Separable semiconductor substrate made of polycrystalline silicon carbide

Abstract

The invention relates to an intermediate substrate (10) for producing a semiconductor substrate, comprising, in order: a. A first semiconductor layer (2); b. A first thermal barrier layer (5); c. A support (13) comprising an absorbing layer (3) configured to absorb laser radiation in a given wavelength range, the temperature of the absorbing layer (3) increasing as it absorbs laser radiation, and a separation zone (8) adjacent to the absorbing layer (3) and configured to be thermally degraded due to an increase in the temperature of the absorbing layer, in this way, at least a part of the support body (13) is separated from the rest of the intermediate substrate (10).

Description

TECHNICAL FIELD

[0001] The present invention relates to the manufacturing of semiconductor substrates, and more particularly to the manufacturing of a polycrystalline silicon carbide support layer for high performance substrates. BACKGROUND

[0002] In the field of power electronics, it is known to use wide band semiconductor materials. These materials have a wider band gap than semiconductor materials such as silicon, which confers to them an electrical insulation performance intermediate between that of semiconductors and insulators. In particular, wide band semiconductors have the advantage of being able to withstand higher temperatures than traditional semiconductors. Furthermore, these materials have a higher power density than traditional semiconductors, making it possible to save volume and weight in electronic systems containing them.

[0003] A commonly used wide band semiconductor material is silicon carbide (SiC). In order to produce power electronic components, in particular metal oxide semiconductor field effect transistors (or MOSFETs), it is necessary to provide SiC substrates having a specific thickness, generally of the order of 300 microns, in order to provide them with a mechanical strength that enables the front-end processes to be performed (i.e. the formation of the electronic functions on the semiconductor substrate). The semiconductor substrate thus obtained is then placed on a metal support (in particular a metal support made of copper) having a Young's modulus and a coefficient of thermal expansion different from those of the semiconductor substrate. Consequently, mechanical stresses can be generated in the semiconductor substrate during the thermal cycles to which the semiconductor substrate is subjected on the metal support. One way of overcoming this problem is to reduce the thickness of the SiC layer, which is only possible after the front-end processes have been performed.

[0004] To this end, a SiC substrate having a given thickness close to 300 microns can be formed before mechanically etching a portion thereof to reduce its thickness, thus reducing the mechanical stresses exerted on the metal support or on any solder joint between the metal support and the SiC substrate during the use and thermal cycles of the electronic component. Furthermore, reducing the thickness of the SiC substrate in this way makes it possible to reduce its on-resistance and thermal resistance, resulting in better electrical performance, and to bring the Young's modulus and the coefficient of thermal expansion of the SiC substrate closer to those of the metal substrate.

[0005] However, due to the hardness of SiC, mechanical etching is relatively expensive and difficult to implement, and the remaining portion of the substrate can not be perfectly flat. Therefore, it is necessary to establish methods to obtain thin semiconductor substrates having a uniform flatness, while reducing the costs and time required to implement these methods. SUMMARY

[0006] The object of the present invention is to overcome the aforementioned drawbacks.

[0007] To this end, according to a first aspect of the application, an intermediate substrate for manufacturing a semiconductor substrate is proposed, the intermediate substrate comprising in order: a. a first semiconductor layer; b. a first thermal barrier layer; c. a support body comprising an absorption layer configured to absorb laser radiation in a determined wavelength range, wherein the temperature of the absorption layer increases during absorption, and a separation zone adjacent to the absorption layer and configured to thermally deteriorate under the effect of the temperature increase of the absorption layer to separate at least a portion of the support body from the rest of the intermediate substrate.

[0008] Thus, once the front-end process has been completed, the application enables the semiconductor substrate to be separated into two distinct parts without mechanical etching, so that only the semiconductor layer of the desired thickness is retained before integrating it into the metallic support body, without compromising the flatness of the semiconductor layer. The separation of the semiconductor substrate into two parts with a laser enables the substrate of the desired thickness to be separated more quickly and at a lower cost than mechanical etching. The use of a thermal barrier layer limits the propagation of heat to the rest of the substrate, thus facilitating separation with reduced laser power and / or exposure time.

