CN117133629A - Preparation method of low-resistance ohmic contact on diamond - Google Patents
Preparation method of low-resistance ohmic contact on diamond Download PDFInfo
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- CN117133629A CN117133629A CN202311221424.6A CN202311221424A CN117133629A CN 117133629 A CN117133629 A CN 117133629A CN 202311221424 A CN202311221424 A CN 202311221424A CN 117133629 A CN117133629 A CN 117133629A
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- 229910003460 diamond Inorganic materials 0.000 title claims abstract description 80
- 239000010432 diamond Substances 0.000 title claims abstract description 80
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 239000000758 substrate Substances 0.000 claims abstract description 78
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 56
- 229910052796 boron Inorganic materials 0.000 claims abstract description 55
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 31
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 31
- 239000010703 silicon Substances 0.000 claims abstract description 31
- 239000007787 solid Substances 0.000 claims abstract description 25
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052582 BN Inorganic materials 0.000 claims abstract description 21
- 238000000151 deposition Methods 0.000 claims abstract description 14
- CFOAUMXQOCBWNJ-UHFFFAOYSA-N [B].[Si] Chemical compound [B].[Si] CFOAUMXQOCBWNJ-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000005530 etching Methods 0.000 claims abstract description 11
- 229910052751 metal Inorganic materials 0.000 claims abstract description 11
- 239000002184 metal Substances 0.000 claims abstract description 11
- 239000010408 film Substances 0.000 claims description 39
- 238000000034 method Methods 0.000 claims description 34
- 229910052739 hydrogen Inorganic materials 0.000 claims description 20
- 239000001257 hydrogen Substances 0.000 claims description 20
- 230000008569 process Effects 0.000 claims description 14
- 239000010409 thin film Substances 0.000 claims description 10
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 5
- 239000002253 acid Substances 0.000 claims description 5
- 238000001755 magnetron sputter deposition Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 239000011259 mixed solution Substances 0.000 claims description 5
- 239000008367 deionised water Substances 0.000 claims description 4
- 229910021641 deionized water Inorganic materials 0.000 claims description 4
- 239000002019 doping agent Substances 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 238000004140 cleaning Methods 0.000 claims description 3
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims 1
- 229910052814 silicon oxide Inorganic materials 0.000 claims 1
- 238000009792 diffusion process Methods 0.000 abstract description 13
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 14
- 238000011065 in-situ storage Methods 0.000 description 7
- 238000005468 ion implantation Methods 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 230000005669 field effect Effects 0.000 description 3
- 238000000137 annealing Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- UORVGPXVDQYIDP-UHFFFAOYSA-N borane Chemical compound B UORVGPXVDQYIDP-UHFFFAOYSA-N 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910002601 GaN Inorganic materials 0.000 description 1
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 229910000085 borane Inorganic materials 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000004047 hole gas Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
- H01L21/02123—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon
- H01L21/02164—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon the material being a silicon oxide, e.g. SiO2
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02367—Substrates
- H01L21/0237—Materials
- H01L21/02373—Group 14 semiconducting materials
- H01L21/02376—Carbon, e.g. diamond-like carbon
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- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
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- H01L21/02518—Deposited layers
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- H01L21/0405—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising semiconducting carbon, e.g. diamond, diamond-like carbon
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Abstract
The invention relates to a preparation method of low-resistance ohmic contact on diamond, which comprises the following steps: selecting diamond which is not intentionally doped as a first substrate layer; depositing a layer of preset film containing silicon element on the first substrate layer; firstly decomposing solid boron nitride at a first preset temperature in a preset system to introduce a boron source, and etching the preset film in the preset system at a second preset temperature to diffuse silicon in the preset film and boron in the preset system into a first substrate layer to obtain a second substrate layer; standing the second substrate layer in air to obtain a third substrate layer; and depositing a metal layer on the diamond surface terminal in the third substrate layer to complete the preparation of the ohmic resistor. According to the invention, the preset film is used as a silicon source, the solid boron nitride is used as a boron source, boron-silicon co-doping in the diamond is realized through the diffusion of silicon and boron, and then a metal layer is deposited, so that good ohmic contact can be directly formed, and the ohmic contact resistance is reduced.
Description
Technical Field
The invention relates to the technical field of semiconductor processes, in particular to a preparation method of low-resistance ohmic contact on diamond.
