Disclosure of Invention
The invention aims to provide a simpler method for simultaneously enlarging the size and the number of single crystal diamond seed crystals aiming at the problem of high technical difficulty in preparing large-size diamond single crystals.
The invention is realized by the following technical scheme:
a method of simultaneously enlarging the size and number of single crystal diamond seeds comprising the steps of:
1) putting the monocrystal diamond with the size of a multiplied by b as a seed crystal into a molybdenum holder, growing the monocrystal diamond to a height h along the direction b by adopting a CVD method, and cutting the monocrystal diamond into two halves along the diagonal line of the face of the monocrystal diamond multiplied by h to form two right-angled triangular cylinder monocrystal diamonds;
2) respectively putting two right-angled triangular cylinder single crystal diamonds as seed crystals into a molybdenum holder provided with V-shaped grooves, and adjusting the sizes
The cutting surface is used as a growth surface to carry out homoepitaxial growth of diamond until the growth height reaches h
1And then, cutting the grown single crystal diamond into four pieces along the line of the right-angle edge of the bottom right-angle triangular cylinder and the left side edge of the top rectangular body, the line of the right-angle edge of the bottom right-angle triangular cylinder and the right side edge of the top rectangular body and the growth direction parallel to the growth direction passing through the right-angle edge of the bottom right-angle triangular cylinder respectively to form two obtuse-angle triangular cylinder single crystal diamonds and two right-angle triangular cylinder single crystal diamonds, wherein the maximum growth surface sizes of the four single crystal diamonds are all larger than the growth surface size of the original single crystal diamond.
In the above method, when h is a, the stepThe right-angled triangular prism single crystal diamond obtained in the step 1) is an isosceles right-angled triangular prism, the maximum growth surfaces of the four single crystal diamonds obtained in the step 2) are equal, and the size is equal
In the method, when h is not equal to a, the maximum growth surface of one obtuse triangular prism single crystal diamond and the maximum growth surface of one right triangular prism single crystal diamond in the four single crystal diamonds obtained in the step 2) are equal, and the size is equal to
The maximum growth surface of the other obtuse-angle triangular cylinder single crystal diamond is equal to that of one right-angle triangular cylinder single crystal diamond, and the size of the other obtuse-angle triangular cylinder single crystal diamond is
In the above method, when h ═ a,
In the second step, the maximum growth surfaces of the four single crystal diamonds obtained in the step 2) are equal and have the size of
In the method, the original single crystal diamond seed crystal in the step 1) is natural single crystal diamond, single crystal diamond prepared by a CVD method or single crystal diamond prepared at high temperature and high pressure.
Further, the obtuse-angle triangular cylinder single crystal diamond and the right-angle triangular cylinder single crystal diamond obtained in the step 2) can be continuously used as seed crystals to deposit diamond again, and the method specifically comprises the following steps: taking the maximum square surface of the triangular cylinder monocrystal diamond as a growth surface to carry out homoepitaxial growth until the growth height reaches h
2When h is present
2>a, cutting along the maximum square surface of the triangular cylinder single crystal diamond, removing the original triangular cylinder single crystal diamond to obtain the diamond with the size of
Or
The cuboid type single crystal diamond of (1), the method for producing the same
Or
Cutting to obtain multiple pieces with thickness h
3Of a size of
Or
The single crystal diamond seed of (1).
In the diamond deposition process, when h is a,
When, can obtain the multi-slice size of
The single crystal diamond seed of (1).
The method has the following beneficial effects:
1) the method is simple to operate, can quickly change small-size single crystal diamond seed crystals into large-size single crystal diamond seed crystals, simultaneously increases the size and the number of the single crystal diamonds, and can effectively avoid interface defects and polycrystals introduced by a splicing method.
2) The method can obtain eight pieces with the size of
The single crystal diamond seed crystal is deposited for three times to obtain multiple pieces with the size of
A single crystal diamond seed.
3) The method of the invention adopts the triangular column single crystal diamond as the seed crystal and combines with the specially designed molybdenum support, so that the single crystal diamond can be more stably placed in the molybdenum support, and the problems of single crystal growth quality reduction, polycrystal introduction and the like caused by the displacement of the diamond single crystal in the molybdenum support and the influence of the position of the diamond single crystal in the molybdenum support and the plasma due to factors such as vibration and the like in the lifting process of equipment are avoided.