[0009] According to one embodiment, the support body comprises: a. a separation assembly comprising: i. an absorption layer; and ii. a separation layer adjacent to the absorption layer and comprising a separation zone, wherein the separation zone deteriorates when the absorption layer reaches a threshold temperature; b. a second thermal barrier layer; c. a support layer; wherein the second thermal barrier layer is located between the separation assembly and the support layer.

[0010] According to one embodiment, the support body comprises: a. an absorption layer; and b. a support layer further forming a second thermal barrier; wherein the separation zone is comprised in the support layer.

[0011] According to one embodiment, the substrate further comprises a seed layer adapted to grow the first semiconductor layer, wherein the seed layer preferably comprises graphite, the first semiconductor layer being interposed between the seed layer and the first thermal barrier layer.

[0012] According to one embodiment, the separation layer is made of silicon nitride.

[0013] According to one embodiment, the absorption layer is made of a material chosen from the group consisting of beta-SiC type polycrystalline silicon carbide, titanium or zirconium nitride.

[0014] According to one embodiment, the substrate further comprises a monocrystalline semiconductor layer, preferably comprising silicon carbide or gallium nitride, wherein a first surface of the monocrystalline semiconductor layer is adjacent to the first semiconductor layer.

[0015] According to one embodiment, the first semiconductor layer is made of a wide band semiconductor material, in particular a material selected from the group consisting of silicon carbide, aluminum nitride and gallium nitride.

[0016] According to one embodiment, the support layer is a second semiconductor layer having a lower mass than the first semiconductor layer, preferably made of a material selected from the group consisting of silicon carbide and silicon nitride.

[0017] According to one embodiment, the support layer has a thickness comprised between 100 nanometers and 200 nanometers.

[0018] According to one embodiment, the first and / or the second thermal barrier layer has a thermal conductivity lower than 25 W / mK, wherein the second thermal barrier layer is preferably made of titanium dioxide or silicon nitride.

[0019] According to one embodiment, the substrate further comprises a monocrystalline semiconductor layer arranged on a surface region of the first semiconductor layer, wherein the first semiconductor layer is located between the first thermal barrier layer and the monocrystalline semiconductor layer.

[0020] Another aspect of the application relates to a method for manufacturing an intermediate semiconductor substrate, comprising successively the following steps: a. growing a first electrical semiconductor layer on a seed layer; b. growing a first thermal barrier layer on the first semiconductor layer; c. growing a support on the first thermal barrier layer, the support comprising an absorption layer configured to absorb laser radiation in a determined wavelength range, wherein, in the course of the absorption, the temperature of the absorption layer increases, the support further comprising a separation zone adjacent to the absorption layer and configured to thermally deteriorate under the effect of the temperature increase of the absorption layer, so as to separate at least a portion of the support from the rest of the intermediate substrate; d. removing the seed layer; wherein the growth steps are obtained in particular by vapor deposition on the previously formed layers.

[0021] According to one implementation of the method, the growing of the support comprises the following successive steps: a. growing a separation assembly composed of an absorption layer and a separation layer, wherein the growing of the separation assembly comprises: - growing the absorption layer; - growing the separation layer, wherein the separation layer comprises the separation zone, the separation zone being adjacent to the absorption layer; b. growing a second thermal barrier layer on the separation assembly; c. growing a support layer on the second thermal barrier layer; The growth step is achieved, in particular, by vapor deposition on a previously formed layer.

[0022] According to one implementation of this method, the growth of the support structure includes the following sequential steps: a. Growing an absorption layer on the first thermal barrier layer; b. A support layer is grown on the absorbent layer, the support layer also serving as a second thermal barrier; The separation zone is included in the support layer; The growth step is achieved, in particular, by vapor deposition on a previously formed layer.

[0023] Another aspect of the invention relates to a method for manufacturing a substrate comprising a single-crystal semiconductor layer on a polycrystalline semiconductor substrate, the method comprising performing the method for manufacturing an intermediate semiconductor substrate as defined above, wherein the first semiconductor layer is polycrystalline. And it further includes the following sequential steps: a. Forming a weakened region in a semiconductor donor substrate by implanting species to define the single-crystal semiconductor layer to be transferred; b. Bond the single-crystal semiconductor layer to be transferred to the surface region of the first semiconductor layer; c. Separate the donor substrate along the weakened region to transfer the single-crystal semiconductor layer onto the first semiconductor layer.

