Complex rapid annealing apparatus and method

Abstract

To provide a composite high-speed annealing device and a method thereof.SOLUTION: A composite high-speed annealing device includes two electrodes, a heating chamber, an induction heating device, and a dielectric heating device. At least one processing object is placed between the two electrodes, and is located inside the heating chamber. In a composite high-speed annealing method, the induction heating device in the composite high-speed annealing device performs an induction heating process to the processing object. When the conductivity of the processing object decreases due to a temperature rise, the two electrodes heat the processing object, and the dielectric heating device also performs the dielectric heating process to the processing object. Thus, the heating rate of the processing object can be kept constant.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an annealing apparatus and method, and more particularly to a multiplex rapid annealing apparatus and method. [Background technology]

[0002] Silicon carbide (SiC) has become an important semiconductor material for the manufacture of high-temperature, high-power, and high-frequency devices due to its wide band gap, high dielectric breakdown field, high thermal conductivity, and excellent chemical inertness. Ion implantation is an essential technology for the fabrication of SiC semiconductor devices. Annealing is a necessary process after ion implantation to remove lattice damage and activate the implanted ions. For silicon carbide, the process effect cannot be obtained unless ions are implanted and annealed at temperatures higher than 1,500°C.

[0003] Conventional annealing is usually carried out in a ceramic furnace equipped with resistive heating or low frequency induction heating. However, the slow heating / cooling rates of ceramic furnaces (20°C / min) make it difficult to anneal silicon carbide at temperatures above 1,500°C. When silicon carbide is exposed to temperatures above 1,400°C for extended periods of time, constituent materials on the substrate surface undergo sublimation and redeposition (commonly known as step bunching), resulting in increased surface roughness on the silicon carbide wafer and limiting the maximum annealing temperature. Such limitations on annealing temperature may result in insufficient activation of the implanted ions, resulting in high contact resistance and channel region resistance.

[0004] Therefore, the development of rapid annealing technology is key to avoid the problem of traditional annealing technology, where the heating rate is too slow and the surface of the silicon carbide wafer is degraded. However, although halogen lamp and laser technology allows for rapid heat treatment, some problems still exist, such as the maximum achievable annealing temperature, surface melting, high residual defect density, and implant redistribution.

[0005] On the other hand, silicon carbide can effectively absorb microwave energy, and with a properly designed annealing system, silicon carbide wafers can be heated or cooled by microwaves at extremely fast rates and with good control over the annealing time. Microwaves have the characteristic of selective heating, they are only absorbed by the semiconductor wafer and not by the surrounding environment, the heating speed of annealing is extremely fast, and during the annealing process, the temperature rise of the surrounding environment of the silicon carbide wafer is small, and the cooling speed of the silicon carbide wafer is fast after the microwave source is turned off. Compared with traditional annealing techniques, when using microwaves to anneal silicon carbide, the results of heating a small area silicon carbide wafer show that the heating rate can exceed 600°C / s and the temperature can reach 2,000°C.

[0006] However, the wavelength of microwaves is shorter, and the distribution of energy is not uniform when heating the reaction chamber, which leads to uneven heating of silicon carbide wafers. In particular, as the area of ​​silicon carbide wafers increases, the volume of the heating reaction cavity increases, and the problem of uneven heating becomes more severe during annealing. And the required energy of microwaves also increases significantly, making the equipment more expensive. Summary of the Invention [Problem to be solved by the invention]

[0007] The main objective of the present invention is to provide a hybrid rapid annealing apparatus and method which combines an induction heating mechanism and a dielectric heating mechanism, thereby allowing conductors and non-conductors to be heated simultaneously, for example, by increasing the temperature of a silicon carbide wafer through the induction heating mechanism, and when the electrical conductivity of the silicon carbide wafer decreases due to the increase in temperature, by increasing the temperature of the silicon carbide wafer through the dielectric heating mechanism, the heating rate of the wafer can be kept constant. [Means for solving the problem]

[0008] When a silicon carbide wafer is heated by electromagnetic waves that generate an alternating magnetic field, an eddy current is generated, resulting in an induction heating effect. However, when the temperature exceeds 500 degrees K, the conductivity of silicon carbide wafers drops rapidly, resulting in an increase in their resistivity. Also, since electromagnetic waves with an alternating electric field can heat silicon carbide wafers by generating a dielectric heating mechanism, the dielectric loss tangent of silicon carbide wafers increases with increasing temperature, and when the temperature exceeds about 1,000 degrees Celsius, the dielectric loss tangent increases rapidly and significantly. For this reason, the present invention proposes a hybrid heating mechanism, which combines induction and dielectric heating mechanisms to heat a workpiece, such as a silicon carbide wafer.

