CN219759532U

CN219759532U - Combined type rapid annealing device

Info

Publication number: CN219759532U
Application number: CN202320666455.1U
Authority: CN
Inventors: 寇崇善
Original assignee: Mingyuan Precision Technology Co ltd
Current assignee: Mingyuan Precision Technology Co ltd
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2023-09-26
Anticipated expiration: 2033-03-30

Abstract

The utility model relates to a compound rapid annealing device, which comprises two electrodes, a heating cavity, an induction heating device and a dielectric heating device, wherein at least one object to be processed is placed between the two electrodes and is positioned in a cavity of the heating cavity. The induction heating device of the composite rapid annealing device performs an induction heating step on the object to be processed. When the conductivity of the object to be processed is reduced due to the temperature rise, the two electrodes can heat the object to be processed, and the dielectric heating device can also perform dielectric heating step on the object to be processed, thereby maintaining a certain heating rate of the object to be processed. The present utility model overcomes the problems caused by hardware in the prior art by improving the hardware.

Description

Combined type rapid annealing device

Technical Field

The present utility model relates to an annealing device, and more particularly, to a composite rapid annealing device.

Background

Silicon carbide (SiC) has a wide band gap, a 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 technique for manufacturing SiC semiconductor components. Simultaneous Annealing (Annealing) is a necessary step to remove lattice damage and activate implanted ions after ion implantation. For silicon carbide, it is necessary to perform ion implantation post-annealing at a temperature greater than 1,500 ℃ to achieve the process effect.

Conventional annealing is typically performed in a ceramic furnace, either resistive 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 perform silicon carbide annealing at temperatures above 1,500 ℃ C. This limits the maximum annealing temperature because if silicon carbide is exposed to temperatures exceeding 1,400 ℃ for a long period of time, constituent species on the substrate surface sublimate and redeposit (commonly known as Step Bunching), causing an increase in silicon carbide Wafer (Wafer) surface roughness. Such a limitation on the annealing temperature may result in insufficient activation of the implanted ions, resulting in higher contact and channel region resistance.

Therefore, in order to avoid the problem of surface degradation of the silicon carbide wafer caused by too slow heating speed in the conventional annealing technology, the development of the rapid annealing technology is critical. Although halogen lamp and laser technology can achieve rapid thermal processing, there are problems such as the highest achievable annealing temperatures, surface melting, high residual defect densities, and implant redistribution.

On the other hand, silicon carbide is effective in absorbing microwave energy, and with a properly designed annealing system, microwaves can provide very fast heating and cooling rates and good control of the annealing time for silicon carbide wafers. Microwaves have the characteristic of selective heating, because the microwaves are only absorbed by the semiconductor wafer, but not by the surrounding environment, and the annealing heating rate is very fast. Meanwhile, in the annealing process, the temperature of the environment around the silicon carbide wafer is limited to be raised, and the cooling rate of the silicon carbide wafer can be high after the microwave source is turned off. Compared with the traditional annealing technology, the silicon carbide annealing is carried out by utilizing microwaves, and the heating result of the silicon carbide wafer with a small area shows that the heating rate can exceed 600 ℃/s, and the temperature can reach 2,000 ℃.

However, the wavelength of the microwave is shorter, and the energy distribution in the heating reaction chamber is uneven, so that the problem of uneven heating of the silicon carbide wafer is caused, especially when the area of the silicon carbide wafer is increased, the volume of the heating reaction chamber is enlarged, and the problem of uneven heating during annealing heating is more serious. At the same time, the required microwave energy is also greatly increased, rendering the device more expensive. It is known that there is still a considerable need for improvement in the art, and the problems of the prior art are all caused by hardware.

Disclosure of Invention

Accordingly, one or more objects of the present utility model are to provide a hybrid rapid annealing device, which overcomes the above-mentioned problems caused by hardware in the prior art by improving hardware.

