Film layer monitoring device and epitaxy equipment

Abstract

The invention discloses a film layer monitoring device and epitaxy equipment, the film layer monitoring device is used for vapor phase epitaxy equipment, and the film layer monitoring device comprises an electron beam emission mechanism which comprises an electron emission assembly and an electron channel; the electron emitting assembly is used for generating electron beams; an inlet of the electron channel is communicated with an emitting end of the electron emitting assembly, and an outlet of the electron channel is arranged at a position close to the edge of the wafer; electron beams generated by the electron emitting assembly are glanced to the surface of the wafer through the electron channel so as to be diffracted on the surface of the wafer to form diffracted electron beams; a receiving end of the electron beam receiving mechanism is located in the epitaxial chamber; the electron beam receiving mechanism is configured to capture diffracted electron beams and convert the diffracted electron beams into quantizable signals; the electron beam receiving mechanism is further configured to perform in-situ monitoring on the wafer film layer based on the quantizable signal. The crystal quality and the deposition thickness of the film layer can be monitored in situ in the film growth process, and high-quality imaging of electron diffraction signals can be ensured.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a film monitoring device and an epitaxial device. Background Technology

[0002] In the semiconductor manufacturing field, epitaxy (EPI) technology is a key process for preparing high-quality single-crystal thin films, widely used in the manufacture of advanced logic devices, power devices, optoelectronic devices, and third-generation semiconductor materials. During epitaxial growth, real-time, in-situ monitoring of film crystal quality and thickness is crucial for process control, defect suppression, and material performance optimization. Currently, the evaluation of film quality and thickness mainly relies on offline characterization methods, such as X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), or ellipsometers. These methods require transferring the wafer to independent metrology equipment for analysis after growth, introducing additional process delays and contamination risks, and failing to provide dynamic feedback during the growth process, severely limiting process development efficiency and yield improvement.

[0003] Reflection high-energy electron diffraction (RHEED), a highly sensitive surface analysis technique, has been widely applied in in-situ real-time monitoring under high vacuum environments such as molecular beam epitaxy (MBE). RHEED uses a high-energy electron beam incident at an extremely small grazing angle on the sample surface, utilizing the diffraction effect of the surface atomic layers to obtain information such as the surface morphology, crystal structure, growth mode, and thickness oscillations of the thin film. It has the advantages of being non-destructive and having high temporal resolution. However, the application of RHEED technology is limited by high vacuum conditions (typically better than 10⁻⁶). -6 Pa) to ensure that the electron beam is not affected by scattering of gas molecules during transmission.

[0004] Unlike molecular beam epitaxy (MBE), epitaxial processes based on chemical vapor deposition (CVD) are typically performed in a low-vacuum environment, with a high density of process gases within the reaction chamber. In this environment, the high-energy electron beam in a traditional RHEED system experiences strong scattering from the electron gun to the sample surface and along the diffraction path, leading to a sharp decrease in signal intensity, blurred or even complete disappearance of the diffraction pattern, rendering RHEED ineffective. Therefore, although RHEED has been successfully applied in high-vacuum epitaxy, its integration and application in mainstream CVD-type low-vacuum epitaxy equipment has long been limited.

[0005] Currently, there is a lack of technical solutions for achieving in-situ, real-time, and highly sensitive surface structure characterization under CVD epitaxial growth conditions. Overcoming the adverse effects of low vacuum environment on electron beam propagation, effectively integrating RHEED technology into EPI equipment, and thus realizing dynamic monitoring of crystal quality and thickness during thin film growth have become urgent technical challenges in the field of in-situ monitoring of epitaxial processes.

[0006] The statements herein provide only background information in relation to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0007] The purpose of this invention is to provide a film monitoring device and epitaxial equipment that can monitor the crystallization quality and deposition thickness of the film in situ during the film growth process, effectively overcome the limitations of the low vacuum atmosphere of vapor deposition on characterization technology, and avoid characterization failure caused by gas molecule scattering.

[0008] To achieve the above objectives, the present invention provides a film monitoring device for use in a vapor phase epitaxy apparatus, the vapor phase epitaxy apparatus including an epitaxial chamber for accommodating a wafer; the film monitoring device includes:

[0009] An electron beam emitting mechanism includes an electron emission assembly and an electron channel; the electron emission assembly is used to generate an electron beam; the inlet of the electron channel is connected to the emission end of the electron emission assembly, and the outlet of the electron channel is located near the edge of the wafer; the electron beam generated by the electron emission assembly is grazed onto the wafer surface via the electron channel to form a diffracted electron beam on the wafer surface.

