CN117888189A - Method for manufacturing self-supporting monocrystalline substrate - Google Patents
Method for manufacturing self-supporting monocrystalline substrate Download PDFInfo
- Publication number
- CN117888189A CN117888189A CN202311780294.XA CN202311780294A CN117888189A CN 117888189 A CN117888189 A CN 117888189A CN 202311780294 A CN202311780294 A CN 202311780294A CN 117888189 A CN117888189 A CN 117888189A
- Authority
- CN
- China
- Prior art keywords
- layer
- transition metal
- substrate
- gan epitaxial
- epitaxial layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 128
- 238000000034 method Methods 0.000 title claims abstract description 77
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 23
- 229910052723 transition metal Inorganic materials 0.000 claims abstract description 109
- 150000003624 transition metals Chemical class 0.000 claims abstract description 109
- 239000013078 crystal Substances 0.000 claims abstract description 37
- 230000006911 nucleation Effects 0.000 claims abstract description 37
- 238000010899 nucleation Methods 0.000 claims abstract description 37
- 238000005229 chemical vapour deposition Methods 0.000 claims abstract description 21
- 229910052751 metal Inorganic materials 0.000 claims description 39
- 239000002184 metal Substances 0.000 claims description 39
- 239000002390 adhesive tape Substances 0.000 claims description 24
- 239000002243 precursor Substances 0.000 claims description 14
- 238000001039 wet etching Methods 0.000 claims description 10
- 229910052736 halogen Inorganic materials 0.000 claims description 7
- 150000002367 halogens Chemical class 0.000 claims description 7
- 238000010297 mechanical methods and process Methods 0.000 claims description 6
- 238000000151 deposition Methods 0.000 claims description 5
- 229910015275 MoF 6 Inorganic materials 0.000 claims description 4
- 238000003486 chemical etching Methods 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- 229910016001 MoSe Inorganic materials 0.000 claims description 3
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 claims description 2
- 230000001070 adhesive effect Effects 0.000 claims description 2
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 94
- 229910002601 GaN Inorganic materials 0.000 description 93
- 239000000463 material Substances 0.000 description 10
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 8
- 230000007547 defect Effects 0.000 description 8
- 238000005530 etching Methods 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 238000000227 grinding Methods 0.000 description 7
- 238000002248 hydride vapour-phase epitaxy Methods 0.000 description 7
- 238000001451 molecular beam epitaxy Methods 0.000 description 7
- 239000000243 solution Substances 0.000 description 7
- 238000000926 separation method Methods 0.000 description 6
- 238000000231 atomic layer deposition Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005498 polishing Methods 0.000 description 3
- 229910052594 sapphire Inorganic materials 0.000 description 3
- 239000010980 sapphire Substances 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- PIGFYZPCRLYGLF-UHFFFAOYSA-N Aluminum nitride Chemical compound [Al]#N PIGFYZPCRLYGLF-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000001534 heteroepitaxy Methods 0.000 description 1
- 238000001657 homoepitaxy Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
- Recrystallisation Techniques (AREA)
Abstract
The invention provides a manufacturing method of a self-supporting monocrystalline substrate, which comprises the following steps: providing a substrate, and forming a transition metal dihalide layer on the substrate through a chemical vapor deposition process; pretreating the transition metal dihalide layer to form dangling bonds on the surface of the transition metal dihalide layer; forming a nucleation layer on the transition metal dihalide layer; growing a first GaN epitaxial layer on the nucleation layer; peeling the first GaN epitaxial layer and the substrate from the transition metal dihalide layer; and growing a second GaN epitaxial layer on the first GaN epitaxial layer. According to the invention, the GaN layer is epitaxially grown on the transition metal dihalide layer, so that the GaN crystal with high quality and high stability can be obtained. The self-supporting single crystal process has the characteristics of simplicity in operation, low cost, wide application range and the like, and has higher practical value and application prospect.
Description
Technical Field
The invention belongs to the field of semiconductor integrated circuit design and manufacture, and particularly relates to a manufacturing method of a self-supporting monocrystalline substrate.
Background
The third generation semiconductor material represented by gallium nitride (GaN) and the alloy thereof is a novel semiconductor material which is valued internationally in recent decades, has a large forbidden band width, high electron saturation drift speed, small dielectric constant, good heat conduction performance, stable structure and other excellent performances, and has great application prospect in the technical fields of photoelectrons and microelectronics.