Since the silicon carbide wafer is heated by electromagnetic waves that generate an alternating magnetic field (Alternating Magnetic Field), eddy currents (Eddy Current) may be induced to provide an inductive heating (Induction Heating, or induction heating) effect. However, when the temperature exceeds 500 degrees K, the conductivity of the silicon carbide wafer rapidly decreases, resulting in an increase in the resistivity thereof. Moreover, since electromagnetic waves with alternating electric fields (Alternating Electric Field) can also heat silicon carbide wafers by generating a dielectric heating (Dielectric Heating) mechanism (or dielectric heating mechanism), the dielectric Loss tangent (Loss tangent) of silicon carbide wafers increases with increasing temperature, and when the temperature increases to about 1,000 degrees celsius, the dielectric Loss tangent increases rapidly and greatly. Therefore, the present utility model provides a composite heating mechanism, which combines an induction heating mechanism and a dielectric heating mechanism to heat an object to be processed (Workpiece), such as a silicon carbide wafer.

In order to achieve the above-mentioned object, the present utility model 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 cavity having a chamber for accommodating at least 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 heats the object to be processed between the two electrodes by generating an electric field on the two electrodes.

Wherein the induction heating device performs the induction heating step on the object to be processed and the two electrodes in the heating cavity, thereby heating the object to be processed and the two electrodes.

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

The composite rapid annealing device further comprises a Faraday shielding layer arranged on the heating cavity, wherein the induction heating device penetrates through the Faraday shielding layer to form the induction magnetic field in the cavity of the heating cavity.

Wherein the Faraday shielding layer is a metal cylinder with a plurality of openings.

Wherein the metal tube has a reflective surface for reducing radiation loss of the heating chamber.

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

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

Wherein the number of the objects to be processed is plural, and at least one barrier layer is disposed between the objects to be processed.

Wherein one of the barrier layer and the object to be processed is of a polycrystalline structure, and the other of the barrier layer and the object to be processed is of 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.

Wherein the object to be processed is a wafer.

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

Wherein the two electrodes are made of 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, so as to generate the induction magnetic field on the object to be processed and the two electrodes.

Wherein the first predetermined frequency ranges from 50kHz to 200kHz.

Wherein 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.

Wherein the second predetermined frequency ranges from 10MHz to 900MHz.

The dielectric heating device comprises a radio frequency power supply and a matcher, wherein the radio frequency power supply provides the second alternating current electromagnetic signal with the second preset frequency, and the matcher is electrically connected between the radio frequency power supply and the two electrodes and is used for reducing reflection of the second alternating current electromagnetic signal.

Wherein, the composite rapid annealing device of the present utility model further comprises a gas input unit and a pumping unit respectively connected to the chamber of the heating chamber for maintaining the chamber of the heating chamber at a predetermined pressure.

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

The utility model also includes a measuring and controlling system, which includes a pressure detecting unit and a controller, the pressure detecting unit is used to measure the air pressure of the heating chamber, the controller correspondingly controls the operation of the air input unit and/or the air pumping unit according to the value of the air pressure.

Wherein the measurement and control system further comprises a pyrometer for measuring the temperature of the chamber of the heating chamber.

The heating cavity comprises a cavity, an upper cover and a lower cover, wherein the cavity is connected between the upper cover and the lower cover, so that the cavity is formed among the cavity, the upper cover and the lower cover.

Wherein the heating chamber is made of quartz tube or ceramic tube.

In view of the foregoing, the hybrid rapid annealing apparatus according to the present utility model, rather than improving software or program, overcomes the problems caused by hardware in the prior art by improving hardware, and has one or more advantages or technical effects:

(1) The induction heating mechanism and the dielectric heating mechanism are combined, so that the induction heating mechanism can be used for heating conductive and nonconductive objects at the same time, for example, the induction heating mechanism can be used for heating the silicon carbide wafer to a high temperature, and when the conductivity of the silicon carbide wafer is reduced due to the high temperature, the dielectric heating mechanism can be used for heating the silicon carbide wafer to a high temperature, so that the wafer can maintain a certain heating rate.