[0010] An electron beam receiving mechanism is provided, with its receiving end located within the epitaxial cavity; the electron beam receiving mechanism is configured to capture the diffracted electron beam and convert the diffracted electron beam into a quantifiable signal; the electron beam receiving mechanism is also configured to perform in-situ monitoring of the wafer film layer based on the quantifiable signal.

[0011] Optionally, the electronic channel includes three differential evacuation channel segments connected in sequence; the three differential evacuation channel segments are, from the entrance to the exit of the electronic channel, the first differential evacuation channel segment, the second differential evacuation channel segment, and the third differential evacuation channel segment, respectively.

[0012] The electron beam emitting mechanism also includes a vacuum pumping component; the vacuum pumping component is connected to each differential pumping channel segment; the vacuum pumping component is configured to perform staged evacuation of the three differential pumping channel segments, so that the vacuum level in the three differential pumping channel segments increases segment by segment along the electron emission path.

[0013] Optionally, the vacuum assembly includes:

[0014] The first extraction pipe connected to the first differential extraction channel section;

[0015] A first molecular pump connected to the first evacuation pipe is used to evacuate the first differential evacuation channel section to regulate the vacuum level within the first differential evacuation channel section.

[0016] The second extraction pipe is connected to the second differential extraction channel section;

[0017] A third suction pipe is connected to both the second suction pipe and the third differential suction channel section; the inner diameter of the third suction pipe is smaller than the inner diameter of the second suction pipe.

[0018] A second molecular pump, connected to the second evacuation pipe, is used to evacuate air from the second differential evacuation channel section and the third differential evacuation channel section to regulate the vacuum level within them.

[0019] Optionally, the third suction pipe is a bent pipe to extend the suction path of the third suction pipe.

[0020] Optionally, the ratio of the inner diameter a1 of the first suction pipe, the inner diameter a2 of the second suction pipe, and the inner diameter a3 of the third suction pipe is a1:a2:a3 = 10:10:1.

[0021] Optionally, the vacuum level within the first differential pumping channel section is maintained at 10. -6 Torr, the vacuum level in the second differential pumping channel section is maintained at 10. -4 Torr, the vacuum level in the third differential pumping channel section is maintained at 10. -3 Torr.

[0022] Optionally, the third differential extraction channel section includes a bellows, a profile transition tube, and a capillary tube connected in sequence; the bellows is connected to the second differential extraction channel section; the profile transition tube is used to achieve a tube diameter transition between the bellows and the capillary tube; the capillary tube extends into the epitaxial cavity, and the outlet end of the capillary tube is close to the edge of the wafer.

[0023] Optionally, the projection of the capillary on the plane where the top surface of the wafer is located falls completely outside the wafer outline; the outlet end of the capillary is 170-200 mm away from the center of the wafer.

[0024] Optionally, the capillary tube is made of quartz; the inner diameter of the capillary tube is set to 0.1-0.5 mm.

[0025] Optionally, the electron emission component has an electron emission energy of 50-70 keV and a beam current of 130-190 uA to ensure that the electrons have sufficient path of freedom.

[0026] Optionally, the electron emission assembly includes an electron gun and an electromagnetic lens connected to the electron gun; the electromagnetic lens is used to focus the electron beam.

[0027] Optionally, the electron beam receiving mechanism includes:

[0028] A microchannel plate, located within the epitaxial cavity and positioned opposite the electron channel, is used to capture the diffracted electron beam and convert the captured diffracted electron beam into an optical signal;

[0029] A CCD camera, which is communicatively connected to the microchannel plate, is used to receive and process optical signals transmitted by the microchannel plate.

[0030] Optionally, the projection of the electronic channel on the horizontal plane is set at a predetermined angle relative to the flow direction of the process gas in the epitaxial chamber, and the predetermined angle ranges from 45 degrees to 90 degrees.

[0031] The present invention also provides an epitaxial device in which the aforementioned film monitoring device is installed.

[0032] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. By setting the exit of the electron channel near the edge of the wafer, the present invention significantly shortens the propagation distance of the electron beam in a low vacuum environment. This design reduces the probability of collision between the electron beam and gas molecules, thereby reducing scattering loss.

[0034] 2. This invention controls the output energy of the electron beam within the range of 50-70 keV. The higher output energy gives the electron beam stronger penetration ability and can overcome the scattering effect of gas molecules in a low vacuum environment to a certain extent, thereby extending the mean free path of the electron beam. In addition, this invention adjusts the beam current intensity of the electron beam to the range of 130-190 uA. The appropriate beam current intensity ensures the signal strength while avoiding the problem of aggravated electron beam scattering caused by excessive beam current.

