JP4997711B2 - Silicon carbide substrate, method for manufacturing the same, and method for manufacturing a semiconductor device - Google Patents

Description

  The present invention relates to a silicon carbide (SiC) substrate in which defects penetrating the inside of the substrate are eliminated, a method for manufacturing the substrate, and a method for manufacturing a semiconductor device using the substrate.

  SiC (silicon carbide) is not only excellent in heat resistance and mechanical strength, but also resistant to radiation, and by adding impurities, it is easy to control the valence electrons of electrons and holes, and has a wide band gap. have. Due to such characteristics, SiC single crystal substrates having a hexagonal crystal structure are widely used as substrates for semiconductor devices. This can realize a large capacity, high frequency, withstand voltage, and environmental performance that cannot be realized by existing semiconductor materials such as conventional Si (silicon) and GaAs (gallium arsenide). In particular, SiC has thermal conductivity. Is not less than 3 times that of Si, and the electrical characteristics are stable even at a high temperature of 300 ° C. Generation power and potential as a semiconductor material for high frequency devices.

In addition, the Group III-V compound semiconductor, for example, a GaN-based semiconductor material such as GaN, InGaN, AlGaN, AlInGaN has a larger band gap energy and higher heat resistance than, for example, a GaAs-based material, Because of its excellent high-temperature operation, research and development of electronic devices such as field effect transistors (FETs) and high electron mobility transistors (HEMTs) are being promoted using GaN. . In the GaN-based HEMT structure, for example, a layer formed by sequentially laminating a buffer layer made of, for example, GaN, an undoped GaN layer, and an undoped AlGaN layer that is much thinner than the undoped GaN layer on the semi-insulating substrate 1. A structure is formed. GaN (gallium nitride) has a characteristic of high carrier mobility like gallium arsenide (GaAs). Further, GaN has a band gap of 3.4 eV, which is larger than 1.4 eV of GaAs, and has a characteristic that an electric field causing avalanche breakdown is large.
Furthermore, since GaN-based compound semiconductor devices are used for base station amplifiers for mobile phones, etc., AlGaN / GaN crystals are grown using SiC as a substrate, and high electron mobility transistors are being actively developed. This is because the lattice constants of GaN-based compounds and SiC are close to each other, so that a GaN-based HEMT is formed using a GaN layer epitaxially grown on a SiC substrate as a carrier traveling layer and an AlGaN layer as a carrier supply layer. It is advantageous.
Furthermore, the development of MOSFETs and Schottky barrier diode (SBD) devices using a homoepitaxial substrate in which a SiC epitaxial layer is grown on a SiC substrate is being developed.

However, conventionally used SiC substrates have many through defects called micropipes. The micropipe is a large screw dislocation and a crystal defect penetrating in the C-axis direction of the SiC single crystal. The through hole has a diameter of several μm to a maximum of about 200 μm. Furthermore, it is known that the micropipe is inherited in an epitaxially grown thin film on the SiC substrate and causes dielectric breakdown or leakage current when a semiconductor device is manufactured. Furthermore, the presence of the micropipe has the disadvantage that the resist is removed from the back surface of the substrate in the resist coating process in the semiconductor manufacturing process, and the opening of the resist pattern becomes unstable, resulting in poor production yield in semiconductor device manufacturing. there were. In addition, many semiconductor process apparatuses transport a wafer by vacuum-sucking a semiconductor wafer. However, there is a problem that vacuum suction cannot be performed due to the presence of a through-hole and the wafer cannot be transported into the apparatus.
Therefore, in the past, the presence or absence of micropipes was inspected to obtain an SiC substrate without micropipes, but this would be very expensive to increase the yield. Furthermore, the inspection is often not complete, and the obtained SiC substrate was mixed with substrates having micropipes. For this reason, an additional sorting step was provided at the stage before epitaxial growth of this SiC substrate, and sorting was performed so that only the substrate without micropipes was used, but there was a problem that the production cost was high. .

