Laser anneal reactor

Abstract

The application provides a kind of laser annealing reaction device, it includes: high pressure cavity, slide carrier, penetrate plate, first pressure regulating valve and second pressure regulating valve;The inside of high pressure cavity is provided with reaction chamber, the surface of high pressure cavity is provided with irradiation port, gas inlet and exhaust port, irradiation port, gas inlet and exhaust port are communicated with reaction chamber respectively;High pressure cavity is used to fill reaction gas to reaction chamber by gas inlet, and the reaction gas in reaction chamber is discharged from high pressure cavity by exhaust port;First pressure regulating valve is fixedly arranged at the gas inlet of high pressure cavity;Second pressure regulating valve is fixedly arranged at the exhaust port of high pressure cavity;Penetrate plate is located at irradiation port and is sealingly connected with high pressure cavity, penetrate plate is used to make laser pass through penetrate plate to carry out laser annealing to wafer in reaction chamber;Slide carrier is fixedly connected with high pressure cavity, and slide carrier is used to carry wafer in reaction chamber.The application can improve the quality of wafer crystallization after laser annealing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a laser annealing reaction apparatus. Background Technology

[0002] During semiconductor chip manufacturing, ion implantation is performed on the back side of the wafer or the source / drain of certain devices. This step can cause severe damage to the crystal lattice, and the doped impurity ions are not located in the correct lattice positions, so they do not have effective electroactivity. At this time, the material needs to be heated to repair the lattice damage and activate the electroactivity of the impurity ions. This heating process is called annealing.

[0003] Traditional annealing processes include furnace tube annealing and flash lamp annealing. However, due to their disadvantages such as low annealing temperature, long annealing time, and large heat-affected zone, their use in many processes is limited.

[0004] Laser annealing is a process that uses pulsed laser output to heat-treat materials. Due to its advantages such as high instantaneous temperature, short treatment time, and small heat-affected zone, laser annealing can well meet the process requirements for efficient activation and has become one of the key processes in chip manufacturing.

[0005] However, existing methods for laser annealing wafers involve directly aligning the laser output port with the wafer for annealing. This inevitably introduces impurities into the process. Although the risk of contamination can be reduced by creating a vacuum chamber, the vacuum environment is not only costly and structurally complex, but also unfavorable for achieving oxidation processes with low thermal budgets. Summary of the Invention

[0006] To address the aforementioned problems, the laser annealing reaction apparatus provided by this invention, by providing a high-pressure, dust-free reaction chamber, can improve the quality of wafer crystallization after laser annealing within the reaction chamber and rapidly complete thermal annealing.

[0007] This invention provides a laser annealing reaction device, comprising: a high-pressure chamber, a stage, a penetration plate, a first pressure regulating valve, and a second pressure regulating valve;

[0008] The high-pressure chamber has a reaction chamber inside, and the surface of the high-pressure chamber has an irradiation port, an air inlet, and an exhaust port, which are connected to the reaction chamber.

[0009] The high-pressure chamber is used to fill the reaction chamber with reaction gas through the air inlet and to discharge the reaction gas from the reaction chamber through the air outlet.

[0010] The first pressure regulating valve is fixedly installed at the air inlet of the high-pressure chamber and is used to regulate the flow rate of gas passing through the air inlet;

[0011] The second pressure regulating valve is fixedly installed at the exhaust port of the high-pressure chamber and is used to regulate the flow rate of gas passing through the exhaust port;

[0012] The penetrating plate is located at the irradiation port and is sealed to the high-pressure chamber. The penetrating plate is used to allow the laser to pass through the penetrating plate to perform laser annealing on the wafer in the reaction chamber.

[0013] The wafer stage is fixedly connected to the high-voltage chamber and is used to support the wafers inside the reaction chamber.

[0014] Optionally, the number of exhaust ports can be multiple.

[0015] Optionally, multiple exhaust ports are evenly distributed around the periphery of the stage.

[0016] Optionally, the laser annealing reaction apparatus also includes: a vacuum pump;

[0017] The wafer stage has suction holes on its surface facing the penetration plate. The wafer stage has an internal ventilation channel that is connected to the suction holes. The vacuum pump's air inlet is connected to the ventilation channel. The vacuum pump is used to adsorb the wafer onto the wafer stage through the suction holes.