Currently, gallium nitride devices (including LEDs, LDs, power devices) are structured, typically GaN heteroepitaxy on sapphire, silicon carbide or silicon substrates. Due to lattice and thermal mismatch, there is a large stress inside heteroepitaxial GaN, resulting in serious defects (defect density>10 8 /cm 3 ) So that the device characteristics are limited and Reliability (Reliability) is affected.
One approach to addressing lattice mismatch is to use GaN single crystal substrates. The gallium nitride device is homoepitaxial on the GaN single crystal substrate, so that the stress and defects can be greatly reduced (the defect density can be as low as 10) 5 /cm 3 ) Homoepitaxy has great potential to meet high performance device or LD application requirements. Current GaN single crystal substrates are expensive and limit the applications.
It should be noted that the foregoing description of the background art is only for the purpose of facilitating a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background section of the present application.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a method for fabricating a self-supporting single crystal substrate, which is used to solve the problem of large stress existing in heteroepitaxial GaN due to lattice mismatch and thermal mismatch in the prior art.
To achieve the above and other related objects, the present invention provides a method for fabricating a self-supporting single crystal substrate, the method comprising: providing a substrate, and forming a transition metal dihalide layer on the substrate through a chemical vapor deposition process; pretreating the transition metal dihalide layer to form dangling bonds on the surface of the transition metal dihalide layer; forming a nucleation layer on the transition metal dihalide layer; growing a first GaN epitaxial layer on the nucleation layer; stripping the substrate from the transition metal dihalide layer; and growing a second GaN epitaxial layer on the first GaN epitaxial layer.
Optionally, the first GaN epitaxial layer may be self-supporting, and the peeling the substrate includes: adhering one surface of the first GaN epitaxial layer to an adhesive tape; mechanically removing the substrate; the adhesive tape is removed by wet etching or directly after losing the adhesive force by a high-temperature process.
Optionally, the first GaN epitaxial layer may be self-supporting, and the peeling the substrate includes: stripping the substrate by a laser stripping process, comprising: the transition metal dihalide layer is irradiated with a laser having a wavelength of 366 to 689 nm at normal temperature to separate the transition metal dihalide layer from the nucleation layer.
Optionally, the thickness of the first GaN epitaxial layer is 50 micrometers to 150 micrometers.
Optionally, the first GaN epitaxial layer is not self-supporting, and the peeling the substrate comprises: depositing a metal layer on the first GaN epitaxial layer to promote self-supporting force of the first GaN epitaxial layer; adhering the metal layer to an adhesive tape; removing the substrate by a mechanical method, and bonding the nucleation layer to a thermal expansion matching substrate; removing the adhesive tape and the metal layer by wet etching; and after a second GaN epitaxial layer grows on the first GaN epitaxial layer, removing the thermal expansion matching substrate.
Optionally, the first GaN epitaxial layer is not self-supporting, and the peeling the substrate comprises: depositing a metal layer on the first GaN epitaxial layer to promote self-supporting force of the first GaN epitaxial layer; adhering the metal layer to an adhesive tape; stripping the substrate by a laser stripping process, comprising: irradiating the transition metal dihalide layer with a laser having a wavelength of 366 to 689 nanometers at normal temperature to separate the transition metal dihalide layer from the nucleation layer; bonding the nucleation layer to a thermally expanded matching substrate; removing the adhesive tape and the metal layer by wet etching; and after a second GaN epitaxial layer grows on the first GaN epitaxial layer, removing the thermal expansion matching substrate.
Optionally, the thickness of the first GaN epitaxial layer is 5 micrometers to 20 micrometers.
Optionally, before adhering the adhesive tape, further comprising: the bonding force between the transition metal dihalide layer and the nucleation layer is reduced by a heat treatment or chemical etching method.
Alternatively, the substrate includes one of a sapphire substrate, a Si single crystal substrate, a SiC single crystal substrate, and a gallium nitride single crystal substrate.