Therefore, in order to cope with these problems, for example, in Patent Document 1, the opening of the micropipe defect of the SiC substrate is covered with a coating material, and heat treatment is performed to close the inside of the SiC substrate, thereby removing the coating material. Subsequently, a technique is disclosed in which the micropipe defects existing in the SiC single crystal are closed inside the SiC single crystal by repeating the process of growing the SiC single crystal using the substrate crystal as a seed crystal.
Moreover, in patent document 2, the sublimation gas of SiC sublimated from the vicinity of the high temperature SiC substrate under high temperature of 1800 ° C. moves to the vicinity of the substrate surface at a low temperature through a micropipe defect that is hollow. A technique has been disclosed in which recrystallization occurs in the vicinity and micropipe defects are blocked.
However, the techniques disclosed in Patent Documents 1 and 2 have achieved certain results in terms of blocking the micropipe of the SiC substrate, but require a high temperature environment of about 2000 ° C. There is a problem that the manufacturing cost becomes high because the alignment with the process is difficult, and further, it takes time to manufacture the substrate in the semiconductor manufacturing process.

In Patent Document 3, a GaN single crystal substrate and a Mg-doped Al _x Ga _y In _1-xy N (y> 0) epitaxially grown on one side of the GaN single crystal substrate. A nitride system comprising: one layer; and a second layer made of undoped insulating Al _x Ga _y In _1-xy N (y> 0) epitaxially grown on one side of the first layer A semiconductor epitaxial substrate is disclosed.
Further, in Patent Document 4, a silicon layer is formed on the surface of a single crystal silicon carbide substrate in a CVD apparatus, the silicon layer is melted by heating in an inert atmosphere or a vacuum atmosphere, and the substrate is made of molten silicon. A semiconductor element or the like in which the micropipe is closed is disclosed. Thus, it is described that a semiconductor element and a method for manufacturing the same can be provided without deterioration of element characteristics due to micropipes or dislocations.
However, the techniques disclosed in Patent Documents 3 and 4 have a problem that the manufacturing cost increases because it takes time to manufacture the substrate in the semiconductor manufacturing process.

Japanese Patent Laid-Open No. 2001-158697 JP 2002-179498 A JP 2004-311913 A JP 2004-172556 A

Therefore, the present invention has been made in view of the above problems, and a manufacturing method of an SiC substrate capable of closing a through micropipe, which is a defect existing inside the SiC substrate, by a simple method, and It is an object of the present invention to provide a method for manufacturing a used semiconductor device.
Another object of the present invention is to provide an inexpensive SiC substrate that is highly compatible with existing semiconductor manufacturing processes.

In order to solve the above problems, one aspect of the present invention is that a through micropipe existing in a SiC substrate having a through hole that is a micropipe is sealed or coated with an insulating material or a heat-resistant polymer material. A method of manufacturing an SiC substrate includes a step of sealing by embedding.
In this way, by filling the through-holes existing in the epitaxial substrate with the above-described material, the conventional screening process can be omitted.
Another aspect of the present invention is that the through micropipes present in the SiC substrate having through holes that are micropipes are sealed with an insulating material or a heat-resistant polymer material, or sealed by coating and embedding. It is in the SiC substrate characterized by the above.
By using such a substrate, it is possible to prevent the problem of causing vacuum adsorption failure in a process having vacuum adsorption in the semiconductor manufacturing process. In addition, in the resist coating process, the resist comes off on the back surface of the substrate, and the resist pattern The phenomenon that the opening becomes unstable can be prevented.

According to the present invention, it is possible to provide an SiC substrate manufacturing method and a semiconductor device manufacturing method using the same, which can close through micropipes, which are defects existing inside the SiC substrate, by a simple method.
In addition, it is possible to provide an inexpensive SiC substrate that is highly compatible with existing semiconductor manufacturing processes.

  The best mode for carrying out the present invention will be described below with reference to the drawings. The following description is an example of the best mode of the present invention, and it is easy for a person skilled in the art to make other embodiments within the scope of the claims by making changes and modifications within the scope of the claims. However, this does not limit the scope of the claims.

