TWI872501B - Composite-type rapid annealing device and method - Google Patents

Abstract

A composite-type rapid annealing device, which includes two electrodes, a heating chamber, an induction heating device, and a dielectric heating device is disclosed. At least one workpiece is placed between the two electrodes and located in a chamber of the heating chamber. In a composite-type rapid annealing method, the induction heating device of the composite-type rapid annealing device performs an induction heating step on the workpiece. When the conductivity of the workpiece decreases due to temperature rise, the two electrodes can be used to heat the workpiece, and the dielectric heating device can also perform a dielectric heating step on the workpiece, thereby maintaining a certain heating rate of the workpiece.

Description

Composite rapid annealing device and method

The present invention relates to an annealing device and method, and in particular to a composite rapid annealing device and method.

Silicon carbide (SiC) has a wide bandgap, high breakdown electric field, high thermal conductivity and excellent chemical inertness, making it an important semiconductor material for manufacturing high-temperature, high-power and high-frequency devices. Ion implantation is an indispensable technology for manufacturing SiC semiconductor components. At the same time, annealing is a necessary step after ion implantation to remove lattice damage and activate implanted ions. For silicon carbide, annealing after ion implantation is required at a temperature greater than 1,500 °C to achieve the process effect.

Traditional annealing is usually performed in a ceramic furnace with resistance heating or low-frequency induction heating. However, the heating/cooling rate of the ceramic furnace is slow (20 °C/min), which makes it difficult to anneal silicon carbide at temperatures above 1,500 °C. Because if silicon carbide is exposed to a temperature of more than 1,400 °C for a long time, the components on the surface of the substrate will sublime and re-deposit (commonly known as step bunching), causing the surface roughness of the silicon carbide wafer to increase, which limits the maximum annealing temperature. This limitation on the annealing temperature may result in an inability to fully activate the implanted ions, resulting in higher contact and channel resistance.

Therefore, in order to avoid the problem of surface degradation of silicon carbide wafers caused by slow heating speed in traditional annealing technology, the development of rapid annealing technology becomes the key. Although halogen lamp and laser technology can achieve rapid heat treatment, there are still some problems, such as the maximum achievable annealing temperature, surface melting, high residual defect density and redistribution of implants.

On the other hand, silicon carbide can effectively absorb microwave energy. With a properly designed annealing system, microwaves can provide very fast heating and cooling rates for silicon carbide wafers and good control of annealing time. Microwaves have the characteristics of selective heating, because microwaves are only absorbed by semiconductor wafers and not by the surrounding environment, and the annealing heating rate is very fast. At the same time, during the annealing process, the temperature of the environment around the silicon carbide wafer increases only to a limited extent. When the microwave source is turned off, the cooling rate of the silicon carbide wafer can be very high. Compared with traditional annealing technology, the heating results of small-area silicon carbide wafers using microwaves for silicon carbide annealing show that the heating rate can exceed 600 °C/s and the temperature can be as high as 2,000 °C.

However, microwaves have a short wavelength, and the energy distribution in the heating reaction chamber is uneven, which causes the problem of uneven heating of the silicon carbide wafer. Especially when the area of the silicon carbide wafer increases, the volume of the heating reaction chamber expands, and the problem of uneven heating during annealing will become more serious. At the same time, the required microwave energy is also greatly increased, making the equipment more expensive.

In view of this, one purpose of the present invention is to provide a composite rapid annealing device and method to solve the above-mentioned problems of the traditional technology.

When the silicon carbide wafer is heated by electromagnetic waves that generate an alternating magnetic field, eddy currents can be generated to provide an induction heating (or induction heating) effect. However, when the temperature exceeds 500 degrees K, the conductivity of the silicon carbide wafer will drop rapidly, causing its resistivity to increase. In addition, since electromagnetic waves with an alternating electric field can also heat the silicon carbide wafer by generating a dielectric heating mechanism (or dielectric heating mechanism), the dielectric loss tangent of the silicon carbide wafer will increase as the temperature rises. When the temperature rises to more than about 1,000 degrees Celsius, the dielectric loss tangent will increase rapidly and significantly. Therefore, the present invention proposes a composite heating mechanism that combines an induction heating mechanism with a dielectric heating mechanism to heat a workpiece, such as a silicon carbide wafer.