[0018] Optionally, the laser annealing reaction apparatus further includes: a second pressure gauge and a third pressure gauge;

[0019] The second pressure gauge is fixedly connected to the high-pressure chamber and is used to monitor the pressure inside the reaction chamber.

[0020] The third pressure gauge is fixedly connected to the slide stage and is used to monitor the pressure in the ventilation duct.

[0021] Optionally, the reactant gas includes at least one of oxygen, nitrogen, and argon.

[0022] Alternatively, the material of the penetrating plate may include quartz or sapphire.

[0023] Optionally, the laser annealing apparatus further includes: a heating element;

[0024] The heating element is located inside the reaction chamber and is fixedly connected to the high-pressure chamber. The heating element is used to regulate the temperature of the wafer surface.

[0025] Optionally, the inner wall of the high-pressure cavity is coated with a light-absorbing material to form a light-absorbing layer;

[0026] The surface of the light-absorbing layer has a velvety structure.

[0027] Optionally, the laser annealing reaction apparatus further includes: a first pressure gauge;

[0028] The first pressure gauge is fixedly connected to the high-pressure chamber and is located at the exhaust port. The first pressure gauge is used to monitor the pressure at the exhaust port.

[0029] The laser annealing reaction apparatus provided in this embodiment of the invention provides a high-pressure, dust-free reaction chamber and a penetrating plate, which allows the laser to pass through the penetrating plate to perform laser heat treatment on the wafer in the reaction chamber and recrystallize the wafer in a high-pressure, dust-free environment. This improves the quality of the wafer crystallization after laser annealing and quickly completes the thermal annealing. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic structural diagram of a laser annealing reaction apparatus according to an embodiment of this application.

[0032] Figure Labels

[0033] 1. High-pressure chamber; 11. Reaction chamber; 12. Irradiation port; 13. Gas inlet; 14. Exhaust port; 2. Slab stage; 21. Suction port; 22. Ventilation channel; 3. Penetration plate; 41. First pressure regulating valve; 42. Second pressure regulating valve; 43. Third pressure regulating valve; 51. First pressure gauge; 52. Second pressure gauge; 53. Third pressure gauge; 61. Vacuum pump; 62. Heating element; 63. Wafer. Detailed Implementation

[0034] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0037] It should be noted that when an element is referred to as "fixedly connected" to another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is referred to as being "directly on" another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0038] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0039] This embodiment provides a laser annealing reaction device, see [link / reference] Figure 1 The laser annealing reaction device includes: a high-pressure chamber 1, a slide stage 2, a penetrating plate 3, a first pressure regulating valve 41, and a second pressure regulating valve 42.

[0040] The main body of the high-pressure chamber 1 and the slide stage 2 are cylindrical, but not limited to this.

[0041] The high-pressure chamber 1 has a reaction chamber 11 inside. The surface of the high-pressure chamber 1 has an irradiation port 12, an air inlet 13, and an exhaust port 14. The irradiation port 12, the air inlet 13, and the exhaust port 14 are connected to the reaction chamber 11.

[0042] The high-pressure chamber 1 is used to introduce reactive gas into the reaction chamber 11 through the inlet 13 to increase the pressure inside the reaction chamber 11, and to discharge the reactive gas from the reaction chamber 11 into the high-pressure chamber 1 through the outlet 14 to reduce the pressure inside the reaction chamber 11. A first pressure regulating valve 41 is fixedly installed at the inlet 13 of the high-pressure chamber 1 and is used to regulate the flow rate of the gas passing through the inlet 13. A second pressure regulating valve 42 is fixedly installed at the outlet 14 of the high-pressure chamber 1 and is used to regulate the flow rate of the gas passing through the outlet 14.

[0043] Specifically, when it is necessary to increase the pressure inside the reaction chamber 11, the first pressure regulating valve 41 is opened, allowing the external gas filling device to fill the reaction chamber 11 with reactive gas through the exhaust port 14. Once the pressure inside the reaction chamber 11 reaches a specified value, closing the first pressure regulating valve 41 stops the entry of reactive gas into the reaction chamber 11, thus stopping the further increase in pressure. Specifically, the first pressure regulating valve 41 can be closed when the gas pressure inside the reaction chamber 11 is one to two atmospheric pressures higher than the ambient pressure, but this is not a limitation. The exact number of atmospheric pressures above the ambient pressure required to close the first pressure regulating valve 41 depends on the actual site conditions and process requirements, and this embodiment does not impose a specific limitation on this.