A silicon carbide (hereinafter simply referred to as “SiC”) single crystal substrate is formed by a sublimation recrystallization method or the like. It is inevitable that micropipe defects penetrating the single crystal SiC substrate formed by the sublimation recrystallization method will occur. It is inevitable that point defects and line defects exist thermodynamically in the single crystal. Among these, there are edge dislocations and screw dislocations as line defects, and in particular, they tend to exist in the C-axis direction in the hexagonal crystal type. Furthermore, since these defects can be gathered to reduce the internal energy, the number of these defects is reduced and becomes larger as a defect. As a result, micropipe defects penetrating through the single crystal SiC substrate exist. Therefore, when the semiconductor element layer is formed on the single crystal SiC substrate by epitaxial growth, the through micropipe is taken over by the epitaxial layer, and the through micropipe is also generated in the epitaxial layer. Therefore, these penetrating micropipes cause a vacuum suction failure in a process having vacuum suction, the resist comes out to the back surface of the substrate, and the opening of the resist pattern becomes unstable, making it difficult to manufacture a semiconductor device. In addition, a defect in the semiconductor element occurs due to an intrusion of impurities such as N ₂ or an intrusion of the electrode material itself by CVD / vacuum evaporation or the like to form a leakage current path.
Therefore, these can be prevented by sealing the back surface of the SiC substrate having through micropipes where the semiconductor elements are not provided and closing the through micropipes. It is preferable to seal the inside of the through micropipe. This is because, even if the surface of the SiC substrate is sealed by applying an insulating material, for example, in order to provide the semiconductor element on the other sealed surface of the SiC substrate, the electrode material is used during the manufacture of the semiconductor element. This is because it may enter the inside and become a leakage current path.

An insulating material is used to seal the through micropipe present on the SiC substrate. The material to be sealed is the back surface of the SiC substrate, and is not the surface on which the semiconductor element is provided. Therefore, the material is not limited as long as the through micropipe can be sealed. However, in order to suppress the occurrence of leakage current, it is preferable to use an insulating material. In addition, it is preferable to use a low dielectric constant material in order to prevent the semiconductor element from being affected by polarization due to the influence of an electric field or current. Furthermore, in the manufacturing process of the semiconductor device described later, since it may be heated up to about several hundreds of degrees Celsius, it is preferable that the viscosity decreases and does not leak out even at this temperature. An insulating material with high heat resistance that does not change quality is used.
Further, the through micropipe has a maximum of about 200 μm, and in order to be embedded and sealed up, a low-viscosity micropipe with good wettability is used. Therefore, the through micropipe of this SiC substrate is sealed with a heat-resistant polymer material whose viscosity is lowered by suspending or dissolving in a solvent. Sealing can block the through micropipe by applying a heat-resistant polymer material to the surface opposite to the surface on which the semiconductor element is provided. For the application, an insulating material is applied by a coating means such as spin coating or spraying. Alternatively, the viscosity may be lowered to flow into a through micropipe on the surface of the SiC substrate, and a heat resistant polymer material may be embedded and sealed.
As the solvent, an organic solvent is preferable because it is evaporated later. For example, hexane, tetrahydrofuran, butyl acetate, hexamethyldisilazane, methyl methacrylate, isopropyl, or the like can be used. In particular, hexane is preferable because it is chemically stable and has a low boiling point.

Examples of the heat-resistant polymer material include spin-on glass (SOG), phosphide oxide film glass (PSG), and boron-doped phosphide oxide film glass (BPSG). The spin-on glass may be either an inorganic or organic silicone resin, and these materials are preferable because of their low dielectric constant. PSG and BPSG are silicone resins, and these are preferable because they have a characteristic that the dielectric constant is low. Silicone resins have high heat resistance when cured, and can be easily applied after being dissolved in a solvent.
Further, the polymer material may contain ceramics such as inorganic oxide, nitride, carbide, etc. as a filler. Examples of the filler include oxides such as alumina, silica, titania, iron oxide, and chromium oxide, nitrides such as boron nitride and alumina nitride, and carbides such as boron carbide and SiC. The ceramic continuous fiber is one in which these fillers having a large aspect ratio are suspended in a solvent together with a silicone resin or the like. In particular, alumina paste is used. As the polymer material, a thermosetting resin such as an epoxy resin or a phenol resin can be used in addition to the silicone resin.