To achieve the above-mentioned purpose, the present invention provides a composite rapid annealing device, comprising: two electrodes, wherein at least one object to be processed is placed between the two electrodes; a heating chamber having a chamber for at least accommodating the object to be processed; an induction heating device for performing an induction heating step on the object to be processed in the heating chamber, wherein the induction heating device generates an eddy current in the object to be processed by generating an induction magnetic field, thereby heating the object to be processed; and a dielectric heating device for performing a dielectric heating step on the object to be processed in the heating chamber, wherein the dielectric heating device generates an electric field on the two electrodes, thereby heating the object to be processed between the two electrodes.

The induction heating device performs the induction heating step on the object to be processed and the two electrodes in the heating chamber, so as to heat the object to be processed and the two electrodes.

The induction heating device and the dielectric heating device respectively perform the induction heating step and the dielectric heating step simultaneously, sequentially, intermittently or alternately.

The invention further comprises a Faraday shielding layer disposed on the heating cavity, and the induction heating device penetrates through the Faraday shielding layer to form the induction magnetic field in the chamber of the heating cavity.

The Faraday shielding layer is a metal tube with a plurality of openings.

The metal tube has a reflective surface to reduce the radiation heat loss of the heating chamber.

The reflective surface of the metal tube is further covered with a reflective layer.

There is at least one barrier layer between the two electrodes and the object to be processed.

There are plural objects to be processed, and at least one barrier layer is disposed between the objects to be processed.

One of the barrier layer and the object to be processed is a polycrystalline structure, and the other of the barrier layer and the object to be processed is a single crystal structure.

The induction heating device and the dielectric heating device perform the induction heating step and the dielectric heating step on the object to be processed and the barrier layer, so as to heat the object to be processed and the barrier layer.

The object to be processed is a wafer.

The object to be processed is selected from a group consisting of a conductive object and a non-conductive object.

Wherein, the material of the two electrodes is graphite.

The induction heating device comprises an induction coil wound around the heating chamber, wherein the induction heating device applies a first alternating electromagnetic signal with a first predetermined frequency to the induction coil to generate the induction magnetic field on the object to be processed and the two electrodes.

The first predetermined frequency ranges from 50 kHz to 200 kHz.

The dielectric heating device applies a second alternating electromagnetic signal with a second predetermined frequency to generate the electric field on the two electrodes located on both sides of the object to be processed.

The second predetermined frequency ranges from 10 MHz to 900 MHz.

The dielectric heating device includes a radio frequency power source and a matcher. The radio frequency power source provides the second alternating electromagnetic signal with the second predetermined frequency. The matcher is electrically connected between the radio frequency power source and the two electrodes to reduce reflection of the second alternating electromagnetic signal.

It also includes a gas input unit and an exhaust unit which are respectively connected to the chamber of the heating chamber so as to keep the chamber of the heating chamber at a predetermined pressure.

Wherein, the predetermined pressure of the heating chamber ranges from 0.1 atm to 10 atm.

It also includes a measurement and control system, including a pressure detection unit and a controller. The pressure detection unit is used to measure the air pressure of the chamber of the heating chamber, and the controller controls the operation of the gas input unit and/or the exhaust unit accordingly according to the value of the air pressure.

The measurement and control system further comprises a high temperature thermometer for measuring the temperature of the chamber of the heating chamber.

The heating chamber includes a cavity, an upper cover and a lower cover, and the cavity is connected between the upper cover and the lower cover to form the chamber between the cavity, the upper cover and the lower cover.

Wherein, the material of the heating chamber is a quartz tube or a ceramic tube.

To achieve the aforementioned purpose, the present invention further proposes a composite rapid annealing method, comprising: performing an induction heating step on at least one object to be processed using an induction heating device, wherein the induction heating device generates an eddy current in the object to be processed by generating an induction magnetic field to heat the object to be processed; and performing a dielectric heating step on the object to be processed using a dielectric heating device, wherein the dielectric heating device generates an electric field to heat the object to be processed.

The object to be processed is carried between two electrodes, the induction heating device performs the induction heating step on the object to be processed and the two electrodes to heat the object to be processed and the two electrodes, and the dielectric heating device generates the electric field on the two electrodes to heat the object to be processed.

As mentioned above, the composite rapid annealing device and method of the present invention has the following effects and advantages:

(1) By combining the induction heating mechanism and the dielectric heating mechanism, it can be used to heat both conductive and non-conductive objects at the same time. For example, the temperature of a silicon carbide wafer can be increased by the induction heating mechanism, and when the 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 wafer maintains a certain heating rate.

(2) The induction heating mechanism can also increase the temperature of the electrode, so that when the conductivity of the silicon carbide wafer decreases due to the increase in temperature, the silicon carbide wafer can be continuously heated by the heating electrode so that the silicon carbide wafer maintains a certain heating rate.

(3) The electrode can be used as a supporting base and a heating base.