[0044] When the pressure inside the reaction chamber 11 exceeds a specified value, after closing the first pressure regulating valve 41, the second pressure regulating valve is opened to allow an appropriate amount of reaction gas to be discharged from the reaction chamber 11 through the exhaust port 14, thereby reducing the pressure inside the reaction chamber 11 to the specified value. Similarly, after the annealing process of the wafer 63 is completed, the second pressure regulating valve 42 can also be opened to allow the reaction gas inside the reaction chamber 11 to be discharged from the reaction chamber 11 through the exhaust port 14, thereby reducing the pressure inside the reaction chamber 11 to the same as the external air pressure, thus facilitating the removal of the wafer 63 from the high-pressure chamber 1.

[0045] The laser-penetrating plate 3 is located at the irradiation port 12 and is sealed to the high-pressure chamber 1. The laser-penetrating plate 3 is used to allow the laser to pass through the laser to perform laser annealing on the wafer 63 inside the reaction chamber 11. The wafer stage 2 is fixedly connected to the high-pressure chamber 1. The wafer stage 2 is used to support the wafer 63 inside the reaction chamber 11.

[0046] The reaction gas includes at least one of oxygen, nitrogen, and argon; the material of the penetrating plate 3 includes, but is not limited to, quartz or sapphire; the stage 2 can be completely located within the high-pressure cavity 1 or partially embedded within it. In this embodiment, the reaction gas is oxygen, which allows for rapid oxidation treatment of the wafer 63 surface during laser annealing under high pressure; the material of the penetrating plate 3 is quartz; the irradiation port 12 is located at the top of the high-pressure cavity 1; the top of the stage 2 is embedded within the high-pressure cavity 1, the sidewall of the stage 2 is sealed to the bottom of the high-pressure cavity 1, and the upper surface of the stage 2 faces the penetrating plate 3, so that the laser output from the laser output port can pass through the penetrating plate 3 from top to bottom and perform laser heat treatment on the wafer 63 on the stage 2.

[0047] Furthermore, there are multiple exhaust ports 14. These multiple exhaust ports 14 are evenly distributed around the periphery of the stage 2. The number of exhaust ports 14 can be 2n or 2... n The number of exhaust ports 14 is not limited to this, where n is an integer greater than 1. This allows for precise calculation of the included angle between two adjacent exhaust ports 14, facilitating the design of the exhaust port arrangement and ensuring uniform venting on the surface of the wafer 63. In this embodiment, the number of exhaust ports 14 is eight, but not limited to this, and the eight exhaust ports 14 are evenly spaced around the periphery of the wafer stage 2. By limiting the number of exhaust ports 14 and their positions relative to the wafer stage 2, when the pressure inside the reaction chamber 11 is reduced through the exhaust ports 14, the reactive gas on the surface of the wafer 63 can flow uniformly from the periphery of the wafer 63 to the corresponding exhaust ports 14. This ensures a uniform decrease in pressure on the surface of the wafer 63 and prevents uneven gas flow on the surface of the wafer 63, which could affect the quality of recrystallization of the wafer 63 after laser annealing.

[0048] It should be noted that the laser annealing reaction device also includes a sealed door. The high-pressure chamber 1 also has a pick-and-place port. The sealed door is movably connected to the high-pressure chamber 1 and is used to seal the pick-and-place port. The sealed door facilitates the pick-and-place of the wafer 63.

[0049] In one optional embodiment, the aforementioned sealing door is part of the high-pressure chamber, and the irradiation port 12 is opened on the sealing door. This optional embodiment does not specifically limit this aspect.

[0050] In an optional embodiment, the laser annealing reaction apparatus further includes a plurality of first pressure gauges 51. The plurality of first pressure gauges 51 are respectively fixedly connected to the high-pressure chamber 1, and each first pressure gauge 51 is located at an exhaust port 14 on the high-pressure chamber 1. The first pressure gauges 51 are used to monitor the pressure at the exhaust port 14. By setting the first pressure gauges 51, the pressure at each exhaust port 14 can be monitored in real time. Based on the known pressure at each exhaust port 14, the corresponding second pressure regulating valve 42 can be adjusted to ensure that the pressure at each exhaust port 14 remains consistent, further guaranteeing the quality of recrystallization of the wafer 63 after laser annealing.