[0024] Another aspect of the present invention relates to a method for manufacturing electronic components, comprising the following sequential steps: a. Perform the method for manufacturing a substrate as defined above; b. Perform front-end processes in a single-crystal semiconductor layer to form the electronic component.

[0025] According to one implementation, the method includes the step of applying laser radiation to an intermediate substrate within a defined wavelength range after the front-end process is completed, so as to thermally degrade the separation region and separate at least a portion of the support from the remainder of the intermediate substrate.

[0026] According to one implementation, the method includes the step of removing a residual layer on the surface of a first semiconductor layer opposite to the single-crystal semiconductor layer after applying laser radiation, wherein the residual layer originates from the step of applying laser radiation.

[0027] Another aspect of the present invention relates to an intermediate substrate for manufacturing a semiconductor substrate, comprising, in sequence: - A first semiconductor layer made of polycrystalline silicon carbide (pSiC); - The first thermal barrier layer is made of titanium dioxide (TiO2); - An absorber layer made of 3C-type polycrystalline silicon carbide (3C-pSiC); - Separation layer made of silicon nitride (Si3N4); - A second thermal barrier layer made of titanium dioxide (TiO2); - A support layer made of 4H-type polycrystalline silicon carbide (4H-pSiC).

[0028] Another aspect of the present invention relates to an intermediate substrate for manufacturing a semiconductor substrate, comprising, in sequence: - A first semiconductor layer made of polycrystalline silicon carbide (pSiC); - The first thermal barrier layer is made of titanium dioxide (TiO2); - An absorber layer made of titanium nitride (TiN); - Separation layer made of silicon nitride (Si3N4); - A second thermal barrier layer made of titanium dioxide (TiO2); The support layer is made of 4H-type polycrystalline silicon carbide (4H-pSiC). Attached Figure Description

[0029] Further features, objects, and advantages of the invention will become apparent from the following description, which is purely illustrative and non-limiting and should be read with reference to the accompanying drawings, wherein: Figure 1 , Figure 2 , Figure 3 and Figure 4 An intermediate substrate for manufacturing a semiconductor substrate is schematically shown according to various embodiments of the first aspect of the invention; Figure 5 , Figure 6 and Figure 7 Methods for manufacturing an intermediate substrate for subsequent manufacturing of a semiconductor substrate are shown according to various embodiments of the second aspect of the invention; Figure 8 A method for fabricating a substrate comprising a single-crystal semiconductor layer on a polycrystalline semiconductor substrate is shown according to a third aspect of the present invention; Figure 9 A method for manufacturing electronic components according to a fourth aspect of the present invention is shown; Figure 10 , Figure 11 and Figure 12 The results of a simulation of the temperature change of the intermediate substrate when laser radiation is applied are shown.

[0030] Throughout the accompanying drawings, similar elements use the same reference numerals. Detailed Implementation

[0031] According to a first aspect of the invention, Figure 1 The diagram shows an intermediate substrate 10. It comprises an arrangement of layers that can be sequentially formed from the graphite seed layer 1. The formation of the various layers of the intermediate substrate 10 may involve the sequential implantation of gases that enable condensation deposition.

[0032] The first layer formed is a first "high-quality" semiconductor layer 2, configured to support the layer that will form the component (particularly for manufacturing power electronic components). The first semiconductor layer 2 is intended to remain in the final electronic component. The first semiconductor layer 2 can be a polycrystalline silicon carbide layer, particularly of the 4H or 3C type (also known as β-pSiC). Alternatively, depending on the application, it can be made of 4H-type single-crystal silicon carbide. The first semiconductor layer 2 can also be made of another wide-bandgap semiconductor material, such as aluminum nitride (AlN) or gallium nitride (GaN).

[0033] In some implementations, the first semiconductor layer 2 is further configured to conduct current. In particular, the first semiconductor layer 2 is doped.

[0034] When the first semiconductor layer 2 is made of silicon carbide, it can be highly nitrogen-doped (N++ doping). N-type doping with phosphorus or P-type doping with gallium or aluminum can also be considered. This doping provides the first semiconductor layer 2 with very low resistivity and high thermal conductivity approaching that of solid silicon carbide. However, when the first semiconductor layer 2 is formed of other materials, other forms of doping can be considered: for example, for a first semiconductor layer 2 made of gallium nitride (GaN), silicon or magnesium doping can be used. To minimize the resistance of the first semiconductor layer 2, a thickness between 10 µm and 300 µm is advantageous, preferably less than 100 µm.