Optionally, forming the transition metal dihalide layer on the substrate by a chemical vapor deposition process comprises: introducing a metal precursor and a halogen precursor into a reaction chamber, and reacting to form a transition metal dihalide layer on the surface of the substrate, wherein the metal precursor is WF 6 And MoF 6 One or two of the halogen precursors are H 2 S and H 2 One or two of Se, the transition metal dihalide layer comprises WS 2 、MoS 2 、WSe 2 And MoSe 2 One or more of the above.
Optionally, the transition metal dihalide layer has a thickness of 1 to 5 atomic layers.
Optionally, forming dangling bonds on the surface of the transition metal dihalide layer includes one of:
a) Etching the transition metal dihalide layer by adopting HCl solution or HCl gas to form dangling bonds on the surface of the transition metal dihalide layer; b) By Cl 2 Etching the transition metal dihalide layer by gas to form dangling bonds on the surface of the transition metal dihalide layer; c) Etching the transition metal dihalide layer by adopting ammonia gas to form dangling bonds on the surface of the transition metal dihalide layer; d) Etching the transition metal dihalide layer by adopting an HF aqueous solution or a buffered HF solution so as to form dangling bonds on the surface of the transition metal dihalide layer.
Optionally, a nucleation layer is formed on the transition metal dihalide layer by a sputtering process (Sputter), a metal organic chemical vapor deposition process or an atomic layer deposition process (Atomic layer deposition, ALD), the nucleation layer comprising an AlN layer.
Optionally, the first GaN epitaxial layer is grown by a molecular beam epitaxy process (Molecular beam epitaxy, MBE), a metal organic chemical vapor deposition process (Metal organic chemical vapor deposition, MOCVD) or a hydride vapor phase epitaxy process (Hydride vapor phase epitaxy, HVPE), and the second GaN epitaxial layer is grown on the first GaN epitaxial layer by a molecular beam epitaxy process, a metal organic chemical vapor deposition process or a hydride vapor phase epitaxy process.
Optionally, the method further comprises the steps of: and grinding the stripped substrate to remove surface defects, and obtaining the reusable substrate.
As described above, the method for manufacturing a self-supporting single crystal substrate of the present invention has the following advantageous effects:
the invention can obtain GaN crystal with high quality and high stability, such as MoS, by epitaxially growing GaN layer on transition metal dihalide layer 2 The lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is 0.6%, the lattice mismatch degree of the transition metal dihalide layer and the AlN buffer layer is 1.6%, the lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is far smaller than 29.6%, and the lattice mismatch degree of the transition metal dihalide layer and the AlN buffer layer is far smaller than 26.5%. In addition, the transition metal dihalide layer is a two-dimensional material layer, most of the connection with the substrate is physical adsorption, weak connection and easy separation, and convenience is provided for removing the substrate by a mechanical method.
The invention can realize the complete separation of the substrate by adopting a mechanical stripping or laser stripping method; the peeled substrate can be repeatedly applied after polishing and grinding treatment, and meanwhile, the grinding and thinning process of the substrate in the process of manufacturing devices can be omitted.
The invention can improve the mechanical strength of the GaN epitaxial layer by bonding the thermal expansion matching substrate again.
The self-supporting single crystal process has the characteristics of simplicity in operation, low cost, wide application range and the like, and has higher practical value and application prospect.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is apparent that the drawings in the following description are only some of the embodiments of the present application.
Fig. 1 to 14 are schematic structural views showing steps of a method for fabricating a self-supporting single crystal substrate according to an embodiment of the present invention.
Description of element reference numerals
101. Substrate and method for manufacturing the same
102. Transition metal dihalide layer
103. Suspension key
104. Nucleation layer
105. First GaN epitaxial layer
106. Adhesive tape
107. Second GaN epitaxial layer
201. Metal layer
202. Thermal expansion matching substrate
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
It should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.
As described in detail in the embodiments of the present invention, the cross-sectional view of the device structure is not partially enlarged to a general scale for convenience of explanation, and the schematic drawings are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.
For ease of description, spatially relative terms such as "under", "below", "beneath", "above", "upper" and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Furthermore, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers or one or more intervening layers may also be present.
In the context of this application, a structure described as a first feature being "on" a second feature may include embodiments where the first and second features are formed in direct contact, as well as embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.
It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings rather than the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.
