Laser-assisted microwave plasma chemical vapor deposition system and application thereof

Abstract

The invention provides a laser-assisted microwave plasma chemical vapor deposition system and application thereof, and the system comprises: a deposition module for depositing a film on the surface of a substrate in a resonant cavity by using a microwave plasma chemical vapor deposition method; the laser module is used for providing an irradiation laser beam to the surface of the substrate; the laser module comprises at least one laser unit, and each laser unit comprises a femtosecond laser used for emitting a laser beam with a preset wavelength, and a mask plate which is arranged on an emitting light path of the femtosecond laser and carries a design pattern, and enabling the laser beam penetrating through the mask plate to react with the reaction gas on the substrate by utilizing the exposure masking effect of the mask plate to carry out patterning growth. The mask technology is creatively adopted, direct irradiation of the area light source is achieved, the problems of low speed and light spot control of traditional laser direct writing are effectively solved, and one-time batch growth of semiconductor devices and high-cleanliness and high-consistency devices is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of microwave plasma chemical vapor deposition, and particularly to a laser-assisted microwave plasma chemical vapor deposition system and its application. Background Art

[0002] The existing MPCVD (microwave plasma chemical vapor deposition) technology is mostly used for preparing diamond films. Its device includes a microwave source, a waveguide, and microwave plasma resonators in the form of a quartz bell jar and a quartz plate. By adjusting the length and thickness of the mode conversion antenna, the microwave electric field distribution and impedance are adjusted to optimize the excitation of the plasma and reduce the reflected power of the device.

[0003] In the research and development of semiconductor thin film patterning, laser direct writing exhibits unique advantages: high precision, high resolution, fast processing speed, high efficiency, true three-dimensional processing ability. The laser direct writing technology has high flexibility and can write patterns on a printed circuit board by laser without using traditional photoresist films, improving production efficiency and printing accuracy and reducing costs, which is suitable for the field of micro-nano manufacturing. However, it has the following defects:

[0004] (1) High equipment cost and complex maintenance;

[0005] (2) Heat and stress are generated during the processing, which may affect the properties and processing quality of the material;

[0006] (3) For large-area processing, since the laser direct writing technology needs to write patterns point by point, the speed is relatively slow, so it is not as efficient as the mask lithography technology in large-scale production;

[0007] (4) In chip manufacturing, the laser direct writing technology may face problems such as wavelength issues, spot enlargement caused by spherical aberration of the focusing lens, and the problem that the beam walking accuracy cannot reach the nanometer level;

[0008] (5) Although the parallel processing method based on the microlens array and interference lattice can improve the laser direct writing efficiency, there is a problem that the spots cannot be individually controlled. Summary of the Invention

[0009] The purpose of the present invention is to overcome the disadvantages and deficiencies existing in the prior art, and to provide a laser-assisted microwave plasma chemical vapor deposition system and its application.

[0010] The technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a laser-assisted microwave plasma chemical vapor deposition system, and the system includes:

[0011] A deposition module that deposits a thin film on the surface of a substrate located in a resonator by microwave plasma chemical vapor deposition;

[0012] A laser module for providing an irradiating laser beam to the surface of the substrate;

[0013] The laser module includes at least one laser unit, and the laser unit includes:

[0014] A femtosecond laser for emitting a laser beam with a preset wavelength;

[0015] A mask plate is arranged on the light path of the femtosecond laser and carries a designed pattern. The exposure masking effect of the mask plate is used to make the laser beam transmitted through the mask plate react with the reactive gas on the substrate for patterned growth.

[0016] Preferably, the laser unit further includes:

[0017] A beam splitter is arranged on the light path of the femtosecond laser for splitting the preset wavelength laser beam into a transmitted laser beam and a reflected laser beam; the transmitted laser beam of the beam splitter is used to irradiate the surface of the substrate;

[0018] A monitoring member is arranged on the light path of the reflected laser beam of the beam splitter for real-time monitoring of the light intensity of the reflected laser beam of the beam splitter.

