TWI429779B - Method of diamond nucleation - Google Patents

Description

Diamond nucleation method

The invention relates to a diamond nucleation method, in particular to a method for growing a diamond crystal without external bias and without pre-placed diamond seeds on a non-diamond substrate.

Diamonds possess many excellent physical, chemical, optical, mechanical and electrical properties, such as high thermal conductivity, chemical inertness, highest hardness, high Young's modulus and low coefficient of friction, wide energy gap and wide optical wear. Through the frequency domain. Therefore, polycrystalline diamond (PCD) is a material widely used in the industrial field in recent years, and its advantages are in addition to the excellent mechanical properties of a single crystal diamond, and can be processed into a desired shape in accordance with the purpose.

When diagnosing diamonds on non-diamond substrates, nucleation or seeding must be performed. Since self-nucleation can simplify the diamond deposition process, many studies are devoted to the self-nucleation of diamonds. method. The heterogeneous nucleation method is bias-enhanced nucleation (BEN), which increases the kinetic energy of the species by applying a negative bias to the substrate, and effectively impacts the substrate to nucleate, wherein the bias is applied. It can be DC bias or RF self-bias; other related research indicates that the additional coating layer (such as amorphous carbon layer) can help to carry out the subsequent nucleation process; however, the nuclear species formed by this method are less likely to be uniform. The distribution is also difficult to penetrate into the groove of the substrate.

The use of chemical vapor deposition (CVD) to grow polycrystalline diamond films is a well-established and common method, mainly using argon, hydrogen, oxygen, nitrogen, hydrocarbons and others. A precursor material such as a carbon material, by using various forms of energy, to free and excite a mixed gas containing a precursor material, thereby growing a polycrystalline diamond film; wherein microwave plasma chemical vapor deposition (MPCVD) One or more reaction materials are introduced into the cavity, activated by microwave plasma to cause ionization and electrochemical reaction, and a solid film is deposited on the surface of the non-diamond substrate of the existing diamond crystal. However, it is currently difficult to deposit a diamond film on a substrate without diamonds or without a negative bias using MPCVD.

The main object of the present invention is to provide a novel diamond nucleation method capable of performing diamond nucleation directly on a non-crystallized non-diamond substrate without external biasing, and growing a high purity diamond crystal. .

To achieve the above object, the diamond nucleation method of the present invention comprises the steps of: providing a substrate and pretreating a surface of the substrate with a chemical reagent, wherein the chemical reagent is at least one selected from the group consisting of monosulfate, monophosphate, And a group of persulfate; providing a mixed gas in a reaction chamber, wherein the mixed gas comprises a carbon-containing gas, and more optionally an inert gas, a hydrogen gas or a carbon dioxide; A plasma is formed in the reaction chamber, and the carbon-containing gas is reacted on the surface of the pretreated substrate to form a plurality of core species without applying a bias voltage.

Here, the chemical vapor deposition system used in the present invention is not limited, and is generally used for formation in addition to a plasma enhanced CVD and a hot-filament CVD system. Diamond chemical vapor deposition systems are suitable for use in the present invention, preferably in a microwave plasma chemical vapor deposition system for diamond nucleation.

In the diamond nucleation method of the present invention, the substrate only needs to be temperature resistant, and is not easily reacted with or corroded by the chemical reagent, so the substrate can be the target of any crystal to be deposited. Here, the present invention can nucleate directly on a conductive substrate or an insulating substrate without applying a bias voltage (such as a DC bias or an RF self-bias); in particular, a carbon coating is additionally formed as a transition The prior art of the layer, the invention can directly nucleate on the surface of the non-carbon phase, without additionally forming a carbon coating as a transition layer, that is, the invention can directly nucleate on a non-diamond substrate without carbon coating, The substrate is preferably a germanium substrate or a germanium dioxide substrate.

Wherein the chemical reagent on the surface of one of the pretreatment substrates is at least one selected from the group consisting of monosulfate, monophosphate, and monopersulfate, preferably at least one selected from the group consisting of ammonium monosulfate and metal monosulfate. More preferably, at least one selected from the group consisting of ammonium persulfate, copper sulfate, and ammonium phosphate, the group consisting of a salt, an ammonium monophosphate salt, a metal monophosphate salt, an ammonium persulfate salt, and a metal persulfate salt. Group, the best is ammonium persulfate.