[0051] In an optional embodiment, the laser annealing apparatus further includes a vacuum pump 61. A suction port 21 is provided on the upper surface of the wafer stage 2. A ventilation channel 22 is provided inside the wafer stage 2. The ventilation channel 22 communicates with the suction port 21, and the vacuum pump 61 is connected to the wafer stage 2, with its air inlet 13 communicating with the ventilation channel 22. The vacuum pump 61 is used to adsorb the wafer 63 onto the wafer stage 2 through the suction port 21.

[0052] It should be noted that a third pressure regulating valve 43 is also fixedly installed on the wafer stage 2, located at the connection between the wafer stage 2 and the vacuum pump 61. In this optional embodiment, the vacuum pump 61 can adjust the vent 22 to a vacuum state when the wafer stage 2 is holding the wafer 63. Even if the pressure in the vent 22 is 0 Pa, it can be adjusted to be above 0 Pa and below the pressure in the reaction chamber 11. By setting the third pressure regulating valve 43, when the vacuum pump 61 adjusts the pressure in the vent 22 to a specified value, the connection between the inlet 13 of the vacuum pump 61 and the vent 22 can be blocked. This stabilizes the pressure in the vent 22 while keeping the vacuum pump 61 in a powered-off state, thereby reducing the power consumption of the vacuum pump 61.

[0053] In this optional embodiment, the vacuum pump 61 adjusts the vent 22 to a vacuum state; there are multiple suction holes 21, and except for the suction hole 21 located at the exact center of the upper surface of the wafer stage 2, the remaining suction holes 21 are evenly arranged in one or more annular patterns around the central suction hole 21 on the upper surface of the wafer stage 2 to suit the shape of the wafer 63. Thus, when the vacuum pump 61 adjusts the vent 22 to a vacuum state, it can ensure that the pressure on the lower surface of the wafer 63 on the wafer stage 2 is evenly distributed, which not only ensures the stability of the wafer 63 on the wafer stage 2, but also further ensures the quality of the recrystallization of the wafer 63 after laser annealing.

[0054] Furthermore, the laser annealing reaction apparatus also includes a second pressure gauge 52 and a third pressure gauge 53. The second pressure gauge 52 is fixedly connected to the side wall of the high-pressure chamber 1, and its monitoring end is connected to the reaction chamber 11. The second pressure gauge 52 is used to monitor the pressure within the reaction chamber 11. The third pressure gauge 53 is fixedly connected to the stage 2, and its monitoring end is connected to the vent 22. The third pressure gauge 53 is used to monitor the pressure within the vent 22.

[0055] By setting a second pressure gauge 52, the pressure inside the reaction chamber 11 can be monitored in real time. This allows for adjustment of the first pressure regulating valve 41 or the second pressure regulating valve 42 based on the monitoring results of the second pressure gauge 52, ensuring that the pressure inside the reaction chamber 11 reaches a specified level. Similarly, by setting a third pressure gauge 53, the pressure inside the ventilation channel 22 can be monitored in real time. This allows for adjustment of the third pressure regulating valve 43 based on the monitoring results of the third pressure gauge 53, ensuring that the pressure inside the ventilation channel 22 reaches a specified level.

[0056] In an optional embodiment, the laser annealing reaction apparatus further includes a heating element 62. The heating element 62 is located within the reaction chamber 11 and is fixedly connected to the side wall of the high-pressure chamber 1. The heating element 62 is used to regulate the temperature of the wafer 63 surface.

[0057] The heating element 62 can be a heating tube, a halogen lamp, or other similar devices, but is not limited to these. In this optional embodiment, the heating element 62 is a halogen lamp. By using a halogen lamp, the temperature of the wafer 63 surface can be adjusted, further ensuring the quality of recrystallization of the wafer 63 after laser annealing. It also allows operators to easily monitor the processing status of the wafer 63 through the penetrating plate 3.