[0035] However, the intermediate semiconductor substrate must have sufficient mechanical strength to withstand the front-end processes applied to it. To this end, the intermediate substrate 10 includes a support 13 with a thickness configured to provide a given mechanical strength to the substrate 10, for example, between approximately 100 µm and 400 µm.

[0036] Depending on the possible variations, the first semiconductor layer 2 may also be undoped or even electrically insulating (e.g., in the case of a silicon carbide layer, by vanadium doping).

[0037] The support 13 includes an absorption layer 3 and a separation region 8 adjacent to the absorption layer. The absorption layer 3 is configured to absorb laser radiation within a defined wavelength range, thereby increasing its temperature.

[0038] The wavelength range of the laser radiation is selected such that the seed layer 1 and the first thermal barrier layer 5 (described below) are substantially transparent to the radiation, so as to ensure that a sufficient portion of the radiation reaches the absorption layer 3 and prevents the radiation from damaging these layers.

[0039] The temperature rise caused by the absorption of laser radiation by the absorption layer 3 degrades the separation region 8, thereby enabling the intermediate substrate 10 to be separated into two parts. Therefore, an intermediate substrate can be fabricated, and front-end processes can then be performed from the semiconductor layer 2, wherein the total thickness of the intermediate substrate 10 provides it with sufficient mechanical strength to prevent damage from these processes. Finally, a laser can be applied within a defined wavelength range to separate the thin portion of the substrate, including the first semiconducting layer 2, from the remainder of the substrate 10 without resorting to mechanical polishing or grinding, which could damage the first semiconductor layer 2 and would be more time-consuming and expensive.

[0040] The absorber layer 3 can be made of a material selected from β-SiC type polycrystalline silicon nitride, titanium nitride (TiN), or zirconium (Zr). When it is made of β-SiC, the absorber layer 3 can be configured to absorb laser radiation with wavelengths between 380 nm and 410 nm. Titanium nitride has the advantage of being able to absorb a wider range of radiation wavelengths, so when the absorber layer is made of this material, it can be configured to absorb laser radiation with wavelengths between 380 nm and 1.7 μm. Silicon carbide itself has the advantage of being a material that can be used to manufacture the first semiconductor layer 2, so no new chemical elements are introduced during the manufacture of the intermediate substrate 10.

[0041] The intermediate substrate further includes a first thermal barrier layer 5 interposed between the first semiconductor layer 2 and the support 13. This layer is configured to form a thermally conductive barrier between the absorption layer 3 and the first semiconductor layer 2, thereby limiting the temperature rise of the first semiconductor layer as much as possible. In fact, the first thermal barrier layer 5 is configured to have a lower thermal conductivity than the first semiconductor layer 2; therefore, without the first thermal barrier layer 5, the temperature of the first semiconductor layer 2 would rise. Nevertheless, the first semiconductor layer 2 must have a low absorption coefficient in the wavelength range used for laser radiation (e.g., between 380 nm and 410 nm) so that it does not absorb radiation used to heat the absorption layer 3.

[0042] according to Figure 2 In one embodiment shown, the support 13 includes a separation assembly 12, which includes an absorption layer 3 on one side and a separation layer adjacent to the absorption layer, called a sacrificial separation layer 4, which includes a separation region 8 on the other. The separation layer 4 is configured such that when the absorption layer 3 reaches a threshold temperature, the separation region 8 deteriorates, thereby enabling precise control of separation from the intermediate substrate 10. The separation assembly 12 is disposed between a first thermal barrier layer 5 and a second thermal barrier layer 6. Finally, the second thermal barrier layer 6 is adjacent to the support layer 7 on its side opposite to the separation assembly. The two thermal barriers 5 and 6 limit temperature rise to the separation assembly, so that only the separation assembly experiences a significant temperature rise, allowing the substrate to separate into two parts along the separation region 8 without deteriorating the rest of the substrate 10.