Although the dielectric constant is high, (Ba, Sr) TiO ₃ (BST), SrTiO ₃ (ST), BaTiO ₃ , Ba (Zr, Ti) O ₃ , Ba (Ti, Sn) O ₃ , Pb (Zr, A solution formed by hydrolysis or polycondensation of a plurality of metal alkoxides to form Ti) O ₃ (PZT), (Pb, La) (Zr, Ti) O ₃ (PLZT), or a metal salt such as carboxylic acid You may seal with the solution which melt | dissolved in the organic solvent. This is because they have high electrical resistance and little alteration due to heat.

The SiC substrate is sealed and then sintered. With this heating by sintering, the solvent is first evaporated. The spion glass (SOG) can be sintered by heating at 60 to 800 ° C. In particular, the through micropipe can be sealed from the inside by being sintered after being poured by pouring SOG into the through micropipe. As a result, it is possible to suppress the vacuum adsorption failure, the resist coming out to the back surface of the substrate, the occurrence of leakage current, and the like.
Further, thereafter, the coated and sealed surface of the SiC substrate is polished and flattened. The polishing method is not particularly limited. A CMP (chemical mechanical polishing) method or the like is used.

Next, a semiconductor element is provided on this SiC substrate. Although it does not specifically limit as a semiconductor element, Since adjustment of the electrical resistance of a SiC substrate is possible and its heat conductivity is high, it is effective as a board | substrate of power electronics with high heat generation and a highly integrated circuit. Furthermore, since the SiC substrate has a high saturation electron velocity and a high breakdown voltage, it is suitable for a high electron mobility element (HEMT) or the like.
This semiconductor device includes a HEMT having a carrier travel layer made of a first compound semiconductor on a SiC substrate in which a through micropipe is sealed, and a carrier supply layer made of a second compound semiconductor on the carrier travel layer. Prepare. In this HEMT, a barrier is formed at a junction having different band gaps at the interface between the carrier running layer and the carrier supply layer that are heterojunction, and a two-dimensional electron gas is formed at the junction interface in a thermal equilibrium state. Then, by applying a bias voltage of a predetermined value between the source electrode and the drain electrode provided on the carrier supply layer, electrons are supplied and supplied from the carrier supply layer to the carrier traveling layer located therebelow. Electrons form a two-dimensional electron gas layer at the junction interface, and the electrons flow at high speed to the drain electrode while being confined in the carrier traveling layer.
For this purpose, a so-called III-V compound semiconductor such as GaAs, GaAlAs, InGaAs, InAlAs or the like, or a GaN-based GaN-based semiconductor is used as a carrier traveling layer on the SiC substrate. A carrier supply layer serving as a barrier is formed thereon with a material having a larger band gap than the material used for the carrier traveling layer. As the carrier supply layer, a so-called III-V group compound semiconductor such as GaAs or an AlGaN-based semiconductor is used. In particular, since a GaN-based semiconductor has a large band gap and a high breakdown voltage, it is preferable to form the carrier travel layer from GaN and the carrier supply layer from AlGaN.
The semiconductor device using the HEMT is excellent in high speed / high frequency operation characteristics, low noise characteristics, and the like, and can be a high output amplifier such as a microwave device.