[0058] In one optional embodiment, the inner wall of the high-voltage cavity 1 is coated with a light-absorbing material to form a light-absorbing layer. The surface of the light-absorbing layer is textured to form a textured structure. The light-absorbing material includes, but is not limited to, at least one of silicon and aluminum oxide. In this optional embodiment, the light-absorbing material is silicon. By providing the light-absorbing layer, light reflected onto the inner wall of the high-voltage cavity 1 can be absorbed, preventing secondary reflection of laser light onto the wafer 63 and affecting the recrystallization quality of the wafer 63. Furthermore, forming a textured structure on the light-absorbing layer further improves its light-absorbing effect.

[0059] This laser annealing reactor has a simple structure and low manufacturing cost. By providing a high-pressure, dust-free reaction chamber 11 and setting a penetrating plate 3, the laser can pass through the penetrating plate 3 to perform laser heat treatment on the wafer 63 inside the reaction chamber 11, and recrystallize the wafer 63 in a high-pressure, dust-free environment. This improves the quality of the wafer 63 after laser annealing and rapidly completes the thermal annealing. Furthermore, compared to the conventional annealing method for forming polycrystalline silicon on a silicon substrate, the laser annealing reactor provided by this invention can, under high pressure, especially with the participation of H2O, cause the dangling bonds in the silicon substrate and at its interfaces to combine with H or O atoms, thereby reducing the density of states at the interface. In addition, the change in the melting point of the material under high pressure improves the thermal stability of the material, avoiding the problem of film cracking due to thermal mismatch, thus improving the surface roughness of the film and enhancing its quality.

[0060] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A laser annealing reaction apparatus, characterized in that, include: High-pressure chamber, slide stage, penetration plate, first pressure gauge, second pressure gauge, first pressure regulating valve and second pressure regulating valve; The high-pressure chamber has a reaction chamber inside, and the surface of the high-pressure chamber has an irradiation port, an air inlet, and an exhaust port. The irradiation port, the air inlet, and the exhaust port are respectively connected to the reaction chamber. There are multiple exhaust ports, which are evenly distributed around the periphery of the slide stage. The high-pressure chamber is used to fill the reaction chamber with reaction gas through the air inlet and to discharge the reaction gas from the reaction chamber through the exhaust port. The first pressure regulating valve is fixedly installed at the air inlet of the high-pressure chamber and is used to regulate the flow rate of the gas passing through the air inlet; The second pressure regulating valve is fixedly installed at each exhaust port of the high-pressure chamber and is used to regulate the flow rate of gas passing through the exhaust port; The penetrating plate is located at the irradiation port and is sealed to the high-pressure cavity. The penetrating plate is used to allow the laser to pass through the penetrating plate to perform laser annealing on the wafer in the reaction chamber. The wafer stage is fixedly connected to the high-pressure chamber, and the wafer stage is used to support the wafer inside the reaction chamber; The first pressure gauge is fixedly connected to the high-pressure chamber and is located at the exhaust port. The first pressure gauge is used to monitor the pressure at the exhaust port. The second pressure gauge is fixedly connected to the high-pressure chamber and is used to monitor the pressure inside the reaction chamber.

2. The laser annealing reaction apparatus according to claim 1, characterized in that, The laser annealing reaction device also includes: a vacuum pump; The wafer stage has suction holes on its surface facing the penetration plate. The wafer stage has an internal ventilation channel that communicates with the suction holes. The air inlet of the vacuum pump is connected to the ventilation channel. The vacuum pump is used to adsorb the wafer onto the wafer stage through the suction holes.

3. The laser annealing reaction apparatus according to claim 2, characterized in that, The laser annealing reaction device also includes: a third pressure gauge; The third pressure gauge is fixedly connected to the slide stage, and the third pressure gauge is used to monitor the pressure in the ventilation duct.

4. The laser annealing reaction apparatus according to claim 1, characterized in that, The reacting gas includes at least one of oxygen, nitrogen, and argon.

5. The laser annealing reaction apparatus according to claim 1, characterized in that, The material of the penetrating plate includes quartz or sapphire.

6. The laser annealing reaction apparatus according to claim 1, characterized in that, The laser annealing reaction device further includes: a heating element; The heating element is located in the reaction chamber and is fixedly connected to the high-pressure chamber. The heating element is used to regulate the temperature of the wafer surface.

7. The laser annealing reaction apparatus according to claim 1, characterized in that, The inner wall of the high-pressure cavity is coated with a light-absorbing material to form a light-absorbing layer; The surface of the light-absorbing layer has a velvety structure.

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