Background
The ultra-wide band gap semiconductor diamond has the advantages of large band gap, high breakdown field intensity, high carrier mobility, high heat conductivity, irradiation resistance and the like, and has great potential in power electronic device application when the hydrogen terminal diamond field effect transistor which uses the surface hydrogen terminal to induce two-dimensional hole gas as a conductive channel becomes the current mainstream device selection at the present time under the condition that the high-efficiency body doping of the diamond has not yet achieved a great breakthrough. The hydrogen termination diamond FET (Field Effect Transistor ) device is currently in a large performance gap with gallium nitride based HEMT (High Electron Mobility Transistor ) devices, one key point being the large ohmic contact resistance of the hydrogen termination diamond FET device. The frequency and output power characteristics of diamond microwave power devices are greatly affected by ohmic contact problems. In a high-frequency small-size device, a source-drain series resistance using an ohmic contact resistance as a main component becomes a main factor restricting the frequency characteristics of the device; in the power device, the ohmic resistance directly influences the saturation voltage and the on-current of the device, and the output power of the device is restrained from two aspects of voltage swing and current swing.
At present, the ohmic contact of the diamond field effect transistor is mainly obtained by depositing Au metal on the hydrogen terminal diamond, and the ohmic contact resistance is generally about 5 omega-mm, but still is an order of magnitude higher than the ohmic contact resistance value (less than or equal to 0.5 omega-mm) prepared by other mature semiconductor processes such as Si, gaN and the like.
When the boron doping concentration exceeds 10 20 cm -3 Diamond becomes a degenerate semiconductor when it exhibits metallic conductivity at room temperature. Ion implantation or in-situ growth doping in ohmic contact area to prepare boron with doping concentration higher than 10 20 cm -3 Is one of the possible schemes for reducing ohmic contact resistance. At present, the boron doping concentration is more than 1 multiplied by 10 22 cm -3 The high temperature annealing on the heavy boron doped diamond forms TiC alloy, which achieves an ohmic contact resistance of about 1 Ω -mm at a minimum. However, the ion implantation boron doping technology can cause a certain degree of damage to the diamond lattice, thereby reducing the substrate quality and affecting the performance of the device; achieving boron doping concentrations exceeding 10 20 cm -3 The in-situ growth heavy boron doping process of (2) requires special diamond doping equipment, which is only owned by Kawarda subject group of university of early paddy field internationally.
The ohmic contact of the diamond FET device with the hydrogen terminal prepared by the prior method has the problems of large contact resistance, large process difficulty, high cost and the like, and the requirements of the performance improvement and the application of the diamond FET device are difficult to meet, so that how to realize the low ohmic contact resistance of the diamond device becomes a problem to be solved urgently for the research of the diamond FET device.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a preparation method of low-resistance ohmic contact on diamond. The technical problems to be solved by the invention are realized by the following technical scheme:
a method of making a low resistance ohmic contact on diamond, the method comprising:
selecting diamond which is not intentionally doped as a first substrate layer;
depositing a layer of preset film containing silicon element on the first substrate layer;
at a first preset temperature, diffusing boron elements in solid boron nitride in a preset system to introduce a boron source, etching the preset film in the preset system at a second preset temperature to diffuse silicon in the preset film and boron elements in the preset system into a first substrate layer to obtain a second substrate layer, wherein the second substrate layer sequentially comprises an undoped diamond layer, a silicon-boron co-doped diamond layer and a diamond surface terminal from bottom to top, the diamond surface terminal is a diamond layer comprising carbon-hydrogen bonds and carbon-silicon bonds, and the preset system is provided with a solid boron source dopant;
standing the second substrate layer in air to obtain a third substrate layer;
and depositing a metal layer on the terminal of the diamond surface in the third substrate layer to finish the preparation of the ohmic resistor.
In one embodiment of the present invention, before depositing a preset film containing silicon element on the first substrate layer, the method further includes:
and at a third preset temperature, treating the first substrate layer by using a strong acid mixed solution, and then cleaning the first substrate layer by using acetone, ethanol and deionized water in sequence under the normal temperature condition to obtain a clean first substrate layer.
In one embodiment of the present invention, depositing a predetermined thin film containing silicon on the first substrate layer includes:
and depositing a layer of the preset film on the first substrate layer through a magnetron sputtering process.
In one embodiment of the present invention, the preset film includes a silicon film or a silicon dioxide film.