In the HEMT provided in the semiconductor device of the present invention, a source electrode and a drain electrode are provided on a carrier supply layer, and an insulating layer is provided between the source electrode and the drain electrode, and the source metal electrode and the drain metal electrode serve as the carrier supply layer. Make an ohmic connection. Such a HEMT also has high parasitic resistance as well as high contact resistance between the source and drain metal electrodes and the carrier generation layer as miniaturization progresses. For this purpose, the source electrode and the drain electrode are brought close to each other, and an insulating layer is provided therebetween to suppress the occurrence of leakage current. As the insulating material, oxides such as silicon oxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ), and nitrides such as silicon nitride (SiN) can be used. In particular, SiN is preferable because the change in electric resistance with respect to temperature is small. Further, Ti, Al, Mo, W, or the like is used as a metal film as a source electrode and a drain electrode.
In addition, in order to make the source metal electrode and the drain metal electrode ohmic-connect to the carrier supply layer, the source / drain electrode is formed on the carrier supply layer, the gate electrode is formed, and then the source / drain ohmic connection is made. Heat treatment for forming is performed. Further, after forming a silicon oxide film on the metal thin film of the electrode, a heat treatment for forming an ohmic connection may be performed.
Thus, the semiconductor device of the present invention can be provided with a HEMT that can move electrons at a higher speed by reducing the gate length and reducing the parasitic component between the electrode and the carrier supply layer. .

Hereinafter, a semiconductor device provided with a HEMT using a SiC substrate will be described in detail.
First, the manufacturing process of the HEMT epitaxial substrate of the present invention will be described as a first stage.
FIG. 1 is a cross-sectional view of an HEMT epitaxial substrate according to the present invention. This is an epitaxial substrate in which GaN and AlGaN are stacked on a semi-insulating SiC substrate 1. An i-type GaN electron transit layer 2 having a thickness of, for example, 3 μm is epitaxially grown on the SiC substrate 1 by, for example, a MOCVD (Metal Organic Chemical Vapor Deposition) method. For example, an i-type AlGaN spacer layer 3 having a thickness of, for example, 2 nm, an n-type AlGaN electron supply layer 4 having a thickness of, for example, 25 nm and Si introduced as a dopant impurity, and a thickness of, for example, 5 nm, Si being introduced as a dopant impurity The n-type GaN protective layer 5 is sequentially deposited to complete the epitaxial substrate.
Here, the n-type GaN protective layer 5 is not necessarily required, but can reduce the tunnel current to the gate electrode and improve the breakdown voltage. In this case, an i-type AlGaN protective layer may be used instead of the n-type GaN protective layer 5, but the n-type GaN protective layer 5 can further improve the conduction performance and the like.
Conventionally, after this, an insulating film is formed to form a source / drain region, a gate electrode, and the like, but at this stage, the micropipe existing on the epitaxial substrate has not been closed yet, and the semiconductor manufacturing process remains as it is. When proceeding, the above-described problems occur.

Next, as a second stage, a process of closing a micropipe existing on an epitaxial substrate having SiC as a base substrate will be described.
FIG. 2 is a diagram illustrating a process of closing the micropipe of the epitaxial substrate. As shown in FIG. 2A, in the epitaxial substrate in which GaN and AlGaN are stacked on the SiC substrate, the micropipe is present in the Gan / AlGaN layer epitaxially grown.
First, an insulating film 22 is formed on the surface of the epitaxial substrate 20 on which GaN and AlGaN are stacked, that is, on the surface of the uppermost n-type GaN protective layer 5, and the surface is protected as shown in FIG. To do. The insulating film 22 can be formed by a thermal oxidation method, and an insulator of a metal or a plurality of metal oxides, nitrides, or oxynitrides is used. Specifically, SiN, SiO ₂ , SiON or the like can be used.

Next, as shown in FIG. 2C, a high heat-resistant material 23 is applied and sintered at about 500 ° C. in order to fill the micropipe from the back surface (SiC substrate 1 surface) of the epitaxial substrate 20. By using the high heat-resistant material 23, it is not affected by heat in the subsequent semiconductor manufacturing process, and peeling or the like can be prevented.
Next, as shown in FIG. 2D, the back surface, which is the SiC substrate surface sintered using CMP (Chemical Mechanical Polishing) or the like, is polished and flattened.
Next, as shown in FIG. 2E, the insulating substrate on the GaN surface is removed by etching, and an epitaxial substrate 30 in which a micropipe that can be vacuum-adsorbed and does not allow water, chemicals, etc. to escape to the back surface is closed. It ’s done.