Example 1
As shown in fig. 1 to 8, the present embodiment provides a method for manufacturing a self-supporting single crystal substrate, the method comprising the steps of:
as shown in fig. 1, step 1) is first performed, a substrate 101 is provided, and a transition metal dihalide layer 102 is formed on the substrate 101 by a chemical vapor deposition process, where the transition metal dihalide layer 102 is a two-dimensional material.
In one embodiment, the substrate 101 includes one of a sapphire substrate, a silicon (Si) single crystal substrate, a silicon carbide (SiC) single crystal substrate, and a gallium nitride single crystal substrate.
In one embodiment, forming the transition metal dihalide layer 102 on the substrate 101 by a chemical vapor deposition process (Chemical vapor deposition, CVD) includes: introducing a metal precursor and a halogen precursor into a reaction chamber, and reacting at a suitable temperature and pressure on the surface of the substrate 101 to form a transition metal dihalide layer 102, wherein the metal precursor is WF 6 And MoF 6 One or two of the halogen precursors are H 2 S and H 2 One or two of Se, the transition metal dihalide layer 102 includes WS 2 、MoS 2 、WSe 2 And MoSe 2 One or more of the above. In a specific example, the metal precursor is MoF 6 The halogen precursor is H 2 S, the transition metal dihalide layer 102 comprises MoS 2 。
In one embodiment, the transition metal dihalide layer 102 has a thickness of 1 to 5 atomic layers. Preferably, the transition metal dihalide layer 102 has a thickness of 1 atomic layer.
In one embodiment, the apparatus used for the chemical vapor deposition process (CVD) is an All-gaseous hot wall chemical vapor deposition apparatus (All-gas hot-wall chemical vapor deposition apparatus).
As shown in fig. 2, step 2) is then performed to pretreat the transition metal dihalide layer 102 to form dangling bonds 103 on the surface of the transition metal dihalide layer 102;
in one embodiment, forming dangling bonds 103 on the surface of the transition metal dihalide layer 102 includes one or a combination of two or more of the following a), b), c), d):
a) Etching the transition metal dihalide layer 102 by using HCl solution or HCl gas to form dangling bonds 103 on the surface of the transition metal dihalide layer 102;
b) By Cl 2 The gas etches the transition metal dihalide layer 102Etching to form dangling bonds 103 on the surface of the transition metal dihalide layer 102;
c) Etching the transition metal dihalide layer 102 by ammonia gas to form dangling bonds 103 on the surface of the transition metal dihalide layer 102;
d) Aqueous HF solution (volume ratio HF: h 2 O>1:40 A Buffered HF (BHF) or a Buffered HF solution to etch the transition metal dihalide layer 102 to form dangling bonds 103 on the surface of the transition metal dihalide layer 102.
Wherein, when the etching is performed in the form of gas, the etching gas may be diluted by adding hydrogen, nitrogen, or the like.
The dangling bonds 103 of the transition metal dihalide layer 102 can improve the growth quality of the subsequent nucleation layer 104 on the surface thereof and improve the structural stability. The invention can obtain GaN crystal with high quality and high stability, such as MoS, by epitaxially growing GaN layer on transition metal dihalide layer 2 The lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is 0.6%, the lattice mismatch degree of the transition metal dihalide layer and the AlN buffer layer is 1.6%, the lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is far smaller than 29.6%, and the lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is far smaller than 26.5%, so that the transition metal dihalide layer and the GaN epitaxial layer pass MoS 2 The transition metal dihalide layer can greatly reduce lattice mismatch between the substrate and the GaN epitaxial layer. In addition, the transition metal dihalide layer is a two-dimensional material layer, most of the connection with the substrate is physical adsorption, weak connection and easy separation, and convenience is provided for removing the substrate by a subsequent mechanical method.
As shown in fig. 3, step 3) is then performed to form a nucleation layer 104 on the transition metal dihalide layer 102.
In one embodiment, the nucleation layer 104 is formed on the transition metal dihalide layer 102 by a sputtering process, a metal organic chemical vapor deposition process, or an atomic layer deposition process, the nucleation layer 104 comprising an aluminum nitride (AlN) layer. The nucleation layer 104 may provide seed for subsequent GaN epitaxial growth, improving GaN epitaxial quality and stability.