[0009] The composite rapid annealing apparatus according to the present invention includes two electrodes, at least one workpiece being placed between the two electrodes; A heating chamber having at least a chamber for accommodating an object to be processed; an induction heating device that performs an induction heating process on the workpiece in the heating chamber and generates an induction magnetic field to generate eddy currents in the workpiece and heat the workpiece; a dielectric heating device for performing a dielectric heating process on the workpiece in the heating chamber and heating the workpiece located between the two electrodes by generating an electric field between the two electrodes; Equipped with The induction heating device and the dielectric heating device are characterized in that they perform the induction heating process and the dielectric heating process, respectively, simultaneously, sequentially, intermittently, or alternately.

[0010] According to the composite rapid annealing apparatus of the present invention, the induction heating apparatus is characterized in that it heats the workpiece and the two electrodes by performing the induction heating process on the workpiece and the two electrodes in the heating chamber.

[0011] The composite rapid annealing apparatus according to the present invention further comprises a Faraday shield layer provided in the heating chamber, and the induction heating device forms the induction magnetic field in the heating chamber through the Faraday shield layer.

[0012] According to the composite rapid annealing apparatus of the present invention, the Faraday shield layer is a metal cylinder having a plurality of openings.

[0013] According to the composite rapid annealing apparatus of the present invention, the metal cylinder has a reflective surface to reduce radiant heat loss in the heating chamber.

[0014] According to the composite rapid annealing apparatus of the present invention, the reflective surface of the metal cylinder is further covered with a reflective layer.

[0015] The composite rapid annealing apparatus according to the present invention is characterized in that at least one barrier layer is provided between the two electrodes and the workpiece.

[0016] The composite rapid annealing apparatus according to the present invention is characterized in that the workpieces are multiple in number and at least one barrier layer is provided between the workpieces.

[0017] The composite rapid annealing apparatus according to the present invention is characterized in that one of the barrier layer and the workpiece has a polycrystalline structure, and the other of the barrier layer and the workpiece has a single crystalline structure.

[0018] According to the composite rapid annealing apparatus of the present invention, the induction heating device and the dielectric heating device are characterized in that they heat the workpiece and the barrier layer by performing the induction heating process and the dielectric heating process on the workpiece and the barrier layer.

[0019] According to the composite rapid annealing apparatus of the present invention, the workpiece is selected from the group consisting of conductors and non-conductors.

[0020] The composite rapid annealing apparatus according to the present invention is characterized in that the object to be processed is a wafer.

[0021] According to the composite rapid annealing apparatus of the present invention, the material of the two electrodes is graphite.

[0022] According to the composite rapid annealing apparatus of the present invention, the induction heating device includes an inductance coil wound around the heating chamber, and the induction heating device generates the induced magnetic field between the workpiece and the two electrodes by applying a first alternating electromagnetic signal having a first predetermined frequency to the inductance coil.

[0023] The composite rapid annealing apparatus according to the present invention is characterized in that the first predetermined frequency ranges from 50 kHz to 200 kHz.

[0024] According to the composite rapid annealing apparatus of the present invention, the dielectric heating device generates the electric field in the two electrodes located on both sides of the workpiece by applying a second alternating electromagnetic signal having a second predetermined frequency.

[0025] The composite rapid annealing apparatus according to the present invention is characterized in that the second predetermined frequency ranges from 10 MHz to 900 MHz.

[0026] According to the composite rapid annealing apparatus of the present invention, the dielectric heating device includes an RF power source and an adapter, the RF power source supplies the second alternating electromagnetic signal having the second predetermined frequency, and the adapter is located between the RF power source and the two electrodes and electrically connected to both, thereby reducing reflection of the second alternating electromagnetic signal.

[0027] The composite rapid annealing apparatus of the present invention is further characterized in that it includes a gas input unit and a gas exhaust unit, each of which is connected to the chamber of the heating chamber, so that the chamber of the heating chamber is maintained at a predetermined pressure.

[0028] The composite rapid annealing apparatus according to the present invention is characterized in that the predetermined pressure of the heating chamber is in the range of 0.1 atm to 10 atm.

[0029] The composite rapid annealing apparatus of the present invention further comprises a measurement and control system including a pressure detection unit and a controller, the pressure detection unit is for measuring the air pressure in the heating chamber, and the controller controls the operation of the gas input unit and / or the gas exhaust unit according to the magnitude of the air pressure.

[0030] In the combined rapid annealing apparatus according to the present invention, the measurement and control system further comprises a pyrometer for measuring the temperature of the heating chamber.

[0031] According to the composite rapid annealing apparatus of the present invention, the heating chamber comprises a cavity, an upper lid, and a lower lid, and the cavity is located between the upper lid and the lower lid, and by connecting the two, the chamber is formed between the cavity, the upper lid, and the lower lid.

[0032] According to the composite rapid annealing apparatus of the present invention, the heating chamber is made of a quartz tube or a ceramic tube.