Next, as a third stage, an electrode or the like is formed on the epitaxial substrate 30 whose back surface is closed.
FIG. 3 is a diagram showing a manufacturing process of the HEMT according to the present invention. FIG. 3A shows the epitaxial substrate 30 manufactured in the first stage. On the epitaxial substrate 30, as shown in FIG. 3B, a SiN film 31 having a thickness of, for example, 20 nm is deposited on the entire surface of the n-type GaN protective layer 5 by CVD.
Next, as shown in FIG. 3C, a gate electrode made of Ni / Au is formed by providing an opening in the gate formation region, and a source electrode made of Ti / Au by providing an opening in the source / drain region. Then, the basic shape of the GaN-based HEMT is completed by forming the drain electrode.
The above is described as a single HEMT, but it is also possible to integrate by element isolation by ion implantation or mesa etching.
Conventionally, since an epitaxial substrate in which the micropipe is not blocked was used, a phenomenon that the resist escaped to the back surface of the epitaxial substrate in the photoresist coating process was seen, but by using the epitaxial substrate of the present invention, Such a phenomenon can be prevented. Further, in a semiconductor manufacturing apparatus using vacuum suction, it is possible to prevent suction failure.
Further, by closing micropipes existing in an epitaxial substrate having a semi-insulating SiC substrate as a base substrate by a simple method, the conventional sorting process can be omitted, and the existing semiconductor manufacturing process It is possible to provide an HEMT epitaxial substrate with high consistency and low cost.

The above has described the semiconductor device using the nitride semiconductor epitaxial layer on the SiC substrate, but the same applies to the semiconductor device using the SiC epitaxial layer on the SiC substrate.
FIG. 4 shows an epitaxial substrate having a SiC epitaxial layer on the SiC substrate according to the present invention. On the ^{n +} -type substrate 11 made of SiC is, n of SiC ^- -type epitaxial layer 12 is formed, n ^- -type epitaxial layer 12 the high heat-resistant material 23 to the n ⁺ -type substrate 11 of the surface different from the that Embedded. By using this epitaxial substrate 40, it can be applied to a high breakdown voltage semiconductor device such as a MOSFET or a Schottky barrier diode.

As SiC, a SiC bulk single crystal is grown on a seed crystal by sublimating a raw material at a temperature of 2000 ° C. or higher. Usually, the {0001} plane orientation is used as the seed crystal, but other plane orientations may be used as the seed crystal. Also, N atoms from nitrogen gas are used as impurities for n-type, and Al atoms from trimethylaluminum (TMA) and B atoms from B ₂ H ₆ are used for p-type. Electric resistance can be controlled. Here, in particular, a semiconductor device capable of high withstand voltage, low loss, and high temperature operation can be manufactured by using it in a semi-insulating state without doping atoms or the like.

The above is the description according to the embodiment of the present invention. As the invention, for example, the following features can be extracted, and are listed here.
(Additional remark 1) The silicon carbide (SiC) board | substrate which has a penetration micropipe for providing a semiconductor element, The said SiC substrate is a SiC substrate by which the penetration micropipe is sealed with the insulating material.
(Additional remark 2) The SiC substrate of Additional remark 1 WHEREIN: The said SiC substrate is sealed by apply | coating and embedding an insulating material to a penetration micropipe, The SiC substrate characterized by the above-mentioned.
(Supplementary note 3) The SiC substrate according to supplementary note 1, wherein the SiC substrate is sealed with a heat-resistant polymer material suspended or dissolved in a solvent.
(Additional remark 4) The SiC substrate of Additional remark 1 WHEREIN: The said SiC substrate is sealed with the heat resistant polymer material which contained the filler and was suspended or dissolved in the solvent, The SiC substrate characterized by the above-mentioned.
(Supplementary note 5) The SiC substrate according to supplementary note 1, wherein the SiC substrate is sealed with a material containing a metal salt or metal alkoxide suspended or dissolved in a solvent.
(Supplementary note 6) The SiC substrate according to supplementary note 1, wherein the SiC substrate is sintered after sealing the through micropipe.