As shown in fig. 4, step 4) is then performed to grow a first GaN epitaxial layer 105 on the nucleation layer 104.
In one embodiment, the first GaN epitaxial layer 105 is grown by a molecular beam epitaxy process, a metal organic chemical vapor deposition process, or a hydride vapor phase epitaxy process.
As shown in fig. 5 to 7, step 5) is then performed, including:
in one embodiment, the first GaN epitaxial layer 105 may be self-supporting, and the first GaN epitaxial layer 105 may have a thickness of 50 micrometers to 150 micrometers. Step 5) comprises:
adhering one surface of the first GaN epitaxial layer 105 to an adhesive tape 106, which may be, for example, a heat release adhesive tape, as shown in fig. 5;
removing the substrate 101 by a mechanical method, as shown in fig. 6, since the connection force between the transition metal dihalide layer 102 and the substrate 101 and/or the connection force between the transition metal dihalide layer 102 and the nucleation layer 104 is smaller than the adhesion force between the adhesive tape 106 and the first epitaxial layer 105, the first epitaxial layer 105 can be directly peeled off; depending on the difference in the bonding force between the transition metal dihalide layer 102 and the substrate 101 and the bonding force between the transition metal dihalide layer 102 and the nucleation layer 104, no or some or all of the transition metal dihalide layer 102 remains at the bottom of the nucleation layer 104, which, if left, may be removed by a subsequent lapping process or by a bonding tape (not shown) followed by tearing off the tape at the bottom.
The adhesive tape 106 is removed by wet etching or the adhesive tape 106 is directly removed or torn off after the adhesive tape 106 loses its adhesion by a high temperature process, as shown in fig. 7.
In a specific example, before adhering one side of the first GaN epitaxial layer 105 to the adhesive tape 106, the method further includes: the bonding force between the transition metal dihalide layer 102 and the nucleation layer 104 is reduced by a heat treatment or chemical etching method, so as to avoid the problems of cracking or cracking of the first GaN epitaxial layer 105 during the lift-off process.
Alternatively, in another embodiment, the first GaN epitaxial layer 105 may be self-supporting, the first GaN epitaxial layer 105The thickness is 50-150 microns. Step 5) comprises: the first GaN epitaxial layer 105 may be self-supporting, and the peeling off the first GaN epitaxial layer 105 and the substrate 101 includes: the peeling of the substrate 101 by a laser peeling process includes: the transition metal dihalide layer 102 is irradiated with a laser having a wavelength of 366 to 689 nm at normal temperature to separate the transition metal dihalide layer 102 from the nucleation layer 104. For example, the transition metal dihalide layer 102 is selected as a two-dimensional material MoS 2 The band gap is 1.8eV, and lasers with the wavelength of 366-689 nanometers can be selected, so that high-price lasers such as 248 nanometers, 266 nanometers, 355 nanometers and the like are avoided, and the substrate 101 can be stripped and removed at normal temperature, thereby greatly reducing the cost. The laser wavelength energy is located between the transition metal dihalide and the GaN band gap energy such that the transition metal dihalide layer absorbs laser light and the first GaN epitaxial layer does not. In particular, when the substrate is a gallium nitride single crystal, the gallium nitride substrate does not absorb laser light either.
As shown in fig. 8, step 6) is finally performed to grow a second GaN epitaxial layer 107 on the first GaN epitaxial layer 105.
In one embodiment, the second GaN epitaxial layer 107 may be grown on the first GaN epitaxial layer 105 by a molecular beam epitaxy process, a metal organic chemical vapor deposition process, or a hydride vapor phase epitaxy process. During the growth of the second GaN epitaxial layer 107, the growth conditions and material composition may be adjusted as needed to obtain the desired epitaxial quality and performance index.
Finally, the substrate 101 may also be polished to remove surface defects, resulting in a reusable substrate 101. In particular, when the substrate is a gallium nitride single crystal, multiplexing of a high-value substrate can be achieved. The invention can realize the complete separation of the substrate by adopting a mechanical stripping or laser stripping method; the peeled substrate can be repeatedly applied after polishing and grinding treatment, and meanwhile, the grinding and thinning process of the substrate in the process of manufacturing devices can be omitted.