[0043] When the absorption coefficients of the absorption layer 3 and the separation layer 4 at the expected wavelength of the laser radiation are permissible, the absorption layer 3 can be arranged closer to the first thermal barrier layer 5 within the separation assembly 12, such as... Figure 2 As shown, or alternatively, the separation layer 4 can be arranged closer to the first thermal barrier layer 5. In other words, the absorption coefficients of the absorption layer 3 and the separation layer 4 must allow the absorption layer 3 to be heated, and the separation region 8 of the separation layer 4 can be degraded depending on the arrangement of the two layers 3 and 4 selected in the separation assembly 12.

[0044] The wavelength range of the laser radiation is selected such that the second thermal barrier layer 6 and the support layer 7 are substantially transparent to the radiation, so as to prevent the radiation from damaging these layers.

[0045] Advantageously, the separation layer 4 is very thin, for example, less than 100 micrometers thick, to avoid weakening the intermediate substrate before separation. Providing a thin separation layer 4 also allows for a limitation on the cost of manufacturing this layer. A thick separation layer 4 is not necessary, as it is not intended to contribute to the mechanical strength of the substrate. This layer can be made of silicon nitride (chemical formula Si3N4).

[0046] The thermal conductivity of thermal barrier layers 5 and 6 can be less than 25 W / mK, preferably less than 10 W / mK. In particular, they can be made of titanium dioxide (TiO2) or silicon nitride (Si3N4).

[0047] The primary function of the support layer 7 is to increase the thickness of the intermediate substrate 10 to provide it with suitable mechanical strength for front-end processes. Specifically, the semiconductor properties of this layer are not critical. Therefore, minimizing the cost of this layer is advantageous. Consequently, the quality of the support layer 7 is preferably lower than that of the first semiconductor layer 2: in particular, the thermal resistivity and resistivity of the support layer 7 are higher than those of the first semiconductor layer 2. For example, the resistivity of the first semiconductor layer 2 is less than 5 mΩ / cm, while the resistivity of the support layer 7 is greater than 5 mΩ / cm.

[0048] The support layer 7 can be made of 4H-SiC type polycrystalline silicon carbide or silicon nitride (Si3N4). Its thickness can be between 100 nanometers and 200 nanometers. In addition, like the first semiconductor layer 2, it is advantageous for the support layer 7 to have a low absorption coefficient in the wavelength range used for laser radiation, so that it will not absorb radiation used to heat the absorption layer 3.

[0049] Figure 3Another embodiment is shown. According to this embodiment, the intermediate substrate 10 does not include a second thermal barrier 6. In this case, the support layer 7 is made of a material with a low absorption coefficient (i.e., transparent to the wavelength of the laser radiation used) and low thermal conductivity. For example, this could be silicon nitride (Si3N4). Therefore, a second thermal barrier layer 6 is unnecessary because the support layer 7 is not at risk of radiation damage. Furthermore, the coefficient of thermal expansion of silicon nitride is substantially close to that of polycrystalline silicon carbide, thus not introducing additional mechanical stress compared to the aforementioned embodiment. This method has the advantages of compatibility with the methods used to manufacture layer 2 (silicon and nitrogen in the deposition reactor) and simplification of layer stacking compared to the aforementioned embodiment.

[0050] according to Figure 4 In one embodiment shown, the intermediate substrate 10 includes a single-crystal semiconductor layer 14, the first surface of which is adjacent to the first semiconductor layer 2 on the side opposite to the first thermal barrier layer 5. The single-crystal semiconductor layer may include silicon carbide or gallium nitride (GaN).

[0051] A second aspect of the invention relates to a method for manufacturing the intermediate semiconductor substrate 10 as described above. The method includes several stages of layer growth, preferably achieved by sequentially depositing gases on previously formed layers. However, other deposition methods known to those skilled in the art fall within the scope of the invention: for example, liquid phase epitaxy, molecular jet epitaxy, or cathode sputtering. Advantageously, all successive layers can be deposited in the same housing using the same deposition method.