(4) The heating chamber has a metal tube that can serve as a reflective layer and a Faraday shielding layer. It can not only reduce the radiation heat loss of the heating chamber, but also allow the AC magnetic field to enter the heating chamber to generate eddy current in the wafer.

(5) A barrier layer is located between the electrode and the wafer or between the wafers to prevent diffuse contamination. The barrier layer can also be used as a supporting base and a heating base.

In order to enable Junshen to have a deeper understanding and recognition of the technical features and technical effects of the present invention, a preferred embodiment and a detailed description are provided as follows.

In order to facilitate understanding of the technical features, content and advantages of this invention and the effects it can achieve, this invention is described in detail as follows with the help of diagrams and in the form of embodiments. The diagrams used are only for illustration and auxiliary instructions, and may not be the true proportions and precise configurations of this invention after implementation. Therefore, the proportions and configurations of the attached diagrams should not be interpreted to limit the scope of rights of this invention in actual implementation. In addition, for ease of understanding, the same elements in the following embodiments are indicated by the same symbols.

In addition, the terms used throughout the specification and the patent application generally have the ordinary meaning of each term used in this field, in the content disclosed herein, and in the specific content, unless otherwise specified. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the present invention.

The use of "first", "second", "third", etc. in this article does not specifically refer to the order or sequence, nor is it used to limit the present creation. It is only used to distinguish components or operations described with the same technical terms.

Secondly, the terms "include", "including", "have", "contain", etc. used in this article are open terms, which mean including but not limited to.

The present invention is a composite rapid annealing device and method. Taking the object to be processed as a wafer (e.g., a silicon carbide wafer) as an example, the physical property of silicon carbide is that during the heating process and other processing procedures, the conductivity drops rapidly at high temperatures, but the dielectric absorption rate of electromagnetic waves rises rapidly. In addition, other wafer materials also have similar or similar properties. Therefore, the present invention adopts a composite heating mechanism, including the use of a medium-frequency induction heating (Induction Heating) mechanism to quickly increase the temperature of the wafer. For a doped wafer, when its temperature rises rapidly to a certain value, its conductivity drops rapidly, and its conductivity will change differently with the temperature change of the wafer due to different doping concentrations or types. Therefore, the present invention adopts a composite heating mechanism, which also includes using a radio frequency power source to perform a dielectric heating mechanism on wafers with rapidly decreasing conductivity, to achieve a rapid wafer annealing effect.

Please refer to Figures 1 to 5. Figure 1 is a schematic diagram of the cross-sectional structure of an implementation of the composite rapid annealing device of the present invention. Figure 2 is a schematic diagram of the three-dimensional structure of the Faraday shielding layer of the composite rapid annealing device of the present invention. Figure 3 is a schematic diagram of the operation of the dielectric heating mechanism of the composite rapid annealing device of the present invention. Figure 4 is a schematic diagram of the operation of the induction heating mechanism of the composite rapid annealing device of the present invention. Figure 5 is a schematic diagram of the flow of the composite heating procedure of the composite rapid annealing method of the present invention. The composite rapid annealing device 10 of the present invention includes two electrodes 20, a heating chamber 30, an induction heating device 40 and a dielectric heating device 50, as shown in Figure 1. The object to be processed is, for example, placed between the two electrodes 20. For example, the electrode 20 is used to carry the object to be processed, and the object to be processed is, for example, a material whose conductivity decreases as the temperature increases, or a material whose conductivity changes as the temperature changes, such as a wafer 22. The object to be processed may be, for example, a silicon carbide wafer 22 or a wafer 22 of other materials (such as Si, SiGe, Ge, GaAs, GaN or InP), and may be a wafer at any stage in any semiconductor manufacturing process, and whether or not the object to be processed is doped or what kind of substance is doped, it falls within the scope of protection claimed in the present invention. However, the present invention is not limited thereto, and the object to be processed may also be, for example, other materials or objects, such as a crystal ingot or any other object that needs to be heated. The material of the electrode 20 is, for example, graphite, so that when the wafer 22 is placed between the two electrodes 20, the electrode 20 can be used as a supporting base for the wafer 22 and also as a heatable electrode (or heating base). Therefore, the electrode 20 can also be made of other materials with similar or identical effects. Although the present invention uses the object to be processed whose conductivity decreases as the temperature increases or whose conductivity changes as the temperature changes as an illustrative example, it is not intended to limit the scope of the rights of the present invention. That is, any object, regardless of whether its conductivity (or conductivity) changes as the temperature changes, as long as it can be heated using the composite rapid annealing device 10 of the present invention, falls within the scope of protection claimed by the present invention.