(2) The induction heating mechanism can also raise the temperature of the electrode, so that when the conductivity of the silicon carbide wafer is reduced due to the raised temperature, the silicon carbide wafer can be continuously heated by heating the electrode, and a certain heating rate of the silicon carbide wafer can be maintained.

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

(4) The heating cavity is provided with a metal cylinder which can be used as a reflecting layer and also can be used as a Faraday shielding layer, so that not only can the radiation heat dissipation loss of the heating cavity be reduced, but also an alternating current magnetic field can enter the heating cavity to enable the wafer to generate eddy current.

(5) The barrier layer is arranged between the electrode and the wafer or between the wafer and the wafer, can prevent the diffusion pollution phenomenon, and can also be used as a bearing base and a heating base.

In order to further understand and appreciate the technical features and effects of the present utility model, a preferred embodiment and a detailed description are provided.

Drawings

FIG. 1 is a schematic cross-sectional view of an embodiment of a composite rapid annealing apparatus according to the present utility model.

FIG. 2 is a schematic perspective view of a Faraday shielding layer of a composite rapid annealing device according to the present utility model.

FIG. 3 is a schematic diagram of the operation of the dielectric heating mechanism of the composite rapid annealing device of the present utility model, wherein FIGS. 3 (A), (B) and (C) show the aspects of a plurality of wafers, a single wafer and an unused barrier layer, respectively.

FIG. 4 is a schematic diagram illustrating the operation of the induction heating mechanism of the composite rapid annealing device of the present utility model.

FIG. 5 is a flow chart of a composite heating process of the composite rapid annealing method of the present utility model.

FIG. 6 is a schematic cross-sectional view of another embodiment of the composite rapid annealing device of the present utility model.

Reference numerals illustrate:

10: combined type rapid annealing device

20: electrode

22: wafer with a plurality of wafers

24: barrier layer

30: heating cavity

32: chamber chamber

34: cavity body

35: metal layer

36: upper cover

37: thermal insulation material layer

38: lower cover

40: induction heating device

42: inductance coil

50: dielectric heating device

52: radio frequency power supply

54: matcher

60: metal tube

62: reflective layer

64: perforating the hole

66: faraday shielding layer

70: measurement and control system

72: gas input unit

73: air inlet pipe fitting

74: air extraction unit

75: exhaust pipe fitting

76: pressure detection unit

78: controller for controlling a power supply

79: pyrometer

AC: ac electromagnetic signal

Φ: magnetic flux

I _EC : eddy current

S10, S20: step (a)

Detailed Description

For the purpose of promoting an understanding of the principles of the utility model, including its principles, its advantages, and its advantages, reference should be made to the drawings and to the accompanying drawings, in which there is illustrated and described herein a specific example of an embodiment of the utility model. In addition, for ease of understanding, like elements in the following embodiments are denoted by like reference numerals.

Furthermore, the terms used throughout the specification and claims, unless otherwise indicated, shall generally be construed to have the ordinary meaning and meaning given to each term in the art, both in the context of the disclosure and in the specific context. Certain words used to describe the utility model will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the utility model.

The use of "first," "second," "third," and the like herein does not specifically refer to order or sequence, nor is it intended to limit the utility model to only distinguish between components or operations that may be described in the same technical term.

Second, the words "comprising," "including," "having," "containing," and the like, as used herein, are open-ended terms, meaning including, but not limited to.

The utility model relates to a compound rapid annealing device and a method, taking an object to be processed as a wafer (such as a silicon carbide wafer) as an example, wherein the physical characteristics of the silicon carbide are that the conductivity rapidly decreases at high temperature but the dielectric absorptivity of electromagnetic waves rapidly increases in processing procedures such as a heating process and the like. Other wafer materials may have similar or similar properties. Therefore, the utility model adopts a composite heating mechanism, including using an intermediate frequency induction heating (Induction Heating) mechanism, to rapidly raise the temperature of the wafer. For doped wafers, when the temperature increases rapidly to a value, the conductivity decreases rapidly and the conductivity changes differently with the temperature change of the wafer due to the doping concentration or type. Therefore, the utility model adopts a composite heating mechanism and also comprises a dielectric heating (Dielectric Heating) mechanism for the wafer with the conductivity rapidly reduced by using a radio frequency power source, thereby achieving the effect of rapid wafer annealing.