[0052] refer to Figure 5 The first step 101 involves growing a high-quality first semiconductor layer 2 on the seed support 1. The method then includes growing a first thermal barrier layer 5 102 on the first semiconductor layer 2, and then growing a support 13 103 on the first thermal barrier layer 5. Finally, once these three growth steps are completed, the method includes removing the seed layer 104, particularly by grinding or mechanical polishing. The substrate 13 includes an absorption layer 3 and a separation region 8 adjacent to the absorption layer. As described with respect to an intermediate substrate 10 according to a first aspect of the invention, the absorption layer 3 is configured to absorb light radiation within a given wavelength range, and the temperature of the absorption layer 3 increases due to radiation. The separation region 8 is configured to weaken and separate under heating, thereby allowing at least a portion of the support 13 to be separated from the remainder of the intermediate substrate 10.

[0053] according to Figure 6One implementation of the method shown divides the growth 103 of the support 13 into several consecutive sub-steps. The first sub-step involves growing a separation assembly 12 comprising an absorption layer 3 and a separate adjacent separation layer 4, wherein the separation layer 4 includes a separation region 8, and the separation layer 4 is configured such that the separation region 8 degrades when the absorption layer 3 reaches a threshold temperature. This first sub-step includes growing the absorption layer 3 1031 and then growing the separation layer 4 1032. The second sub-step 1033 involves growing a second thermal barrier layer 6 1033 on the thus formed separation assembly 12, such that the temperature rise caused by irradiation can be controlled between the two thermal barrier layers 5, 6 (i.e., near the separation assembly 12), thus not compromising the quality of the first semiconductor layer 2. Finally, the step 103 of growing the support 13 includes a third sub-step 1034 of growing a support layer 7, which is configured such that the thickness and mechanical strength of the intermediate substrate 10 are suitable for performing front-end processes.

[0054] Based on the alternative implementations described in the preceding paragraphs, such as Figure 7 As shown, the growth of the support 13 includes a first step 1031 of growing an absorption layer 3 on the first thermal barrier layer 5, followed by a second step 1035 of growing a support layer 7 including a separation region 8. In this case, the support layer 7 is made of a material with low thermal conductivity, and this material is transparent to the wavelength of light radiation applied to the intermediate substrate 10 to separate the substrate 10 along the separation region 8. The quality of the support layer 7 is lower than that of the first semiconductor layer 2. For example, the support layer 7 is deposited at a higher growth rate than the growth rate of the first semiconductor layer 2.

[0055] A third aspect of the invention relates to a method for manufacturing high-performance substrates. For example... Figure 8 As shown, the method includes a first step of implementing a method for manufacturing an intermediate substrate 10 according to a second aspect of the invention. The method then includes forming a weakening region 109 in the donor semiconductor substrate 9 by implanting species through the surface of the donor substrate 9, thereby separating the donor substrate into two parts, one part defining a single-crystal semiconductor layer 14. This is followed by a step 110 of bonding the donor substrate 9 to a surface region of the first semiconductor layer 2 near the single-crystal semiconductor layer 14, and a step 111 of separating the donor substrate along the weakening region. Thus, this produces a semiconductor substrate comprising a single-crystal semiconductor layer 14 disposed on the semiconductor layer 2, which itself may be single-crystal or polycrystalline, depending on the application.

[0056] The fourth aspect of the present invention relates to a method for manufacturing electronic components, such as... Figure 9As shown. The method includes a first step of implementing a method for manufacturing a semiconductor-type substrate according to a third aspect of the invention, as described in the preceding paragraphs. The method then includes step 112 of performing a front-end process in the first layer to form an electronic component. The term "front-end" process is understood to mean the production of individual components, such as transistors, resistors, capacitors, or other components, integrated into the single-crystal semiconductor layer 14 of the substrate.

[0057] According to one implementation, the method may further include: after performing the 112 front-end process, applying 113 laser radiation to the intermediate substrate 10 within a given wavelength range, thereby increasing the temperature of the absorption layer 4 and causing the separation region 8 to deteriorate when the temperature of the absorption layer 4 reaches a threshold, thus enabling at least a portion of the support 13 to separate from the remainder of the intermediate substrate 10. Specifically, the laser radiation 113 may be applied to the support layer 7.

[0058] According to one implementation, after applying laser radiation 113, the method may further include a step 114 of removing a residual layer 15 located on the surface of the first semiconductor layer 2 opposite to the single-crystal semiconductor layer. The residual layer 15 originates from step 113 of applying laser radiation and specifically includes a first thermal barrier layer 5, an optional absorption layer 3, and a portion of a separation layer 4.

