JPS6057507B2 - Manufacturing equipment and method for manufacturing ultra-hard high-purity silicon nitride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing ultrahard high-purity silicon nitride and a method for producing the same.

One of the inventors of the present invention is Japanese Patent Application No. 51-2468.
2-9699 Wani Publication), he invented and filed a patent application for ultra-hard high-purity silicon nitride, a method for manufacturing the same, and an apparatus for manufacturing the same.

The invented ultra-hard high-purity silicon nitride is of three types: oriented crystalline, fine-grained crystalline, and amorphous,
Oriented crystalline silicon nitride has a hexagonal crystal system, and its crystal plane is one selected from (HkO), (HOl), or (Hkl), or two or more planes are parallel to each other. It has an oriented structure and has a micro Vickers hardness of 3000k9/T when the load is 100g.
ld or more, the crystal grain size is 1 to 50 pm, and fine-grained crystalline silicon nitride has a crystal grain size of 1 μm or less on average, the primary pyramidal structure is composed of fine-grained crystals, and the micro-Vickers hardness is 3500 when the load is 100g
k9/i, and the micro Vickers hardness of amorphous silicon nitride is 2000k91rd when the load is 100g.
That's all.

According to JP-A-52-96999, the three types of silicon nitride are prepared by combining a nitrogen deposition source gas and a silicon deposition source gas onto a substrate heated within a temperature range of 1000 to about 1900°C using a tube. The periphery of the nitrogen deposition source gas flux sprayed onto the substrate is surrounded by the silicon deposition source gas, and a gas phase decomposition reaction of both of the gases occurs. is produced on or near the substrate to produce silicon nitride, and the silicon nitride is deposited on the substrate, and
The manufacturing device includes a container, a means for gripping and heating a substrate sealed in the container, and a spray tube for spraying a nitrogen deposition source gas and a silicon deposition source gas onto the substrate, respectively. In the silicon nitride manufacturing apparatus, the blowing tube is a combination tube, and the nitrogen deposition source gas blowing tube is surrounded by a silicon deposition source gas blowing tube, and the open end of the nitrogen deposition source gas blowing tube is We have proposed an apparatus for producing ultrahard high-purity silicon nitride, characterized in that the distance between the silicon deposition source gas blowing tube and the substrate is shorter than the distance between the opening end of the silicon deposition source gas blowing tube and the substrate.

After filing a patent application for the invention, the present inventors tried direct heating means and indirect heating means as means for heating the substrate sealed in the container.

When the substrate is electrically conductive, direct heating means by directly applying electricity can be used, but when the substrate is non-conductive, indirect heating means must be used. Also,
In order to industrially produce ultra-hard, high-purity silicon nitride, the present invention has found that it is advantageous to use indirect heating means in order to greatly alleviate restrictions on the material and shape of the substrate and to improve productivity. With this in mind, the authors attempted to research the production of ultra-hard, high-purity silicon nitride using indirect heating means.

However, with the indirect heating means, the tolerance range of manufacturing conditions for depositing the silicon nitride on the substrate is extremely narrow, the Si yield is poor, and the open ends of both the deposition source gas blowing pipes are too thin. However, there was a drawback in that a blockage phenomenon occurred, making operation impossible. The present invention is based on the above-mentioned Japanese Unexamined Patent Publication No. 5
In the manufacturing apparatus and manufacturing method of the invention described in 2-9699 Wani, it is possible to eliminate and improve the above-mentioned defects that occur when heating the substrate using indirect heating means, and furthermore, it is possible to eliminate and improve the limitations on the material and shape of the substrate. The object is to provide an efficient manufacturing device and manufacturing method that can be relaxed to a large extent, and the above object is achieved by providing the manufacturing device and manufacturing method described in the claims. be able to.

Next, the present invention will be explained in detail.

The present inventors investigated in detail the cause of the phenomenon in which the open ends of both deposition source gas blowing tubes are blocked when heating a substrate by the indirect heating means, and found that nitrogen deposition source gas and silicon deposition source The gases are heated, decomposed, and activated in the pipes of both deposition source gas spray pipes heated by indirect heating means, and are activated, and at the moment they merge at the open ends of the respective spray pipes, a rapid reaction occurs. The main cause is that a reaction occurs, and various compounds of silicon, nitrogen, and hydrogen become solid and precipitate, and adhere to the open end of the gas blowing tube, thereby blocking the open end of the gas blowing tube. In addition to finding out that this is the cause, the permissible range of manufacturing conditions for ultrahard, high-purity silicon nitride is extremely narrowly restricted due to decomposition, alteration, or activation of each of these gases, and the Si yield also decreases. We were also able to investigate the cause of this.