Referring to fig. 1 to 5, fig. 1 is a schematic cross-sectional view illustrating an embodiment of a hybrid rapid annealing apparatus according to the present utility model. FIG. 2 is a schematic perspective view of a Faraday shielding layer of a composite rapid annealing device according to the present utility model. FIG. 3 is a schematic diagram illustrating the operation of the dielectric heating mechanism of the composite rapid annealing device of the present utility model. FIG. 4 is a schematic diagram illustrating the operation of the induction heating mechanism of the composite rapid annealing device of the present utility model. FIG. 5 is a flow chart of a composite heating process of the composite rapid annealing method of the present utility model. The hybrid rapid annealing device 10 of the present utility model comprises two electrodes 20, a heating chamber 30, an induction heating device 40 and a dielectric heating device 50, as shown in FIG. 1. The object to be processed is placed, for example, between the two electrodes 20. For example, the electrode 20 is used to carry an object to be processed, such as a material whose electrical conductivity decreases with increasing temperature, or a material whose electrical conductivity changes with changing temperature, such as a wafer 22. The object to be processed may be, for example, a silicon carbide wafer 22 or a wafer 22 of another material (e.g., 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 has a dopant or what is doped is within the scope of the claimed utility model. However, the present utility model is not limited thereto, and the object to be processed may be, for example, another material or object, such as an ingot or any other object to be heated. The electrodes 20 are made of graphite, for example, so that when the wafer 22 is placed between the two electrodes 20, the electrodes 20 can serve as a carrier for the wafer 22 and also serve as a heatable electrode (or heating base). Therefore, the electrode 20 can be made of other materials with similar or same effects. The utility model is not limited to the scope of the claims, but is exemplified by the object to be processed whose electrical conductivity decreases with increasing temperature or whose electrical conductivity changes with changing temperature. That is, any object, regardless of whether its electrical conductivity (or conductivity) changes with temperature, can be heated using the present hybrid rapid annealing device 10, and is within the scope of the present utility model.

The hybrid rapid annealing apparatus 10 of the present utility model performs a hybrid heating process for the wafer 22 in the heating chamber 30, which comprises 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 the two electrodes 20 and the wafer 22. In the composite heating process, the induction heating apparatus 40 of the composite rapid annealing apparatus of the present utility model performs an induction heating step (shown in step S10 of FIG. 5) on the wafer 22 and the two electrodes 20 in the heating chamber 30. Wherein the induction heating device 40 generates an alternating Magnetic Field (Magnetic Field) by a first alternating electromagnetic signal (AC), and generates an Eddy Current (Eddy Current, I) by generating an induced Magnetic Field (Induced Magnetic Field) having a Magnetic Flux (phi) variation _EC ) In the wafer 22 and the two electrodes 20 (as shown in fig. 4), the wafer 22 and the two electrodes 20 are heated.

In the induction heating mechanism, the heating energy generated per unit volume for the object to be processed can be expressed by the following equation:wherein sigma _m The Conductivity (Conductivity) of the material to be processed, ω=2pi f, f=electromagnetic frequency, and B is the intensity of the alternating magnetic field. For doped silicon carbide wafers, the electrical conductivity (i.e., 1/resistivity) increases with increasing heating temperature, but the electrical conductivity decreases rapidly (i.e., resistivity increases) when the temperature exceeds 500 degrees K, for example.