In one embodiment of the present invention, the thickness of the preset thin film is 200-500nm.
In one embodiment of the present invention, diffusing boron element in solid boron nitride in a preset system at a first preset temperature to introduce a boron source, etching the preset film in the preset system at a second preset temperature to diffuse silicon in the preset film and boron element in the preset system into a first substrate layer to obtain a second substrate layer, including:
placing solid boron nitride into the preset system, heating the solid boron nitride to the first preset temperature, and decomposing the solid boron nitride in the preset system at the first preset temperature to introduce a boron source into the preset system;
and placing a first substrate layer with the surface deposited with the preset film into the preset system with the boron element introduced, starting the system by utilizing hydrogen, and etching the preset film at a second preset temperature to diffuse the boron element in the preset system and silicon in the preset film into the first substrate layer to obtain the second substrate layer.
In one embodiment of the present invention, the first preset temperature ranges from 600 ℃ to 700 ℃.
In one embodiment of the present invention, the second preset temperature ranges from 900 ℃ to 1000 ℃.
In one embodiment of the present invention, the second substrate layer is left standing in air to obtain a third substrate layer, including:
and standing the second substrate layer in air for 1-12 h to obtain the third substrate layer.
In one embodiment of the invention, the material of the metal layer comprises Au.
Compared with the prior art, the invention has the beneficial effects that:
according to the invention, the preset film containing silicon elements is deposited on the first substrate layer, the preset film is used as a silicon source, the boron elements in the solid boron nitride are used as a boron source, boron-silicon co-doping in the diamond is realized through diffusion of silicon and boron, the silicon-boron co-doping is adopted to form a high-concentration doped layer on the surface of the diamond, then a metal layer is deposited, good ohmic contact can be directly formed after annealing, and ohmic contact resistance is reduced.
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Drawings
Fig. 1 is a schematic flow chart of a method for preparing low-resistance ohmic contact on diamond according to an embodiment of the present invention;
FIGS. 2 a-2 c are schematic process diagrams of a method for fabricating a low resistance ohmic contact on diamond according to embodiments of the present invention;
fig. 3 is a graph of SIMS test results after an intentionally undoped diamond was doped by the preparation method according to the present invention.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but embodiments of the present invention are not limited thereto.
Example 1
Referring to fig. 1 and fig. 2a to fig. 2c, fig. 1 is a schematic flow chart of a method for preparing a low-resistance ohmic contact on a diamond according to an embodiment of the present invention, and fig. 2a to fig. 2c are schematic flow charts of a method for preparing a low-resistance ohmic contact on a diamond according to an embodiment of the present invention, and the method for preparing a low-resistance ohmic contact on a diamond according to an embodiment of the present invention includes:
in step 1, please refer to fig. 2a, an un-intentionally doped diamond is selected as the first substrate layer 1.
And 2, treating the first substrate layer by using a strong acid mixed solution at a third preset temperature, and then cleaning the first substrate layer by using acetone, ethanol and deionized water in sequence at normal temperature to obtain a clean first substrate layer.
Specifically, firstly cutting and polishing pretreatment is carried out on a first substrate layer, then a third preset temperature is set to be 200 ℃, the first substrate layer is treated by using a strong acid mixed solution, and then the first substrate layer is sequentially cleaned by using acetone, ethanol and deionized water under the normal temperature condition, so that a clean first substrate layer is obtained.
Optionally, the strong acid mixed solution is H 2 SO 4 :HNO 3 (3:1)。
Step 3 referring to fig. 2b, a predetermined thin film 2 containing silicon is deposited on the first substrate layer 1.
Specifically, a preset film 2 is deposited on the first substrate layer 1 through a magnetron sputtering process.
Alternatively, the preset film 2 includes a silicon film or a silicon dioxide film.
Optionally, the thickness of the preset film is 200-500nm.
Step 4, please refer to fig. 2C, at a first preset temperature, diffusing boron element in solid Boron Nitride (BN) in a preset system to introduce a boron source, at a second preset temperature, etching the preset thin film 2 in the preset system to diffuse silicon in the preset thin film 2 and boron element in the preset system into the first substrate layer 1 to obtain a second substrate layer 3, wherein the second substrate layer 3 sequentially comprises an undoped diamond layer 31 (the undoped diamond layer 31 is the original first substrate layer), a silicon-boron co-doped diamond layer 32 and a diamond surface terminal 33 from bottom to top, and the diamond surface terminal 33 is a diamond layer comprising carbon-hydrogen bonds (C-H) and carbon-silicon bonds (C-Si), and the preset system is provided with boron element decomposed and diffused by solid boron nitride.