The present inventors discovered that the nitrogen deposition source gas and the silicon deposition source gas are
In order to prevent decomposition, alteration, or activation due to heating in the gas blowing tube, we have come up with the idea of shielding the gas blowing tube from the high temperatures that occur when the substrate is heated by indirect heating means. The manufacturing apparatus of the present invention was completed. That is, in the apparatus of the present invention, in order to prevent the heating of the gas blowing tube that occurs secondarily by the substrate heating means, a means for forcibly cooling the gas blowing tube is provided, By suppressing the decomposition and alteration and activation caused by heating during the process in which both deposition source gases flow through the gas blowing pipe, it is possible to prevent clogging of the open end of the gas blowing pipe and to limit the tolerance range of manufacturing conditions. It has now become possible to expand the Si yield and improve the Si yield. Next, the drawings of seven apparatuses showing one embodiment of the manufacturing apparatus of the present invention will be explained. FIG. 1 is a longitudinal cross-sectional view of the above-mentioned apparatus, in which a substrate 3 held by a substrate gripping means 2 is enclosed in a container 1. As shown in FIG.

The container 1 has a double blower structure, in which a nitrogen deposition source gas blowing tube 4 is an inner tube, a silicon deposition source gas blowing tube 5 is an outer tube, and a fluid cooling jacket 6 is provided on the outer circumferential surface of the outer tube 5. A fitting pipe is provided. The open end of the inner tube 4 of the double blow tube is closer to the outer peripheral surface of the base body 3, while the open end of the outer tube 5 of the double blow tube is closer to the base body than the open end of the inner tube 4. more widely separated from Furthermore, a heating element 7 is disposed to surround the base body 3 in the vertical direction. Base body 3 by heating element 7
After being indirectly heated to a predetermined temperature, each gas is blown onto the substrate 3 from a double blowing tube, and a gas phase decomposition reaction occurs on or near the outer circumferential surface of the substrate 3. Ultra-hard high-purity silicon nitride is precipitated.

The gas produced by the gas phase decomposition reaction is discharged to the outside of the container through the exhaust pipe 8. The container 1 is made with double walls so that it can be cooled by fluid, and a heat shielding means 9 is provided between the container 1 and the heating element 7 to improve thermal efficiency. It is cut off from In FIG. 1, a fluid cooling jacket 6 is provided on the outer circumferential surface of the outer tube 5 as a means for forcibly cooling the double blow tube, but as shown in FIG. A cooling jacket 6 may be provided on the partition wall of the inner tube 5, or a cooling pipe tube 10 may be provided on the axis of the inner tube 4 as shown in FIG. 3, or a combination of these may be used. can. Note that water as well as other liquids or gases can be used as the refrigerant for the cooling jacket. In FIG. 1, the open end of the double blow tube is attached so as to be close to the bottom surface of the base 3, but in addition to this mounting method and the opening direction of the double blow tube, there is also a grip for gripping the base. It is also possible for means to extend from below the container into the central region of the container to grip the substrate and open the double blow tube downwardly or laterally.

Furthermore, the base body gripping means can vertically move, horizontally move, and rotate the base body while gripping the base body. By selecting the arrangement method between the open end of the double blowing tube and the base body, and performing the above-mentioned movements of the base body, silicon nitride can be efficiently, homogeneously and uniformly applied to predetermined locations on the outer peripheral surface of the base body. It becomes possible to precipitate it. In the manufacturing apparatus of the present invention, the heating element 7 generates heat by its electrical resistance and heats the base 3 with radiant heat. It is also possible to inductively heat the heating element 7 using indirect heating means using a device or high frequency induction heating. Further, as the heating element 7, a carbon-based heating element, a molybdenum silicide-based heating element, a silicon carbide-based heating element, or a lanthanum chromite-based heating element can be used. Although the heating element 7 is housed in the container 1 in FIG. 1, it is not necessary to house it; for example, the container may be an alumina tube, and the base body may be housed in the tube to cover the outer periphery of the tube. Next, the manufacturing method of the present invention will be described, in which a method of heating the substrate by surrounding it with a heating element can also be adopted.