Example 2
As shown in fig. 1 to 4 and 9 to 14, this embodiment provides a method for producing a self-supporting single crystal substrate, in which steps 1) to 4) are substantially the same as embodiment 1, and the difference from embodiment 1 is that:
in step 5), the first GaN epitaxial layer 105 is not self-supporting, and the thickness of the first GaN epitaxial layer 105 is 5 micrometers to 20 micrometers;
in one embodiment, step 5) comprises:
as shown in fig. 9, a metal layer 201 is deposited on the first GaN epitaxial layer 105 to promote self-supporting force of the first GaN epitaxial layer 105; the tape 106 is adhered to the metal layer 201.
For example, a metal layer 201 may be deposited on the first GaN epitaxial layer 105 through a sputtering process or an evaporation process, etc., the metal layer 201 may be copper or nickel, for example, and the metal layer 201 is selected to be a metal material that may be removed through a wet etching process.
As shown in fig. 10-11, the substrate 101 is mechanically removed and the nucleation layer 104 is bonded to a thermal expansion matching substrate 202, such as an AlN ceramic substrate; since the connection force between the transition metal dihalide layer 102 and the substrate 101 and/or the connection force between the transition metal dihalide layer 102 and the nucleation layer 104 is smaller than the adhesion force between the tape 106 and the metal layer 201, the first epitaxial layer 105 can be directly peeled off; depending on the difference in the bonding force between the transition metal dihalide layer 102 and the substrate 101 and the bonding force between the transition metal dihalide layer 102 and the nucleation layer 104, no or some or all of the transition metal dihalide layer 102 remains at the bottom of the nucleation layer 104, which, if left, can be removed by a subsequent lapping process or by a bonding tape (not shown) followed by tearing off the tape at the bottom;
as shown in fig. 12, the tape 106 and the metal layer 201 are removed by wet etching;
as shown in fig. 13, a second GaN epitaxial layer 107 is grown on the first GaN epitaxial layer 105.
In one embodiment, the second GaN epitaxial layer 107 may be grown on the first GaN epitaxial layer 105 by a molecular beam epitaxy process, a metal organic chemical vapor deposition process, or a hydride vapor phase epitaxy process. During the growth of the second GaN epitaxial layer 107, the growth conditions and material composition may be adjusted as needed to obtain the desired epitaxial quality and performance index.
As shown in fig. 14, the thermal expansion matching substrate 202 is removed by a debonding method.
In one embodiment, before adhering the metal layer 201 to the adhesive tape 106, further comprising: the bonding force between the transition metal dihalide layer 102 and the nucleation layer 104 is reduced by heat treatment or chemical etching.
In another embodiment, step 5) may also include:
depositing a metal layer 201 on the first GaN epitaxial layer 105 to promote self-supporting forces of the first GaN epitaxial layer 105;
adhering one side of the metal layer 201 to the adhesive tape 106;
the peeling of the substrate 101 by a laser peeling process includes: irradiating the transition metal dihalide layer 102 with a laser having a wavelength of 366 to 689 nm at normal temperature to separate the transition metal dihalide layer 102 from the nucleation layer 104;
bonding the nucleation layer 104 to a thermal expansion matching substrate 202, such as an AlN ceramic substrate;
removing the tape 106 and the metal layer 201 by wet etching;
growing a second GaN epitaxial layer 107 on the first GaN epitaxial layer 105;
the thermal expansion matching substrate 202 is removed by a debonding method.
For example, the transition metal dihalide layer 102 is selected as a two-dimensional material MoS 2 The band gap is 1.8eV, and lasers with the wavelength of 366-689 nanometers can be selected, so that high-price lasers such as 248 nanometers, 266 nanometers, 355 nanometers and the like are avoided, and the substrate 101 can be stripped and removed at normal temperature, thereby greatly reducing the cost. The laser wavelength energy is located between the transition metal dihalide and the GaN band gap energy such that the transition metal dihalide layer absorbs laser light and the first GaN epitaxial layer does not. In particular, when the substrate is a gallium nitride single crystal, the gallium nitride substrate does not absorb laser light either.
The invention can improve the mechanical strength of the GaN epitaxial layer by bonding the thermal expansion matching substrate again.
Finally, the substrate 101 may also be polished to remove surface defects, resulting in a reusable substrate 101. In particular, when the substrate is a gallium nitride single crystal, multiplexing of a high-value substrate can be achieved.