In a specific embodiment, step 4 may specifically include:
and 4.1, placing the solid boron nitride into a preset system, heating the solid boron nitride to a first preset temperature, and decomposing the solid boron nitride in the preset system at the first preset temperature to introduce a boron source into the preset system.
Alternatively, the preset system is an MPCVD (Microwave Plasma Chemical Vapor Deposition ) system.
In this embodiment, solid boron nitride is put into a microwave plasma chemical vapor deposition system as a solid boron source dopant for etching with hydrogen plasma, the microwave plasma chemical vapor deposition system is heated to a first preset temperature to decompose the solid boron nitride, so that boron elements are enriched in the system environment, and then the remaining object after decomposition is taken out, so that a certain amount of boron elements exist in a chamber of the MPCVD system to provide a boron source for boron in the chamber of the MPCVD system.
Optionally, the first preset temperature ranges from 600 ℃ to 700 ℃.
And 4.2, placing the first substrate layer 1 with the preset film 2 deposited on the surface into a preset system with boron, starting by utilizing hydrogen (namely, hydrogen is externally added with microwave energy under low pressure to form hydrogen plasma), and etching the preset film 2 at a second preset temperature to diffuse the boron in the preset system and silicon in the preset film 2 into the first substrate layer 1 to obtain a second substrate layer 3.
Optionally, the second preset temperature ranges from 900 ℃ to 1000 ℃.
For example, the first substrate layer 1 with the pre-set film 2 deposited on the surface is placed in an MPCVD system, and the vacuum is evacuated to 10 - 5 And (3) introducing hydrogen to start the process below mbar, heating to 900 ℃ and carrying out surface etching to obtain the silicon-boron co-doped second substrate layer 3 with silicon thermal diffusion doping.
Alternatively, the hydrogen flow is 600sccm.
In the embodiment, the preset film is etched by high-temperature hydrogen plasma, and silicon and boron are subjected to boron-silicon co-doping under the effect of high-temperature diffusion in the process.
And 5, standing the second substrate layer in air to obtain a third substrate layer.
Optionally, the standing time is 1h-12h.
And 6, depositing a metal layer on the diamond surface terminal in the third substrate layer.
Optionally, the material of the metal layer includes Au, and the thickness is 100nm.
The invention can effectively reduce the process difficulty. The invention deposits the preset film in a magnetron sputtering mode, takes the preset film as a silicon source and solid BN as a boron source, realizes the boron-silicon co-doping of diamond by a thermal diffusion method, and can realize that the diamond exceeds 10 based on common MPCVD equipment 20 cm -3 The boron doping concentration of (see fig. 3) is high, so that high charged carriers can be still realized under low activation energy, good bulk conductivity is realized, and the requirement of in-situ growth of heavy boron doped diamond on equipment is reduced.
The invention can effectively reduce the process cost. The invention deposits the preset film in a magnetron sputtering mode, takes the preset film as a silicon source and takes the solid BN as a boron source, and has lower price compared with silane and borane for the existing MPCVD growth. In additionThe invention realizes the boron-silicon co-doping of the diamond by a thermal diffusion method, boron atoms can be directly doped into the diamond structure by high-temperature diffusion without introducing new equipment, and the invention is compatible with the prior process. Compared with the ion implantation method, the thermal diffusion method adds new equipment in the ion implantation method, and increases the process cost; compared with an in-situ doping growth method, the in-situ doping growth method cannot well control the in-situ doping growth of the diamond when two elements are doped simultaneously. The thermal diffusion doping is carried out at high temperature, and the high temperature can increase the kinetic energy of carbon atoms in the diamond so as to promote the doping of boron and silicon elements; at the same time, in the initial stage of thermal diffusion doping, silicon on the surface of diamond and boron element existing in a large amount in the environment form a significant concentration gradient under the high-temperature condition, and the diffusion is driven based on the concentration gradient, so that the diffusion of the dopant into the interior is accelerated, therefore, the doping speed is high, and through verification, the method can realize the thickness of more than 300nm and the peak concentration of more than 10 minutes 20 cm -3 The diamond boron doping of (2) is faster and less costly than conventional boron doped diamond in situ growth rates (1 μm/h).