The present invention provides a container, a means for gripping a substrate sealed in the container, a means for indirectly heating the substrate, and a mixture of a nitrogen deposition source gas and a carrier gas for transporting this gas if necessary. enclosing a blowing tube for blowing gas onto the substrate; enclosing it with a blowing tube for blowing a mixed gas of a silicon deposition source gas and optionally a carrier gas carrying this gas onto the substrate; A double blowing tube consisting of an outer tube and an inner tube, in which the distance between the open end of the nitrogen deposition source gas blowing tube and the base body is shorter than the distance between the open end of the silicon deposition source gas blowing tube and the base body. Then, using a device equipped with cooling means with a fluid and a jacket for forcibly cooling at least the outer tube of the double blow tube, the substrate was held in the container, and then the inside of the container was heated for 10 minutes. After reducing the pressure to -2mHg or less, use indirect heating means to heat the substrate to a temperature of 1000 to 16
The nitrogen deposition source gas and the silicon deposition source gas, or if necessary, both of the above gases and the carrier gas, are heated to within a temperature range of 00°C and at least the outer tube of the double blowing tube is forcibly cooled with a fluid. A mixed gas is sprayed onto the substrate, a gas phase decomposition reaction is caused at or near the outer circumferential surface of the substrate by contact between the two deposition source gases, and silicon nitride is generated, and the silicon nitride is transferred onto the outer circumferential surface of the substrate. The present invention relates to a method for producing ultra-hard high-purity silicon nitride, characterized in that the method of producing ultra-hard, high-purity silicon nitride is characterized in that the method of producing ultra-hard, high-purity silicon nitride is prevented from clogging at the open end of the double blowing tube.

Silicon halides (SiCl4,
SiF4, SiBr4, Si■,, Si2Cl6, Si
2Br6, Sl2l6, SiBrCl3, SiBr2C
l2, SiBr3Cl, SiICl, ), hydride (S
iH4, Sl2H6, Si3H8, Si4HlO), hydrogen halides (SiHCl3, SiHBr3, SiH
Any one or more selected from among F3, SiHI3, SiH3Br) can be used, and SiH4, which is gaseous at room temperature, or SiHCl3, SiCl, which has a high vapor pressure at room temperature, is preferably used. can be used. In addition, nitrogen deposition source compounds include nitrogen hydrides (HN3, NH3, N2H4), ammonium halides (NH4Cl, NH, F, NH4HF2,
Any one or two or more selected from NH, I) can be used, and NH3 and N2H4 are relatively inexpensive and easily available, so they can be preferably used. The main reaction formulas for obtaining silicon nitride from a silicon deposition source compound and a nitrogen deposition source compound are as follows (a), (b),
(c) and (d).

(a) When silicon tetrachloride and ammonia are used as raw materials 351
C14+4NH3→Sl3N4+121-[C1(b)
3S1H4 when silicon tetrahydride and ammonia are used as raw materials
+4NH3-Si, N4+12H2 (C) When using silicon tetrafluoride and ammonia as raw materials 3SiF4+4NH3→
Si3N4+12HF (d) When silicon tetrachloride and hydrazine are used as raw materials 3SiC14+2N2H1 → Sl3N4
+8HC1+2C12 The temperature of the substrate for causing the above reaction to obtain silicon nitride must be within the temperature range of 1000 to 1600°C.

Note that in order to transport one or more of the nitrogen deposition source and silicon deposition source compounds, one or more of N2, H2, Ar, and He may be used as a carrier gas, if necessary. . The carrier gas is used to control the total gas pressure in the container containing the substrate, to control the mixing ratio of nitrogen and the vapors of the silicon deposition source compound, and to control the flow rate of the gas blown by the double blow tube. Furthermore, silicon nitride can be produced without using a carrier gas. Next, a method for producing silicon nitride using NH3 and SlCl4 as deposition source materials and H2 as a carrier gas will be described.

After gripping the base body in the container and arranging the double blowing tube at a predetermined position, the pressure inside the container is reduced to 10 −2 mHg or less.