Further, pretreating the surface of the substrate with a chemical reagent may include the steps of: coating a chemical reagent solution on the surface of the substrate; and removing one of the solvents in the chemical reagent solution. The coating method and the removal method are not limited, and may be carried out by any conventional method, for example, permeable droplet coating. a method, a dip coating method, a dip coating method, an oscillating treatment, a spray coating method, or a curtain coating method for coating the chemical reagent solution on the surface of the substrate; and removing the chemical by heat treatment The solvent in the reagent solution and the amount of the chemical agent on the surface of the coated substrate.

In the present invention, the carbon-containing gas can be nucleated by reaction with or without hydrogen. Accordingly, compared to the conventional nucleation method rich in hydrogen, since the microwave power required for the free inert gas (such as argon) is small, and the atomic hydrogen content generated under the condition of no hydrogen doping is small, it is favorable for low temperature. Process. In detail, the heat released by the combination of microwave energy and atomic hydrogen causes the substrate temperature to rise. Therefore, the process conditions of low microwave power and low atomic hydrogen content help to reduce the heat load of the substrate, and can be used at lower temperatures. Nucleation under the conditions of the process is conducive to expanding the application range of synthetic diamonds. In addition, nucleation under conditions of no hydrogen doping has the advantage of being safer in process. Furthermore, the present invention can also perform diamond nucleation under conditions of hydrogen (small amount of hydrogen), requiring only high microwave power to generate plasma, and the substrate temperature will be higher, but the diamond nucleation can still be smoothly performed.

In the present invention, the carbon-containing gas is not particularly limited, and may be any carbon-containing gas used in a conventional chemical vapor deposition method, but is preferably a hydrocarbon gas such as methane or acetylene. The volume percentage of the carbon-containing gas in the mixed gas is not limited, and is preferably from 0.05% to 50%, more preferably from 0.1% to 10%.

Further, the mixed gas may further include a hydrogen gas, and the volume percentage of the hydrogen in the mixed gas is not limited, and is preferably from 0.05% to 50%, more preferably from 0.1% to 20%.

Further, in the present invention, the mixed gas may be used: any mixed gas conventionally used in a chemical vapor deposition system for forming diamonds.

In the present invention, those skilled in the art can adjust the appropriate microwave power according to the microwave frequency and the reactor size. For example, if a substrate carrier of 5 cm to 7 cm diameter and a 2.45 GHz microwave are used, the microwave power is compared. Preferably, the process parameters of the diamond nucleation are: the substrate temperature is about 200 ° C to 1000 ° C, and the deposition pressure (ie, the mixed gas pressure) is about 1 Torr to 300 Torr.

Thereby, the invention can further improve the purity and quality of the synthetic diamond by controlling the flow rate of the mixed gas and avoiding excessive carbon-containing gas in the reaction chamber to form carbon soots. In detail, the conventional method often causes the plasma to form an unstable orange-red plasma region due to gas phase synthesis of carbon particles, thereby affecting the purity and quality of the diamond, resulting in process failure. However, the present invention can vary with the size of the reaction chamber. The size of the microwave power, the deposition pressure, and the content of the carbon-containing gas in the mixed gas, lowering the total flow rate of the mixed gas to prolong the residence time of the reaction gas in the reaction chamber, thereby making the amount of carbon in the reaction chamber It is equivalent to the amount required for the synthesis of carbon particles in the gas phase to avoid the instability of the plasma caused by the gas phase synthesis of carbon particles, thereby improving the quality of diamond nucleation. Specifically, in actual operation, the operator can adjust the total mixed gas flow rate by observing whether an unstable orange-red plasma region is formed in the plasma; that is, in the present invention, preferably, By adjusting the total flow rate of the mixed gas, the plasma is prevented from forming an orange-red plasma region. Taking the volume of 4 liters of the reaction chamber as an example, the present invention preferably controls the total flow rate of the mixed gas at about 1200 watts of microwave power and 110 Torr deposition pressure (i.e., by reaction). The volume per chamber is preferably from 1 sccm to 25 sccm, more preferably from 30 sccm to 60 sccm (i.e., the total flow rate is preferably from 7 sccm to 15 sccm based on the volume per liter of the reaction chamber). To improve the quality of diamond nucleation. Here, the volume percentage of the carbon-containing gas in the mixed gas is preferably from about 0.05% to 50%, more preferably from about 0.1% to 10%, most preferably from about 0.5% to 5%, for example, one of the present inventions. The embodiment uses methane as the carbonaceous gas in an amount of about 0.5 to 3%; in addition, those having ordinary knowledge in the art can modulate the diamond nucleation density by adjusting the content of the carbon-containing gas in the mixed gas. Accordingly, when the present invention performs diamond nucleation under conditions of microwave power of 200 W to 1200 W, carbon-containing gas of 0.1% to 10%, and deposition pressure of 50 Torr to 300 Torr, based on the volume per liter of the reaction chamber, Preferably, the present invention controls the total flow rate of the mixed gas from about 1 sccm to 50 sccm to facilitate the formation of high purity and high quality synthetic diamond.

