises the following steps:

[0007] (1) Cleaning the quartz boat and substrate: Place the quartz boat and growth substrate in acetone ultrasound for 15 min, anhydrous ethanol for 15 min, and deionized water for 15 min, and blow dry with a nitrogen gun.

[0008] (2) Use an electronic scale to weigh sulfur (S) powder and molybdenum pentachloride (MoCl5) powder, put the weighed S powder and MoCl5 powder into a quartz boat, and send them into two temperature zones of a tube furnace. Put the S powder into the first temperature zone, and put the MoCl5 powder and the growth substrate into the second temperature zone according to the direction of the air flow. The schematic diagram of the device is shown in the figure. Figure 1 As shown; under argon gas 500sccm, the first temperature zone and the second temperature zone were heated to 110°C and kept warm for 10 minutes to remove water vapor.

[0009] (3) A certain flow rate of argon gas is introduced to pump the growth chamber to the growth pressure, and then the first temperature zone and the second temperature zone are heated to the growth temperature respectively; then, while keeping the argon gas flow rate unchanged, a certain flow rate of oxygen is added, and then the temperature is kept for a certain period of time. The schematic diagram of the device is shown in FIG. Figure 2 As shown; then, turn off the oxygen and continue to keep warm for a certain period of time. The schematic diagram of the device is as follows Figure 3 shown.

[0010] (4) The first temperature zone stops heating, the second temperature zone is cooled to a certain temperature (defect passivation temperature), a certain flow of oxygen is introduced while the argon flow rate remains unchanged, and then the temperature is kept for a certain period of time. The schematic diagram of the device is shown in the figure. Figure 4 As shown; then, turn off the oxygen and cool naturally to room temperature to obtain a high-quality MoS2 film. The schematic diagram of the device is shown in Figure 5 shown.

[0011] Furthermore, in step (2), the mass of S powder is 30-2000 mg.

[0012] Furthermore, in step (2), the mass of MoCl5 powder is 1-50 mg.

[0013] Furthermore, in step (3), the argon gas flow rate is 50-300 sccm.

[0014] Furthermore, in step (3), the growth pressure is 100-10000Pa.

[0015] Furthermore, in step (3), the temperature in the first temperature zone is 150-350°C.

[0016] Furthermore, in step (3), the temperature of the second temperature zone is 750-900°C.

[0017] Furthermore, in step (3), the oxygen flow rate is 1-10 sccm.

[0018] Furthermore, in step (3), the aerobic insulation time is 1-5 minutes.

[0019] Furthermore, in step (3), the anaerobic insulation time is 10-30 minutes.

[0020] Furthermore, in step (4), the temperature of the second temperature zone is 300-600°C.

[0021] Furthermore, in step (4), the oxygen flow rate is 0.01-1 sccm.

[0022] Furthermore, in step (4), the aerobic insulation time is 5-30 minutes.

[0023] In summary, by adopting the above technical solution, the beneficial effects of the present invention are:

[0024] (1) In the present invention, in step (3), oxygen is introduced in the initial stage of MoS2 growth, and MoS2 is selectively etched by adjusting the oxygen flow rate, pressure and oxidation time to etch away defective grains, leaving high-quality MoS2 grains as nucleation points for subsequent growth.

[0025] (2) In the present invention, in step (4), oxygen is introduced at the end of the growth of MoS2, and the degree of oxidation reaction between oxygen and MoS2 is controlled by adjusting the oxygen flow rate, passivation temperature and passivation time to passivate the sulfur vacancy defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 It is a schematic diagram of the device for preparing MoS2 thin film of the present invention.

[0028] Figure 2 It is a schematic diagram of the device for preparing MoS2 thin film of the present invention.

[0029] Figure 3 It is a schematic diagram of the device for preparing MoS2 thin film of the present invention.

[0030] Figure 4 It is a schematic diagram of the device for preparing MoS2 thin film of the present invention.

[0031] Figure 5 It is a schematic diagram of the device for preparing MoS2 thin film of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] 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 those skilled in the art without making creative work are within the scope of protection of the present invention.

[0034] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0035] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0036] Example 1

[0037] (1) Cleaning the quartz boat and substrate: Separately clean the quartz boat and ~1×1cm 2 The heavily doped p-type SiO2 / Si substrate growth substrate was placed in acetone ultrasonication for 15 min, anhydrous ethanol for 15 min, deionized water for 15 min, and dried with a nitrogen gun.