[0035] 3. This invention creates a gradient vacuum environment along the electron beam propagation path by adjusting the vacuum level within the electron channel segment by segment. By setting different vacuum levels in different sections, this invention minimizes the scattering loss of the electron beam in low vacuum environments. Specifically, the first differential pumping channel segment with relatively high vacuum near the electron emission component ensures that the electron beam propagates with high energy and high directionality in the initial stage. The third differential pumping channel segment with relatively low vacuum near the wafer surface adapts to the process environment of the epitaxial chamber. Through this gradient vacuum design, the electron beam gradually adapts to different vacuum levels during propagation, reducing scattering losses caused by sudden changes in vacuum level.

[0036] 4. By setting the electron channel at a certain angle to the process gas flow direction, this invention effectively reduces the interference of the process gas flow on the electron beam, reduces the probability of collision between the electron beam and gas molecules, thereby reducing scattering loss and ensuring the stability and directionality of electron beam propagation. Furthermore, setting the electron channel at an angle to the process gas flow direction helps to reduce the influence of the electron channel on the gas flow, ensuring the uniformity of the flow field in the epitaxial chamber and ensuring the stable distribution of the process gas in the epitaxial chamber, thus providing a uniform reaction environment for epitaxial growth.

[0037] 5. This invention uses a microchannel plate (MCP) to capture the diffracted electron beam. The microchannel plate (MCP) has high temperature resistance, thereby realizing electron detection in high temperature environments.

[0038] 6. In this invention, the capillary outlet is positioned at a distance from the edge of the wafer (the outlet of the capillary is 170-200 mm away from the center of the wafer), so that the heat generated by the heating lamp assembly above the wafer can be fully applied to the wafer surface without being blocked by the capillary. This arrangement effectively ensures that the wafer is heated uniformly and stably. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the epitaxial device equipped with a film monitoring device according to the present invention;

[0040] Figure 2 This is a top view of the electron beam emitting mechanism of the present invention extending into the epitaxial cavity;

[0041] Figure 3 This is a schematic diagram of the electron beam emitting mechanism of the present invention;

[0042] Figure 4 This is a schematic diagram of the electron beam receiving mechanism of the present invention;

[0043] Explanation of reference numerals in the attached figures:

[0044] 200: Electron beam emitting mechanism; 300: Electron beam receiving mechanism; 201: Electron gun; 202: Electromagnetic lens; 213: First differential pumping channel section; 214: Second differential pumping channel section; 216: Third differential pumping channel section; 203: Bellows; 204: Shaped transition tube; 205: Capillary tube; 206: First pumping tube; 208: Second pumping tube; 207: Third pumping tube; 209: First molecular pump; 210: Second molecular pump; 215: Dry pump; 311: Microchannel plate; 312: CCD camera; 211: First vacuum gauge; 212: Second vacuum gauge; 402: Temperature measuring instrument; 404: Wafer; 405: Base; 406: Upper flange; 407: Lower flange; 408: Lower dome; 409: Rotary support shaft; 412: Lower liner; 413: Upper liner; 414: Wafer transfer port; 416: Upper dome; 420: Sidewall; 430: Centerline; 1000: Heating lamp assembly. Detailed Implementation

[0045] The following will be combined with the appendix Figures 1-4 The present invention will be further described in detail through preferred embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of the present invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0046] like Figure 1 As shown, the present invention provides a film monitoring device, which is integrated into a vapor phase epitaxy device for in-situ monitoring of the film layer of a wafer 404 placed in the epitaxial chamber of the vapor phase epitaxy device.