Next, while cooling the double spray tube by flowing water through the cooling jacket, the substrate is heated to 1,000 to 16
Heat to within the temperature range of 00°C. After reaching a predetermined temperature, the NH3 and S
iCl4 is sprayed onto the substrate in each container via dual spray tubes. At this time, since SiCl4 is a liquid at room temperature, S
Using the vapor pressure of iCI, H2 is used as a carrier gas.
The substrate is conveyed using a carrier gas and sprayed onto the substrate together with a carrier gas. The NH3 and SiCl4 cause a gas phase decomposition reaction on or near the outer circumferential surface of the substrate to form Si.
3N, is generated and deposited on the outer peripheral surface of the substrate. In the above method, if the composition ratio of NH and SiCl4 is out of the range of 0.6 to 2.0 in terms of the atomic ratio of nitrogen to silicon, the gas that is excessively contained in either of the two gases will be replaced by silicon nitride. It does not take part in the production reaction and is only decomposed and degraded before being discharged from the container, making it extremely uneconomical to industrially produce ultra-hard, high-purity silicon nitride. That is, it is particularly undesirable to use too much SiCl4, which is relatively expensive, because it lowers the Si yield. NH3 is S
Although it is cheaper than iCl, if there is too little SiCl, the precipitation rate of silicon nitride will be slow, and it will take a long time to obtain a certain precipitated layer, resulting in a loss in power costs, so it is still not economical. . As a result of the experiment, the composition ratio of N and SiCl needs to be in the range of 0.6 to 2.0 in terms of the atomic ratio of nitrogen to silicon, and in particular, it is highest in the range of 0.8 to 1.2. Si yield was obtained. Furthermore, at the open end of the double blowing tube, the open end of the inner tube that blows out NH3 and the SiCl,
When the flow velocity ratio per unit area between the open end of the outer pipe and the open end of the outer pipe that blows out the mixed gas of In addition, uniform silicon nitride is deposited on the outer peripheral surface of the substrate.

In particular, it is most preferable when the flow rates of both gases match, that is, when the flow rate ratio is 1. Note that the flow rate ratio can be adjusted using a carrier gas. In other words, for the flow rate per unit area (MI/Min-CIi) of NH3 at the open end of the inner pipe of the double blowing pipe, the N
H, and S゛JSiCl4, which is close to the stoichiometric amount of silicon nitride
The flow rate per unit area at the open end of the outer tube of the mixed gas of the carrier gas and the carrier gas is within the above range. If the flow velocity ratio is less than 0.5 or more than 2.0, even if the gas blowing tube is cooled, the open end of the gas blowing tube is likely to become clogged if used for a long time. The reason for this is that the gas with a higher flow rate wraps around the gas outlet with a lower flow rate, restricting the blowout, and a reaction occurs near the open end of the blowpipe, resulting in various compounds of silicon, nitrogen, and hydrogen. It is thought that the substance precipitates as a solid and is deposited near the open end of the spray pipe, resulting in blockage. Therefore, if the flow velocity ratio is less than 0.5, the inner pipe of the double spraying pipe is likely to be clogged because the NH3 flow velocity is low, whereas if it exceeds 2.0, the flow velocity of SiCl4 and H2 is low, resulting in double spraying. The outer tube of the tube is likely to become obstructed.
Next, in a method using indirect heating means as a heating method, ultra-hard high-purity silicon nitride was manufactured using a gas blowing tube without a cooling jacket as shown in FIG.
As shown in Figure 4, the ultra-hard high-purity silicon nitride precipitated homogeneously at a substrate temperature of 1500'C and a vessel internal pressure of 10T.
It was only within a very narrow range around 0rr, and even under that condition, a lot of solid matter was observed to be attached to the open end of the gas blowing tube.

By using the gas blowing tube equipped with the cooling jacket of the present invention and blowing both deposition source gases while cooling the gas blowing tube, the range of manufacturing conditions can be changed as shown in FIG. It has become possible to produce ultra-hard high-purity silicon nitride at a container internal pressure of 5 to 50 T0rr and a substrate temperature of 1000 to 1600°C. At that time, an amorphous material is produced when the temperature of the substrate is within a range of 1000 to less than 1350°C, and an oriented crystalline material is produced when the temperature of the substrate is within a range of 1350 to 1600°C. Also, there was no longer any blockage at the open end of the gas blowing pipe. Next, the present invention will be explained with reference to examples.
Example Using the apparatus shown in FIG. 1, NH3 gas is made to flow out from the spray pipe 4, and at the same time, a mixed gas of SiCl and H2 is made to flow out from the spray pipe 5. Silicon nitride was deposited on the surface of a substrate made of a carbon molded body under the experimental conditions of temperature, pressure, and time shown in Table 1 below, with a flow velocity ratio of 0.8.