The composite rapid annealing device 10 of the present invention performs a composite heating process on the wafer 22 in the heating chamber 30. The composite heating process includes using an induction heating mechanism (as shown in FIG. 4 ) and a dielectric heating mechanism (as shown in FIG. 3 ). The heating chamber 30 has a chamber 32 for accommodating two electrodes 20 and the wafer 22. In the composite heating process, the induction heating device 40 of the composite rapid annealing device of the present invention performs an induction heating step on the wafer 22 and the two electrodes 20 in the heating chamber 30 (as shown in step S10 of FIG. 5 ). 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) with a changing magnetic flux (Magnetic Flux, Φ) to generate an eddy current (Eddy Current, _IEC ) in the wafer 22 and the two electrodes 20 (as shown in FIG. 4), thereby heating the wafer 22 and the two electrodes 20.

In the induction heating mechanism, the heating energy generated per unit volume of the object to be processed can be expressed by the following equation: p = .in, is the conductivity of the material to be processed, 𝜔 = 2𝜋𝑓, 𝑓 = electromagnetic wave frequency, and B is the strength of the alternating magnetic field. For doped silicon carbide wafers, the conductivity (i.e., 1/resistivity) increases with the increase in heating temperature, but when the temperature exceeds 500 degrees K, for example, the conductivity drops rapidly (i.e., the resistivity increases).

In the composite heating process of the composite rapid annealing device 10 of the present invention, the dielectric heating device 50 performs a dielectric heating step on the wafer 22 in the heating chamber 30 (as shown in step S20 of FIG. 5 ). The dielectric heating device 50 generates an electric field on the two electrodes 20 to heat the wafer 22 between the two electrodes 20. The number of wafers 22 can be one (as shown in FIG. 3 (B) and (C)) or multiple (as shown in FIG. 3 (A)). In addition, at least one barrier layer 24 can be selectively provided between the two electrodes 20 and the wafer 22 and between two adjacent wafers 22 according to actual needs (as shown in FIG. 3 (A) and (B)), or the barrier layer 24 can be omitted (as shown in FIG. 3 (C)), and a barrier layer 24 can also be selectively provided between two adjacent wafers 22. The purpose of the barrier layer 24 is to prevent contamination such as cross-border diffusion of impurities between the wafers 22 or between the wafer 22 and the electrode 20 due to temperature increase. The barrier layer 24 can also be used as a supporting base and a heating base for the wafer 22. The barrier layer 24 may also be selectively made of a material that can be heated by the induction heating device 40 and the dielectric heating device 50. Thus, the induction heating device 40 and the dielectric heating device 50 may simultaneously perform an induction heating step (S10) and a dielectric heating step (S20) on the wafer 22 and the barrier layer 24, thereby heating the wafer 22 and the barrier layer 24. For example, if the material of the wafer 22 is a single crystal structure (e.g., single crystal silicon carbide), the composition of the barrier 24 is, for example, a polycrystalline structure (e.g., polycrystalline silicon carbide), and vice versa. That is, the wafer 22 and the barrier 24 are, for example, different materials. However, the present invention is not limited thereto. As long as the barrier layer 24 can exert a barrier effect, such as a diffusion barrier effect, it should fall within the scope of the present invention regardless of the material it is made of or whether it can be heated. In order to facilitate the description of the technical means and technical effects of the present invention, the present invention takes the wafer 22 (such as a silicon carbide wafer) as the object to be processed and the graphite electrode 20 as an example for illustration. However, any substance, object or structure as long as it can be heated by the composite rapid annealing device of the present invention falls within the scope of the present invention. In the combined heating process, the induction heating device 40 and the dielectric heating device 50 are not limited to performing the induction heating step (step S10) and the dielectric heating step (step S20) simultaneously, sequentially, intermittently or alternately.

The heating mechanism of the composite rapid annealing device of the present invention adopts a medium frequency induction heating mechanism. The reason is that there are two considerations for using a heating power source of a high-frequency and low-frequency electromagnetic field. The first is that the efficiency of dielectric heating is more effective in the effect of high-frequency electromagnetic waves, and the second is to consider the penetration depth of electromagnetic waves. The graphite electrode 20 is not only used as a base for the silicon carbide wafer 22, but also a heating electrode. The main purpose is to use its penetration depth for electromagnetic waves that is less than 400 𝜇𝑚 when it is greater than 10 MHz. It can be used as an electrode material to generate an AC electric field between the upper and lower electrodes 20 without attenuating too much. As for low-frequency electromagnetic waves, their penetration depth is greater than the entire heating base composed of the graphite electrode 20 and the silicon carbide wafer 22. In other words, the medium-frequency first alternating electromagnetic signal can effectively heat the entire body. In particular, graphite can withstand high temperatures and its inductive heating mechanism is highly efficient, so the temperature of the heating base composed of the graphite electrode 20 and the silicon carbide wafer 22 can be quickly increased. However, although the present invention uses a medium-frequency electromagnetic field as an example, the scope of the present invention is not limited thereto. Any electromagnetic field of any frequency that can be applied to the present invention to cause the graphite electrode 20 and the silicon carbide wafer 22 to produce inductive heating is within the scope of the present invention.