[0059] Figure 10 The temperature change of the intermediate substrate 10 during simulated substrate irradiation using a 50-watt laser with a diameter of 125 micrometers and a wavelength of 404 nanometers is shown. Three curves, I, II, and III, are shown, corresponding to irradiation times of 47.2 ms, 47.9 ms, and 50 ms, respectively. The intermediate substrate 10 used for simulation includes two separate thermal barrier layers 5 and 6, and a separation layer 4. Laser radiation is applied to the free surface of the support layer 7, which is opposite to the other layers of the intermediate substrate 10. It can be seen that the temperature of the absorption layer exceeds 2000°C, while the temperatures of the first semiconductor layer 2 and the support layer 7 increase to a maximum of approximately 800°C.

[0060] Figure 11 It shows that in relation to Figure 10 Under the same simulation conditions, the highest temperature in the separation layer 4 varies depending on the diameter of the laser used. Curves I, II, and III correspond to exposure times of the intermediate substrate 10 of 50 microseconds, 100 microseconds, and 200 microseconds, respectively. It can be seen that a small diameter laser beam is required to achieve a sufficiently high temperature rise in the separation layer 4. To raise the temperature in the separation layer 4 to above 2000°C, a laser beam with a diameter less than 150 micrometers is needed under these simulation conditions.

[0061] Under the same simulation conditions, Figure 12 It is shown that: - The change in the highest temperature in the separation layer 4, wherein the layer is represented by curves from I to VI; - The change in substrate surface temperature represented by curve VII for a laser beam with a diameter of 125 micrometers and an exposure time of 200 microseconds.

[0062] The diameter of the laser radiation can vary depending on several factors, such as the laser power or the material present in the substrate. Table 1 below lists the laser parameters used for each curve, assuming the maximum temperature in separation layer 4.

[0063] Regarding the surface temperature of the substrate, it can be seen that it reaches a maximum of about 200°C, which is much lower than the temperature obtained in the separation layer, thus proving the effectiveness of thermal barrier layers 5 and 6.

[0064] for Figure 12 Other parameters not shown (i.e., simulation parameters corresponding to curves I to V) show similar changes in substrate surface temperature observed during these simulations.

[0065] [Table 1]

Claims

1. An intermediate substrate (10) for manufacturing a semiconductor substrate, comprising, in sequence: a. First semiconductor layer (2); b. First thermal barrier layer (5); c. A support (13), comprising: i. An absorption layer (3) configured to absorb laser radiation within a defined wavelength range, wherein the temperature of the absorption layer (3) increases during absorption; and ii. A separation layer (4) comprising a separation region (8) adjacent to the absorption layer (3) and configured to thermally degrade under the action of temperature rise of the absorption layer to separate at least a portion of the support (13) from the remainder of the intermediate substrate (10), wherein the separation region (8) degrades when the absorption layer (3) reaches a threshold temperature; iii. Second thermal barrier layer (6); and iv. Support layer (7), wherein the support layer (7) is a second semiconductor layer with a lower mass than the first semiconductor layer (2).

2. The intermediate substrate (10) according to claim 1 further includes a seed layer (1) suitable for growing a first semiconductor layer (2), the seed layer (1) preferably including graphite, and the first semiconductor layer (2) is inserted between the seed layer (1) and the first thermal barrier layer (5).

3. The intermediate substrate according to any one of claims 1 and 2, wherein, The separation layer (4) is made of silicon nitride.

4. The intermediate substrate according to any one of claims 1 to 3, wherein, The absorber layer (3) is made of a material selected from β-SiC type polycrystalline silicon carbide, titanium nitride or zirconium.

5. The intermediate substrate according to any one of claims 1 to 4, further comprising a single-crystal semiconductor layer (14), preferably comprising silicon carbide (SiC) or gallium nitride (GaN), wherein, The first surface of the single-crystal semiconductor layer (14) is adjacent to the first semiconductor layer (2).

6. The intermediate substrate according to any one of claims 1 to 5, wherein, The first semiconductor layer (2) is made of a broadband semiconductor material, particularly a material selected from silicon carbide, aluminum nitride and gallium nitride.

7. The intermediate substrate according to any one of claims 1 to 6, wherein, The support layer (7) is made of a material selected from silicon carbide and silicon nitride.

