JP2006070325A - Cvd system for high temperature use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high temperature vapor deposition system which solves the problem that, though the conventional MOCVD (Metal Organic Chemical Vapor Deposition) system is used for the deposition of a thin film of GaN or the like, a substrate temperature is increased only to about 1,000 to 1,100°C at the most, and can heat a substrate to about 1,800°C, so as to grow a thin film. <P>SOLUTION: In the system, a flow channel is produced by carbon (C), molybdenum (Mo), pyrolytic graphite (PG), PG coat carbon, TaC coat carbon or conductive BN, a window for holding a substrate is opened in the upper sidewall of the flow channel, a substrate is held to the window downward by an opened substrate holder, the upper part of the flow channel window is provided with a resistance heating heater freely ascendable and descendable, radiation heat is generated from the upper part to the lower part to heat the substrate and the flow channel, and gaseous starting materials of ammonia and organometallic gas such as TMA (trimethylaluminum) are fed from cooled two gaseous starting material nozzles, so as to grow an AlN thin film on the substrate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

It is an object of the present invention to provide a high-temperature CVD apparatus capable of growing at 1800 ° C. suitable for growing an AlN thin film. In the MOCVD method in which a nitride semiconductor thin film such as a GaN or InGaN thin film is grown on a sapphire substrate, the heating temperature is about 1000 ° C. or about 1100 ° C. Even if it was very high, 1300 ° C was the limit. Therefore, there is no nitride semiconductor MOCVD apparatus capable of heating the substrate to 1300 ° C. or higher.
The currently used MOCVD apparatus for growing GaN and InGaN has a sapphire substrate on the susceptor, the substrate is heated from below, and a source gas (ammonia, TMG, TMI, TMA) is flowed from the lateral direction to GaN, A thin film such as InGaN or AlGaN is grown. InGaN-based light emitting diodes can emit blue light but cannot generate light having a shorter wavelength.

  Light-emitting diodes and semiconductor lasers that emit ultraviolet light of 250 nm to 300 nm are not possible with the InGaN system. A material with a wider band gap is required. The inventor of the present invention pays attention to AlN as a material of a light emitting element that emits such ultraviolet light. AlN has a wider band gap than GaN and a width corresponding to the energy of ultraviolet light. Since AlN has a wide band gap, it may be an ultraviolet light emitting diode. Therefore, if the thin film structure of AlN can be made well, a light emitting element that emits ultraviolet rays of 200 nm to 300 nm should be able to be produced.

  Further, if a high-efficiency, high-power, small-sized semiconductor laser capable of emitting laser light with a wavelength of 250 nm or less can be produced, it will be useful as a light source for processing, medical use, and sterilization. Since the wavelength is short, it may be used as writing / reading light for optical disks with higher recording density. Furthermore, it may be possible to manufacture ultra high frequency devices and ultra high power electronic devices.

  In addition to the ones mentioned above, there are also unique applications. Ultraviolet light emitting diodes may be used as flame sensors. The flame contains light of various wavelengths, but there is a possibility of malfunction when attempting to detect the flame with visible light. It is said that ultraviolet rays can be detected without fail because ultraviolet rays are inherent to flames.

  AlN substrates are sold by CrystalIS, but not by Japanese companies. Generally, an attempt is made to produce a light emitting diode by growing an AlN thin film on a sapphire or SiC substrate. The thickness of the thin film is as thin as about 0.1 μm to 0.5 μm. Experiments are made to make n-, p- AlN or AlGaN thin films on a substrate. The MOCVD method using ammonia and an organic metal as raw materials is promising.

The MOCVD method using an organic metal raw material is widely used in the manufacture of GaN-based light emitting diodes for forming InGaN and GaN thin films on a sapphire substrate. A GaN-based thin film having a good quality can be obtained at about 1000 ° C. to 1100 ° C. Attempts have been made to make AlN thin films with equipment similar to GaN, but do not produce good results. There is still no technology for producing a satisfactory AlN thin film with good reproducibility. The inventor thinks that there are various reasons, but one is that the film forming temperature is too low.
It is expected that a good thin film of AlN can be formed by manufacturing at a higher temperature, for example, a high temperature MOCVD method of about 1800 ° C.