For example, in the early stage of the heating reaction, the present invention can quickly increase the temperature of the graphite electrode 20 and the silicon carbide wafer 22 through the induction heating mechanism. When the temperature of the silicon carbide wafer 22 is higher than 500 degrees K, for example, the conductivity of silicon carbide decreases and the heating effect becomes worse, but the graphite electrode 20 is still heated by induction, and its temperature can still maintain a certain heating rate. In the process of temperature rise, the dielectric loss tangent of silicon carbide continues to increase, improving the efficiency of dielectric heating. When the temperature rises to about 1,000 degrees Celsius, the dielectric loss tangent increases significantly, so the effect of dielectric heating can be accelerated.

In detail, 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 induced magnetic field on 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 may include, for example, a chamber 34, an upper cover 36, and a lower cover 38, and the chamber 34 is connected between the upper cover 36 and the lower cover 38, so as to form a chamber 32 between the chamber 34, the upper cover 36, and the lower cover 38. The inductor coil 42 is wound around the cavity 34 of the heating cavity 30. In order to perform the induction heating mechanism, the cavity 34 of the heating cavity 30 is made of materials such as quartz or ceramic. The radio frequency power source 52 of the dielectric heating device 50 applies a second alternating electromagnetic signal of a second predetermined frequency to the two electrodes 20 through the upper cover 36 and the lower cover 38. The upper cover 36 and the lower cover 38 are composed of, for example, a metal layer 35 and a heat insulating material layer 37. However, the present invention is not limited to this. In other feasible aspects, the heating cavity 30 of the present invention can also be composed of, for example, quartz, ceramic or other materials.

The present invention can selectively add a reflective design to the heating chamber 30 to increase the reflectivity of infrared light to minimize radiation loss. For example, the present invention can set a metal cylinder 60 outside the cavity 34 of the heating chamber 30, as shown in Figures 1 and 2. The metal cylinder 60 is, for example, an optically polished metal cylinder, which can be used as a reflective surface and can be selectively coated with a reflective layer (such as gold) 62 to increase the reflectivity of infrared light, thereby reducing the radiation heat loss generated by the heating base composed of the graphite electrode 20 and the silicon carbide wafer 22 under extremely high temperature conditions. In addition, the present invention can also selectively add a plurality of openings 64 on the metal tube 60. The openings 64 are, for example, longitudinal openings (e.g., strip-shaped) and are distributed around the metal tube 60. The metal tube 60 can thereby serve as a Faraday shield layer 66 to facilitate the AC 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, so that the electrode 20 and the wafer 22 generate an eddy current I _EC , as shown in FIG. 4 .

The dielectric heating device 50 is a radio frequency dielectric heating device (or radio frequency heating device), as shown in FIG. 1 and FIG. 3 , which applies a second alternating electromagnetic signal having a second predetermined frequency to generate an electric field between two electrodes 20 located on both sides of the wafer 22, thereby performing a dielectric heating step on the wafer 22 in the heating chamber 30, thereby maintaining a certain heating rate of the wafer 22. For example, the dielectric heating device 50 includes a radio frequency power source 52, and optionally further includes a matcher 54, and the radio frequency power source 52 provides the second alternating electromagnetic signal of the second predetermined frequency. The radio frequency power source 52 is, for example, directly electrically connected to the two electrodes 20 or electrically connected to the two electrodes 20 via a wire (not shown). The matcher 54 is electrically connected between the RF power source 52 and the two electrodes 20 to reduce the reflection of the second AC electromagnetic signal. That is, the matching circuit of the matcher 54 is specially designed to adjust the impedance of the heating chamber 30 to match the RF power source 52 (e.g., RF/microwave power source) to reduce the reflection of electromagnetic waves (e.g., RF or microwave). The frequency of the RF power source 52 is greater than 10 MHz, and considering the uniformity of the electromagnetic field distribution, the frequency is less than 900 MHz. That is, the second predetermined frequency ranges from 10 MHz to 900 MHz, but is not limited thereto, for example, from 10 MHz to 400 MHz, and the output power is adjusted within the range of 1 kilowatt and above, which can be any numerical value interval or upper and lower limit endpoint values in the above frequency range and power range. The parameters of the inductor L and the capacitor C in the matching circuit of the matcher 54 can be changed as the operating conditions change to maintain good coupling conditions. The existing L and C components in the matching circuit of the matcher 54 can be electronically tuned, so there is no delay in the tuning response time, and a higher heating rate can be achieved. Impedance matching is crucial to achieving rapid heating. The optimal design of the matching network varies depending on the application. Since a person having ordinary knowledge in the technical field to which the present invention belongs should be able to understand how to implement the dielectric heating device 50 and how to use the matching circuit of the corresponding matcher 54 and the radio frequency power supply 52 based on the disclosure of the present invention, it will not be further described here.