[0033] According to the composite rapid annealing method of the present invention, the following steps are performed: an induction heating process is performed on at least one workpiece by an induction heating device, and the induction heating device generates an induction magnetic field to generate an eddy current in the workpiece, thereby heating the workpiece; performing a dielectric heating process on the workpiece by a dielectric heating device, the dielectric heating device generating an electric field to heat the workpiece; The present invention is characterized in that it includes:

[0034] According to the composite rapid annealing method of the present invention, the workpiece is placed between two electrodes, and the induction heating device heats the workpiece and the two electrodes by performing the induction heating process on the workpiece and the two electrodes, and the dielectric heating device heats the workpiece by generating the electric field on the two electrodes. Effect of the Invention

[0035] The complex rapid annealing apparatus and method according to the present invention have the following advantages. (1) The induction heating mechanism and the dielectric heating mechanism are combined, so that conductors and non-conductors can be heated simultaneously. For example, the temperature of a silicon carbide wafer can be increased by the induction heating mechanism, and when the electrical conductivity of the silicon carbide wafer decreases due to the increase in temperature, the temperature of the silicon carbide wafer can be increased by the dielectric heating mechanism, so that the heating rate of the wafer can be kept constant.

[0036] (2) The temperature of the electrode can also be increased by the induction heating mechanism, so that when the temperature of the silicon carbide wafer increases and its electrical conductivity drops, the silicon carbide wafer can be heated continuously by heating the electrode, and thus the heating rate of the silicon carbide wafer can be kept constant.

[0037] (3) The electrode can be used as a support base and a heating base.

[0038] (4) The heating chamber has a metal cylinder which can be a reflective layer and can also be a Faraday shield layer. The metal cylinder can reduce the radiative heat loss in the heating chamber, and can also allow an alternating magnetic field to enter the heating chamber and generate eddy currents in the wafer.

[0039] (5) The barrier layer between the electrode and the wafer or between the wafers can prevent the diffusion of contamination. The barrier layer can also be used as a support and a heating base.

[0040] In order to better understand the technical features and achievable technical effects of the present invention, better embodiments and detailed descriptions are provided below. [Brief description of the drawings]

[0041] [Figure 1] 1 is a cross-sectional view showing the structure of an embodiment of a composite rapid annealing apparatus according to the present invention; [Diagram 2]FIG. 2 is a perspective view showing a Faraday shield layer of the combined rapid annealing apparatus according to the present invention. [Diagram 3] 3A, 3B, and 3C are schematic diagrams illustrating the operation of the dielectric heating mechanism of the combined rapid annealing apparatus of the present invention, showing multiple wafer, single wafer, and no barrier layer embodiments, respectively. [Figure 4] FIG. 2 is a schematic diagram showing the operation of the induction heating mechanism of the combined rapid annealing apparatus according to the present invention. [Diagram 5] 2 is a flow chart illustrating the hybrid heating process of the hybrid rapid annealing method according to the present invention. [Figure 6] FIG. 2 is a cross-sectional view showing the structure of another embodiment of a composite rapid annealing apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The ratio of each member in the drawings of the embodiment of the present invention is shown for easy understanding of the description, and is not the actual ratio. Furthermore, the dimensional ratio of the assembly shown in the drawings is for explaining each part and its structure, and the present invention is not limited thereto. Meanwhile, for convenience of understanding, the same parts in the following embodiments will be described with the same reference numerals.

[0043] Furthermore, the terms used throughout the specification and claims generally have their ordinary meanings as used in the art, in the context disclosed herein, and in the particular context, unless otherwise specified. Some of the terms used to describe the present invention are explained below or elsewhere in this specification to provide those of ordinary skill in the art with additional guidance regarding the description of the present invention.

[0044] The use of "first," "second," "third," etc. in this article is not intended to denote a specific order or sequence, nor is it used to limit the invention, but is merely used to distinguish between components or operations that are described with the same terminology.

[0045] Secondly, when terms such as "including," "comprising," "having," and "containing" are used in this article, they are all open terms, meaning including but not limited to.

[0046] The composite rapid annealing apparatus and method according to the present invention will be described by taking as an example that the object to be processed is a wafer (e.g., a silicon carbide wafer). The physical properties of silicon carbide are that when it is heated or otherwise processed, its electrical conductivity drops rapidly, but its electromagnetic wave dielectric absorption rate rises rapidly. Other wafer materials also have similar properties. For this reason, the present invention adopts a composite heating mechanism, including the use of a medium frequency induction heating mechanism, to rapidly increase the temperature of the wafer. For a doped wafer, when the temperature rises rapidly to a certain value, the conductivity drops rapidly, and the conductivity changes differently as the wafer temperature changes due to different doping concentrations and types. For this reason, the present invention employs a composite heating mechanism and further uses an RF power source to perform a dielectric heating mechanism on a wafer whose conductivity drops rapidly, thereby achieving the effect of rapidly annealing the wafer.