In the composite heating process of the composite rapid annealing apparatus 10 of the present utility model, the dielectric heating apparatus 50 performs a dielectric heating step (shown as step S20 in FIG. 5) on the wafer 22 in the heating chamber 30. The dielectric heating device 50 heats the wafer 22 between the two electrodes 20 by generating an electric field across the two electrodes 20. The number of wafers 22 may be one (as shown in fig. 3 (B) and (C)) or plural (as shown in fig. 3 (a)). In addition, at least one barrier layer 24 (as shown in fig. 3 (a) and (B)) may be selectively disposed between two electrodes 20 and the wafer 22 and between two adjacent wafers 22 according to practical requirements, or the barrier layer 24 may be omitted (as shown in fig. 3 (C)), and the barrier layer 24 may be selectively disposed between two adjacent wafers 22. The purpose of the barrier layer 24 is to prevent contamination phenomena such as out-of-range diffusion of doping components due to temperature increase between the wafers 22 or between the wafers 22 and the electrodes 20. Wherein the barrier layer 24 can also be used as a load-bearing base and a heating base for the wafer 22. Wherein, the barrier layer 24 can be selectively 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 can perform the induction heating step (S10) and the dielectric heating step (S20) on the wafer 22 and the barrier layer 24, for example, simultaneously, so as to heat the wafer 22 and the barrier layer 24. For example, if the material of the wafer 22 is a monocrystalline structure (e.g., monocrystalline silicon carbide), the composition of the barrier 24 is, for example, polycrystalline structure (e.g., polycrystalline silicon carbide), and vice versa. That is, the wafer 22 and the barrier 24 are made of different materials, for example. However, the present utility model is not limited thereto, and any material or whether heated or not, such as diffusion barrier, may be used for the barrier layer 24. For convenience of description of the technical means and technical effects of the present utility model, the object to be processed is a wafer 22 (e.g. silicon carbide wafer), and the electrode 20 is a graphite electrode, however, any material, object or structure can be heated by the compound rapid annealing device of the present utility model, which falls within the scope of the present utility model. In the hybrid 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), respectively.

The heating mechanism of the composite rapid annealing device adopts a medium frequency induction heating (induction heating) mechanism, and is characterized in that the consideration of a heating power supply using a high-frequency electromagnetic field and a low-frequency electromagnetic field is two aspects, namely, the efficiency of medium heating is more effective on the effect of the high-frequency electromagnetic wave, and the penetration depth of the electromagnetic wave is considered. The graphite electrode 20 is used as a base of the silicon carbide wafer 22 and is also used as a heating electrode, and the penetration depth of electromagnetic waves is smaller than 400 μm when the penetration depth is larger than 10MHz, so that an alternating current electric field is generated between the upper electrode 20 and the lower electrode 20 without much attenuation. The penetration depth of the low-frequency electromagnetic wave is larger than that of the heating base formed by the graphite electrode 20 and the silicon carbide wafer 22. In other words, the intermediate frequency first ac electromagnetic signal can be heated effectively. In particular, graphite is resistant to high temperatures and has high efficiency in its induction heating mechanism, so that the temperature of the heating susceptor formed by graphite electrode 20 and silicon carbide wafer 22 can be rapidly raised. However, although the present utility model is illustrated with an intermediate frequency electromagnetic field, the scope of the present utility model is not limited in this respect, and any frequency electromagnetic field may be used in the present utility model to induce inductive heating of the graphite electrode 20 and silicon carbide wafer 22, as long as it is within the scope of the present utility model.

For example, in the initial stage of the heating reaction, the temperature of the graphite electrode 20 and the silicon carbide wafer 22 can be raised rapidly by 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 is reduced, the heating effect is poor, but the graphite electrode 20 is still heated by induction, and the temperature can still maintain a certain heating rate. In the process of temperature rise, the dielectric Loss tangent (Loss tangent) of silicon carbide is continuously increased, so that the efficiency of dielectric heating is improved. When the temperature is raised to about 1,000 degrees centigrade, the dielectric loss tangent is greatly raised, so that the effect of dielectric heating can be accelerated.