Since the present invention has both an induction heating mechanism and a dielectric heating mechanism, it can perform rapid annealing on wafers selected from a group consisting of conductive materials (e.g., conductive wafers) and non-conductive materials (e.g., non-conductive wafers). Although the present invention uses non-conductive and conductive silicon carbide wafers as examples, it is not limited to this. Moreover, since the electromagnetic field distribution of the present invention is easy to control and adjust, it can be applied to the annealing of multiple wafers. For large-sized silicon carbide wafers (e.g., larger than 8 inches), the design of the annealing system can also be modified accordingly according to the operating principle and structure of the composite rapid annealing device of the present invention. In addition, it should be specially stated that although the present invention uses the electrode 20 that can carry the wafer 22 and can be heated by the induced magnetic field as an example, the scope of the present invention is not limited to this. For example, the electrode 20 of the present invention can also be used for example not to carry the wafer 22, such as being located on both sides of the wafer 22, such as on the upper cover 36 and the lower cover 38 of the heating chamber 30 (as shown in FIG. 6 ). Although this modified design cannot heat the silicon carbide wafer 22 by heating the electrode 20, it still belongs to the feasible aspect of the present invention and therefore still belongs to the scope of protection claimed by the present invention. That is, as long as the electrode 20 can function when the dielectric heating device 50 applies an alternating electric field, it can be applied to the present invention and fall within the scope of protection claimed by the present invention.

The composite rapid annealing device 10 of the present invention may optionally include a gas input unit 72 and an exhaust unit 74 connected to the chamber 32 of the heating chamber 30 through an air inlet pipe 73 and an exhaust pipe 75, respectively, so as to keep the chamber 32 of the heating chamber 30 at a predetermined pressure. Similarly, the composite rapid annealing device 10 of the present invention may further optionally include a measurement and control system 70, which is an air pressure and air flow control system, including a pressure detection unit 76 and a controller 78. The pressure detection unit 76 is used to measure the air pressure of the chamber 32 of the heating chamber 30, and the controller 78 controls the operation of the gas input unit 72 and/or the exhaust unit 74 according to the above-mentioned air pressure values.

For example, the operating range of the air pressure and air flow control system is, for example, from 0.1 atmosphere to 10 atmospheres. The pressure of the gas is monitored by the pressure detection unit 76. In addition, the gas input unit 72 injects the gas into the chamber 32 of the heating chamber 30 through the air inlet pipe 73 according to the gas flow setting, and uses the exhaust unit 74 to exhaust the gas from the chamber 32 of the heating chamber 30 through the exhaust pipe 75, wherein the exhaust unit 74 is, for example, a vacuum pump. In detail, before the gas is introduced into the chamber 32 of the heating chamber 30, the present invention may first evacuate the chamber 32 of the heating chamber 30 by the evacuation unit 74. After the chamber 32 of the heating chamber 30 is in a vacuum state, the gas is introduced into the chamber 32 of the heating chamber 30 by the gas introduction unit 72 until the chamber 32 of the heating chamber 30 reaches a predetermined pressure. The predetermined pressure of the chamber 32 of the heating chamber 30 ranges from 0.1 atm to 10 atm, and may be any numerical value interval or upper and lower limit values within the predetermined pressure range. The gas mentioned above can be pure gas such as nitrogen or argon, but any gas that can make the chamber 32 of the heating chamber 30 reach the set gas and its predetermined pressure range belongs to the scope of protection claimed by the present invention. In addition, the present invention can control and set the flow rate of the gas input unit 72 through the controller 78, and cooperate with the operation of the exhaust unit 74 to keep the chamber 32 of the heating chamber 30 at the above-mentioned predetermined pressure.