[0019] Preferably, the monitoring member is a photodiode.

[0020] Preferably, the laser unit further includes:

[0021] A plane mirror is arranged on the transmitted light path of the beam splitter for changing the direction of the irradiating laser beam;

[0022] A lens A is located on the reflected light path of the plane mirror for collimating / focusing the laser beam;

[0023] A lens B is located on the transmitted light path of the lens A for focusing / adjusting the beam;

[0024] An objective lens is located on the transmitted light path of the lens B for transmitting the laser beam onto the mask plate.

[0025] Preferably, the laser module includes a plurality of laser units, and the plurality of laser units are used to provide irradiating laser beams with different wavelengths to the surface of the substrate.

[0026] Preferably, the system further includes:

[0027] A temperature monitoring module is connected to the deposition module for monitoring the temperature of the surface of the substrate;

[0028] A control module is connected to both the laser module and the temperature monitoring module for controlling the power of the irradiating laser beam according to the temperature of the surface of the substrate.

[0029] Preferably, a sample stage for placing a substrate and a driving mechanism for driving the sample stage to move in three directions of X, Y, and Z are provided in the resonant cavity, and the driving mechanism is connected to the control module.

[0030] The second aspect of the present invention provides an application of the laser-assisted microwave plasma chemical vapor deposition system as described above in depositing patterned thin films.

[0031] Preferably, it includes the following steps:

[0032] (1) Perform plasma pretreatment on the surface of the substrate;

[0033] (2) The irradiation laser beam provided by the femtosecond laser forms a patterned thin film on the substrate through the exposure masking effect of the mask template and reacts with the reaction gas on the substrate.

[0034] Preferably, in step (2), the microwave power in the resonant cavity is 500 - 1200 W, the cavity pressure is 2.0 - 3.4 Kpa, the pulse width of the laser beam emitted by the femtosecond laser is 100 - 140 fs, the repetition frequency is 30 - 70 KHz, the scanning rate is 300 - 700 μm / s, the single-pulse energy is 0.1 - 0.22 μJ, and the growth time is 5 - 15 min.

[0035] The beneficial effects of the present invention are as follows:

[0036] 1. Based on MPCVD, the present invention installs a femtosecond (or picosecond) laser to construct an efficient laser direct writing configuration. Different from traditional laser direct writing technology, the present invention innovatively adopts the mask template technology to achieve direct irradiation of the surface light source, effectively overcoming the problems of slow speed and spot control in traditional laser direct writing, and is conducive to batch growth of semiconductor devices at one time, with high cleanliness and high consistency devices.

[0037] 2. Advantages of the mask template technology: The mask template technology plays a key role in the lithography process. It can accurately transfer the circuit pattern to the silicon wafer to achieve high-density integration of microelectronic devices. The mask template technology adopted by the present invention improves production efficiency and ensures product consistency through accurate pattern transfer, which is of great significance for the standardized production and quality control in the semiconductor industry.

[0038] 3. Advantages of surface light source irradiation: Compared with the traditional point light source scanning mode, the direct irradiation method of the surface light source adopted by the present invention can greatly improve the processing speed and efficiency, while maintaining the accuracy and consistency of the pattern. This irradiation method avoids the speed limitation and spot control problems that may be brought by point light source scanning, making large-area patterned growth possible.

[0039] 4. Advantages of the combination of MPCVD and laser lithography: The present invention combines the advantages of MPCVD and laser lithography to achieve the patterned growth of semiconductor thin films. This combination not only improves production efficiency but also reduces costs, making large-scale production a reality. The present invention can grow semiconductor devices with specific patterns in one step. Since it avoids the intermediate steps caused by the separation of growth and lithography, it reduces contamination and additional costs, and improves the cleanliness and economy of the overall process. This integrated preparation method simplifies the production process and reduces errors and defects that may be caused by multiple steps. This method not only improves the performance and reliability of the device but also provides a new and efficient production mode for the semiconductor manufacturing field.