(Additional remark 7) In the manufacturing method of the SiC substrate which has a penetration micropipe for providing a semiconductor element, the manufacturing method of the SiC substrate includes a sealing step of sealing the penetration micropipe from the back surface of the SiC substrate, and sealing A method of manufacturing a SiC substrate, comprising a sintering step of sintering after the step.
(Additional remark 8) The manufacturing method of the SiC substrate of Additional remark 7 WHEREIN: The manufacturing method of the said SiC substrate has the process of grind | polishing the SiC substrate surface after a sintering process, The manufacturing method of the SiC substrate characterized by the above-mentioned.
(Additional remark 9) The manufacturing method of the SiC substrate of Additional remark 7 WHEREIN: The manufacturing method of the said SiC substrate is sealed with the material in any one of Claim 3 thru | or 5 in the sealing process, It is characterized by the above-mentioned. A method for manufacturing a SiC substrate.

(Appendix 10) In a semiconductor device in which a semiconductor element is provided on a SiC substrate having a through micropipe, the semiconductor device is sealed after sealing the through micropipe from the back surface of the SiC substrate with an insulating material. A semiconductor device having a SiC substrate, having a semiconductor element provided on the other surface of the SiC substrate after sintering, and a carrier running layer made of a first compound semiconductor on the SiC substrate, and the carrier running layer A semiconductor device comprising a high electron mobility element having a carrier supply layer made of a second compound semiconductor on the substrate.
(Supplementary note 11) The semiconductor device according to supplementary note 10, wherein the carrier travel layer is formed of GaN and the carrier supply layer is formed of AlGaN.
(Supplementary note 12) The semiconductor device according to supplementary note 10, wherein the semiconductor device has a source electrode, a drain electrode, and a gate electrode on the carrier supply layer.
(Supplementary note 13) In a semiconductor device in which a semiconductor element is provided on a SiC substrate having a through micropipe, the semiconductor device is sealed after sealing the through micropipe with an insulating material from the back surface of the SiC substrate. A semiconductor device having a SiC substrate, having a semiconductor element provided on another surface of the SiC substrate after sintering, and having a SiC layer on the SiC substrate.

(Additional remark 14) In the manufacturing method of the semiconductor device which provides a semiconductor element on the SiC substrate which has a penetration micropipe, the manufacturing method of the said semiconductor device includes a sealing process which seals a penetration micropipe from the back of a SiC substrate, and sealing A method for manufacturing a semiconductor device, comprising: a sintering step for sintering after the stopping step, and thereafter providing a semiconductor element on the other surface of the silicon carbide substrate.
(Additional remark 15) The manufacturing method of the semiconductor device of Additional remark 14 WHEREIN: The manufacturing method of the said semiconductor device has the process of grind | polishing the SiC substrate surface, The manufacturing method of the semiconductor device characterized by the above-mentioned.
(Additional remark 16) In the manufacturing method of the semiconductor device according to Additional remark 14, the manufacturing method of the semiconductor device further includes a carrier traveling layer made of a first compound semiconductor on the other surface of the SiC substrate, and a channel layer. A method of manufacturing a semiconductor device, comprising: providing a high electron mobility element having a carrier supply layer made of a second compound semiconductor thereon.
(Supplementary Note 17) In the method of manufacturing a semiconductor device according to Supplementary Note 14, in the high electron mobility element, a carrier travel layer is formed of GaN and a carrier supply layer is formed of AlGaN. Manufacturing method.
(Supplementary note 18) In the semiconductor device manufacturing method according to supplementary note 14, the semiconductor device manufacturing method includes providing a source electrode, a drain electrode, and a gate electrode on a carrier supply layer. Method.
(Supplementary note 19) The semiconductor device manufacturing method according to supplementary note 14, wherein the semiconductor device manufacturing method includes providing a SiC layer on the SiC substrate.