In the present invention, the inert gas is preferably an inert gas other than helium, such as argon gas, helium gas, neon gas or a mixed gas thereof, and more preferably argon gas.

In summary, the present invention can form a nuclear species on a pre-treated substrate, and can further grow a high-purity diamond crystal from a nucleation-derived nuclear species. Moreover, the present invention not only accomplishes diamond nucleation and growth under the described process, but also prepares diamonds of various structures and sizes by adjusting appropriate diamond growth parameters. In particular, the step of processing the substrate before the present invention is simple, and the nucleation method of the present invention does not require biasing as in the bias-assisted nucleation method, and there is no need to additionally form a carbon coating. Therefore, the diamond nucleation method of the present invention can grow high-purity diamond crystals by a simple process.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention.

[Substrate before processing] Example 1

First, the ruthenium substrate and the ruthenium dioxide substrate were washed with acetone, isopropyl alcohol, ethanol, and deionized water in sequence using ultrasonic vibration, and each substrate was washed for 1 minute. Next, the ruthenium substrate and the ruthenium dioxide substrate were treated with a saturated (NH ₄ ) ₂ S ₂ O ₈ , CuSO ₄ , or (NH ₄ ) ₃ PO ₄ deionized water solution for 30 minutes using ultrasonic vibration. Thereafter, the ruthenium substrate and the ruthenium dioxide substrate were immersed in deionized water and then blown dry with N ₂ .

Example 2

First, the ruthenium substrate and the ruthenium dioxide substrate were washed with acetone, isopropyl alcohol, ethanol, and deionized water in sequence using ultrasonic vibration, and each substrate was washed for 1 minute. Next, a saturated (NH ₄ ) ₂ S ₂ O ₈ or (NH ₄ ) ₃ PO ₄ deionized water solution is dropped on the ruthenium substrate and the ruthenium dioxide substrate, and then the two substrates are heated by a heating plate to about 500-550 ° C. The (NH ₄ ) ₂ S ₂ O ₈ solution on the substrate was evaporated. Thereafter, the ruthenium substrate and the ruthenium dioxide substrate were immersed in deionized water and then blown dry with N ₂ . Therefore, a trace of coffee rings appears on the substrate after the pretreatment.

[Microwave plasma assisted chemical vapor deposition]

The following example uses a SEKI 1.5 kW microwave plasma chemical vapor deposition system using a quartz bell jar type in which the mixed gas contains 94% Ar, 3% CH ₄ , and 3% H ₂ ; and a 532 nm laser is used. The excitation source was subjected to Raman spectroscopy, and a diamond-specific signal peak was found at about 1330-1366 cm ^-1 .

Example 3

The pretreated copper oxide substrate (substrate size: 1 x ¹ cm ² ) of Example 1 was used for experiments with a non-pretreated ceria substrate. The MPCVD reaction conditions at 2.45 GHz were as follows: mixed gas: 47 sccm Ar, 1.5 sccm CH ₄ , and 1.5 sccm H ₂ ; deposition pressure: 190 Torr; microwave power: 1200 W; substrate temperature: 963 ° C; reaction time: 2 hours. Please refer to FIG. 1 , which is a Raman spectrum of a diamond crystal grown under 532 nm laser excitation, in which saturated (NH ₄ ) ₂ S ₂ O ₈ , CuSO ₄ , and (NH ₄ ) ₃ PO _{4 are used} . The cerium oxide substrates treated with aqueous ion solution are abbreviated as "NS", "NCu", and "NP", respectively. The untreated pre-treated cerium oxide substrate is abbreviated as "control group"; at 1335 cm ^-1 Raman shift Discover the peak of the signal of diamonds.