[0047] The vapor phase epitaxy equipment includes a cavity and a heating lamp assembly 1000. The cavity is composed of an upper dome 416, a lower dome 408, a side wall 420, an upper liner 413, and a lower liner 412, all sealed together. The cavity is arranged approximately symmetrically along the center line 430 of the process chamber. The upper dome 416 is approximately convex and circular, including a circular light-transmitting portion and flanges surrounding the light-transmitting portion. The lower dome 408 is approximately umbrella-shaped. Both the upper and lower domes 416 and 408 are made of quartz. The upper and lower liner 413 and 412 are approximately annular and are located on the inner surface of the side wall 420. The cavity is secured to the side wall 420 by an upper flange 406 and a lower flange 407, respectively. The cavity contains a base 405 for supporting a wafer 404. The base 405 is connected to a rotating support shaft 409. Rotation and vertical movement of the base 405 via the rotating support shaft 409 cause the base 405 and wafer 404 to rotate together around the central axis of the rotating support shaft 409, or vice versa. One end of the cavity has an air inlet, and the opposite end has an exhaust outlet. Process gases flow into the cavity through the air inlet, reach the surface of the wafer 404, perform the required processes within the cavity, and then exit the cavity through the exhaust outlet. A wafer transfer port 414 is also provided perpendicular to the line connecting the air inlet and exhaust outlet for transferring wafers into and out of the cavity. The process cavity also includes piping for supplying coolant to the process cavity for thermal management of the components within. A heating lamp assembly 1000 is positioned above and / or below the cavity. When the required process is performed within the cavity, the upper and lower heating lamp groups 1000 heat the wafer 404 to the required process temperature so that the process gases within the cavity can react. To facilitate monitoring of the process temperature of the wafer 404 within the cavity, the cavity is also equipped with a temperature sensor 402 that measures the process temperature of the wafer 404 in real time through the upper dome 416 and the lower dome 408, respectively, in order to regulate the process temperature.

[0048] Preferably, the vapor phase epitaxy equipment is based on the principle of chemical vapor deposition (CVD), which is carried out in a low vacuum environment and contains a high density of process gas in the cavity; the process pressure of the cavity of the vapor phase epitaxy equipment is 5-650 torr and the process temperature is 600-800℃; for example, in one embodiment, the process pressure of the cavity is 5-50 torr and the process temperature is 600-700℃.

[0049] Please continue reading. Figure 1 The membrane monitoring device includes:

[0050] An electron beam emitting mechanism 200 enters the interior of the vapor phase epitaxy equipment from the outside of the equipment and is used to glide the generated electron beam onto the surface of the wafer 404 to form a diffracted electron beam. The electron beam emitting mechanism 200 is located near the air inlet end of the cavity. The electron beam emitting mechanism 200 passes through the side wall 420 and the inner liner 413 of the vapor phase epitaxy equipment, and at least a portion of the electron beam emitting mechanism 200 extends into the cavity.

[0051] An electron beam receiving mechanism 300 is located within the vapor phase epitaxy apparatus and is disposed opposite to the electron beam emitting mechanism 200. It is used to receive diffracted electron beams. The electron beam receiving mechanism 300 is positioned near the exhaust end of the cavity. The receiving end of the electron beam receiving mechanism 300 is located within the cavity and is disposed opposite to the electron channel. It is used to capture the diffracted electron beam and convert the captured diffracted electron beam into an optical signal. Specifically, the receiving end of the electron beam receiving mechanism 300 and the emitting end of the electron beam emitting mechanism 200 are located on opposite sides of the cavity.

[0052] The electron beam emitting mechanism 200 includes an electron emission component and an electron channel. The electron emission component generates an electron beam. The inlet of the electron channel is connected to the emission end of the electron emission component, and the electron channel maintains a high vacuum state in the electron beam propagation path. The outlet of the electron channel is located near the edge of the wafer 404, which significantly shortens the path length that the electron beam needs to travel before reaching the wafer surface. This reduces the probability of the electron beam colliding with gas molecules in a low vacuum environment, thereby reducing the scattering loss of the electron beam and improving the transmission efficiency and signal strength of the electron beam.

[0053] The electron beam generated by the electron emission component is grazed onto the surface of wafer 404 via the electron channel to form a diffracted electron beam on the surface of wafer 404.

[0054] Furthermore, the electron beam output from the electron channel is grazing at the surface of the wafer 404 with a grazing angle of 0 to 1.8 degrees; the grazing angle is the angle between the central axis of the electron channel and the surface of the wafer 404 within the cavity; controlling the grazing angle of the electron beam within the range of 0 to 1.8 degrees has the following beneficial effects: First, this grazing angle range optimizes the propagation path of the electron beam, shortening its journey to the monitored position on the wafer surface, thereby reducing energy loss and signal attenuation during propagation; Second, a smaller grazing angle brings the electron beam closer to the wafer surface, and due to the distribution characteristics of the process gas flow, the gas molecule density is lower closer to the wafer surface. A smaller grazing angle allows the electron beam propagation path to avoid areas with dense process gas flow, thereby effectively reducing the scattering and interference of the process gas flow on the electron beam.