In detail, the induction heating device 40 comprises, for example, an induction Coil (42) wound around the heating chamber 30. The induction heating device 40 generates an induction magnetic field on the wafer 22 and the two electrodes 20 by applying a first ac electromagnetic signal of a first predetermined frequency to the inductor coil 42. The inductor 42 is driven by an intermediate frequency AC power source, the first predetermined frequency ranging from about 50kHz to 200kHz, but is not limited thereto. In this embodiment, the heating chamber 30 may, for example, comprise a chamber 34, an upper lid 36 and a lower lid 38, wherein the chamber 34 is connected between the upper lid 36 and the lower lid 38, thereby forming a chamber 32 between the chamber 34, the upper lid 36 and the lower lid 38. An inductor 42 is wound around the cavity 34 of the heating cavity 30. To enable the induction heating mechanism, the cavity 34 of the heating chamber 30 is made of quartz or ceramic, for example. The RF power source 52 of the dielectric heating device 50 applies a second AC electromagnetic signal with a second predetermined frequency to the two electrodes 20 through the upper cover 36 and the lower cover 38, and 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 utility model is not limited thereto, and in other possible aspects, the heating chamber 30 of the utility model may be composed entirely of quartz, ceramic, or other materials, for example.

The present utility model optionally adds a reflective design to the heating chamber 30 to increase the reflectivity of the infrared light to minimize radiation losses. For example, the metal cylinder 60 may be disposed outside the cavity 34 of the heating chamber 30, as shown in fig. 1 and 2, and the metal cylinder 60 may be, for example, an optically polished metal cylinder, which may be used as a reflective surface and may be selectively coated with a reflective layer (e.g., gold) 62 to increase the reflectivity of infrared light, thereby reducing the radiation heat dissipation loss generated by the heating base composed of the graphite electrode 20 and the silicon carbide wafer 22 in an extremely high temperature state. In addition, a plurality of openings 64 may be optionally formed in the metal tube 60, for example, the openings 64 may be longitudinally open (e.g., elongated) and distributed around the metal tube 60, such that the metal tube 60 may serve as a faraday shield (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, such that eddy currents I are generated between the electrode 20 and the wafer 22 _EC As shown in fig. 4.

The dielectric heating device 50 is a radio frequency dielectric heating device (or rf heating device), as shown in fig. 1 and 3, which applies a second ac electromagnetic signal with a second predetermined frequency to generate an electric field between the two electrodes 20 located on both sides of the wafer 22, so as to perform 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, wherein the radio frequency power source 52 provides the second ac electromagnetic signal with the second predetermined frequency. The rf power source 52 is, for example, directly electrically connected to the two electrodes 20 or electrically connected to the two electrodes 20 via wires (not shown). The matcher 54 is electrically connected between the rf power source 52 and the two electrodes 20 for reducing reflection of the second ac electromagnetic signal. That is, the matching circuit of the matcher 54 is specifically designed to adjust the impedance of the heating chamber 30 to match the radio frequency power source 52 (e.g., RF/microwave power source) to reduce reflection of electromagnetic waves (e.g., RF or microwave). The radio frequency power supply 52 is selected to have a frequency of more than 10MHz, and a frequency of less than 900MHz in consideration of uniformity of electromagnetic field distribution. That is, the second predetermined frequency ranges from 10MHz to 900MHz, but is not limited thereto, and for example, from 10MHz to 400MHz, the output power is adjusted in the range of 1 kw or more, which may be any numerical value between the above frequency range and the power range or upper and lower limit end points. Wherein the inductance L and capacitance C parameters in the matching circuit of matcher 54 may be varied as operating conditions change to maintain good coupling conditions. The existing L and C components in the matching circuit of matcher 54 may be electronically tuned so that the tuning response time is not delayed and a higher heating rate may be achieved. Impedance matching is critical to achieving rapid heating. The optimal design of the matching network varies from application to application. It should be understood that, according to the disclosure of the present utility model, a person having ordinary skill in the art can understand how to implement the dielectric heating device 50 and use the matching circuit of the matching unit 54 and the rf power source 52, and therefore, the description thereof is omitted herein.