Japanese Patent Laid-Open No. 10-167897 “Growth Method of GaN Film”

JP-A-8-139026 “Thin Film Vapor Deposition Apparatus”

Japanese Patent Laid-Open No. 7-78773 “Thin Film Vapor Deposition Apparatus”

  There are vertical and horizontal CVD apparatuses. The present invention is in the horizontal category. The prior art of the horizontal CVD apparatus will be described. In Patent Document 1, the substrate is held upward by a susceptor, exposed to a part of the flow channel path, and heated from below, and the source gas is flowed laterally and the source gas is pressed against the substrate with an obliquely downward hydrogen purge gas. An apparatus for causing a reaction on a substrate and depositing a GaN thin film on the substrate is proposed. The flow channel heated from below has high temperature at the bottom and low temperature at the top, and the convection is so intense that the source gas rises. Therefore, the source gas is pressed downward with an obliquely downward hydrogen gas and forcedly brought into contact with the substrate.

  Patent Document 2 is a lateral MOCVD apparatus for growing GaAs. The situation is quite different because the Group 5 source gas is not ammonia but arsine and the growth temperature is low. In order to prevent the reaction product from falling to the shaft mechanism of the susceptor, purge gas (hydrogen) is blown out from below the susceptor to prevent the product from falling, and the raw material gas is prevented from flowing down to the susceptor and causing loss. Patent Document 3 is a horizontal MOCVD apparatus for producing a 2-6 group ZnSe thin film. If the gas stays in the dead space when the source gas is switched, the switching is not sharp, so purge gas is blown.

JP-A-11-74203 "Growth Method and Growth Apparatus for Nitride III-V Compound Semiconductor"

In Patent Document 4, a substrate and a susceptor are placed in a quartz tube, and a GaN and InGaN thin film is grown at a pressure of about 1.5 atm by blowing a mixed gas of source gas and hydrogen into the quartz tube. Conventional MOCVD has been low pressure CVD (lower than 1 atm), but it is difficult for nitrogen to enter the thin film. Therefore, a pressure CVD method in which the pressure is 1.2 atm or more is proposed. A method is also disclosed in which a substrate is held downward on a susceptor and placed in a quartz tube, and a mixed raw material gas is flowed to 1.2 atm or higher. It states that the thermal convection is directed upward and hits the substrate surface, so that the growth proceeds efficiently and the separation of nitrogen can be prevented. The growth temperature is 700 ° C. to 800 ° C., which is a considerably low temperature.

Japanese Patent Application Laid-Open No. 7-111245 “Vapor Phase Growth Device”

In Patent Document 5, a substrate is held on the back surface of a susceptor supported from below and can be raised and lowered, and the susceptor is lowered to introduce the substrate into a raw material gas flow so that a thin film is grown on the substrate by a gas phase reaction. Such a device is proposed. This asserts that the rotation operation is stabilized because the substrate is held downward and the susceptor is also supported rotatably from below.

  However, since the susceptor is supported by the rod from below and the rod is supported by the bearing, the heater cannot be provided directly under the substrate. The heater is provided near the upper gate valve of the susceptor. The heater heat can only heat the susceptor and indirectly heat the substrate. Therefore, the substrate temperature is not so high. After the film formation is finished, it is lifted toward the heater, the gate valve is opened, and the susceptor is lifted with a fork. The contact part between the removable susceptor and the column is unstable. This does not grow a GaN film or an AlN film.

  FIG. 1 shows a conventional MOCVD apparatus. This is a MOCVD apparatus for a horizontally upward substrate that was previously manufactured by the present inventors. This is the device that was the prototype of Patent Document 1. The flow channel 7 extending in the horizontal direction is a fluid flow path having a square cross section.

A susceptor 6 for supporting a substrate holder 2 that holds the substrate 1 is provided at the center of the furnace. The susceptor 6 has a resistance heater 3 inside. A plurality of reflectors 4 for reflecting the heater heat upward are provided below the heater 3. A thermocouple 5 protrudes above the heater 3 and is provided close to the back surface of the substrate holder 2. The entire susceptor 6 can move in the vertical direction. A horizontal flow channel 7 guides the source gas to the substrate 1. A gas nozzle 8 for supplying a raw material gas is provided on the upstream side of the flow channel 7. This blows out the gas of ammonia gas NH ₃ and organic metal raw material (trimethylgallium TMG) into the flow channel 7.

  FIG. 1 shows an MOCVD apparatus for producing a GaN-based light emitting diode (LED) on a sapphire substrate. Used at a temperature of 1000 ° C or 1100 ° C. The maximum rises only to about 1300 ° C. In order to divert this to epitaxial growth of an AlN thin film, the source gas may be changed from trimethylgallium (TMG) to trimethylaluminum (TMA). Then, the reaction between TMA and ammonia will produce AlN, which should be deposited on the sapphire substrate. Some have attempted to grow an AlN film at about 1000 ° C. in that way.