4) The method adopts the molybdenum holder with the V-shaped groove, so that two contact surfaces are arranged between the triangular cylinder monocrystal diamond seed crystal and the molybdenum holder, the heat dissipation area of the diamond monocrystal is increased, the use power of CVD equipment is increased, and the growth speed of the monocrystal diamond is increased.
Detailed Description
In order that those skilled in the art will better understand the present invention, a more complete and complete description of the present invention is provided below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.
A method of simultaneously enlarging the size and number of single crystal diamond seeds comprising the steps of:
1) primary deposition: putting the single crystal diamond with the size of a multiplied by b as a seed crystal 1 into a molybdenum holder 2, growing the seed crystal to a height h along the direction b by adopting a CVD method, then cutting the single crystal diamond into two halves along the diagonal line of the single crystal diamond multiplied by h to form two right-angled triangular cylinder single crystal diamonds, and the process steps are shown as primary deposition in figure 1;
2) secondary deposition: respectively putting two right-angled triangular cylinder single crystal diamonds as
seed crystals 1 into a
molybdenum holder 2 provided with V-shaped grooves, and adjusting the sizes
The cutting surface is used as a growth surface to carry out homoepitaxial growth of diamond until the growth height reaches h
1And then, cutting the grown single crystal diamond into four pieces along the growth direction parallel to the growth direction along the connecting line of the bottom right-angled triangular cylinder right-angled edge and the top rectangular body left-side edge, the connecting line of the bottom right-angled triangular cylinder right-angled edge and the top rectangular body right-side edge and the connecting line passing through the bottom right-angled triangular cylinder right-angled edge respectively to form two obtuse-angle triangular cylinder single crystal diamonds and two right-angled triangular cylinder single crystal diamonds, wherein the process steps are shown in secondary deposition in fig. 1.
In the method, when h is equal to a, the right-angled triangular prism single crystal diamond obtained in the step 1) is an isosceles right-angled triangular prism, and the maximum growth surfaces of the four single crystal diamonds obtained in the step 2) are equal and have the size of
When h is not equal to a, the maximum growth surface of one obtuse triangular prism single crystal diamond and the maximum growth surface of one right-angled triangular prism single crystal diamond in the four single crystal diamonds obtained in the step 2) are equal, and the size is
The maximum growth surface of the other obtuse-angle triangular cylinder single crystal diamond is equal to that of one right-angle triangular cylinder single crystal diamond, and the size of the other obtuse-angle triangular cylinder single crystal diamond is
When h is a,
In the second step, the maximum growth surfaces of the four single crystal diamonds obtained in the step 2) are equal and have the size of
In the method, the original single crystal diamond seed crystal in the step 1) is natural single crystal diamond, single crystal diamond prepared by a CVD method or single crystal diamond prepared at high temperature and high pressure.
Further, the obtuse-angle triangular cylinder single crystal diamond and the right-angle triangular cylinder single crystal diamond obtained in the step 2) can be continuously used as
seed crystals 1 to perform three times of diamond deposition again, and the method specifically comprises the following steps: taking the maximum square surface of the triangular cylinder monocrystal diamond as a growth surface to carry out homoepitaxial growth until the growth height reaches h
2When h is present
2>a, cutting along the maximum square surface of the triangular cylinder single crystal diamond, removing the original triangular cylinder single crystal diamond to obtain the diamond with the size of
Or
The cuboid type single crystal diamond of (1), the method for producing the same
Or
Cutting to obtain multiple pieces with thickness h
3Of a size of
Or
The process steps for the single
crystal diamond seed 1 are shown in figure 1 as three depositions.
In the three deposition processes, when h is a,
When, can obtain the multi-slice size of
The single
crystal diamond seed 1 of (1).
The process of the invention is further described below with reference to several specific examples:
example 1
A method of simultaneously enlarging the size and number of single crystal diamond seeds comprising the steps of:
1) primary deposition: cleaning single crystal diamond seed crystal 1 with orientation of (100) and size of 5mm × 5mm × 1mm and molybdenum holder 2 matched with the seed crystal, placing into vacuum chamber of Microwave Plasma Chemical Vapor Deposition (MPCVD) device, and lowering vacuum degree of the vacuum chamber to 5 × 10-4After Pa is less, H is introduced2When the air pressure reaches 0.8KPa, starting a microwave source to excite the plasma, wherein the input power is 1 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4And N2Until stable deposition is achieved: the microwave power is 5kW, H2、CH4And N2The flow rates of the microwave source and the microwave source are respectively 300sccm, 15sccm and 1sccm, the temperature is 1000 ℃, when the monocrystalline diamond seed crystal 1 grows to 5.3mm along the height direction, the air pressure and the power are reduced, when the air pressure and the power respectively reach 0.8Kpa and 1KW, the microwave source is closed, and the monocrystalline diamond is taken out; and polishing to remove polycrystal at the edge of the growth surface to enable the height after polishing to reach 5mm, and cutting the single crystal diamond into two halves along the diagonal line of the side surface of the single crystal diamond by adopting a laser cutting method to form two isosceles right-angle triangular cylinder single crystal diamonds with the cutting surface size of 7.07mm multiplied by 5 mm.
2) Secondary deposition: taking the two right-angled triangular cylinder single crystal diamonds with the cutting surfaces of 7.07mm multiplied by 5mm as seed crystals 1, polishing the cutting surfaces, putting the polished surfaces upwards into a specially designed molybdenum holder 2 containing a V-shaped groove, and then putting the molybdenum holder into a vacuum chamber of an MPCVD device for homoepitaxial growth of the diamonds; wait for vacuum chamber trueThe void degree is reduced to 5 multiplied by 10-4After Pa is less, H is introduced2When the air pressure reaches 0.8KPa, starting a microwave source to excite the plasma, wherein the input power is 1 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4And N2Until stable deposition is achieved: the microwave power is 5kW, H2、CH4And N2The flow rates of the microwave source and the microwave source are respectively 300sccm, 15sccm and 1sccm, the temperature is 1100 ℃, when the monocrystalline diamond seed crystal 1 grows to 7.4mm along the height direction, the air pressure and the power are reduced, when the air pressure and the power respectively reach 0.8Kpa and 1KW, the microwave source is closed, and the monocrystalline diamond is taken out; and polishing to remove polycrystal at the edge of the growth surface, so that the height after polishing can reach 7.07mm, and cutting the grown single crystal diamond into four pieces along the connection line of the right-angle edge of the bottom right-angle triangular cylinder and the left-side edge of the top rectangular body, the connection line of the right-angle edge of the bottom right-angle triangular cylinder and the right-side edge of the top rectangular body and the connection line of the right-angle edge of the bottom right-angle triangular cylinder and the right-side edge of the top rectangular body respectively, wherein the right-angle edge of the bottom right-angle triangular cylinder is parallel to the growth direction, so that two obtuse-angle triangular cylinder single crystal diamonds and two right-angle triangular cylinder single crystal diamonds are obtained, the maximum growth surface sizes of the four single crystal diamonds are all larger than the growth surface size of the original single crystal diamond, and the maximum growth surface size is 11.18mm multiplied by 5 mm.
Example 2
A method of simultaneously enlarging the size and number of single crystal diamond seeds comprising the steps of:
1) primary deposition: cleaning single crystal diamond seed crystal 1 with orientation of (100) and size of 10mm × 10mm × 1mm and molybdenum holder 2 specially matched with the seed crystal, placing into vacuum chamber of MPCVD device, and lowering vacuum degree of the vacuum chamber to 1 × 105After Pa is less, H is introduced2When the air pressure reaches 1KPa, starting a microwave source to excite the plasma, wherein the input power is 1.5 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4Until stable deposition is achieved: the microwave power is 10kW, CH4And H2The flow rate is 400sccm and 30sccm respectively, the temperature is 950 ℃, when the monocrystalline diamond seed crystal 1 grows to 10.2-10.4mm along the height direction, the air pressure and the power are reduced, and when the air pressure is reachedAnd when the power reaches 0.8KPa and 1KW respectively, closing the microwave source, and taking out the single crystal diamond; and polishing to remove polycrystal at the edge of the growth surface to enable the height after polishing to reach 10mm, and cutting the single crystal diamond into two halves along the diagonal line of the side surface of the single crystal diamond by adopting a laser cutting method to form two isosceles right-angle triangular cylinder single crystal diamonds with the cutting surface size of 14.14mm multiplied by 10 mm.
2) Secondary deposition: the two isosceles right-angled triangular cylinder single crystal diamonds with the cutting surface size of 14.14mm multiplied by 10mm are used as seed crystals 1, the cutting surfaces are polished, the polished surfaces are placed into a specially designed molybdenum holder 2 containing a V-shaped groove upwards, and then the molybdenum holder is placed into a vacuum chamber of an MPCVD device for homoepitaxial growth of the diamonds; when the vacuum degree of the vacuum chamber is reduced to 1 x 105After Pa is less, H is introduced2When the air pressure reaches 1KPa, starting a microwave source to excite the plasma, wherein the input power is 1.5 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4Until stable deposition is achieved: the microwave power is 10kW, CH4And H2The flow rates of the microwave source and the microwave source are respectively 400sccm and 30sccm, the temperature is 1000 ℃, when the monocrystalline diamond seed crystal 1 grows to 14.3-14.5mm along the height direction, the air pressure and the power are reduced, when the air pressure and the power respectively reach 0.8Kpa and 1KW, the microwave source is closed, and the monocrystalline diamond is taken out; and polishing to remove polycrystal at the edge of the growth surface, so that the height after polishing can reach 14.14mm, and cutting the grown single crystal diamond into four pieces along the connecting line of the right-angle edge of the bottom right-angle triangular cylinder and the left-side edge of the top rectangular body, the connecting line of the right-angle edge of the bottom right-angle triangular cylinder and the right-side edge of the top rectangular body and the connecting line of the right-angle edge of the bottom right-angle triangular cylinder and the right-side edge of the top rectangular body respectively, wherein the two pieces of the grown single crystal diamond are parallel to the growth direction through the right-angle edge of the bottom right-angle triangular cylinder, two pieces of obtuse-angle triangular cylinder single crystal diamond and two pieces of right-angle triangular cylinder single crystal diamond are obtained, the maximum growth surface sizes of the four single crystal diamonds are all larger than the growth surface size of the original single crystal diamond, and the maximum growth surface size is 22.36mm multiplied by 10 mm.
3) And (3) deposition for three times: polishing the cut surface of large isosceles triangle cylinder monocrystal diamond with the size of 22.36mm multiplied by 10mm, cleaning, putting the polished surface upwards into a specially designed monocrystal diamond containing large isosceles triangle cylinder monocrystal diamondPutting the molybdenum support 2 with the V-shaped groove into a vacuum chamber of an MPCVD device to carry out homoepitaxial growth of diamond; when the vacuum degree of the vacuum chamber is reduced to 1 x 10-5After Pa is less, H is introduced2When the air pressure reaches 1KPa, starting a microwave source to excite the plasma, wherein the input power is 1.5 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4Until stable deposition is achieved: the microwave power is 10kW, CH4And H2The flow rates of the microwave source and the microwave source are respectively 400sccm and 30sccm, the temperature is 950 ℃, when the monocrystalline diamond seed crystal 1 grows to 22.4-22.6mm along the height direction, the air pressure and the power are reduced, when the air pressure and the power respectively reach 0.8Kpa and 1KW, the microwave source is closed, and the monocrystalline diamond is taken out; and (3) removing polycrystals appearing at the edge of the growth surface by polishing to enable the polished height to reach 22.36mm, cutting off the large isosceles triangle cylinder single crystal diamond with the original size of 22.36mm multiplied by 10mm to obtain a cuboid single crystal diamond with the size of 22.36mm multiplied by 10mm, and performing laser cutting and polishing on the single crystal diamond along the direction parallel to the 22.36mm multiplied by 22.36mm plane to obtain a plurality of single crystal diamond seed crystals 1 with the size of 22.36mm multiplied by 22.36 mm.
Example 3
A method of simultaneously enlarging the size and number of single crystal diamond seeds comprising the steps of:
1) primary deposition: cleaning single crystal diamond seed crystal 1 with orientation of (100) and size of 8mm × 8mm × 0.5mm and molybdenum holder 2 matched with the seed crystal, placing into vacuum chamber of MPCVD device, and lowering vacuum degree of the vacuum chamber to 1 × 10- 4After Pa is less, H is introduced2When the air pressure reaches 1.2KPa, starting a microwave source to excite the plasma, wherein the input power is 2 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4、N2And O2Until stable deposition is achieved: the microwave power is 4kW, H2、CH4、N2And O2The flow rates are respectively 200sccm, 20sccm, 0.2sccm and 4sccm, the temperature is 920 ℃, when the monocrystalline diamond seed crystal 1 grows to 6.2-6.4mm along the height direction, the air pressure and the power are reduced, and when the air pressure and the power respectively reach 0.8Kpa and 0.8KpaWhen the power is 1KW, the microwave source is closed, and the single crystal diamond is taken out; and polishing to remove polycrystal at the edge of the growth surface to enable the height after polishing to reach 6mm, and cutting the single crystal diamond into two halves along the diagonal line of the side surface of the single crystal diamond by adopting a laser cutting method to form two isosceles right triangle cylinder single crystal diamonds with the cutting surface size of 10mm multiplied by 8 mm.
2) Secondary deposition: the two isosceles right-angle triangular cylinder single crystal diamonds with the cutting surface sizes of 10mm multiplied by 8mm are used as seed crystals 1, the cutting surfaces are polished, the polished isosceles right-angle triangular cylinder single crystal diamonds are placed in a specially designed molybdenum support 2 containing a V-shaped groove, and the polished surfaces are upward for homoepitaxial growth of the diamonds; when the vacuum degree of the vacuum chamber is reduced to 1 x 10-4After Pa is less, H is introduced2When the air pressure reaches 1.2KPa, starting a microwave source to excite the plasma, wherein the input power is 2 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4、N2And O2Until stable deposition is achieved: the microwave power is 4kW, H2、CH4、N2And O2The flow rates of the microwave source and the microwave source are respectively 200sccm, 20sccm, 0.2sccm and 4sccm, the temperature is 950 ℃, when the monocrystalline diamond seed crystal 1 grows to 8.2-8.4mm along the height direction, the air pressure and the power are reduced, when the air pressure and the power respectively reach 0.8Kpa and 1KW, the microwave source is closed, and the monocrystalline diamond is taken out; polishing to remove polycrystal on the edge of a growth surface, enabling the height after polishing to reach 8mm, cutting the grown single crystal diamond into four pieces along the connection line of the right-angle edge of the bottom right-angle triangular cylinder and the left-side edge of the top rectangular body, the connection line of the right-angle edge of the bottom right-angle triangular cylinder and the right-side edge of the top rectangular body and the growth direction parallel to the bottom right-angle triangular cylinder right-angle edge to obtain two obtuse-angle triangular cylinder single crystal diamonds and two right-angle triangular cylinder single crystal diamonds, wherein the maximum growth surface sizes of the four single crystal diamonds are all larger than the growth surface size of the original single crystal diamond, the maximum growth surface sizes of one of the obtuse-angle triangular cylinder single crystal diamonds and one of the right-angle triangular cylinder single crystal diamonds are equal and are 14.31mm multiplied by 8mm, and the other obtuse-angle triangular cylinder single crystal diamond is goldThe maximum growth surface sizes of the diamond and the single crystal diamond of a right-angled triangular column are equal and are both 13.3mm multiplied by 8 mm.
3) And (3) deposition for three times: polishing the cutting surfaces of triangular cylinder single crystal diamonds with the sizes of 14.31mm multiplied by 8mm and 13.3mm multiplied by 8mm respectively, cleaning, putting the polished surfaces upwards into a specially designed molybdenum holder 2 containing a V-shaped groove, and then putting the molybdenum holder into a vacuum chamber of an MPCVD device for the homoepitaxial growth of the diamonds; when the vacuum degree of the vacuum chamber is reduced to 1 x 10-4After Pa is less, H is introduced2When the air pressure reaches 1.2KPa, starting a microwave source to excite the plasma, wherein the input power is 2 KW; with the increase of the air pressure, the input power is slowly increased and CH is introduced4、N2And O2Until stable deposition is achieved: the microwave power is 4kW, H2、CH4、N2And O2The flow rates of the microwave source and the microwave source are respectively 200sccm, 20sccm, 0.2sccm and 4sccm, the temperature is 920 ℃, when the monocrystalline diamond seed crystal 1 grows to 10.2-10.4mm along the height direction, the air pressure and the power are reduced, when the air pressure and the power respectively reach 0.8Kpa and 1KW, the microwave source is closed, and the monocrystalline diamond is taken out; and polishing to remove polycrystal at the edge of the growth surface to enable the polished height to reach 10mm, cutting off the large isosceles triangle cylinder single crystal diamond with the original size, cutting and polishing the cuboid single crystal diamond with the size of 14.31mm multiplied by 8mm multiplied by 10mm and 13.3mm multiplied by 8mm multiplied by 10mm to obtain a plurality of single crystal diamond seed crystals 1 with the size of 14.31mm multiplied by 10mm and 13.3mm multiplied by 10mm along the direction parallel to the surface of 14.31mm multiplied by 10mm and 13.3mm multiplied by 10 mm.
The technical solutions in the embodiments of the present invention are clearly and completely described above, and the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.