[0055] like Figure 2 As shown, in a preferred embodiment of the present invention, the projection of the electron channel on the horizontal plane is set at a predetermined angle relative to the flow direction of the process gas in the epitaxial chamber, the predetermined angle ranging from 45 degrees to 90 degrees; wherein, the flow direction of the process gas in the epitaxial chamber is from the inlet end of the chamber to the outlet end of the chamber; this angle setting reduces the probability of collision between the electron beam and gas molecules. By setting the electron channel at an angle of 45 degrees to 90 degrees with the gas flow direction, collisions between the electron beam and gas molecules during propagation are reduced, thereby reducing scattering losses and ensuring the stability and directionality of electron beam propagation; in addition, the angle setting between the electron channel and the gas flow direction reduces the influence of the electron beam on the gas flow, thereby ensuring the uniform distribution of the process gas in the epitaxial chamber and providing a stable reaction environment for epitaxial growth;

[0056] Preferably, the predetermined included angle is 90 degrees. At this time, the projection of the electron channel on the horizontal plane is perpendicular to the flow direction of the process gas in the epitaxial chamber. This vertical arrangement minimizes the contact volume between the electron beam and the process gas flow, thereby reducing the scattering and interference of the process gas flow on the electron beam.

[0057] Please continue reading. Figure 2 Although there is a predetermined angle between the electron beam emission and reception paths and the process gas flow, the electron beam emission mechanism 200 is positioned near the inlet end of the cavity, and the electron beam receiving mechanism 300 is positioned near the exhaust end of the cavity. This ensures that the overall emission and reception paths of the electron beam remain coordinated with the flow direction of the process gas. This design reduces the collision frequency between the electron beam and gas molecules, thereby increasing the electron's free path.

[0058] further, Figure 2 The mounting positions of the electron beam emitting mechanism 200 and the electron beam receiving mechanism 300 relative to the wafer 404, as well as the emission and reception paths of the electron beam, are shown. Taking the position of the wafer 404 as a reference point, the electron beam is emitted from the electron beam emitting mechanism 200 located above one side of the wafer 404. After passing through the electron channel and grazing the surface of the wafer 404, it forms a diffracted electron beam, which is then received by the electron beam receiving mechanism 300 on the other side of the wafer 404, forming an obliquely penetrating electron beam diffraction path. The flow direction of the process gas flow within the epitaxial chamber is parallel to the surface of the wafer 404 and flows from one side of the wafer 404 to the other. Therefore, the emission, reception, and diffraction path of the electron beam can effectively avoid the flow path of the process gas flow, thus preventing the diffracted electron beam from interfering with the flow field within the epitaxial chamber.

[0059] An electron beam receiving mechanism 300 is provided, with its receiving end located within the epitaxial cavity; the electron beam receiving mechanism 300 is configured to capture the diffracted electron beam and convert the diffracted electron beam into a quantifiable signal; the electron beam receiving mechanism 300 is also configured to perform in-situ monitoring of the wafer 404 film layer based on the quantifiable signal.

[0060] Among them, such as Figure 3 As shown, the electron emission assembly includes: an electron gun 201 for generating a high-energy electron beam with an energy of 50-70 keV and a beam current intensity of 130-190 μA; and an electromagnetic lens 202 connected to the electron gun 201 to focus the high-energy electron beam into a beam spot with a diameter of approximately Φ = 0.3 mm and precisely collimate it on the central axis of the electron channel.

[0061] In a preferred embodiment of the present invention, the electron gun 201 generates a high-energy electron beam with an energy of 60 keV and a beam current of 160 μA.

[0062] The electronic channel comprises three sequentially connected differential pumping channel segments. From the inlet to the outlet of the electronic channel, these three differential pumping channel segments are, in order, a first differential pumping channel segment 213, a second differential pumping channel segment 214, and a third differential pumping channel segment 216. The end of the first differential pumping channel segment 213 near the inlet is connected to the electromagnetic lens 202. Each differential pumping channel segment is connected to a vacuum pumping assembly for staged evacuation of each segment. This ensures that after evacuation, the vacuum level in the first differential pumping channel segment 213 is less than the vacuum level in the second differential pumping channel segment 214, and the vacuum level in the second differential pumping channel segment 214 is less than the vacuum level in the third differential pumping channel segment 216. This results in the vacuum level in each of the three differential pumping channel segments increasing progressively along the electron emission path.

[0063] Vacuum levels are typically expressed in units of pressure (such as Torr), which is an inverse indicator, as follows:

[0064] The smaller the vacuum value, the lower the pressure; the higher the vacuum, the lower the gas molecule density.

[0065] The higher the vacuum level, the higher the pressure; the lower the vacuum level, the higher the gas molecule density.

[0066] Therefore, the vacuum level in the three differential pumping channel segments decreases segment by segment along the electron emission path.