The present utility model provides a rapid annealing process for wafers selected from the group consisting of conductive (e.g., conductive wafers) and nonconductive (e.g., nonconductive wafers) wafers, as exemplified by, but not limited to, nonconductive and conductive silicon carbide wafers, due to both the inductive heating (induction heating) mechanism and the dielectric heating (dielectric heating) mechanism. Furthermore, the electromagnetic field distribution of the present utility model is easy to control and adjust, so that the present utility model can be applied to annealing treatment of a plurality of wafers. The design of the annealing system can be modified correspondingly according to the operation principle and structure of the composite rapid annealing device for large-sized silicon carbide wafers (for example, more than 8 inches). In addition, it should be specifically noted that although the present utility model is exemplified in that the electrode 20 can carry the wafer 22 and can be heated by the induction magnetic field, the scope of the present utility model is not limited thereto. For example, the electrode 20 of the present utility model may be used to support the wafer 22, such as on both sides of the wafer 22, such as the upper and lower covers 36 and 38 of the heating chamber 30 (as shown in fig. 6), respectively, wherein the modified design is not capable of heating the silicon carbide wafer 22 by heating the electrode 20, but is still within the scope of the present utility model. That is, the electrode 20 may be adapted for use in the present utility model as long as it is capable of functioning when the dielectric heating device 50 applies an alternating electric field and falls within the scope of the claimed utility model.

The inventive rapid annealing device 10 may optionally include a gas input unit 72 and a gas exhaust unit 74 in communication with the chamber 32 of the heating chamber 30 via a gas inlet pipe 73 and a gas exhaust pipe 75, respectively, for maintaining the chamber 32 of the heating chamber 30 at a predetermined pressure. Similarly, the apparatus 10 of the present utility model further optionally comprises a measurement and control system 70, which is a gas pressure and gas flow control system, comprising a pressure detection unit 76 and a controller 78, wherein the pressure detection unit 76 is used for measuring the gas pressure in the chamber 32 of the heating chamber 30, and the controller 78 correspondingly controls the operation of the gas input unit 72 and/or the gas exhaust unit 74 according to the value of the gas pressure.

For example, the pressure and flow control system may operate in a range from, for example, 0.1 atmospheres to 10 atmospheres. The pressure of the gas is monitored by a pressure detection unit 76. In addition, the gas input unit 72 injects gas into the chamber 32 of the heating chamber 30 through the gas inlet pipe 73 according to the gas flow rate setting, and discharges the gas from the chamber 32 of the heating chamber 30 through the gas outlet pipe 75 by the gas exhaust unit 74, wherein the gas exhaust unit 74 is, for example, a vacuum pump. In detail, the present utility model can evacuate the chamber 32 of the heating chamber 30 by the pumping unit 74 before introducing the gas into the chamber 32 of the heating chamber 30, and introduce the gas into the chamber 32 of the heating chamber 30 by the gas introducing unit 72 after the chamber 32 of the heating chamber 30 is in a vacuum state 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 0.1atm to 10atm, and may be any numerical value or upper and lower end points within this predetermined pressure range. The gas may be, for example, pure gas such as nitrogen or argon, but any gas capable of achieving the desired pressure in the chamber 32 of the heating chamber 30 and its predetermined pressure range is within the scope of the present utility model. In addition, the present utility model can control and set the flow rate of the gas inputted from the gas input unit 72 through the controller 78, and operate in conjunction with the pumping unit 74 so that the chamber 32 of the heating chamber 30 is maintained at the above-mentioned predetermined pressure.

In addition, the measurement and control system described above optionally 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. Wherein the wafer (e.g., silicon carbide material) Emissivity (Emissivity) measured using a blackbody radiation source of the present utility model is 0.74, and this Emissivity value is input into the pyrometer 79 for all temperature measurements in the disclosed technique.

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

(1) The combination of the induction heating mechanism and the dielectric heating mechanism can be used for heating conductive and nonconductive objects at the same time, for example, the induction heating mechanism can raise the temperature of the silicon carbide wafer, and the dielectric heating mechanism can raise the temperature of the silicon carbide wafer when the conductivity of the silicon carbide wafer is reduced due to the raised temperature.