  However, in reality, this is not the case, and an AlN thin film that simply changes the source gas from TMG to TMA cannot be obtained. One may be the problem of lattice matching with the substrate, but one is that the temperature is too low. The present inventors consider that the temperature of 1000 ° C. or 1100 ° C. is too low for AlN. In the case of AlN, a high temperature of 1800 ° C. is considered necessary. However, there is still no MOCVD apparatus for nitride semiconductor capable of producing 1800 ° C. However, I would like to make a MOCVD apparatus for nitride semiconductor at 1800 ° C. somehow.

  In the MOCVD apparatus of FIG. 1, the flow channel 7 is made of a quartz tube. However, the quartz tube begins to soften at 1200 ° C., so it cannot withstand the high temperature of 1800 ° C. As such, the apparatus of FIG. 1 cannot be used for 1800 ° C. AlN. The other is a heater. There are three types of heaters: induction heating, resistance heating, and light heating. Induction heating is a method in which a substrate is placed on a susceptor made of a conductive material, high-frequency power is applied to a coil on the outer periphery of the chamber, and eddy currents are generated in the susceptor separated by a high-frequency electric field, thereby heating the susceptor. In induction heating, the loss is too great and the power supply capacity becomes too large. In light heating, light from a lamp is guided into a quartz pillar and irradiated from above the substrate. Using the two quartz pillars from the top and bottom of the substrate, it is possible to finally transport that much heat toward the substrate. However, since the quartz column provided close to the substrate blocks the gas flow, the source gas cannot be supplied to the substrate sufficiently uniformly.

  That's why resistance heating. Resistance heating is to heat an object by radiating Joule heat generated by passing a current through a heat resistant resistor. The resistance heater shown in FIG. 1 is also used, but a resistance heater that can withstand higher temperatures and withstand a gas atmosphere is required. If the heater material is PG, PG coated carbon, Mo, conductive BN, TaC coated carbon, or the like, the heater can withstand a high temperature and gas atmosphere. In the case of growing a nitride semiconductor, since it becomes a hydrogen atmosphere (reducing property) or an ammonia atmosphere, PG coated carbon can be used as a heater. In addition, PG, Mo, conductive BN, and TaC coated carbon can also be used as a heater. When such a heater and a highly reflective reflector are combined to prevent escape of heat, the heater can be heated to a high temperature of about 1900 ° C. Even if a high-power resistance heater is obtained, there are still problems. The source gas supply pipe should be heated as close as possible to the substrate by transporting the gas as close to the substrate as possible. When the distance between the pipe and the substrate is increased, the gas is heated and decomposed on the way, and is consumed before reaching the substrate. In order to avoid this, it is necessary to carry the raw material gas as close to the substrate as possible. However, since the source gas supply pipe is a stainless steel pipe, there is a concern that it may not withstand intense radiant heat near the substrate.

  First, the susceptor is lowered, the substrate and the substrate holder are placed, the susceptor is raised to the height of the flow channel, gas is flowed and heated for epitaxial growth, and then the susceptor is lowered and the substrate and the substrate holder are exchanged. So the susceptor must be able to move up and down. In epitaxial growth, since the source gas passes laterally over the substrate, the height of the substrate relative to the flow channel greatly affects the formation of the thin film. In the apparatus shown in FIG. 1, the elevation of the susceptor 6 is controlled by a step motor. The accuracy in the vertical direction is about ± 1 mm. However, even with a height difference of only ± 1 mm, the gas flow varies and the growth conditions differ. Therefore, the properties of the resulting thin film are greatly different. The properties of the thin film cannot be stabilized unless the height of the substrate is precisely defined.

  In the MOCVD apparatus of the present invention, the flow channel is made of carbon (C), molybdenum (Mo) or pyrolytic graphite (PG), a window is provided on the top of the flow channel, and the substrate is placed in a bottomless substrate holder. A substrate holder is supported by a window frame, the substrate is held at a certain height, the substrate is exposed downward to the flow channel, and a resistance heater is provided above and below the flow channel. The raw material gas is blown out to the flow channel from a gas nozzle that is heated and cooled with water, and the gas flow contacts the lower surface of the heated substrate so that a thin film is grown on the lower surface of the substrate. By such a device, a thin film can be grown on the substrate while being heated to a high temperature of 1800 ° C.