As described above, the method for manufacturing a self-supporting single crystal substrate of the present invention has the following advantageous effects:
the invention can obtain GaN crystal with high quality and high stability, such as MoS, by epitaxially growing GaN layer on transition metal dihalide layer 2 The lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is 0.6%, the lattice mismatch degree of the transition metal dihalide layer and the AlN buffer layer is 1.6%, the lattice mismatch degree of the transition metal dihalide layer and the GaN epitaxial layer is far smaller than 29.6%, and the lattice mismatch degree of the transition metal dihalide layer and the AlN buffer layer is far smaller than 26.5%. In addition, the transition metal dihalide layer is a two-dimensional material layer, most of the connection with the substrate is physical adsorption, weak connection and easy separation, and convenience is provided for removing the substrate by a mechanical method.
The invention can realize the complete separation of the substrate by adopting a mechanical stripping or laser stripping method; the peeled substrate can be repeatedly applied after polishing and grinding treatment, and meanwhile, the grinding and thinning process of the substrate in the process of manufacturing devices can be omitted.
The invention can improve the mechanical strength of the GaN epitaxial layer by bonding the thermal expansion matching substrate again.
The self-supporting single crystal process has the characteristics of simplicity in operation, low cost, wide application range and the like, and has higher practical value and application prospect.
Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (10)
1. A method of fabricating a self-supporting single crystal substrate, the method comprising:
providing a substrate, and forming a transition metal dihalide layer on the substrate through a chemical vapor deposition process;
pretreating the transition metal dihalide layer to form dangling bonds on the surface of the transition metal dihalide layer;
forming a nucleation layer on the transition metal dihalide layer;
growing a first GaN epitaxial layer on the nucleation layer;
stripping the substrate from the transition metal dihalide layer;
and growing a second GaN epitaxial layer on the first GaN epitaxial layer.
2. The method for producing a self-supporting single crystal substrate according to claim 1, wherein: the first GaN epitaxial layer may be self-supporting, and the peeling the first GaN epitaxial layer and the substrate comprises:
adhering one surface of the first GaN epitaxial layer to an adhesive tape;
mechanically removing the substrate;
the adhesive tape is removed by wet etching or directly after losing the adhesive force by a high-temperature process.
3. The method for producing a self-supporting single crystal substrate according to claim 1, wherein: the first GaN epitaxial layer may be self-supporting, and the peeling the substrate includes: stripping the substrate by a laser stripping process, comprising: the transition metal dihalide layer is irradiated with a laser having a wavelength of 366 to 689 nm at normal temperature to separate the transition metal dihalide layer from the nucleation layer.
4. A method of producing a self-supporting single crystal substrate according to claim 2 or 3, characterized in that: the thickness of the first GaN epitaxial layer is 50-150 micrometers.
5. The method for producing a self-supporting single crystal substrate according to claim 1, wherein: the first GaN epitaxial layer is not self-supporting, and the peeling the substrate comprises:
depositing a metal layer on the first GaN epitaxial layer to promote self-supporting force of the first GaN epitaxial layer;
adhering the metal layer to an adhesive tape;
removing the substrate by a mechanical method, and bonding the nucleation layer to a thermal expansion matching substrate;
removing the adhesive tape and the metal layer by wet etching;
and after a second GaN epitaxial layer grows on the first GaN epitaxial layer, removing the thermal expansion matching substrate.
6. The method for producing a self-supporting single crystal substrate according to claim 1, wherein: the first GaN epitaxial layer is not self-supporting, and the peeling the substrate comprises:
depositing a metal layer on the first GaN epitaxial layer to promote self-supporting force of the first GaN epitaxial layer;
adhering the metal layer to an adhesive tape;
stripping the substrate by a laser stripping process, comprising: irradiating the transition metal dihalide layer with a laser having a wavelength of 366 to 689 nanometers at normal temperature to separate the transition metal dihalide layer from the nucleation layer;
bonding the nucleation layer to a thermally expanded matching substrate;
removing the adhesive tape and the metal layer by wet etching;
and after a second GaN epitaxial layer grows on the first GaN epitaxial layer, removing the thermal expansion matching substrate.