[0067] Preferably, both the first differential pumping channel section 213 and the second differential pumping channel section 214 are made of stainless steel.

[0068] Furthermore, the vacuum assembly includes a first evacuation pipe 206 connected to the first differential evacuation channel section 213 to evacuate air from the first differential evacuation channel section 213, thereby maintaining the vacuum level within the differential evacuation channel section at 10. -6 Torr; The second evacuation pipe 208 is connected to the second differential evacuation channel section 214 to evacuate the second differential evacuation channel section 214, so that the vacuum level in the differential evacuation channel section is maintained at 10. -4 Torr; The third evacuation pipe 207 is connected at one end to the second evacuation pipe 208 and at the other end to the third differential evacuation channel section 216 to evacuate air from the third differential evacuation channel section 216, thereby maintaining the vacuum level within the differential evacuation channel section at 10. -3 Torr.

[0069] Furthermore, the vacuum assembly also includes: a first molecular pump 209, connected to the first suction pipe 206, to regulate the gas pressure inside the first suction pipe 206; and a second molecular pump 210, connected to the second suction pipe 208 and indirectly connected to the third suction pipe 207, to regulate the gas pressure inside the second suction pipe 208 and the third suction pipe 207.

[0070] Specifically, the third exhaust pipe 207 is a bent pipe to extend the exhaust path of the third exhaust pipe 207.

[0071] After the first molecular pump 209 is started, air is pumped through the first evacuation pipe 206 to the first differential evacuation channel section 213 to regulate the vacuum level within the first differential evacuation channel section 213 and maintain it at 10. -6 Torr; After the second molecular pump 210 is started, a portion of the pumping kinetic energy is used to pump air through the second pumping pipe 208 to the second differential pumping channel section 214, thereby regulating the vacuum level within the second differential pumping channel section 214 and maintaining it at 10. -4 Torr; Another portion of the pumping kinetic energy, after passing through the second pumping pipe 208, enters the curved and slender third pumping pipe 207, and pumps air into the third differential pumping channel section 216 to regulate the vacuum level within the third differential pumping channel section 216, maintaining it at 10. -3 Torr.

[0072] To facilitate the observation and feedback of the vacuum levels in the first differential pumping channel section 213 and the second differential pumping channel section 214, a first vacuum gauge 211 and a second vacuum gauge 212 are respectively provided on the first differential pumping channel section 213 and the second differential pumping channel section 214; the first vacuum gauge 211 and the second vacuum gauge 212 are used to monitor the vacuum levels in the first differential pumping channel section 213 and the second differential pumping channel section 214, and to feed back the monitoring data of the vacuum levels.

[0073] At the other end of the first molecular pump 209 and the second molecular pump 210, a dry pump 215 is also provided; the dry pump 215 is connected to the first molecular pump 209 and the second molecular pump 210 through a dry pump pipe; the dry pump 215 can discharge the gas extracted by the first molecular pump 209 and the second molecular pump 210.

[0074] Wherein, the inner diameters of the first suction pipe 206 and the second suction pipe 208 are the same, and the inner diameter of the third suction pipe 207 is smaller than that of the second suction pipe 208; specifically, the ratio of the inner diameter a1 of the first suction pipe 206, the inner diameter a2 of the second suction pipe 208, and the inner diameter a3 of the third suction pipe 207 is a1:a2:a3 = 10:10:1;

[0075] The ratio of the inner diameter a2 of the second pumping pipe 208 to the inner diameter a3 of the third pumping pipe 207 is 10:1, which can reasonably distribute the pumping kinetic energy of the second molecular pump 210 and ensure that the vacuum levels of the second differential pumping channel section 214 and the third differential pumping channel section 216 are maintained at 10. -4 Torr and 10 -3 Torr; The smaller inner diameter a3 of the third pumping pipe 207 optimizes the distribution of pumping kinetic energy by increasing gas flow resistance, so that more pumping kinetic energy is preferentially used for vacuum control of the second differential pumping channel section 214.

[0076] The third differential extraction channel section 206 includes a bellows 203, a profile transition tube 204, and a capillary 205 connected in sequence. The end of the bellows 203 that is not connected to the profile transition tube 204 is connected to the second differential extraction channel section 214. The bellows 203 is used to connect the second differential extraction channel section 214. The profile transition tube 204 is used to achieve a tube diameter transition between the bellows 203 and the capillary 205. The capillary 205 extends into the epitaxial chamber, and the outlet end of the capillary is close to the edge of the wafer 404. The capillary 205 can suppress the backflow of gas from the epitaxial chamber to the electron beam source side.