[0038] (2) Use an electronic scale to weigh 200 mg of S powder and 3 mg of MoCl5 powder, put the weighed S powder and MoCl5 powder into a quartz boat, and send them into two temperature zones of a tube furnace. Put the S powder into the first temperature zone, and put the MoCl5 powder and the growth substrate into the second temperature zone according to the direction of the air flow. The schematic diagram of the device is shown in the figure. Figure 1 As shown; under argon gas 500sccm, the first temperature zone and the second temperature zone were heated to 110°C and kept warm for 10 minutes to remove water vapor.

[0039] (3) Argon gas is introduced, and the gas flow rate and growth pressure are adjusted to 100 sccm and 2000 Pa respectively. Then, the first temperature zone and the second temperature zone are heated to 180°C and 850°C respectively. Subsequently, while keeping the argon flow rate unchanged, 3 sccm of oxygen is added, and then the temperature is kept for 3 minutes. The schematic diagram of the device is shown in FIG. Figure 2 As shown; then, turn off the oxygen and continue to keep warm for 10 minutes. The schematic diagram of the device is as follows Figure 3 shown.

[0040] (4) The heating of the first temperature zone is stopped, and the temperature of the second temperature zone is lowered to 500°C (defect passivation temperature). Oxygen gas is introduced at 0.1 sccm while the argon flow rate remains unchanged, and then the temperature is kept for 10 minutes. The schematic diagram of the device is shown in the figure. Figure 4 As shown; then, turn off the oxygen and cool naturally to room temperature to obtain a high-quality MoS2 film. The schematic diagram of the device is shown in Figure 5 shown.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a molybdenum disulfide (MoS2) thin film by segmented oxygen-assisted deposition, comprising the following steps: (1) Cleaning the quartz boat and substrate: Place the quartz boat and growth substrate in acetone ultrasound for 15 min, anhydrous ethanol for 15 min, and deionized water for 15 min, and blow dry with a nitrogen gun. (2) Use an electronic scale to weigh 30-2000 mg of sulfur (S) powder and 1-50 mg of molybdenum pentachloride (MoCl5) powder, put the weighed S powder and MoCl5 powder into a quartz boat, and send them into two temperature zones of a tube furnace. Put the S powder into the first temperature zone, and put the MoCl5 powder and the growth substrate into the second temperature zone according to the direction of the gas flow. The schematic diagram of the device is shown in Figure 1; under 500 sccm of argon, heat the first temperature zone and the second temperature zone to 110°C, keep them warm for 10 minutes, and remove water vapor. (3) Argon gas is introduced at a flow rate of 50-300 sccm, and the growth chamber is evacuated to a growth pressure of 100-10000 Pa. The first temperature zone and the second temperature zone are then heated to 150-350°C and 750-900°C, respectively. Subsequently, while maintaining the argon flow rate unchanged, oxygen gas is added at a flow rate of 1-10 sccm, and then the temperature is kept at this temperature for 1-5 minutes. The schematic diagram of the device is shown in FIG2 . Subsequently, the oxygen gas is turned off, and the temperature is kept at this temperature for another 10-30 minutes. The schematic diagram of the device is shown in FIG3 . (4) Heating in the first temperature zone is stopped, and the temperature in the second temperature zone is lowered to 300-600°C (defect passivation temperature). Oxygen gas is introduced at a rate of 0.01-1 sccm while the argon gas flow rate remains unchanged, and then the temperature is kept constant for 5-30 minutes. The schematic diagram of the device is shown in FIG4 . Subsequently, the oxygen gas is turned off and the film is naturally cooled to room temperature to obtain a high-quality MoS2 film. The schematic diagram of the device is shown in FIG5 .

2. The method for preparing MoS2 thin film by segmented oxygen-assisted method according to claim 1, characterized in that: In step (3), oxygen is introduced at the initial stage of MoS2 growth, and by adjusting the oxygen flow, pressure and oxidation time, MoS2 is selectively etched to etch away defective grains, leaving high-quality MoS2 grains as nucleation points for subsequent growth.

3. The method for preparing MoS2 thin film by segmented oxygen-assisted method according to claim 1, characterized in that: In step (4), oxygen is introduced at the end of the growth of MoS2, and the degree of oxidation reaction between oxygen and MoS2 is controlled by adjusting the oxygen flow rate, passivation temperature and passivation time to passivate the sulfur vacancy defects.

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