Example 4

The pre-treated ruthenium substrate (substrate size: 1 x ¹ cm ² ) of Example 1 was used for experiments with a pre-treated ruthenium substrate. The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 979 °C. Please refer to FIG. 2 , which is a Raman spectrum of a diamond crystal grown under 532 nm laser excitation, in which saturated (NH ₄ ) ₂ S ₂ O ₈ , CuSO ₄ , and (NH ₄ ) ₃ PO _{4 are used} . The ruthenium substrate treated with ionic aqueous solution is abbreviated as "NS", "NCu", and "NP", respectively. The untreated substrate is abbreviated as "control"; the signal of diamond can be found at 1335cm ^-1 Raman shift. peak.

Example 5

The experiment was carried out using the (NH ₄ ) ₂ S ₂ O ₈ pretreated cerium oxide substrate (substrate size: 1 x ¹ cm ² ). The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 941 °C. Figure 3 is a top view of a growing diamond crystal under a scanning electron microscope (SEM).

Example 6

The experiment was carried out using the ruthenium substrate (substrate size: 1 x ¹ cm ² ) subjected to pretreatment with (NH ₄ ) ₂ S ₂ O ₈ in Example 2. The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 973 °C.

Please refer to FIG. 4 , which is a Raman spectrum of a diamond crystal grown in Examples 5 and 6 at a laser excitation of 532 nm. The signal peak of the diamond can be found at a Raman shift of 1336 cm ⁻¹ .

Example 7

The experiment was carried out using the (NH ₄ ) ₂ S ₂ O ₈ pretreated cerium oxide substrate (substrate size: 1 x ¹ cm ² ). The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 989 °C.

Example 8

The experiment was carried out using the ruthenium substrate (substrate size: 1 x ¹ cm ² ) subjected to pretreatment with (NH ₄ ) ₂ S ₂ O ₈ in Example 2. The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 989 °C.

Please refer to FIG. 5 , which is a Raman spectrum of a diamond crystal grown in Examples 7 and 8 at a laser excitation of 532 nm. The signal peak of the diamond can be found at a Raman shift of 1334 cm ⁻¹ .

Example 9

The experiment was carried out using the (NH ₄ ) ₂ S ₂ O ₈ pretreated cerium oxide substrate (substrate size: 1 x ¹ cm ² ). The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 923 ° C, the CH ₄ content was changed to 0.5 sccm, and the deposition pressure was changed to 210 Torr. Figure 6 is a plan view of a growing diamond crystal (central portion) under a scanning electron microscope (SEM).

Example 10

The experiment was carried out using the ruthenium substrate (substrate size: 1 x ¹ cm ² ) subjected to pretreatment with (NH ₄ ) ₂ S ₂ O ₈ in Example 2. The MPCVD reaction conditions were the same as in Example 3 except that the substrate temperature was changed to 923 ° C, the CH ₄ content was changed to 0.5 sccm, and the deposition pressure was changed to 210 Torr.

Example 11

The experiment was carried out using the (NH ₄ ) ₂ S ₂ O ₈ pretreated cerium oxide substrate (substrate size: ² x ² cm ² ) in Example 1. The MPCVD reaction conditions at 2.45 GHz are as follows, as shown in modes 1, 2, and 3, respectively: Mode 1: Mixed gas: 47 sccm Ar, 1.5 sccm CH ₄ , and 1.5 sccm H ₂ , deposition pressure: 100 Torr, microwave power: 1200 W, substrate temperature: 768 ° C, reaction time: 2 hours; mode 2: mixed gas: 1 sccm CH ₄ , and 99 sccm H ₂ , deposition pressure: 50 Torr, microwave power: 1300 W, substrate temperature: 892 ° C, reaction time: 1 Hour; and mode 3: mixed gas: 1 sccm CH ₄ , and 99 sccm H ₂ , deposition pressure: 50 Torr, microwave power: 1300 W, substrate temperature: 878 ° C, reaction time: 5 hours.