The invention adopts the thermal diffusion method to realize the boron-silicon co-doping of the diamond, and the method can be applied to the large-size diamond substrate, thereby being beneficial to further reducing the cost and being beneficial to the preparation of devices.
In MPCVD, the method is annealed at high temperature in a hydrogen atmosphere to realize boron-silicon co-doping of the diamond, so that hydrogen passivation is performed on the surface of the diamond while preparing the boron-silicon co-doped diamond, the work function of the surface of the diamond and the barrier height with Au metal are reduced, and the resistance of ohmic contact is further reduced.
In the description of the present invention, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Further, one skilled in the art can engage and combine the different embodiments or examples described in this specification.
Although the invention is described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. Modifications made by those skilled in the art without departing from the spirit of the invention should be considered as falling within the scope of the invention.
Claims (10)
1. A method for preparing a low-resistance ohmic contact on diamond, comprising the steps of:
selecting diamond which is not intentionally doped as a first substrate layer;
depositing a layer of preset film containing silicon element on the first substrate layer;
at a first preset temperature, diffusing boron elements in solid boron nitride in a preset system to introduce a boron source, etching the preset film in the preset system at a second preset temperature to diffuse silicon in the preset film and boron elements in the preset system into a first substrate layer to obtain a second substrate layer, wherein the second substrate layer sequentially comprises an undoped diamond layer, a silicon-boron co-doped diamond layer and a diamond surface terminal from bottom to top, the diamond surface terminal is a diamond layer comprising carbon-hydrogen bonds and carbon-silicon bonds, and the preset system is provided with a solid boron source dopant;
standing the second substrate layer in air to obtain a third substrate layer;
and depositing a metal layer on the terminal of the diamond surface in the third substrate layer to finish the preparation of the ohmic resistor.
2. The method of fabricating a low resistance ohmic contact on diamond according to claim 1, further comprising, prior to depositing a predetermined film comprising elemental silicon on the first substrate layer:
and at a third preset temperature, treating the first substrate layer by using a strong acid mixed solution, and then cleaning the first substrate layer by using acetone, ethanol and deionized water in sequence under the normal temperature condition to obtain a clean first substrate layer.
3. The method of fabricating a low resistance ohmic contact on diamond according to claim 1, wherein depositing a predetermined thin film containing elemental silicon on the first substrate layer comprises:
and depositing a layer of the preset film on the first substrate layer through a magnetron sputtering process.
4. A method of fabricating a low resistance ohmic contact on diamond according to claim 1 or 3, wherein the predetermined thin film comprises a silicon thin film or a silicon oxide thin film.
5. A method of producing a low resistance ohmic contact on diamond according to claim 1 or 3, wherein the predetermined thin film has a thickness of 200 to 500nm.
6. The method for preparing a low-resistance ohmic contact on diamond according to claim 1, wherein the step of diffusing boron element in solid boron nitride in a preset system at a first preset temperature to introduce a boron source, and etching the preset film in a preset system at a second preset temperature to diffuse silicon in the preset film and boron element in the preset system into the first substrate layer to obtain a second substrate layer, comprises:
placing solid boron nitride into the preset system, heating the solid boron nitride to the first preset temperature, and decomposing the solid boron nitride in the preset system at the first preset temperature to introduce a boron source into the preset system;
and placing a first substrate layer with the surface deposited with the preset film into the preset system with the boron element introduced, starting the system by utilizing hydrogen, and etching the preset film at a second preset temperature to diffuse the boron element in the preset system and silicon in the preset film into the first substrate layer to obtain the second substrate layer.
7. The method of making a low resistance ohmic contact on diamond according to claim 1 or 6, wherein the first predetermined temperature is in a range of 600 ℃ to 700 ℃.
8. The method of making a low resistance ohmic contact on diamond according to claim 1 or 6, wherein the second predetermined temperature is in a range of 900 ℃ to 1000 ℃.
9. The method for manufacturing a low resistance ohmic contact on diamond according to claim 1, wherein the step of standing the second substrate layer in air to obtain a third substrate layer comprises:
and standing the second substrate layer in air for 1-12 h to obtain the third substrate layer.
10. The method of claim 1, wherein the material of the metal layer comprises Au.
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