In addition, the above-mentioned measurement and control system also selectively includes a pyrometer 79 for measuring the temperature of the chamber 32 of the heating chamber 30. The pyrometer 79 is, for example, an infrared pyrometer, but is not limited thereto. The emissivity of the wafer (such as silicon carbide material) measured by the present invention using a black body radiation source is 0.74, and this emissivity value is input into the pyrometer 79, which can be used for all temperature measurements in the technology disclosed in the present invention.

In summary, the composite rapid annealing device and method of the present invention has the following effects and advantages:

(1) Combining the induction heating mechanism and the dielectric heating mechanism, it can be used to heat both conductive and non-conductive objects at the same time. For example, the temperature of a silicon carbide wafer can be increased by the induction heating mechanism, and when the 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.

(2) The induction heating mechanism can also increase the temperature of the electrode. When the conductivity of the silicon carbide wafer decreases due to the increase in temperature, the silicon carbide wafer can be continuously heated by the heating electrode so that the silicon carbide wafer maintains a certain heating rate.

(3) The electrode can be used as a supporting base and a heating base.

(4) The heating chamber has a metal tube that can serve as a reflective layer and a Faraday shielding layer. It can not only reduce the radiation heat loss of the heating chamber, but also allow the AC magnetic field to enter the heating chamber to generate eddy current in the wafer.

(5) A barrier layer is located between the electrode and the wafer or between the wafers to prevent diffuse contamination. The barrier layer can also be used as a supporting base and a heating base.

The above description is for illustrative purposes only and is not intended to be limiting. Any equivalent modifications or changes made to the invention without departing from the spirit and scope of the invention shall be included in the scope of the attached patent application.

10: Composite rapid annealing device 20: Electrode 22: Wafer 24: Barrier layer 30: Heating chamber 32: Chamber 34: Chamber 35: Metal layer 36: Upper cover 37: Insulation material layer 38: Lower cover 40: Induction heating device 42: Inductor 50: Dielectric heating device 52: RF power supply 54: Matching device 60: Metal cylinder 62: Reflection layer 64: Opening 66: Faraday shield 70: Measurement and control system 72: Gas input unit 73: Intake pipe 74: Exhaust unit 75: Exhaust pipe 76: Pressure detection unit 78: Controller 79: Pyrometer AC: Alternating current electromagnetic signal Φ: Magnetic flux _IEC : Eddy current S10, S20: Steps

FIG1 is a schematic cross-sectional view of a composite rapid annealing device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the three-dimensional structure of the Faraday shielding layer of the composite rapid annealing device of the present invention.

FIG. 3 is a schematic diagram of the operation of the dielectric heating mechanism of the hybrid rapid annealing device of the present invention, wherein FIG. 3 (A), (B) and (C) respectively show the states of multiple wafers, a single wafer and no barrier layer used.

FIG. 4 is a schematic diagram showing the operation of the induction heating mechanism of the composite rapid annealing device of the present invention.

FIG. 5 is a schematic flow chart of the composite heating procedure of the composite rapid annealing method of the present invention.

FIG6 is a schematic cross-sectional view of another embodiment of the composite rapid annealing device of the present invention.

10: Composite rapid annealing device 20: Electrode 22: Wafer 24: Barrier layer 30: Heating chamber 32: Chamber 34: Cavity 35: Metal layer 36: Upper cover 37: Insulation material layer 38: Lower cover 40: Induction heating device 42: Inductor coil 50: Dielectric heating device 52: RF power supply 54: Matching device 60: Metal cylinder 62: Reflection layer 66: Faraday shielding layer 70: Measurement and control system 72: Gas input unit 73: Intake pipe fittings 74: Exhaust unit 75: Exhaust pipe fittings 76: Pressure detection unit 78: Controller 79: Pyrometer

Claims (27)