Please refer to FIG. 8 to FIG. 10 , which are top views of the diamond crystal formed by the modes 1 to 3 respectively under a scanning electron microscope; FIG. 11 is a Raman spectrum of the grown diamond crystal excited by a 532 nm laser, which is at 1334 cm. The signal peak of the diamond can be found at the ^-1 Raman shift.

Example 12

The experiment was carried out using the (NH ₄ ) ₃ PO ₄ pretreated cerium oxide substrate (substrate size: 5 x 5 mm ² ) in Example 2. The MPCVD reaction conditions at 2.45 GHz are as follows, as shown in Modes 1 and 2, respectively: Mode 1: Mixed gas: 47 sccm Ar, 1.5 sccm CH ₄ , and 1.5 sccm H ₂ , deposition pressure: 100 Torr, microwave power: 1200 W, substrate Temperature: 752 ° C, reaction time: 2 hours; and mode 2: mixed gas: 1 sccm CH ₄ , and 99 sccm H ₂ , deposition pressure: 50 Torr, microwave power: 1300 W, substrate temperature: 878 ° C, reaction time: 6 hours. Please refer to FIGS. 12 and 13 , which are top views of the diamond crystal formed by the modes 1 and 2 under a scanning electron microscope, respectively.

Example 13

The experiment was carried out by using the (NH ₄ ) ₃ PO ₄ pretreated ruthenium substrate (substrate size: 5 x 5 mm ² ) in Example ² , and the MPCVD reaction conditions were the same as in Example 12. Please refer to FIGS. 14 and 15 , which are top views of the diamond crystal formed by the modes 1 and 2 under a scanning electron microscope, respectively.

Please refer to FIG. 16 , which is a Raman spectrum of a diamond crystal grown in Examples 12 and 13 at a laser excitation of 532 nm. The signal peak of the diamond can be found at a Raman shift of 1332 cm ⁻¹ .

Example 14

The experiment was carried out using Example 2 on a ceria substrate (substrate size: 5 x 5 mm ² ) pretreated with a saturated (NH ₄ ) ₂ S ₂ O ₈ deionized aqueous solution. The MPCVD reaction conditions at 2.45 GHz were as follows, mixed gas: 50 sccm CH ₄ , 50 sccm CO ₂ , deposition pressure: 30 Torr, microwave power: 1000 W, substrate temperature: 840 ° C, reaction time: 3 hours. Please refer to FIG. 17 for a top view of the formed diamond crystal under a scanning electron microscope, and FIG. 18 is a diamond crystal grown by a growing diamond crystal (experimental group) under a laser excitation of 325 nm and a substrate with a preset seed crystal (cf. Comparison of the Raman spectra of the group); the experimental group-1 and the experimental group-2 are different regions of the diamond crystal. The diamond crystals obtained by the pretreatment of Example 2 and the preset seed crystals all showed a diamond Raman signal peak of 1332 cm ^-1 .

Accordingly, the present invention can form a nuclear species on the pretreated substrate, and can further grow high-purity diamond crystals from the nucleation-derived nuclear species. Compared with the conventional method, the step of processing the substrate before the present invention is simple, and it is not necessary to apply a bias voltage as in the bias-assisted nucleation method, and it is not necessary to additionally form a carbon coating. The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

1 is a Raman spectrum of a diamond crystal formed in Example 3 of the present invention under a laser excitation of 532 nm.

2 is a Raman spectrum of a diamond crystal formed in Example 4 of the present invention under a laser excitation of 532 nm.

Figure 3 is a plan view of a diamond crystal formed in Example 4 of the present invention under a scanning electron microscope.

4 is a Raman spectrum of a diamond crystal formed in Examples 5 and 6 of the present invention at a laser excitation of 532 nm.

Figure 5 is a Raman spectrum of a diamond crystal formed in Examples 7 and 8 of the present invention at a laser excitation of 532 nm.

Figure 6 is a plan view of a diamond crystal formed in Example 9 of the present invention under a scanning electron microscope.