The result is the experimental brown of the tree table. Shown in 1 to 5. According to this result, experiment no. According to the present invention shown in 1 to 5, S
Silicon nitride was precipitated at a high yield of 20 to 46%, and unlike the conventional method, no clogging of the spray tube was observed. Similar results were obtained when various 4' ceramic plates such as non-conductive sintered silicon nitride plates and alumina plates were used as substrates. Experiment No. in Table 1. l, 3, 4,
When the micro Vickers hardness of No.5 was measured under a load of 100g, it was 3400k91Td! T,. 335O
k9lTdl3l5Ok9lil3lOOk9lTlU
i, indicating that it is ultra-hard, high-purity silicon nitride. For comparison, silicon nitride was deposited under the same conditions as in the above example using a conventional spray tube without the cooling jacket 6. The results are shown in Table 1. 6 to 10.

According to these results, superhard high-purity silicon nitride was precipitated only when the substrate temperature was 1500°C and the pressure inside the container was 10T'0rr, but the Si yield was extremely low at 3 to 6%, and A large amount of deposits was observed on the open end of the attached pipe.
It became clogged in a short period of 0.5 to 3 hours, making it impossible to operate. According to the present invention, a manufacturing apparatus is used as a heating means for the substrate, which comprises an indirect heating means and a double blowing pipe equipped with a cooling jacket for forced cooling with a fluid, and further includes a nitrogen deposition source gas and a silicon deposition source gas. By making the composition ratio close to the stoichiometric ratio of silicon nitride and making the flow rate ratio of both gases almost the same, the range of manufacturing conditions for ultrahard high-purity silicon nitride is expanded, and the Si yield is significantly increased. However, it is clear that the blockage at the open end of the double blowing pipe is eliminated, and the effect is tremendous.

In addition, in the manufacturing apparatus using the indirect heating means of the present invention, as compared to the conventional direct heating method, (1) the substrate material does not need to be electrically conductive.

(2) As for the shape of the base, it is possible to use not only a flat plate but also a fairly complicated shape such as a crucible shape or a vibrator shape.

(3) Ultra-hard, high-purity silicon nitride can be deposited on multiple substrates simultaneously.

Excellent effects can be obtained when industrially producing products such as

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal cross-sectional view of the device of the present invention, and Figs. 2 and 3 show a double spraying system in which a cooling jacket is provided on the partition wall of the inner tube and the outer tube, and on the axis of the inner tube, respectively. The vertical cross-sectional view of the tube, FIGS. 4 and 5, are diagrams showing the influence of the pressure inside the container and the substrate temperature on the production of silicon nitride when the gas blowing tube is cooled and when it is not cooled, respectively.

DESCRIPTION OF SYMBOLS 1... Container, 2... Base gripping means, 3... Base,
4... Inner pipe of double spray pipe, 5... Outer pipe of double spray pipe, 6... Cooling jacket, 7... Heating element, 8...
...Exhaust port, 9...Insulating material, 10...Cooling pipe tube at the axis of the inner pipe.

Claims (1)