[0047] Please refer to Figures 1 to 5. Figure 1 is a cross-sectional view showing an embodiment of the combined rapid annealing apparatus according to the present invention. Figure 2 is a perspective view showing the Faraday shield layer of the combined rapid annealing apparatus according to the present invention. Figure 3 is a schematic diagram showing the operation of the dielectric heating mechanism of the combined rapid annealing apparatus according to the present invention. Figure 4 is a schematic diagram showing the operation of the induction heating mechanism of the combined rapid annealing apparatus according to the present invention. Figure 5 is a flow chart showing the combined heating process of the combined rapid annealing method according to the present invention. As shown in FIG. 1, the composite rapid annealing apparatus 10 according to the present invention includes two electrodes 20, a heating chamber 30, an induction heating device 40, and a dielectric heating device 50. The workpiece is placed, for example, between two electrodes 20 . For example, the electrode 20 is for carrying a workpiece. The workpiece may be, for example, a wafer 22, and may be made of a material whose electrical conductivity decreases with increasing temperature or whose electrical conductivity changes with changing temperature. The workpiece may be, for example, a silicon carbide wafer 22 or a wafer 22 of other materials (e.g., Si, SiGe, Ge, GaAs, GaN, or InP), and may be a wafer at any stage during the semiconductor fabrication process, and the workpiece, whether or not it is doped, and with what material it is doped, all fall within the scope of protection of the present invention. However, the invention is not so limited and the workpiece may be, for example, any other material or object, such as a crystal ingot or any object that needs to be heated. The material of the electrode 20 is, for example, graphite. Thus, when the wafer 22 is placed between the two electrodes 20, the electrode 20 can function as a support for the wafer 22 and can also be used as a heatable electrode (also called a heating pedestal). Therefore, electrode 20 may employ other materials that have similar or equivalent effects. The present invention will be described with reference to an example of an object to be processed whose electrical conductivity decreases with an increase in temperature or whose electrical conductivity changes with a change in temperature, but the scope of the present invention is not limited thereto. In other words, any object, regardless of whether its electrical conductivity (also called conductivity) changes with temperature, falls within the scope of the present invention as long as it can be heated using the multiple rapid annealing apparatus 10 of the present invention.

[0048] The hybrid rapid annealing apparatus 10 of the present invention performs a hybrid heating process on a wafer 22 in a heating chamber 30 . This hybrid heating process utilizes the induction heating mechanism shown in FIG. 4 and the dielectric heating mechanism shown in FIG. The heating chamber 30 has a chamber 32 for housing the two electrodes 20 and the wafer 22 . In the combined heating process, the induction heating device 40 of the combined rapid annealing apparatus according to the present invention performs an induction heating step shown in step S10 of FIG. The induction heating device 40 generates an alternating magnetic field (Magnetic Field) by a first alternating electromagnetic signal (AC) and generates an induced magnetic field (Induced Magnetic Field) having a changing magnetic flux (Magnetic Flux, Φ), so that eddy currents (I) are generated in the wafer 22 and the two electrodes 20 as shown in FIG. EC ) to heat the wafer 22 and the two electrodes 20.

[0049] In the induction heating mechanism, the heating energy generated per unit volume of the workpiece is expressed by the following formula: this is The file is TIFF0007604564000001.tif12150. σ m is the conductivity of the workpiece, ω = 2πf,f is the frequency of the electromagnetic wave, and B is the strength of the alternating magnetic field. If the workpiece is a doped silicon carbide wafer, the conductivity (i.e., 1 / resistivity) increases with increasing temperature, but once the temperature exceeds, for example, 500 degrees K, the conductivity drops rapidly (i.e., resistivity increases).

[0050] In the hybrid heating process of the hybrid rapid annealing apparatus 10 according to the present invention, the dielectric heating device 50 performs a dielectric heating process on the wafer 22 in the heating chamber 30, as shown in step S20 of FIG. The dielectric heating device 50 generates an electric field between the two electrodes 20 to heat the wafer 22 located between the two electrodes 20 . There may be one wafer 22, as shown in Figures 3(B) and 3(C), or there may be multiple wafers 22, as shown in Figure 3(A). In addition, according to actual needs, at least one barrier layer 24 may be optionally provided between the two electrodes 20 and the wafers 22 and between two adjacent wafers 22, as shown in Figures 3(A) and 3(B), or the barrier layer 24 may be omitted and a barrier layer 24 may be optionally provided between two adjacent wafers 22, as shown in Figure 3(C). The purpose of providing the barrier layer 24 is to prevent contamination between the wafers 22 and between the wafer 22 and the electrode 20 due to diffusion of doping components across boundaries caused by an increase in temperature. The barrier layer 24 may also be used as a support and heating pedestal for the wafer 22 . Barrier layer 24 may optionally employ a material that can be heated by induction heating device 40 and dielectric heating device 50 . As a result, the induction heating device 40 and the dielectric heating device 50 simultaneously perform an induction heating step (S10) and a dielectric heating step (S20) on, for example, the wafer 22 and the barrier layer 24, thereby heating the wafer 22 and the barrier layer 24. For example, if the material of wafer 22 adopts a monocrystalline structure (eg, monocrystalline silicon carbide), then the material of barrier 24 may adopt a polycrystalline structure (eg, polycrystalline silicon carbide), and vice versa. That is, the wafer 22 and the barrier 24 may, for example, be made of different materials. However, the present invention is not limited thereto, and the barrier layer 24 may be any material that can provide a barrier effect (e.g., a diffusion barrier effect), regardless of whether it is made of any material or whether it can be heated. All of these materials are within the scope of the present invention. For the convenience of describing the technical means and effects of the present invention, the present invention takes as an example the object to be processed a wafer 22 (e.g., a silicon carbide wafer) and the electrode 20 as a graphite electrode, but any material, object or structure that can be heated by the composite rapid annealing apparatus of the present invention is within the scope of protection of the present invention. In the combined heating process, the induction heating device 40 and the dielectric heating device 50 are not limited to simultaneously, sequentially, intermittently, or alternately performing the induction heating step (step S10) and the dielectric heating step (step S20).

[0051] The heating mechanism of the composite rapid annealing device of the present invention adopts a medium frequency induction heating mechanism. The reason for this is that when using a heating power source that utilizes high and low frequency electromagnetic fields, there are several things that must be taken into consideration. The first aspect is that the efficiency of heating the medium is better when high frequency electromagnetic waves are used, and the second aspect is that the penetration depth of the electromagnetic waves must be taken into consideration. A graphite electrode 20 serves as a base for a silicon carbide wafer 22 and as a heating electrode. This utilizes the fact that the penetration depth of the electrode 20 is less than 400 μm when the electromagnetic wave is greater than 10 MHz, and by using graphite as the electrode material, even if an alternating electric field is generated between the upper and lower electrodes 20, attenuation is not significant. Furthermore, for low frequency electromagnetic waves, the penetration depth is greater than that of a heating pedestal consisting of a graphite electrode 20 and a silicon carbide wafer 22 . In other words, the entire body can be effectively heated by the first alternating electromagnetic signal of medium frequency. In particular, graphite is highly resistant to high temperatures and the induction heating mechanism is highly efficient, allowing the temperature of the heating pedestal consisting of the graphite electrode 20 and the silicon carbide wafer 22 to be raised rapidly. However, although the present invention has been described using a medium frequency electromagnetic field as an example, the scope of the present invention is not limited thereto, and any electromagnetic field of any frequency falls within the scope of protection of the present invention as long as it can perform induction heating on the graphite electrode 20 and the silicon carbide wafer 22.

[0052] For example, during the initial and middle stages of the heating reaction, the present invention can rapidly increase the temperature of the graphite electrode 20 and the silicon carbide wafer 22 through an induction heating mechanism. When the temperature of the silicon carbide wafer 22 is higher than, for example, 500 degrees K, the electrical conductivity of the silicon carbide drops and the heating effect deteriorates, but the electrode 20 employing graphite can still be inductively heated and maintain a constant rate of temperature rise. Furthermore, during the process of increasing the temperature, the dielectric loss tangent of silicon carbide continues to increase, and the efficiency of dielectric heating increases. When the temperature rises to about 1,000 degrees Celsius, the dielectric loss tangent increases significantly, accelerating the effect of dielectric heating.

[0053] More specifically, the induction heating device 40 includes, for example, an inductance coil 42 wound around the heating chamber 30 . The induction heating device 40 generates an induction magnetic field in the wafer 22 and the two electrodes 20 by applying a first alternating electromagnetic signal of a first predetermined frequency to the inductance coil 42 . The inductance coil 42 is driven by a medium frequency AC power source, and the first predetermined frequency ranges from about 50 kHz to 200 kHz, but is not limited thereto. In this embodiment, the heating chamber 30 includes, for example, a cavity 34 , a top cover 36 , and a bottom cover 38 . The cavity 34 is located between an upper cover 36 and a lower cover 38, and by connecting both, a chamber 32 is formed between the cavity 34 and the upper cover 36 and the lower cover 38. An inductance coil 42 is wound around the cavity 34 of the heating chamber 30 . To implement the induction heating mechanism, the cavity 34 of the heating chamber 30 employs materials such as quartz or ceramics. The RF power supply 52 of the dielectric heating device 50 applies a second alternating electromagnetic signal of a second predetermined frequency to the two electrodes 20 via the top cover 36 and the bottom cover 38. The top cover 36 and the bottom cover 38 are composed of, for example, a metal layer 35 and a heat insulating material layer 37 . However, the present invention is not so limited, and in other possible embodiments, the heating chamber 30 of the present invention may be constructed entirely from, for example, quartz, ceramics, or other materials.

[0054] In the present invention, a reflective design may be optionally added to the heating chamber 30, which can increase the reflectance of infrared rays and minimize the radiation heat loss. For example, the present invention provides a metal cylinder 60 outside the cavity 34 of the heating chamber 30 as shown in FIGS. Metal cylinder 60, for example an optically polished metal drum, may have a reflective surface and may optionally be coated with a reflective layer (eg, gold) 62 to increase infrared reflectance. This makes it possible to reduce the radiation heat loss that occurs when the heating pedestal, which is made up of the graphite electrode 20 and the silicon carbide wafer 22, is in an extremely high temperature state. In addition, in the present invention, the metal cylinder 60 may be optionally provided with a plurality of openings 64 . The openings 64 are, for example, distributed along the vertical direction (e.g., in the form of a long strip) and surrounding the metal cylinder 60, so that the metal cylinder 60 acts as a Faraday shield layer 66, allowing the alternating magnetic field generated by the induction heating device 40 to pass through the Faraday shield layer 66 and enter the chamber 32 of the heating chamber 30. As a result, an eddy current I ECis generated.

[0055] The dielectric heating device 50 is an RF medium heating device (also referred to as an RF heating device), and as shown in Figures 1 and 3, by supplying a second alternating electromagnetic signal having a second predetermined frequency, an electric field is generated between two electrodes 20 located on either side of the wafer 22, thereby performing a dielectric heating process on the wafer 22 in the heating chamber 30. This allows the heating rate of the wafer 22 to be kept constant. For example, a dielectric heating device 50 includes an RF power supply 52 and, optionally, an adapter 54 . RF power source 52 provides a second alternating electromagnetic signal having the second predetermined frequency described above. An RF power source 52 is in electrical communication with, for example, the two electrodes 20 either directly or via conductive wires (not shown). The adapter 54 is positioned between the RF power source 52 and the two electrodes 20 and is electrically connected to both, thereby reducing reflections of the second alternating electromagnetic signal. That is, the matching circuit of the adapter 54 can adjust the impedance of the heating chamber 30 to match the RF power source 52 (e.g., RF / microwave power source), thereby reducing the reflection of electromagnetic waves (e.g., RF and microwave). The RF power supply 52 employs a frequency higher than 10 MHz, and in consideration of the uniformity of the distribution of the electromagnetic field, employs a frequency lower than 900 MHz. That is, the second predetermined frequency range is, but is not limited to, 10 MHz to 900 MHz, for example, 10 MHz to 400 MHz, and the output power may be adjusted to a range of 1 kilowatt or more. The second predetermined frequency range can be any numerical range or upper and lower endpoint values ​​in the frequency and power ranges above. The parameters of inductance L and capacitance C in the matching circuit of the adapter 54 can be changed with the change of operating conditions to maintain good coupling conditions. The existing inductance L and capacitance C in the matching circuit of the adapter 54 can be electronically tuned, so that there is no delay in the tuning response time and the heating rate can be made higher. Impedance matching is extremely important to achieve fast heating. The optimum design of the matching network will vary from application to application. Those skilled in the art can understand how to implement the dielectric heating device 50 based on the disclosure of the present invention, and how to employ the matching circuit of the adapter 54 and the RF power supply 52 corresponding thereto, so the description will be omitted.

[0056] Since the present invention has both induction heating and dielectric heating mechanisms, it is possible to perform a rapid annealing process on a wafer selected from the group consisting of conductors (e.g., conductive wafers) and non-conductors (e.g., non-conductive wafers). The present invention has been described by way of example and not limitation with respect to non-conductive wafers and conductive wafers of silicon carbide. Furthermore, since the distribution of the electromagnetic field according to the present invention is easy to control and adjust, it can be applied to the annealing process of multiple wafers. Even for silicon carbide wafers with large dimensions (e.g., larger than 8 inches), the design of the annealing system can be modified accordingly based on the operation principle and structure of the combined rapid annealing apparatus of the present invention. It should also be noted that, although the present invention has been described with reference to an example in which the electrode 20 can carry the wafer 22 and can be heated by an induced magnetic field, the scope of the present invention is not limited thereto. For example, the electrodes 20 of the present invention may not be for supporting the wafer 22, but may be located on both sides of the wafer 22, or may be located on the upper lid 36 and lower lid 38 of the heating chamber 30 (e.g., a possible embodiment shown in Figure 6). Although such a modified design cannot heat the silicon carbide wafer 22 by heating the electrode 20, it still belongs to a feasible embodiment of the present invention and therefore still falls within the scope of protection of the present invention. That is, if the electrode 20 can be useful in applying an alternating electric field in the dielectric heating device 50, it can be applied to the present invention and is included in the scope of protection claimed by the present invention.

[0057] The composite rapid annealing apparatus 10 of the present invention optionally includes a gas input unit 72 and a gas exhaust unit 74, in which the gas input unit 72 is connected to the chamber 32 of the heating chamber 30 via an intake pipe connector 73 and the gas exhaust unit 74 is connected to the chamber 32 of the heating chamber 30 via an exhaust pipe connector 75, thereby maintaining the chamber 32 of the heating chamber 30 at a predetermined pressure. Similarly, the hybrid rapid annealing apparatus 10 of the present invention may further optionally include a measurement and control system 70 . The measurement and control system 70 is an air pressure and airflow control system and includes a pressure sensing unit 76 and a controller 78 . The pressure detection unit 76 is for measuring the air pressure in the chamber 32 of the heating chamber 30 . The controller 78 is for controlling the operation of the gas input unit 72 and / or the gas exhaust unit 74 depending on the magnitude of the air pressure.

[0058] For example, the operating range of the above air pressure and airflow control system is, for example, 0.1 atm to 10 atm. The pressure of the gas is monitored by a pressure sensing unit 76 . In addition, the gas input unit 72 injects gas into the chamber 32 of the heating chamber 30 via the intake pipe connector 73 according to the gas flow rate setting, and the gas exhaust unit 74 exhausts the gas from the chamber 32 of the heating chamber 30 via the exhaust pipe connector 75. The gas exhaust unit 74 is, for example, a vacuum pump. In detail, in the present invention, before introducing gas into chamber 32 of heating chamber 30, first, chamber 32 of heating chamber 30 is evacuated by gas exhaust unit 74, and after chamber 32 of heating chamber 30 is in a vacuum state, gas is introduced into chamber 32 of heating chamber 30 by gas input unit 72 until chamber 32 of heating chamber 30 reaches a predetermined pressure. The range of the predetermined pressure in chamber 32 of heating chamber 30 is from 0.1 Atm to 10 Atm, and can be any numerical range, or upper and lower endpoints of the predetermined pressure range. The above gas can be selected from pure gases such as nitrogen gas and argon gas, but any gas that can enter the chamber 32 of the heating chamber 30 within the set pressure range is within the scope of protection of the present invention. In addition, in the present invention, the flow rate of gas input to the gas input unit 72 can be controlled or set by the controller 78, and in conjunction with the operation of the gas exhaust unit 74, the chamber 32 of the heating chamber 30 can be maintained at the above-mentioned predetermined pressure.

[0059] Additionally, the measurement and control system may further optionally include a pyrometer 79 for measuring the temperature of the chamber 32 of the heating chamber 30 . Pyrometer 79 may be, for example, but is not limited to, an infrared pyrometer. In the present invention, the emissivity of a wafer (e.g., silicon carbide) measured using a blackbody radiation source is 0.74, and by inputting this value into pyrometer 79, it can be used for all temperature measurements in the technology disclosed in the present invention.

[0060] The complex rapid annealing apparatus and method according to the present invention have the following advantages. (1) The induction heating mechanism and the dielectric heating mechanism are combined, so that conductors and non-conductors can be heated simultaneously. For example, the temperature of a silicon carbide wafer can be increased by the induction heating mechanism, and when the electrical conductivity of the silicon carbide wafer decreases due to the increase in temperature, the temperature of the silicon carbide wafer can be increased by the dielectric heating mechanism, so that the heating rate of the wafer can be kept constant.

[0061] (2) The temperature of the electrode can also be increased by the induction heating mechanism, so that when the temperature of the silicon carbide wafer increases and its electrical conductivity drops, the silicon carbide wafer can be heated continuously by heating the electrode, and thus the heating rate of the silicon carbide wafer can be kept constant.

[0062] (3) The electrode can be used as a support base and a heating base.

[0063] (4) The heating chamber has a metal cylinder which can be a reflective layer and can also be a Faraday shield layer. The metal cylinder can reduce the radiative heat loss in the heating chamber, and can also allow an alternating magnetic field to enter the heating chamber and generate eddy currents in the wafer.

[0064] (5) The barrier layer between the electrode and the wafer or between the wafers can prevent the diffusion of contamination. The barrier layer can also be used as a support and a heating base.

[0065] The above description is illustrative only and not limiting. Any equivalent modifications or variations thereto that do not depart from the spirit and scope of the present invention are intended to be within the scope of the claims. [Explanation of symbols]

[0066] 10. Complex high-speed annealing device 20 electrodes 22 Wafers 24 Barrier Layer 30 Heating Chamber 32 Chamber 34 Cavity 35 Metal layer 36 Top lid 37 Insulation material layer 38 Lower lid 40 Induction heating device 42 Inductance coil 50 Dielectric heating device 52 RF power supply 54 Adapter 60 Metal Cylinder 62 Reflective layer 64 Aperture 66 Faraday Shielding Layer 70 Measurement and Control Systems 72 Gas input unit 73 Intake pipe connector 74 Gas exhaust unit 75 Exhaust pipe connector 76 Pressure detection unit 78 Controller 79 Pyrometer AC Alternating Electromagnetic Signal Φ Magnetic flux I EC eddy current S10 Induction heating process S20 Dielectric heating process

Claims

1. two electrodes with at least one workpiece disposed between the two electrodes; A heating chamber having a chamber for accommodating at least the workpiece; an induction heating device that performs an induction heating process on the object in the heating chamber and generates an induction magnetic field to generate eddy currents in the object to be processed and heat the object; a dielectric heating device for performing a dielectric heating process on the workpiece in the heating chamber and heating the workpiece located between the two electrodes by generating an electric field between the two electrodes; Equipped with The induction heating device and the dielectric heating device perform the induction heating process and the dielectric heating process simultaneously, sequentially, intermittently, or alternately, respectively; The combined rapid annealing apparatus further comprises a Faraday shield layer provided in the heating chamber, and the induction heating device forms the induction magnetic field in the heating chamber through the Faraday shield layer.