Figure 7 is a Raman spectrum of a diamond crystal formed in Examples 9 and 10 of the present invention at a laser excitation of 532 nm.

Figure 8 is a plan view of a diamond crystal formed in the first embodiment of the present invention under a scanning electron microscope.

Figure 9 is a plan view of a diamond crystal formed in the second embodiment of the present invention under a scanning electron microscope.

Figure 10 is a plan view of a diamond crystal formed in the third embodiment of the present invention under a scanning electron microscope.

Figure 11 is a Raman spectrum of a diamond crystal formed in Example 11 of the present invention under a 532 nm laser excitation.

Figure 12 is a plan view of a diamond crystal formed in the first embodiment of the present invention under a scanning electron microscope.

Figure 13 is a plan view of a diamond crystal formed in the second embodiment of the present invention under a scanning electron microscope.

Figure 14 is a plan view of a diamond crystal formed in the first embodiment of the present invention under a scanning electron microscope.

Figure 15 is a plan view of a diamond crystal formed in the second embodiment of the present invention under a scanning electron microscope.

Figure 16 is a Raman spectrum of a diamond crystal formed in Examples 12 and 13 of the present invention at a laser excitation of 532 nm.

Figure 17 is a plan view of a diamond crystal formed in Example 14 of the present invention under a scanning electron microscope.

Figure 18 is a Raman spectrum of a diamond crystal formed in Example 14 of the present invention under a laser excitation of 325 nm and a diamond crystal of a control group.

Claims (17)

A diamond nucleation method comprising the steps of: providing a substrate and pretreating a surface of the substrate with a chemical reagent, wherein the chemical reagent is at least one selected from the group consisting of monosulfate, monophosphate, and monopersulfate a group; providing a mixed gas in a reaction chamber, wherein the mixed gas comprises a carbon-containing gas; and forming a plasma in the reaction chamber, and the carbon-containing gas is not biased A plurality of nucleus species are formed on the surface of the pretreated substrate. The diamond nucleation method according to claim 1, wherein the substrate is a germanium substrate or a germanium dioxide substrate. The diamond nucleation method according to claim 1, wherein the chemical reagent is at least one selected from the group consisting of ammonium monosulfate, metal monosulfate, ammonium monophosphate, metal monophosphate, ammonium persulfate, And a group consisting of a metal sulfate. The method of diamond nucleation according to claim 3, wherein the chemical reagent is at least one selected from the group consisting of ammonium persulfate, copper sulfate, and ammonium phosphate. The method for nucleating a diamond according to claim 1, wherein the surface of the substrate pretreated with the chemical agent comprises the steps of: coating a chemical reagent solution on the surface of the substrate; and removing the chemical Reagent solution. The diamond nucleation method according to claim 5, wherein the droplet coating method, the dip coating method, the dip coating method, the shock treatment, the spray coating method, or the curtain coating method are used. The chemical reagent solution is coated on the surface of the substrate. The diamond nucleation method of claim 5, wherein the chemical reagent solution is removed by heat treatment. The diamond nucleation method of claim 1, wherein the nucleus is formed in a microwave plasma chemical vapor deposition system. The diamond nucleation method of claim 1, wherein the mixed gas further comprises at least one selected from the group consisting of hydrogen or an inert gas. The method of diamond nucleation according to claim 1, wherein the nucleus is formed under conditions of no hydrogen doping. The method of diamond nucleation according to claim 1, wherein the carbon-containing gas is methane and the inert gas is argon. The diamond nucleation method according to claim 1, wherein the volume percentage of the carbon-containing gas in the mixed gas is 0.05% to 50%. The diamond nucleation method according to claim 12, wherein the volume percentage of the carbon-containing gas in the mixed gas is 0.1% to 10%. The method of diamond nucleation according to claim 9, wherein the volume percentage of the hydrogen in the mixed gas is 0.05% to 50%. The method of diamond nucleation according to claim 14, wherein the volume percentage of the hydrogen in the mixed gas is from 0.1% to 20%. The diamond nucleation method according to claim 3, wherein the carbon-containing gas system is nucleated at a substrate temperature of 200 ° C to 1000 ° C. The diamond nucleation method according to claim 1, wherein the carbon-containing gas system is nucleated at a deposition pressure of 50 Torr to 300 Torr.