A composite rapid annealing device comprises: two electrodes, wherein at least one object to be processed is placed between the two electrodes; a heating chamber having a chamber for at least accommodating the object to be processed; an induction heating device for performing an induction heating step on the object to be processed in the heating chamber, wherein the induction heating device generates an eddy current in the object to be processed by generating an induction magnetic field, thereby heating the object to be processed; and a dielectric heating device for performing a dielectric heating step on the object to be processed in the heating chamber, wherein the dielectric heating device generates an electric field on the two electrodes, thereby heating the object to be processed between the two electrodes. The composite rapid annealing device as described in claim 1, wherein the induction heating device performs the induction heating step on the object to be processed and the two electrodes in the heating chamber to heat the object to be processed and the two electrodes. The composite rapid annealing device as described in claim 1, wherein the induction heating device and the dielectric heating device respectively perform the induction heating step and the dielectric heating step simultaneously, sequentially, intermittently or alternately. The composite rapid annealing device as described in claim 1 further comprises a Faraday shielding layer disposed on the heating chamber, and the induction heating device penetrates through the Faraday shielding layer to form the induction magnetic field in the chamber of the heating chamber. A composite rapid annealing device as described in claim 4, wherein the Faraday shielding layer is a metal tube having a plurality of openings. A composite rapid annealing device as described in claim 5, wherein the metal tube has a reflective surface to reduce radiation heat loss in the heating chamber. The composite rapid annealing device as described in claim 6, wherein the reflective surface of the metal tube is further covered with a reflective layer. A composite rapid annealing device as described in claim 1, wherein there is at least one barrier layer between the two electrodes and the object to be processed. The composite rapid annealing device as described in claim 1, wherein the number of the objects to be processed is plural, and at least one barrier layer is provided between the objects to be processed. A composite rapid annealing device as described in claim 8 or 9, wherein one of the barrier layer and the object to be processed is a polycrystalline structure, and the other of the barrier layer and the object to be processed is a single crystal structure. The composite rapid annealing device as described in claim 8 or 9, wherein the induction heating device and the dielectric heating device perform the induction heating step and the dielectric heating step on the object to be processed and the barrier layer, thereby heating the object to be processed and the barrier layer. A composite rapid annealing device as described in claim 1, wherein the object to be processed is selected from a group consisting of a conductive material and a non-conductive material. A composite rapid annealing device as described in claim 1, wherein the object to be processed is a wafer. A composite rapid annealing device as described in claim 1, wherein the material of the two electrodes is graphite. A composite rapid annealing device as described in claim 1, wherein the induction heating device comprises an induction coil wound around the heating chamber, wherein the induction heating device applies a first alternating electromagnetic signal having a first predetermined frequency to the induction coil to generate the induced magnetic field on the object to be processed and the two electrodes. A composite rapid annealing apparatus as described in claim 15, wherein the first predetermined frequency ranges from 50 kHz to 200 kHz. A composite rapid annealing device as described in claim 1, wherein the dielectric heating device applies a second alternating electromagnetic signal having a second predetermined frequency to generate the electric field on the two electrodes located on both sides of the object to be processed. A composite rapid annealing device as described in claim 17, wherein the second predetermined frequency ranges from 10 MHz to 900 MHz. A composite rapid annealing device as described in claim 17, wherein the dielectric heating device includes an RF power supply and a matcher, the RF power supply provides the second AC electromagnetic signal having the second predetermined frequency, and the matcher is electrically connected between the RF power supply and the two electrodes to reduce reflection of the second AC electromagnetic signal. The composite rapid annealing device as described in claim 1 further comprises a gas input unit and a vacuum unit respectively connected to the chamber of the heating chamber, so as to maintain the chamber of the heating chamber at a predetermined pressure. A composite rapid annealing apparatus as described in claim 20, wherein the predetermined pressure of the chamber of the heating chamber ranges from 0.1 atm to 10 atm. The composite rapid annealing device as described in claim 20 further includes a measurement and control system, including a pressure detection unit and a controller. The pressure detection unit is used to measure the gas pressure of the chamber of the heating chamber, and the controller controls the operation of the gas input unit and/or the exhaust unit accordingly according to the value of the gas pressure. A combined rapid annealing device as described in claim 22, wherein the measurement and control system further includes a high temperature thermometer for measuring the temperature of the chamber of the heating chamber. A composite rapid annealing device as described in claim 1, wherein the heating chamber comprises a chamber body, an upper cover and a lower cover, and the chamber body is connected between the upper cover and the lower cover to form the chamber between the chamber body, the upper cover and the lower cover. A composite rapid annealing device as described in claim 24, wherein the material of the heating chamber is a quartz tube or a ceramic tube. A composite rapid annealing method comprises: Performing an induction heating step on at least one object to be processed by an induction heating device, wherein the induction heating device generates an eddy current in the object to be processed by generating an induction magnetic field, thereby heating the object to be processed; and Performing a dielectric heating step on the object to be processed by a dielectric heating device, wherein the dielectric heating device generates an electric field to heat the object to be processed. A composite rapid annealing method as described in claim 26, wherein the object to be processed is carried between two electrodes, the induction heating device performs the induction heating step on the object to be processed and the two electrodes to heat the object to be processed and the two electrodes, and the dielectric heating device generates the electric field on the two electrodes to heat the object to be processed.