7. The method for producing a self-supporting single crystal substrate according to claim 5 or 6, characterized in that: the thickness of the first GaN epitaxial layer is 5-20 microns.
8. The method for producing a self-supporting single crystal substrate according to claim 2 or 5, characterized in that: before the adhesive tape is adhered, the method further comprises: the bonding force between the transition metal dihalide layer and the nucleation layer is reduced by a heat treatment or chemical etching method.
9. The method for producing a self-supporting single crystal substrate according to claim 1, wherein: forming a transition metal dihalide layer on the substrate by a chemical vapor deposition process comprises: introducing a metal precursor and a halogen precursor into a reaction chamber, and reacting to form a transition metal dihalide layer on the surface of the substrate, wherein the metal precursor is WF 6 And MoF 6 One or two of the halogen precursors are H 2 S and H 2 One or two of Se, the transition metal dihalide layer comprises WS 2 、MoS 2 、WSe 2 And MoSe 2 One or more of the above.
10. The method for producing a self-supporting single crystal substrate according to claim 1, wherein: the thickness of the transition metal dihalide layer is 1-5 atomic layers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311780294.XA CN117888189A (en) | 2023-12-21 | 2023-12-21 | Method for manufacturing self-supporting monocrystalline substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311780294.XA CN117888189A (en) | 2023-12-21 | 2023-12-21 | Method for manufacturing self-supporting monocrystalline substrate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117888189A true CN117888189A (en) | 2024-04-16 |
Family
ID=90651582
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311780294.XA Pending CN117888189A (en) | 2023-12-21 | 2023-12-21 | Method for manufacturing self-supporting monocrystalline substrate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117888189A (en) |
-
2023
- 2023-12-21 CN CN202311780294.XA patent/CN117888189A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2075020C (en) | Method for preparing semiconductor member | |
| JP4783288B2 (en) | Realization of III-nitride free-standing substrate by heteroepitaxy on sacrificial layer | |
| US5840616A (en) | Method for preparing semiconductor member | |
| CN109585269B (en) | Method for preparing semiconductor single crystal substrate by using two-dimensional crystal transition layer | |
| JPH07302889A (en) | Manufacture of semiconductor substrate | |
| CN111540684A (en) | Microelectronic device of diamond-based heterogeneous integrated gallium nitride thin film and transistor and preparation method thereof | |
| KR20120001606A (en) | Single-crystal diamond growth base material and method for manufacturing single-crystal diamond substrate | |
| US20230260841A1 (en) | Method for producing a composite structure comprising a thin layer of monocrystalline sic on a carrier substrate of polycrystalline sic | |
| CN110600435A (en) | Multilayer composite substrate structure and preparation method thereof | |
| US20240128080A1 (en) | Compound semiconductor layered structure and process for preparing the same | |
| CN113130296B (en) | Method for growing gallium nitride on hexagonal boron nitride | |
| EP4187576A1 (en) | Heteroepitaxial structure with a diamond heat sink | |
| KR100450781B1 (en) | Method for manufacturing GaN single crystal | |
| JP2004269313A (en) | Method for manufacturing gallium nitride crystal substrate | |
| CN116590795A (en) | Method for growing monocrystalline GaN self-supporting substrate by using ceramic substrate | |
| CN114892264B (en) | Gallium nitride substrate, gallium nitride single crystal layer, and method for producing same | |
| CN115881514A (en) | Method for manufacturing single crystal self-supporting substrate | |
| CN117888189A (en) | Method for manufacturing self-supporting monocrystalline substrate | |
| JP3157030B2 (en) | Semiconductor substrate and manufacturing method thereof | |
| WO2014136573A1 (en) | Composite substrate, semiconductor-wafer production method using said composite substrate, and support substrate for said composite substrate | |
| CN117936365A (en) | Method for manufacturing semiconductor device | |
| WO2023119916A1 (en) | Nitride semiconductor substrate and method for manufacturing nitride semiconductor substrate | |
| KR102393733B1 (en) | Manufacturing semiconductor thin film of diamond | |
| RU2802796C1 (en) | Heteroepitaxial structure with a diamond heat sink for semiconductor devices and method for its manufacture | |
| WO2022017462A1 (en) | Method for preparing self-supporting substrate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |