CN104697331A - Semiconductor material preparation equipment - Google Patents

Abstract

The invention discloses a semiconductor material preparation device. It includes a furnace body with a sealed furnace door, an induction coil, an inductor, an induction power supply, an upper pressure head, a lower pressure head, a thermocouple, and a hydraulic system; the upper pressure head and the lower pressure head have adjustable displacement speed; the sensor is Graphite or stainless steel, with the functions of hot-pressing abrasives and crucibles; the induction coil is located in the center of the furnace cavity, and both ends pass through the furnace body to connect with the induction power supply with adjustable frequency; one end of the thermocouple is connected to the furnace cavity and inserted into the sensor The temperature measuring hole is connected to the temperature control instrument at the other end; the furnace body is equipped with an air charging port, an air discharge port, and a vacuum system interface. The invention has simple structure, convenient operation and multiple functions, and can be used for rapid hot pressing of nano-powders, high-temperature melting of semiconductor materials, rapid solidification of alloys, preparation of large crystal grains or single crystal samples, and vacuum heat treatment. The method can effectively reduce the preparation cost of semiconductor materials, and is especially suitable for the preparation of thermoelectric materials.

Description

Semiconductor material preparation equipment

technical field

The invention relates to semiconductor material manufacturing technology, in particular to a multifunctional semiconductor material preparation equipment.

Background technique

The Seebeck effect discovered in 1823 and the Peltier effect discovered in 1834 provided a theoretical basis for the application of thermoelectric energy converters and thermoelectric refrigeration. Thermoelectric materials are functional semiconductor materials that can convert heat and electricity into each other. They have no moving parts, are reliable and flexible, and are environmentally friendly. They are widely used in national defense, medical care, and people's livelihood. The radioisotope thermoelectric generator (RTG) based on thermoelectric conversion has been used as a power source for spacecraft by the United States and the Soviet Union since the 1970s, and it is still the most reliable and longest-lasting deep space power generation technology. Thermoelectric materials can also directly convert low-grade energy (solar energy, automobile waste heat, factory waste heat, hot spring heat) into electricity. Companies such as BMW and Ford have developed environmentally friendly models that use waste heat from automobile exhaust to generate electricity. Thermoelectricity can also be used as an environmentally friendly cooling method to convert electrical energy into temperature difference. Semiconductor water dispensers, semiconductor wine cabinets, and car thermoelectric seats have been widely used. In recent years, thermoelectric materials have been greatly developed, and the properties of Bi-Sb-Te, Mg-Si-Sn, PbTe, skutterudite, SiGe, AgPbTe-GeTe and other thermoelectric materials used in different temperature regions have made breakthroughs. The conversion efficiency of thermoelectric devices has also risen to about 12%, which is close to that of polycrystalline silicon solar cells and thin-film solar cells.

However, currently high-performance bulk thermoelectric materials suitable for power generation are mostly prepared by discharge plasma sintering furnaces, vacuum hot-pressing sintering furnaces, single crystal growth furnaces, rapid solidification furnaces, vacuum melting furnaces and other equipment. Spark plasma sintering equipment is expensive, while traditional vacuum hot pressing furnaces, single crystal growth furnaces, rapid solidification furnaces, and vacuum melting furnaces only have a single function and their application range is limited. The complex preparation process and high requirements for equipment of existing high-performance thermoelectric materials have increased additional costs for scientific research and enterprise production, which is one of the reasons why international and domestic research and development and industrial investment in thermoelectric technology are far inferior to photovoltaic technology. .

Contents of the invention

The technical problem to be solved by the present invention is to provide a kind of semiconductor material preparation equipment, which has simple structure and convenient operation, has multiple functions such as rapid hot pressing, high temperature sintering, rapid solidification, and single crystal growth, and can solve the problem of existing thermoelectric material preparation equipment. The shortcomings of single function and high cost can not only effectively promote the large-scale mass production of thermoelectric materials, but also be widely used in the preparation of other semiconductor thermoelectric materials and metal materials. .

In order to solve the above technical problems, the semiconductor material preparation equipment provided by the present invention includes a furnace body with a sealed furnace door, an induction coil, an inductor, an upper indenter, a lower indenter, and a thermocouple;

The upper pressure head is located on the top of the furnace body;

The lower pressure head is located at the bottom of the furnace body;

The induction coil is helical, located in the center of the cavity of the furnace body, with both ends passing through the furnace body and connected to the heating head of the induction power supply;

The upper pressure head, the lower pressure head and the induction coil are coaxial, and the cross section is circular;

The cross-sectional area of the induction coil is larger than the cross-sectional area of the upper and lower pressure heads;

The inductor is used to be placed between the induction coil, the lower pressing head, and the upper pressing head;

One end of the thermocouple is connected to the cavity of the furnace body;

The furnace body is provided with an air filling port, an air discharge port, and a vacuum system interface;

The charging port is used to charge gas or liquid nitrogen into the cavity of the furnace body;

The air release port is used to discharge the gas in the cavity of the furnace body;

The vacuum system interface is used for externally connecting the vacuum pumping system.

Preferably, the induction power supply has a power supply frequency of 1000-400000Hz;

The inductor is made of graphite or stainless steel;

One end of the thermocouple is connected into the cavity of the furnace body and inserted into the temperature measuring hole of the inductor.

Preferably, the semiconductor material preparation equipment also includes a hydraulic system;

The hydraulic system is used to control the displacement and speed of the upper and lower pressure heads;

The hydraulic system includes a hydraulic pump, a displacement sensor and a pressure sensor;

The hydraulic pump is used to drive the upper pressure head and the lower pressure head;

The displacement sensor is used to detect the displacement of the upper pressing head and the lower pressing head;

The pressure sensor is used to detect the pressure of the upper pressing head and the lower pressing head.

Preferably, the furnace body is a double-layer or single-layer coiled tube water-cooled furnace body, and cooling water interfaces are provided on the furnace body and the furnace door.

Preferably, the upper pressure head and the lower pressure head are sealed on the top and bottom of the furnace body through flanges;

The induction coil and the thermocouple are sealed into the cavity of the furnace body through the flange.

Preferably, the furnace door is provided with a viewing window.

Preferably, the vacuum pumping system includes a high vacuum pump, a rough vacuum pump, valves and a vacuum gauge.

Preferably, the high vacuum pump is a molecular pump, a diffusion pump, an ion pump, a cryogenic pump or a Roots pump;

The rough vacuum pump is a rotary vane mechanical pump, a direct-coupled mechanical pump, a water ring pump or an oil-free dry pump.

The semiconductor material preparation equipment of the present invention has simple structure, convenient operation, and multiple functions, and can prepare nanocrystals and polycrystals by methods such as vacuum/atmosphere bidirectional hot pressing, vacuum/atmosphere rapid sintering, rapid solidification, and unidirectional slow sintering. 1. Single crystal semiconductor materials can also be used for vacuum/atmosphere heat treatment, especially suitable for manufacturing semiconductor thermoelectric materials, and can effectively reduce the preparation cost of semiconductor thermoelectric materials.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings used in the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings on the premise of not paying creative work.

Fig. 1 is a longitudinal sectional view of an embodiment of the semiconductor material preparation equipment of the present invention;

Fig. 2 is a top view of an embodiment of the semiconductor material preparation equipment of the present invention.

Detailed ways

The technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one

Semiconductor material preparation equipment, as shown in Figure 1 and Figure 2, includes a furnace body 1 with a sealed furnace door 18, an induction coil 11, an inductor 12, an upper pressure head 8, a lower pressure head 4, and a thermocouple 6;

The upper pressing head 8 is located on the top of the furnace body 1;

The lower pressure head 4 is located at the bottom of the furnace body 1;

The induction coil 11 is helical, located in the center of the cavity of the furnace body 1, and the two ends pass through the furnace body 1 and are connected to the heating head of the induction power supply 16;

The induction power supply 16 has a frequency adjustable function, and the frequency range is 1000-400000Hz;

The upper pressing head 8, the lower pressing head 4 and the induction coil 11 are coaxial, and the cross section is circular;

The cross-sectional area of the induction coil 11 is larger than the cross-sectional area of the upper pressing head 8 and the lower pressing head 4;

The inductor 12 is used to be placed between the induction coil 11, the lower pressing head 4, and the upper pressing head 8;

One end of the thermocouple 6 is connected to the cavity of the furnace body 1 for detecting the heating temperature;

The furnace body 1 is provided with an air filling port 2, an air discharge port 7, and a vacuum system interface 5;

The gas charging port 2 is used for externally connecting an inert gas cylinder or liquid nitrogen to inflate or fill the cavity of the furnace body 1 with liquid nitrogen;

The air release port 7 is used to discharge the gas in the cavity of the furnace body 1;

The vacuum system interface 5 is used to connect an external vacuum system.

Preferably, the semiconductor material preparation equipment also includes a hydraulic system, which is used to control the displacement and speed of the upper and lower pressing heads; the hydraulic system includes a hydraulic pump, a displacement sensor and a pressure sensor; the The hydraulic pump is used to drive the upper pressing head 8 and the lower pressing head 4, the displacement sensor is used to detect the displacement of the upper pressing head 8 and the lower pressing head 4, and the pressure sensor is used to detect the upper pressing head 8 and the lower pressing head 4 pressure.

Preferably, the furnace body 1 is a double-layer water-cooled or single-layer coiled tube furnace body, and cooling water interfaces 3 are provided on the furnace body and the furnace door.

Preferably, the upper pressure head 8 and the lower pressure head 4 are sealed on the top and bottom of the furnace body 1 through the flange plate 9; the induction coil 11 and the thermocouple 6 are sealed into the cavity of the furnace body 1 through the flange plate in vivo.

The inductor is made of graphite or stainless steel;

The thermocouple, one end of the thermocouple is connected to the cavity of the furnace body through an insulating flange and inserted into the temperature measuring hole of the sensor, and the part of the thermocouple located in the cavity is covered with an insulating ceramic tube;

According to the different power supply (1-30kW) and the size of the induction coil, the induction power supply adopts a 1000-400000Hz radio frequency induction power supply, which can raise the surface and internal temperature of the graphite sensor to 1000-2000 degrees Celsius in a few seconds or a few minutes. , to achieve rapid heating of the sample.

Preferably, the furnace door 18 is provided with a viewing window 17 .

Preferably, the vacuum pumping system includes a high vacuum pump (one of a molecular pump, a diffusion pump, an ion pump, a cryopump, and a Roots pump), a rough vacuum pump (rotary vane mechanical pump, direct-coupled mechanical pump, water ring pump, oil-free dry pump), valves and vacuum gauges.

The semiconductor material preparation equipment of Embodiment 1, the control systems such as induction power supply, hydraulic system, thermocouple, temperature control instrument, vacuum instrument, etc. are integrated into the electric control cabinet 15 through the man-machine dialogue operation software, and the heating and pressure display in the furnace cavity Real-time monitoring and control of the control of the vacuum valve and the control of the vacuum valve. The induction power supply uses the thermocouple 6 and the temperature control instrument to control the output of the power supply so as to accurately control the temperature of the sample in the sensor 12 . The equipment is equipped with a vacuum system and multiple gas ports. The connection parts between the induction coil 11, the upper pressure head 8, the lower pressure head 4, and the thermocouple 6 and the outside of the chamber adopt "O" type flat seals and axial flanges. Sealed, the vacuum in the furnace cavity can be as low as 10 ^-5 Pa, and it can also be filled with inert gas of several atmospheres, which can realize hot pressing or sintering under different conditions such as high vacuum, high pressure inert atmosphere, and fluid atmosphere. The semiconductor material preparation equipment in Embodiment 1 uses sensors such as graphite or stainless steel, and cooperates with the vacuum system and inert gas interface to realize melting and sintering of semiconductor materials; the semiconductor material preparation equipment in Embodiment 1 starts the hydraulic system and adopts two-way pressurization Mode and high-voltage-resistant conductor sensors (such as graphite, stainless steel, the highest pressure-resistant 100MPa), can prepare nanocrystalline bulk semiconductor materials with a density greater than 95%; it is also possible to stop heating when the melt is at a high temperature, and reduce the sensor to the bottom of the furnace, and then spray inert gas or liquid nitrogen from the gas interface 2 to the inductor (which also has the function of a grinding tool/crucible) to achieve rapid solidification; in addition, the semiconductor material preparation equipment in Embodiment 1 can also realize single crystal/ For large grain growth, add an insulation layer between the inductor and the coil, melt the raw material through the induction power supply, and control the displacement speed of the lower pressure head through the displacement sensor (adjustable within the range of 0.01-150mm/s).

The semiconductor material preparation equipment in Example 1 has simple structure, convenient operation, and multiple functions. It can prepare nanocrystals, multi-layers, etc. Crystal and single crystal semiconductor materials can also be used for vacuum/atmosphere heat treatment, especially suitable for manufacturing semiconductor thermoelectric materials, which can effectively reduce the preparation cost of semiconductor thermoelectric materials.

Embodiment two

Based on the semiconductor material preparation equipment of Embodiment 1, the process of preparing nanocrystalline and microcrystalline bulk semiconductor materials is as follows:

Open the furnace door 18, put the graphite inductor 12 equipped with nanometer and micron powder samples 14 at the center of the lower pressure head 4, start the hydraulic system, lift the lower pressure head 4 to a suitable position, and simultaneously move the upper pressure head 8 Drop to a suitable position, insert the thermocouple 6 into the temperature measuring hole of the graphite sensor 12, close the furnace door 18, and start the vacuum system by heating the induction power supply. Until the vacuum degree meets the requirements, according to the characteristics of the sample, you can choose to keep the vacuum or fill the furnace cavity with inert gas. The sample is heated by the induction power supply, and when the required temperature is reached, the hydraulic system is activated to carry out two-way or one-way hot pressing on the sample 14 . Nanocrystalline and microcrystalline bulk semiconductor materials with a density of 99% can be obtained.

Embodiment Three

Based on the semiconductor material preparation equipment of Embodiment 1, the sintering and smelting process of the semiconductor material is as follows:

Open the furnace door 18, put the graphite inductor 12 with the raw material sample 14 on the center position of the lower pressure head 4, start the hydraulic system, raise the lower pressure head 4 to the middle position in the coil 11, insert the thermocouple 6 into the In the temperature measuring hole of the graphite inductor 12, close the furnace door 18. Until the vacuum degree meets the requirements, you can choose to keep the vacuum or fill the furnace cavity with inert gas. When the desired atmosphere is reached, the sample is heated and sintered by an induction power supply. The sintering and smelting of semiconductor materials in the range of room temperature to 2000°C can be realized.

Embodiment Four

Based on the semiconductor material preparation equipment of Embodiment 1, the process of preparing large grains or even single crystal semiconductor materials is as follows:

Open the furnace door 18, put the graphite inductor 12 equipped with the sample 14 into the center of the lower pressure head 4, add alumina insulation felt between the inductor 12 and the coil, start the hydraulic system, and lift the lower pressure head 4 to Insert the thermocouple 6 into the temperature measuring hole of the graphite inductor 12 at the middle position in the coil 11, and close the furnace door 18. Until the vacuum degree meets the requirements, you can choose to keep the vacuum or fill the furnace cavity with inert gas. When the desired atmosphere is reached, the sample is heated by an induction power supply. Raise to the required temperature and keep it warm, and control the descending speed of the lower indenter 4 through the displacement sensor (adjustable within the range of 0.01-150mm/s), large grains or even single crystal materials can be obtained.

Embodiment five

Based on the semiconductor material preparation equipment of Embodiment 1, the rapid solidification preparation process of the semiconductor material is as follows:

Open the furnace door 18, put the graphite sensor 12 with the sample 14 on the center of the lower pressure head 4, start the hydraulic system, raise the lower pressure head 4 to the middle position in the coil 11, insert the thermocouple 6 into the graphite In the temperature measuring hole of the inductor 12, close the furnace door 18. Until the vacuum degree meets the requirements, you can choose to keep the vacuum or fill the furnace cavity with inert gas. When the desired atmosphere is reached, the sample is heated and sintered by an induction power supply. After rising to the desired temperature, turn off the power supply, and at the same time control the lower pressure head 4 through the displacement sensor to quickly lower the inductor 12 to the bottom of the furnace, and then spray liquid nitrogen or inert gas into the inductor through the interfaces 2 and 5 on both sides. Then start the vacuum system to extract the gas to achieve rapid solidification.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (8)

1. A kind of semiconductor material preparation equipment, is characterized in that, comprises the body of furnace that has sealing furnace door, induction coil, inductor, upper indenter, lower indenter, thermocouple; The upper pressure head is located on the top of the furnace body; The lower pressure head is located at the bottom of the furnace body; The induction coil is helical, located in the center of the cavity of the furnace body, with both ends passing through the furnace body, and connected to the heating head of the frequency-adjustable induction power supply; The upper pressure head, the lower pressure head and the induction coil are coaxial, and the cross section is circular; The cross-sectional area of the induction coil is larger than the cross-sectional area of the upper and lower pressure heads; The inductor is used to be placed between the induction coil, the lower pressing head, and the upper pressing head; One end of the thermocouple is connected to the cavity of the furnace body; The furnace body is provided with an air filling port, an air discharge port, and a vacuum system interface; The charging port is used to charge gas or liquid nitrogen into the cavity of the furnace body; The air release port is used to discharge the gas in the cavity of the furnace body; The vacuum system interface is used for externally connecting the vacuum pumping system. 2. semiconductor material preparation equipment according to claim 1, is characterized in that, The induction power supply has a power supply frequency of 1000-400000Hz; The inductor is made of graphite or stainless steel; One end of the thermocouple is connected into the cavity of the furnace body and inserted into the temperature measuring hole of the inductor. 3. semiconductor material preparation equipment according to claim 1, is characterized in that, Semiconductor material preparation equipment, also including hydraulic systems; The hydraulic system is used to control the displacement and speed of the upper and lower pressure heads; The hydraulic system includes a hydraulic pump, a displacement sensor and a pressure sensor; The hydraulic pump is used to drive the upper pressure head and the lower pressure head; The displacement sensor is used to detect the displacement of the upper pressing head and the lower pressing head; The pressure sensor is used to detect the pressure of the upper pressing head and the lower pressing head. 4. semiconductor material preparation equipment according to claim 2, is characterized in that, The furnace body is a double-layer or single-layer coiled tube water-cooled furnace body, and cooling water interfaces are provided on the furnace body and the furnace door. 5. semiconductor material preparation equipment according to claim 2, is characterized in that, The upper pressure head and the lower pressure head are sealed on the top and bottom of the furnace body through flanges; The induction coil and the thermocouple are sealed into the cavity of the furnace body through the flange. 6. semiconductor material preparation equipment according to claim 2, is characterized in that, The furnace door is provided with a viewing window. 7. semiconductor material preparation equipment according to claim 2, is characterized in that, The vacuum pumping system includes a high vacuum pump, a rough vacuum pump, valves and a vacuum gauge. 8. semiconductor material preparation equipment according to claim 6, is characterized in that, The high vacuum pump is a molecular pump, a diffusion pump, an ion pump, a cryogenic pump or a Roots pump; The rough vacuum pump is a rotary vane mechanical pump, a direct-coupled mechanical pump, a water ring pump or an oil-free dry pump.