[0040] 5. Instead of using photoresist, the present invention uses a pattern formed by a beam of ultraviolet light passing through a mask to undergo photochemical and thermal chemical reactions with the reaction gas on the substrate, enabling patterned growth at the positions irradiated by light; at the same time, another beam of infrared light is used for growth. Lights of two energies can be used for growth of different materials. The infrared light provides a photothermal decomposition effect, and the ultraviolet light provides a photolytic cleavage effect. The functional groups targeted are different, so that functionalized structural materials or devices can be prepared.

[0041] In summary, by combining MPCVD and laser mask lithography technologies and using surface light source irradiation, the present invention not only improves production efficiency and the quality of patterned growth but also reduces costs and maintenance difficulties, providing an innovative solution for the manufacture of semiconductor devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, obtaining other drawings without creative efforts still belongs to the scope of the present invention.

[0043] Figure 1 It is a structural block diagram of a laser-assisted microwave plasma chemical vapor deposition system provided in Embodiment 1 of the present invention;

[0044] Figure 2 It is a schematic structural diagram of a laser module provided in Embodiment 1 of the present invention;

[0045] Figure 3 It is a schematic structural diagram of a sample prepared in Application Example 1 of the present invention: (a) top view, (b) front view;

[0046] Figure 4 It is (a) the pattern of the first mask, (b) the pattern of the second mask, and (c) the schematic structural diagram of the sample prepared in Application Example 2 of the present invention;

[0047] In the figure, 100 is a laser module; 101 is a first femtosecond laser; 102 is a second femtosecond laser; 111 is a first beam splitter; 112 is a second beam splitter; 121 is a first monitor; 122 is a first monitor; 131 is a first plane mirror; 132 is a second plane mirror; 141 is a first lens A; 142 is a second lens A; 151 is a first lens B; 152 is a second lens B; 161 is a first objective lens; 162 is a second objective lens; 171 is a first mask; 172 is a second mask; 200 is a deposition module; 201 is a resonant cavity; 202 is a sample stage; 300 is a temperature monitoring module; 400 is a microwave module; 500 is a gas delivery module; 600 is a control module. Detailed implementation mode

[0048] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0049] Example 1

[0050] This embodiment provides a laser-assisted microwave plasma chemical vapor deposition system. As Figure 1-2 shown, the system includes:

[0051] A deposition module 200, including a resonant cavity 201, for depositing a thin film on the surface of a substrate located in the resonant cavity 201 by microwave plasma chemical vapor deposition. A sample stage 202 for placing the substrate and a driving mechanism for driving the sample stage 202 to move in three directions of X, Y, and Z are arranged in the resonant cavity 201, and the driving mechanism is connected to the control module. The driving mechanism is specifically a driving motor.

[0052] A laser module 100, arranged on one side of the deposition module 200, for providing an irradiation laser beam to the surface of the substrate.

[0053] The laser module 100 includes a femtosecond laser, a water chiller, and some devices for adjusting and monitoring the laser power, and at least one femtosecond laser is provided.

[0054] A temperature monitoring module 300, connected to the deposition module 200, for monitoring the temperature of the specimen surface.

[0055] Generally, an auxiliary heating structure is provided on the base in the resonator cavity 201 to heat the base so that the temperature during the deposition process meets the requirements. The temperature monitoring module 300 can simultaneously monitor the base temperature and the substrate surface temperature. In the embodiments of the present invention, the temperature monitoring module 300 can adopt an infrared thermal imaging temperature monitoring system to detect the temperature of the base surface irradiated by the laser through this indirect measurement method of infrared thermal imaging. Among them, multiple infrared sensors are provided to measure the temperatures at different positions on the surface of the sample stage.

[0056] In practical applications, the microwave plasma chemical vapor deposition system may further include:

[0057] A microwave module 400 that delivers microwaves to the resonator cavity 201. The microwave module 400 includes a microwave source and a microwave transmission device. The microwaves generated by the microwave source can be transmitted to the resonator cavity 201 through the microwave transmission device. The microwave transmission device can adopt a circulator, a straight waveguide, etc.

[0058] A plurality of sealed optical windows are provided on the vacuum chamber 301 of the deposition module 200. The irradiation laser beams emitted by each laser light source respectively irradiate the surface of the specimen obliquely downward through independent optical windows to form light spots, and the optical windows matching the laser light sources are arranged at intervals.

[0059] A gas delivery module 500, which is connected to the deposition module 200 and is used to deliver the gases required for the microwave plasma chemical vapor deposition process to the deposition module 200.

[0060] The gas delivery module 500 is mainly composed of a precursor raw material tank, storage gas cylinders for carrier gas and dilution gas, a delivery pipeline, a flow controller, etc. The gas delivery module 500 can provide precise, stable, and continuous vapor, solving the problem of serious waste of raw materials; accurately controlling the proportion of each metal element in the mixed raw material vapor.

[0061] A control module 600, which is connected to the laser module 100, the deposition module 200, the temperature monitoring module 300, the microwave module 400, and the gas delivery module 500, and is used to control the operation of the laser module 100, the deposition module 200, the temperature monitoring module 300, the microwave module 400, and the gas delivery module 500.

[0062] Specifically, the control module 600 can control the power of the irradiation laser beam according to the temperature of the substrate surface monitored by the temperature monitoring module 300.

[0063] The control module 600 can automatically and accurately control each step to achieve intelligence.

[0064] Furthermore, the laser module 100 can include multiple laser units, and the multiple laser units are used to provide irradiation laser beams with different wavelengths to the substrate surface.

[0065] The present invention does not limit the number of laser units. For example, the number of laser units can be one, two, three, or more.

[0066] In this embodiment, taking the laser module 100 including two laser units as an example, the specific structure of the laser module 100 will be described.

[0067] First, the specific structure of each laser unit will be described. Refer to Figure 2 As shown, each laser unit includes:

[0068] A femtosecond laser for emitting a laser beam with a preset wavelength. In the laser module 100 of the present invention, there are a first femtosecond laser 101 and a second femtosecond laser 102. The two lasers are arranged outside the periphery of the resonator 201 and are symmetrically distributed. The two lasers emit independent optical paths respectively.

[0069] Among them, the preset wavelength is a pre-set wavelength. The type and number of femtosecond lasers are set according to the required deposition material, deposition efficiency, and film characteristics. Infrared femtosecond lasers, ultraviolet femtosecond lasers, KrF femtosecond lasers, etc. can be used. The laser beam emitted by the ultraviolet femtosecond laser can undergo photochemical and thermal chemical reactions with the reaction gas on the substrate, enabling film growth at the position irradiated by the laser beam; lights with two energies of ultraviolet light and infrared light can be used for growth of different materials. The infrared light provides a photothermal decomposition effect, and the ultraviolet light provides a photolytic effect. The functional groups targeted are different, thereby realizing the preparation of functionalized structural materials or devices.

[0070] A beam splitter is arranged on the output optical path of the femtosecond laser for splitting the laser beam with the preset wavelength into a transmitted laser beam and a reflected laser beam; the transmitted laser beam of the beam splitter is used to irradiate the surface of the substrate. In practical applications, the beam splitter can be a beam splitting film. In the laser module 100 of this embodiment, there are two beam splitters, denoted as the first beam splitter 111 and the second beam splitter 112 respectively.

[0071] A monitoring component is arranged on the optical path of the reflected laser beam of the beam splitter for real-time monitoring of the power of the reflected laser beam of the beam splitter. In this embodiment, the monitoring component is a photodiode. In the laser module 100, there are two monitoring components, denoted as the first monitoring component 121 and the second monitoring component 122 respectively.

[0072] A plane mirror is arranged on the transmitted optical path of the beam splitter for changing the direction of the irradiated laser beam. In this embodiment, there are two plane mirrors in the laser module 100, denoted as the first plane mirror 131 and the second plane mirror 132 respectively.

[0073] Lens A is located on the reflected light path of the plane mirror and is used to collimate / focus the laser beam, adjusting the laser beam emitted by the femtosecond laser into a parallel beam or focusing it to a specific position so that subsequent optical elements (such as lens B or the mask) can better process the beam. In the laser module 100 of this embodiment, two lenses A are provided, denoted as the first lens A 141 and the second lens A 142 respectively.

[0074] Lens B is located on the transmitted light path of lens A and is used to focus / adjust the size and shape of the beam to make it more suitable for patterning through the mask and finally irradiate the substrate surface. Lens B can also be used to adjust the spot size to match the pattern size of the mask. In the laser module 100 of this embodiment, two lenses B are provided, denoted as the first lens B 151 and the second lens B 152 respectively.

[0075] The objective lens is located on the transmitted light path of lens B and is used to transmit the laser beam onto the mask. The objective lens is located behind lens B to ensure that the laser beam can be accurately focused onto the mask after being adjusted by lens B, thereby achieving high-precision patterned growth. The overall optical path design takes into account the adjustment, focusing, and monitoring of the laser beam, ensuring the stability and efficiency of the system. In the laser module 100 of this embodiment, two objective lenses are provided, denoted as the first objective lens 161 and the second objective lens 162 respectively.

[0076] The mask is arranged on the outgoing light path of the femtosecond laser and carries the designed pattern. Using the exposure masking effect of the mask, the laser beam transmitted through the mask reacts with the reactive gas on the substrate for patterned growth. In the laser module 100 of this embodiment, two masks are provided, denoted as the first mask 171 and the second mask 172 respectively.

[0077] The three laser units in the laser module 100 of the present invention can be denoted as the first laser unit and the second laser unit respectively.

[0078] Reference Figure 2 As shown, in the first laser unit, the first femtosecond laser 101 emits a laser beam, which is split into two laser beams by the first beam splitter 111. One laser beam reaches the first monitor 121 for monitoring the spot light intensity, and the other laser beam is reflected by the first plane mirror 131 and then passes through the first lens A 141, the first lens B 151, and the first objective lens 161 in sequence. After the exposure masking effect of the first mask 171, the laser beam transmitted through the first mask 171 reacts with the reactive gas on the substrate for patterned growth.

[0079] In the second laser unit, the second femtosecond laser 102 emits a laser beam, which is split into two laser beams by the second beam splitter 112. One laser beam reaches the second monitor 122 for monitoring the spot light intensity, and the other laser beam is reflected by the second plane mirror 132 and then passes through the second lens A 142, the second lens B 152, and the second objective lens 162 in sequence. After that, the exposure masking effect of the second mask 172 causes the laser beam transmitted through the second mask 172 to react with the reactive gas on the substrate for patterned growth.

[0080] Application Example 1

[0081] In this application example, a rectangular graphene thin film is deposited on a substrate by using the laser-assisted microwave plasma chemical vapor deposition system of Example 1. Among them, a single laser beam with a wavelength of 690 - 1080 nm is used, and the pattern of the first mask 171 is rectangular.

[0082] The deposition substrate is a nickel sheet with a purity of 99.99%. Before depositing graphene, the surface of the substrate is cleaned by plasma etching.

[0083] Deposition conditions: A titanium-sapphire femtosecond laser is used, the pulse width of the emitted laser beam is 120 fs, the repetition frequency is 50 KHz, the scanning rate is 500 μm / s, the single-pulse energy is 0.16 μJ, and a linearly polarized light with an adjustable working center wavelength is used; the microwave power is 800 - 900 W, the chamber pressure is 2.6 - 2.8 Kpa, the gas source and ratio (CH4 / H2 / Ar) ( / ml / min) is 1:80:30, and the growth time is 10 min. The Figure 3 patterned thin film as shown is obtained.

[0084] Application Example 2

[0085] In this application example, a diamond thin film is deposited on a substrate by using the laser-assisted microwave plasma chemical vapor deposition system of Example 1 and the deposition conditions of Application Example 1. Among them, a first femtosecond laser 101 with a preset wavelength of 1550 nm and a second femtosecond laser 102 with a preset wavelength of 515 nm are used. The pattern of the first mask 171 is strip-shaped, and the pattern of the second mask 172 is Wifi. The Figure 4 patterned thin film as shown in c is obtained.