It is a figure which shows the epitaxial substrate which concerns on this invention. It is a figure which shows the manufacturing process of the epitaxial substrate which concerns on this invention. It is a figure which shows the manufacturing process of HEMT which concerns on this invention. It is an epitaxial substrate which has a SiC epitaxial layer on the SiC substrate which concerns on this invention.

Explanation of symbols

1 SiC substrate 2 i-type GaN electron transit layer 3 i-type AlGaN spacer layer 4 n-type AlGaN electron supply layer 5 n-type GaN protective layer 11 ^{n +} -type SiC substrate 12 n ^- type SiC epitaxial layer 20 epitaxial substrate (pre-occlusion process)
21 Micropipe (through hole)
22 Insulating film 23 High heat resistant material 30 Epitaxial substrate (after clogging)
31 SiN film 32 Source electrode 33 Drain electrode 34 Gate electrode 40 Epitaxial substrate (after closing process)

Claims (11)

In a silicon carbide (SiC) substrate on which a semiconductor element is provided,
From the back surface is not arranged semiconductor elements, penetrating to micropipe, sealed by embedding a polymeric insulating material suspended or dissolved in Solvent, it has been sintered after sealing, and a flat SiC substrate characterized by being made. The SiC substrate according to claim 1,
The SiC insulating material, wherein the polymer insulating material is a silicone-based resin. In a manufacturing method of a SiC substrate for manufacturing a silicon carbide (SiC) substrate on which a semiconductor element is provided,
A film forming step of forming an insulating film on the front side surface on which the semiconductor element of the SiC substrate is disposed;
The surface of the back side is not arranged the semiconductor element of the SiC substrate, a polymeric insulating material suspended or dissolved in a solvent and applied to the through micropipe, and a sealing step of sealing crowded padded,
A sintering step of sintering after the sealing step;
And a flattening step of polishing and flattening after the sintering step. In the manufacturing method of the SiC substrate according to claim 3,
A method of manufacturing a SiC substrate, comprising polishing and removing the insulating film formed in the film forming step. In the manufacturing method of the SiC substrate according to claim 3 or 4,
The method for manufacturing a SiC substrate, wherein the polymer insulating material is a silicone-based resin. In a semiconductor device in which a semiconductor element is provided on a SiC substrate,
The semiconductor device includes:
A SiC substrate that is sealed with a polymer insulating material suspended or dissolved in a solvent from the back side surface where no semiconductor element is provided to the through micropipe, and then sealed, and on the front side surface A semiconductor device provided with a semiconductor element,
A high electron mobility element having a carrier running layer made of a first compound semiconductor on the SiC substrate and a carrier supply layer made of a second compound semiconductor on the carrier running layer is provided. Semiconductor device. The semiconductor device according to claim 6.
The semiconductor device, wherein the carrier travel layer is made of GaN, and the carrier supply layer is made of AlGaN. The semiconductor device according to claim 7,
The semiconductor device has a source electrode, a drain electrode, and a gate electrode on the carrier supply layer. In a manufacturing method of a semiconductor device for manufacturing a semiconductor device in which a semiconductor element is provided on a SiC substrate,
  A SiC substrate that is sealed with a polymer insulating material suspended or dissolved in a solvent from the back side surface where no semiconductor element is provided to the through micropipe, and then sealed, and on the front side surface A method of manufacturing a semiconductor device in which a semiconductor element is provided,
  A high electron mobility element having a carrier running layer made of a first compound semiconductor on the SiC substrate and a carrier supply layer made of a second compound semiconductor on the carrier running layer is provided.
  A method for manufacturing a semiconductor device. In the manufacturing method of the semiconductor device according to claim 9,
The method of manufacturing a semiconductor device, wherein the carrier travel layer is formed of GaN and the carrier supply layer is formed of AlGaN . In the manufacturing method of the semiconductor device according to claim 10,
A method for manufacturing a semiconductor device, comprising: a source electrode, a drain electrode, and a gate electrode on the carrier supply layer .

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