8. The intermediate substrate according to any one of claims 1 to 7, wherein, The thickness of the support layer (7) is between 100 nanometers and 200 nanometers.

9. The intermediate substrate according to any one of claims 1 to 8, wherein, The thermal conductivity of the first thermal barrier layer (5) and / or the second thermal barrier layer (6) is less than 25 W / mK, and the second thermal barrier layer (6) is preferably made of titanium dioxide or silicon nitride.

10. The intermediate substrate according to any one of claims 1 to 9, further comprising a single-crystal semiconductor layer (14) disposed on a surface region of the first semiconductor layer, wherein, The first semiconductor layer (2) is located between the first thermal barrier layer (5) and the single crystal semiconductor layer (14).

11. A method for manufacturing an intermediate semiconductor substrate (10), comprising the following steps in sequence: a. A first electrical semiconductor layer (2) (101) is grown on the seed layer (1); b. Grow a first thermal barrier layer (5) (102) on the first semiconductor layer (2); c. A support (13) including an absorption layer (3) is grown (103) on a first thermal barrier layer (5), the absorption layer being configured to absorb laser radiation within a defined wavelength range, wherein the temperature of the absorption layer (3) increases during absorption, and the support (13) further includes a separation region (8) adjacent to the absorption layer (3) and configured to thermally degrade under the effect of the temperature increase of the absorption layer, so as to separate at least a portion of the support (13) from the remainder of the intermediate substrate (10); d. Remove the (104) seed layer (1); The growth step is achieved by vapor deposition on a previously formed layer.

12. The method for manufacturing an intermediate semiconductor substrate (10) according to claim 11, wherein, The growth (103) of the support (13) includes the following sequential steps: a. Growing a separation component (12) consisting of an absorption layer (3) and a separation layer (4), wherein the growth of the separation component (12) includes: -Growth (1031) absorption layer (3); -Grow (1032) separation layer (4), wherein the separation layer (4) includes a separation region (8) which is adjacent to the absorption layer (3); b. A second thermal barrier layer (6) is grown on the separation component (12) (1033); c. A (1034) support layer (7) is grown on the second thermal barrier layer (6); The growth step is achieved, in particular, by vapor deposition on a previously formed layer.

13. The method for manufacturing an intermediate semiconductor substrate (10) according to claim 11, wherein, The growth (103) of the support (13) includes the following sequential steps: a. An absorption layer (3) (1031) is grown on the first thermal barrier layer (5); b. A support layer (7) is grown on the absorber layer (3) (1035), the support layer also serving as a second thermal barrier; The separation zone (8) is included in the support layer (7); The growth step is achieved, in particular, by vapor deposition on a previously formed layer.

14. A method for fabricating a substrate comprising a single-crystal semiconductor layer on a polycrystalline semiconductor substrate, the method comprising carrying out the method for fabricating an intermediate semiconductor substrate (10) according to any one of claims 11 to 13, wherein, The first semiconductor layer (2) is polycrystalline. And it further includes the following sequential steps: a. A weakening region (109) is formed in the semiconductor donor substrate (9) by injecting species to define the single-crystal semiconductor layer (14) to be transferred. b. The single-crystal semiconductor layer (14) to be transferred is bonded (110) to the surface region of the first semiconductor layer (2); c. Separate (111) the donor substrate (9) along the weakened region to transfer the single-crystal semiconductor layer (14) onto the first semiconductor layer (2).

15. A method for manufacturing an electronic component, comprising the following sequential steps: a. To carry out the method for manufacturing a substrate according to claim 14; b. Perform the (112) front-end process in the single-crystal semiconductor layer (14) to form the electronic component.

16. The method for manufacturing an electronic component according to claim 15, comprising: After the front-end process is completed, a step (113) is performed to apply laser radiation to the intermediate substrate (10) within a defined wavelength range to thermally degrade the separation region (8) and separate at least a portion of the support (13) from the remainder of the intermediate substrate (10).

17. The method for manufacturing an electronic component according to claim 16, comprising: The step (114) is to remove the residual layer (15) on the surface of the first semiconductor layer (2) opposite to the single crystal semiconductor layer (14) after laser irradiation is applied, wherein the residual layer (15) originates from the step (113) of applying laser irradiation.

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