[Scope of Claims] 1. A silicon deposition source including a container, means for gripping a substrate sealed in the container, means for heating the substrate, and a spray tube for spraying nitrogen deposition source gas onto the substrate. The substrate is surrounded by a blowing tube for blowing gas onto the substrate, and the distance between the open end of the nitrogen deposition source gas blowing tube and the substrate is set such that the distance between the open end of the silicon deposition source gas blowing tube and the substrate is An apparatus for producing ultrahard high-purity silicon nitride, which uses a double blowing tube consisting of an inner tube and an outer tube that are shorter than the distance, and deposits silicon nitride on a substrate by a gas phase decomposition reaction of both deposition source gases. A carbide high-temperature alloy, characterized in that it is equipped with an indirect heating means for heating the base, and a cooling means having a cooling jacket with a fluid that forcibly cools at least an outer tube of the double blow tube. Purity silicon nitride production equipment. 2. The manufacturing apparatus according to claim 1, which is equipped with a cooling means for forcibly cooling the double blow tube by providing a cooling jacket around the outer periphery of the double blow tube. 3. The manufacturing apparatus according to claim 1 or 2, which is equipped with a cooling means for forcibly cooling the double blow tube by using the partition wall between the outer tube and the inner tube of the double blow tube as a cooling jacket. Device. 4. In the manufacturing apparatus according to any one of claims 1 to 3, a cooling means for forcibly cooling the double spray tube by providing a cooling pipe tube in the axial portion of the inner tube of the double spray tube. Manufacturing equipment equipped with. 5. In the manufacturing apparatus according to any one of claims 1 to 4, the open end of the double blowing tube is located on the upper surface of the base body,
Manufacturing equipment that is close to one of the bottom and side surfaces. 6. In the manufacturing apparatus according to any one of claims 1 to 5, the substrate gripping means moves the substrate vertically, horizontally, and rotationally while gripping the substrate. Manufacturing equipment that is a means of movement. 7. In the manufacturing apparatus according to any one of claims 1 to 6, the indirect heating means for heating the substrate is an indirect heating means using an electrical resistance heating element that heats the substrate mainly horizontally and in a centripetal direction; Manufacturing equipment that uses either indirect heating means by heating a heating element with high-frequency induction heating, or indirect heating means using infrared rays or laser beams. 8. The manufacturing apparatus according to claim 7, wherein the electric resistance heating element is any one of a carbon-based heating element, a molybdenum silicide-based heating element, a silicon carbide-based heating element, and a lanthanum/chromite-based heating element. . 9. The manufacturing apparatus according to claim 1, wherein the indirect heating means is surrounded between the container and the indirect heating means for heating the substrate,
A manufacturing device characterized by improved thermal efficiency and container protection by providing at least one of a ceramic heat insulating material and a metallic reflective plate. 10 A container, means for gripping the substrate sealed in the container, means for indirectly heating the substrate, and a means for spraying a mixed gas of a nitrogen deposition source gas and, if necessary, a carrier gas for transporting this gas. The blowing tube is surrounded by a blowing tube for spraying a mixed gas of a silicon deposition source gas and, if necessary, a carrier gas for conveying this gas onto the substrate, and the open end of the nitrogen deposition source gas blowing tube is and the substrate, the distance between which is shorter than the distance between the open end of the silicon deposition source gas injection tube and the substrate, and the double blowing tube is made up of an inner tube and an outer tube, and at least one of the double blowing tubes is Using a device equipped with a cooling means having a cooling jacket with a fluid that forcibly cools the outer tube, the substrate is held in the container by the means for holding the substrate, and then the inside of the container is heated 10^-^2 mm.
After reducing the pressure to below Hg, the substrate is heated to a temperature range of 1000 to 1600°C using an indirect heating means, and while at least the outer tube of the double blowing tube is forcibly cooled with a fluid, the nitrogen deposition source gas is heated. and a silicon deposition source gas, or if necessary a mixed gas of both of the above gases and a carrier gas, are sprayed onto the substrate, and the contact between the two deposition source gases causes a gas phase decomposition reaction on the outer circumferential surface of the substrate or in the vicinity of the outer circumferential surface of the substrate. A method for producing ultrahard high-purity silicon nitride, characterized in that the silicon nitride is deposited on the outer circumferential surface of the substrate, and the opening end of the double blowing tube is prevented from being blocked. . 11 In the manufacturing method according to claim 10, the composition ratio of the nitrogen deposition source gas and the silicon deposition source gas for causing a gas phase decomposition reaction by contacting the two gases is an atomic ratio of nitrogen and silicon. A manufacturing method within the range of 0.6 to 2.0. 12. In the manufacturing method according to claim 10 or 11, the flow velocity ratio per unit area of the inner tube and the outer tube at the open end of the double blowing tube is within the range of 0.5 to 2.0. A manufacturing method. 13 Claims 10th to 12th
In the manufacturing method according to any one of the above, the pressure in the container is in the range of 5 to 50 Torr, and the temperature of the substrate is in the range of 13 Torr.
A method for producing crystalline superhard high purity silicon nitride at a temperature within the range of 50 to 1600°C. 14. In the manufacturing method according to any one of claims 10 to 12, the pressure within the container is within the range of 5 to 50 Torr, and the temperature of the substrate is within the range of 1000 to less than 1350°C. A method for producing ultra-hard, high-purity silicon nitride. 15. In the manufacturing method according to any one of claims 10 to 14, the nitrogen deposition source gas is a nitrogen hydride (
HN_3, NH_3, N_2H_4), ammonium halides (NH_4Cl, NH_4F, NH_4HF
_2, NH_4I), and the silicon deposition source gas is a silicon halide (SiCl_4, SiF_4, SiBr_4, SiI).
_4, Si_2Cl_6, Si_2Br_6, Si_2
I_6, SiBrCl_3, SiBr_2Cl_2, S
iBr_3Cl, SiIC1_3), hydride (SiH
_4, Si_4H_1_0, Si_3H_8, Si_2
H_6), hydrogen halide (SiHCl_3, SiH
Br_3, SiHF_3, SiHI_3, SiH_3B
r), and the carrier gas is at least one selected from N_2, H_2, Ar, and He.