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

The foregoing is by way of example only and is not intended as limiting. Any equivalent modifications or variations to the present utility model without departing from the spirit and scope thereof are intended to be included in the following claims.

Claims

1. A composite rapid annealing device, comprising:

two electrodes, wherein at least one object to be processed is placed between the two electrodes;

a heating cavity having a chamber for accommodating at least 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 heats the object to be processed between the two electrodes by generating an electric field on the two electrodes.

2. The apparatus of claim 1, wherein the induction heating device performs the induction heating step on the workpiece and the two electrodes in the heating chamber, thereby heating the workpiece and the two electrodes.

3. The apparatus of claim 1, wherein the induction heating means and the dielectric heating means perform the induction heating step and the dielectric heating step simultaneously, sequentially, intermittently or alternately, respectively.

4. The apparatus of claim 1, further comprising a faraday shield disposed over the heating chamber, the inductive heating apparatus forming the inductive magnetic field in the chamber of the heating chamber through the faraday shield.

5. The apparatus of claim 4, wherein the faraday shield is a metal cylinder having a plurality of openings.

6. The apparatus of claim 5, wherein the metal tube has a reflective surface for reducing radiation loss from the heating chamber.

7. The apparatus of claim 6, wherein the reflective surface of the canister is further covered with a reflective layer.

8. The apparatus of claim 1, wherein at least one barrier layer is disposed between the two electrodes and the workpiece.

9. The apparatus of claim 1, wherein the number of objects to be processed is plural, and at least one barrier layer is disposed between the objects to be processed.

10. The apparatus of claim 8 or 9, wherein one of the barrier layer and the workpiece is of polycrystalline structure and the other of the barrier layer and the workpiece is of monocrystalline structure.

11. The apparatus of claim 8 or 9, wherein the induction heating means and the dielectric heating means 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.

12. The apparatus of claim 1, wherein the workpiece is selected from the group consisting of a conductive material and a non-conductive material.

13. The apparatus of claim 1, wherein the object to be processed is a wafer.

14. The apparatus of claim 1, wherein the two electrodes are graphite.

15. The apparatus of claim 1, wherein the induction heating means comprises an induction coil wound around the heating chamber, wherein the induction heating means applies a first ac electromagnetic signal having a first predetermined frequency to the induction coil to generate the induction magnetic field on the workpiece and the two electrodes.

16. The apparatus of claim 15, wherein the first predetermined frequency ranges from 50kHz to 200kHz.

17. The apparatus of claim 1, wherein the dielectric heating device applies a second ac electromagnetic signal having a second predetermined frequency to generate the electric field on the two electrodes on both sides of the object.

18. The apparatus of claim 17, wherein the second predetermined frequency ranges from 10MHz to 900MHz.

19. The apparatus of claim 17, wherein the dielectric heating device comprises a radio frequency power source and a matcher, the radio frequency power source providing the second ac electromagnetic signal having the second predetermined frequency, the matcher electrically connected between the radio frequency power source and the two electrodes for reducing reflection of the second ac electromagnetic signal.

20. The apparatus of claim 1, further comprising a gas input unit and a pumping unit respectively connected to the chamber of the heating chamber for maintaining the chamber of the heating chamber at a predetermined pressure.

21. The apparatus of claim 20, wherein the predetermined pressure of the chamber of the heating chamber ranges from 0.1atm to 10atm.

22. The apparatus of claim 20, further comprising a measurement and control system comprising a pressure detection unit for measuring a gas pressure in the chamber of the heating chamber and a controller for controlling operation of the gas input unit and/or the pumping unit according to the value of the gas pressure.

23. The apparatus of claim 22, wherein the measurement and control system further comprises a pyrometer for measuring the temperature of the chamber of the heating chamber.

24. The apparatus of claim 1, wherein the heating chamber comprises a chamber, an upper lid and a lower lid, the chamber being connected between the upper lid and the lower lid, thereby forming the chamber between the chamber, the upper lid and the lower lid.

25. The apparatus of claim 24, wherein the heating chamber is made of quartz tube or ceramic tube.