[0086] Since the wavelength of the second femtosecond laser 102 is 515 nm, this structure is a diamond structure with color centers. The emitted light radiates electromagnetic waves outward through the mutual coupling of the "one" structure and the "Wifi" structure, and a lidar chip can be prepared.

[0087] The above-disclosed is only the preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A laser-assisted microwave plasma chemical vapor deposition system, characterized in that, The system includes: A deposition module, including a resonant cavity, for depositing a thin film on the surface of a substrate located in the resonant cavity by microwave plasma chemical vapor deposition; A laser module, for providing an irradiation laser beam to the surface of the substrate; The laser module includes at least one laser unit, and the laser unit includes: A femtosecond laser, for emitting a laser beam with a preset wavelength; A mask plate, arranged on the outgoing light path of the femtosecond laser and carrying a designed pattern, and using the exposure masking effect of the mask plate to make the laser beam transmitted through the mask plate react with the reaction gas on the substrate for patterned growth.

2. The laser-assisted microwave plasma chemical vapor deposition system according to claim 1, wherein, The laser unit further includes: A beam splitter, arranged on the outgoing light path of the femtosecond laser, for splitting the preset wavelength laser beam into a transmitted laser beam and a reflected laser beam; the transmitted laser beam of the beam splitter is used for irradiating the surface of the substrate; A monitoring component, arranged on the light path of the reflected laser beam of the beam splitter, for monitoring the light intensity of the reflected laser beam of the beam splitter in real time.

3. The laser-assisted microwave plasma chemical vapor deposition system according to claim 2, characterized in that: The monitoring component is a photodiode.

4. The laser-assisted microwave plasma chemical vapor deposition system according to claim 2, wherein, The laser unit further includes: A plane mirror, arranged on the transmitted light path of the beam splitter, for changing the direction of the irradiation laser beam; Lens A, located on the reflected light path of the plane mirror, for collimating / focusing the laser beam; Lens B, located on the transmitted light path of Lens A, for focusing / adjusting the beam; An objective lens, located on the transmitted light path of Lens B, for transmitting the laser beam onto the mask plate.

5. A laser-assisted microwave plasma chemical vapor deposition system according to claim 1, characterized in that: The laser module includes a plurality of laser units, and the plurality of laser units are used for providing irradiation laser beams with different wavelengths to the surface of the substrate.

6. The laser-assisted microwave plasma chemical vapor deposition system according to claim 1, characterized in that, The system further includes: A temperature monitoring module, connected to the deposition module, for monitoring the temperature of the surface of the substrate; A control module, connected to both the laser module and the temperature monitoring module, for controlling the power of the irradiation laser beam according to the temperature of the surface of the substrate.

7. A laser-assisted microwave plasma chemical vapor deposition system according to claim 6, wherein: A sample stage for placing the substrate and a driving mechanism for driving the sample stage to move in three directions of X, Y, and Z are arranged in the resonant cavity, and the driving mechanism is connected to the control module.

8. Application of a laser-assisted microwave plasma chemical vapor deposition system according to any one of claims 1-7 in depositing a patterned thin film.

9. The application according to claim 8, characterized in that, Including the following steps: (1) Performing plasma pretreatment on the surface of the substrate; (2) The irradiation laser beam provided by the femtosecond laser reacts with the reaction gas on the substrate through the exposure masking effect of the mask plate to grow a patterned thin film on the substrate.

10. The application according to claim 9, wherein : In step (2), the microwave power in the resonant cavity is 500-1200W, the cavity air pressure is 2.0-3.4Kpa, the pulse width of the laser beam emitted by the femtosecond laser is 100-140fs, the repetition frequency is 30-70KHz, the scanning rate is 300-700μm / s, the single pulse energy is 0.1-0.22μJ, and the growth time is 5-15min.

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