[0077] Preferably, the capillary 205 is cylindrical, and the upper liner 413 in the epitaxial device has an inner liner through hole adapted to the capillary 205. The capillary 205 passes through the inner liner through hole and enters the cavity. The profile transition tube 204 connected to the capillary 205 passes through the side wall 420 of the epitaxial device, and the profile transition tube 204 is located outside the upper liner 413. The cooperation between the cylindrical capillary 205 and the inner liner through hole reduces the size of the inner liner through hole, thereby effectively reducing the risk of the quartz upper liner 413 breaking during the drilling process and ensuring the structural integrity of the liner.

[0078] Preferably, the corrugated tube 203 and the profile transition tube 204 are both made of stainless steel; the capillary tube 205 is made of quartz; the inner diameter of the capillary tube 205 is set to 0.1-0.5 mm. This inner diameter setting of the capillary tube 205 can effectively suppress the backflow of gas in the epitaxial chamber and achieve a leakage rate of less than 1 sccm when the total flow rate of process gas is 0.05%.

[0079] In one embodiment of the present invention, the inner diameter of the capillary 205 is set to 0.5 mm.

[0080] According to the empirical formula for the mean free path of high-energy electrons, it can be calculated that at a vacuum degree of 10... -4 Within the differential pumping channel section of the torr, the mean free path of the 60keV electron beam can reach 10m, indicating that it is almost unaffected by scattering interference during propagation. Even under typical epitaxial chamber conditions (10Torr, 600℃), the mean free path of the electron beam can reach 600mm, which is significantly larger than the diameter of the 404 wafer (300mm). Therefore, the electron beam generated by the electron beam emitting mechanism 200 of the present invention and the propagation of the electron beam fully meet the incident path requirements for in-situ characterization of the epitaxial chamber, and also ensure high-quality imaging of the electron diffraction signal.

[0081] The empirical formula for the mean free path of high-energy electrons is: In the formula, R is the thermodynamic constant, T is the process temperature (e.g., 600℃), and N is the process temperature. A It is Avogadro's constant, and σ is the inelastic collision cross section of high-energy electrons, with a typical value of 1 × 10⁻⁶. -24 m 2 .

[0082] Furthermore, the capillary tube 205 is positioned above the plane on which the wafer 404 is located, and the projection of the capillary tube 205 onto the plane on which the top surface of the wafer 404 is located falls completely outside the outline of the wafer 404. That is, there is a gap between the outlet end of the capillary tube 205 and the edge of the wafer 404. The existence of this gap ensures that the wafer 404 is fully exposed to the irradiation range of the heating lamp assembly 1000 throughout the entire heating process, thereby maintaining a uniform and stable temperature of the wafer 404. Furthermore, the outlet end of the capillary tube 205 is 170-200 mm away from the center of the wafer 404.

[0083] Among them, such as Figure 4As shown, the electron beam receiving mechanism 300 includes: a microchannel plate 311 located within the epitaxial cavity and disposed opposite to the electron channel, for capturing the diffracted electron beam and converting the captured diffracted electron beam into an optical signal; and a CCD camera 312 disposed behind the microchannel plate 311 and communicatively connected to the microchannel plate 311, for receiving and processing the optical signal transmitted by the microchannel plate 311.

[0084] Preferably, the microchannel plate 311 is made of a high-temperature resistant material.

[0085] In addition, to avoid the impact of high temperature environment on CCD camera 312, CCD camera 312 does not directly contact the epitaxial chamber.

[0086] The present invention also provides an epitaxial apparatus in which the aforementioned film monitoring device is installed, so as to facilitate direct monitoring of the film layer of wafer 404 in the epitaxial apparatus.

[0087] In summary, the film monitoring device and epitaxial equipment provided by this invention can monitor the crystallization quality and deposition thickness of the film in situ during the film growth process, thereby effectively avoiding characterization failure caused by the low vacuum atmosphere of vapor deposition. In addition, this invention is suitable for electron detection in high-temperature environments and can significantly reduce the scattering interference of the electron beam on the propagation path, thereby ensuring high-quality imaging of electron diffraction signals.