2. 2. The composite rapid annealing apparatus according to claim 1, wherein the induction heating apparatus heats the workpiece and the two electrodes in the heating chamber by performing the induction heating process on the workpiece and the two electrodes.

3. 2. The composite rapid annealing apparatus according to claim 1, wherein the Faraday shield layer is a metal cylinder having a plurality of openings.

4. 4. The composite rapid annealing apparatus according to claim 3, wherein the metal cylinder has a reflective surface for reducing radiant heat loss in the heating chamber.

5. 5. The composite rapid annealing apparatus according to claim 4, wherein the reflective surface of the metal cylinder is further covered with a reflective layer.

6. 2. The composite rapid annealing apparatus according to claim 1, further comprising at least one barrier layer between the two electrodes and the workpiece.

7. 2. The composite rapid annealing apparatus according to claim 1, wherein the workpiece is a plurality of workpieces, and at least one barrier layer is provided between the workpieces.

8. 8. The composite rapid annealing apparatus according to claim 6, wherein one of the barrier layer and the workpiece has a polycrystalline structure, and the other of the barrier layer and the workpiece has a single crystalline structure.

9. 8. The composite rapid annealing apparatus according to claim 6 or 7, wherein the induction heating device and the dielectric heating device heat the workpiece and the barrier layer by performing the induction heating process and the dielectric heating process on the workpiece and the barrier layer.

10. 2. The composite rapid annealing apparatus according to claim 1, wherein the workpiece is selected from the group consisting of conductors and non-conductors.

11. 2. The composite rapid annealing apparatus according to claim 1, wherein the workpiece is a wafer.

12. 2. The composite rapid annealing apparatus as claimed in claim 1, wherein the material of the two electrodes is graphite.

13. 2. The composite rapid annealing apparatus according to claim 1, wherein the induction heating device comprises an inductance coil wound around the heating chamber, and the induction heating device generates the induction magnetic field between the workpiece and the two electrodes by applying a first alternating electromagnetic signal having a first predetermined frequency to the inductance coil.

14. 14. The composite rapid annealing apparatus according to claim 13, wherein the first predetermined frequency ranges from 50 kHz to 200 kHz.

15. 2. The composite rapid annealing apparatus according to claim 1, wherein the dielectric heating device generates the electric field in the two electrodes located on both sides of the workpiece by applying a second alternating electromagnetic signal having a second predetermined frequency.

16. 16. The composite rapid annealing apparatus according to claim 15, wherein the second predetermined frequency ranges from 10 MHz to 900 MHz.

17. 16. The hybrid rapid annealing apparatus according to claim 15, wherein the dielectric heating apparatus comprises an RF power source and an adapter, the RF power source supplies the second alternating electromagnetic signal having the second predetermined frequency, and the adapter is located between the RF power source and the two electrodes and electrically connected to both, thereby reducing reflection of the second alternating electromagnetic signal.

18. 2. The composite rapid annealing apparatus of claim 1, further comprising: a gas input unit and a gas exhaust unit, each of which is connected to the chamber of the heating chamber, so that the chamber of the heating chamber is maintained at a predetermined pressure.

19. 20. The composite rapid annealing apparatus according to claim 18, wherein the predetermined pressure of the heating chamber is in the range of 0.1 atm to 10 atm.

20. 20. The composite rapid annealing apparatus of claim 18, further comprising a measurement and control system including a pressure detection unit and a controller, the pressure detection unit is for measuring an air pressure in the heating chamber, and the controller controls the operation of the gas input unit and / or the gas exhaust unit according to the magnitude of the air pressure.

21. 21. The hybrid rapid annealing apparatus of claim 20, wherein the measurement and control system further comprises a pyrometer for measuring the temperature of the heating chamber.

22. 2. The composite rapid annealing apparatus according to claim 1, wherein the heating chamber comprises a cavity, an upper lid, and a lower lid, the cavity being located between the upper lid and the lower lid, and the chamber being formed between the cavity, the upper lid, and the lower lid by connecting the upper lid and the lower lid.

23. 23. The composite rapid annealing apparatus according to claim 22, wherein the heating chamber is made of a quartz tube or a ceramic tube.

24. performing an induction heating process on at least one workpiece by an induction heating device, the induction heating device generating an induction magnetic field to generate eddy currents in the workpiece, thereby heating the workpiece; performing a dielectric heating process on the object to be processed by a dielectric heating device, the dielectric heating device generating an electric field to heat the object to be processed; Including, A composite rapid annealing method, characterized in that, in a step of heating the workpiece by generating eddy currents in the workpiece, the induction heating device forms the induction magnetic field in the heating chamber through a Faraday shield layer provided in the heating chamber having at least a chamber for accommodating the workpiece.

25. The composite rapid annealing method according to claim 24, wherein the workpiece is placed between two electrodes, the induction heating device heats the workpiece and the two electrodes by performing the induction heating process on the workpiece and the two electrodes, and the dielectric heating device heats the workpiece by generating the electric field to the two electrodes.

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