[0088] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0089] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0090] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0091] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0092] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A membrane monitoring device, characterized in that, The film monitoring device is used in a vapor phase epitaxy apparatus, the vapor phase epitaxy apparatus including an epitaxial chamber for accommodating a wafer; the film monitoring device includes: An electron beam emitting mechanism includes an electron emission assembly and an electron channel; the electron emission assembly is used to generate an electron beam; the inlet of the electron channel is connected to the emission end of the electron emission assembly, and the outlet of the electron channel is located near the edge of the wafer; the electron beam generated by the electron emission assembly is grazed onto the wafer surface via the electron channel to form a diffracted electron beam on the wafer surface. An electron beam receiving mechanism is provided, with its receiving end located within the epitaxial cavity; the electron beam receiving mechanism is configured to capture the diffracted electron beam and convert the diffracted electron beam into a quantifiable signal; the electron beam receiving mechanism is also configured to perform in-situ monitoring of the wafer film layer based on the quantifiable signal.

2. The membrane monitoring device as described in claim 1, characterized in that, The electronic channel includes three differential evacuation channel segments connected in sequence; the three differential evacuation channel segments are, from the entrance to the exit of the electronic channel, the first differential evacuation channel segment, the second differential evacuation channel segment, and the third differential evacuation channel segment, respectively. The electron beam emitting mechanism also includes a vacuum pumping component; the vacuum pumping component is connected to each differential pumping channel segment; the vacuum pumping component is configured to perform staged evacuation of the three differential pumping channel segments, so that the vacuum level in the three differential pumping channel segments increases segment by segment along the electron emission path.

3. The membrane monitoring device as described in claim 2, characterized in that, The vacuum pumping assembly includes: The first extraction pipe connected to the first differential extraction channel section; A first molecular pump connected to the first evacuation pipe is used to evacuate the first differential evacuation channel section to regulate the vacuum level within the first differential evacuation channel section. The second extraction pipe is connected to the second differential extraction channel section; A third suction pipe is connected to both the second suction pipe and the third differential suction channel section; the inner diameter of the third suction pipe is smaller than the inner diameter of the second suction pipe. A second molecular pump, connected to the second evacuation pipe, is used to evacuate air from the second differential evacuation channel section and the third differential evacuation channel section to regulate the vacuum level within them.

4. The membrane monitoring device as described in claim 3, characterized in that, The third extraction pipe is a bent pipe to extend the extraction path of the third extraction pipe.

5. The membrane monitoring device as described in claim 3, characterized in that, The ratio of the inner diameter a1 of the first suction pipe, the inner diameter a2 of the second suction pipe, and the inner diameter a3 of the third suction pipe is a1:a2:a3 = 10:10:

1.

6. The membrane monitoring device as described in claim 2, characterized in that, The vacuum level in the first differential pumping channel section is maintained at 10. -6 Torr, the vacuum level in the second differential pumping channel section is maintained at 10. -4 Torr, the vacuum level in the third differential pumping channel section is maintained at 10. -3 Torr.

7. The membrane monitoring device as described in claim 2, characterized in that, The third differential extraction channel section includes a bellows, a profile transition tube, and a capillary tube connected in sequence; the bellows is connected to the second differential extraction channel section; the profile transition tube is used to achieve a tube diameter transition between the bellows and the capillary tube; the capillary tube extends into the epitaxial cavity, and the outlet end of the capillary tube is close to the edge of the wafer.

8. The membrane monitoring device as described in claim 7, characterized in that, The projection of the capillary on the plane of the top surface of the wafer falls completely outside the wafer outline; the outlet end of the capillary is 170-200 mm away from the center of the wafer.

9. The membrane monitoring device as described in claim 7, characterized in that, The capillary tube is made of quartz; the inner diameter of the capillary tube is set to 0.1-0.5 mm.

10. The membrane monitoring device as described in claim 1, characterized in that, The electron emission component has an electron emission energy of 50-70 keV and a beam current of 130-190 uA to ensure that the electrons have sufficient free path.

11. The membrane monitoring device as described in claim 1, characterized in that, The electron emission assembly includes an electron gun and an electromagnetic lens connected to the electron gun; the electromagnetic lens is used to focus the electron beam.

12. The membrane monitoring device as described in claim 1, characterized in that, The electron beam receiving mechanism includes: A microchannel plate, located within the epitaxial cavity and positioned opposite the electron channel, is used to capture the diffracted electron beam and convert the captured diffracted electron beam into an optical signal; A CCD camera, which is communicatively connected to the microchannel plate, is used to receive and process optical signals transmitted by the microchannel plate.

13. The membrane monitoring device as described in claim 1, characterized in that, The projection of the electronic channel on the horizontal plane is set at a predetermined angle relative to the flow direction of the process gas in the epitaxial chamber, and the predetermined angle ranges from 45 degrees to 90 degrees.

14. An epitaxial device, characterized in that, The epitaxial device is equipped with a film monitoring device as described in any one of claims 1 to 13.

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