  When the flow channel is a quartz tube, softening starts when the temperature is raised to 1300 ° C. or higher. It cannot withstand high temperatures of 1800 ° C. In the present invention, since the flow channel is made of carbon, Mo, PG or PG coated carbon, TaC coated carbon, or conductive BN, it can withstand high heat of 1800 ° C. It withstands over 1800 ° C and up to about 1850 ° C and 1900 ° C. Carbon is resistant to high temperatures and withstands 1800 ° C. to 1900 ° C. in an oxygen-free atmosphere. Since the source gas is ammonia or organic metal using hydrogen as a carrier gas, oxygen does not exist and carbon is stable. Since Mo is a metal with excellent heat resistance, it withstands such temperatures. Pyrolytic graphite is carbon that is particularly excellent in heat resistance. This also withstands 1800 ° C. to 1900 ° C. sufficiently. Although the entire flow channel does not reach 1800 ° C. or higher, the portion close to the heater becomes a high temperature of 1800 ° C. or higher. Therefore, it is useful to make the flow channel a material having excellent heat resistance. As a result, it is possible to provide for the first time an MOCVD apparatus for nitride semiconductors for high temperatures of about 1300 ° C. to 1900 ° C.

  Rather than allowing the substrate to move up and down, the substrate is placed face down on the flow channel window frame so that the height is accurately determined. Since the gas flow is blown from the side, even if the height difference is 1 mm, the properties of the produced thin film vary greatly. However, in the case of the present invention, the error of 0.1 mm does not occur in the substrate height, so the reproducibility. Rich. This is the most devised aspect of the present invention. The reason why the substrate is placed downward on the window frame member is to make the height constant. Therefore, a substrate is provided on the upper side of the flow channel. Therefore, a heater is also provided above the flow channel. A heater heats the substrate from above. Since it is necessary to remove the tray placed on the window frame in order to replace the substrate, the heater can be moved up and down, and the heater is lifted to replace the tray. Since the heater can be moved up and down, even if some variation appears in the height of the heater at the bottom dead center, the influence is small.

  In the flow channel space, the upper part is hot and the lower part is low, so convection hardly occurs. Therefore, the source gas exits from the nozzle and goes straight to the substrate without being disturbed by convection. Since the substrate is mounted face down, there is also an advantage that dust and particles do not adhere to the substrate surface.

  Furthermore, since the vicinity of the substrate is heated to a temperature higher than that of the conventional MOCVD method by heating the heater, if the material gas supply pipe is made of stainless steel, it cannot withstand the heat. It is difficult to manufacture the raw material gas supply pipe with materials other than stainless steel. Therefore, in the present invention, a water cooling jacket is provided in the source gas supply pipe. By water cooling, stainless steel pipes can withstand high heat. When the source gas exits the pipe and enters the flow channel, it is heated and thermally decomposed.In the present invention, however, the pipe is cooled with water and the source gas is also cooled, so it does not thermally decompose in a short distance from the pipe to the substrate. You can get to the board. Therefore, the utilization efficiency of the raw material gas is high.

  By such a device, the substrate can be heated to 1800 ° C. to about 1900 ° C. As a result, a good AlN thin film can be grown on a substrate such as sapphire or SiC.

  The horizontal flow channel is PG-coated carbon. Unlike quartz, carbon withstands heat even at temperatures exceeding 1200 ° C., and withstands repeated use near 1800 ° C. Since the substrate holder on which the substrate is placed is placed on the window above the flow channel, the positional relationship between the gas nozzle and the substrate is constant, and a thin film with high reproducibility can be formed. Since the substrate is face down and heated from above, there is no difficulty in thermal convection. Since the gas nozzle is cooled, the SUS nozzle can sufficiently withstand heat. Since the gas is cooled, thermal decomposition does not occur while leaving the nozzle to the substrate.

  A high-temperature CVD apparatus according to an embodiment of the present invention will be described with reference to FIG. This is the internal structure of the furnace, with a chamber surrounding these lateral flow channels and nozzles. Since there is a chamber, the atmosphere and pressure can be controlled. The chamber is not shown. The flow channel 27 having a square cross section and provided horizontally is made of carbon, molybdenum, PG, or the like. Since black powder may be generated by rubbing with only carbon, carbon is coated with a PG thin film. In the middle of the flow channel 27, a window 34 having the same size as the substrate is provided on the upper wall. The size of the window is determined to match the substrate size. Here, since the substrate size is 15 mmφ, the window is also about 16 mm to 20 mmφ. In the case of a 1 inch substrate or a 2 inch substrate, the window is also sized to be 26 mm to 30 mm or 52 mm to 55 mm accordingly.

  The base substrate 20 is placed on a frame-only substrate holder 22 without a bottom that fits into a window 34 opened in the flow channel 27, and the substrate holder 22 is placed so as to be suspended from the frame of the window 34 of the flow channel 27. The lower piece of the substrate holder 22 supports the substrate, and the upper piece of the substrate holder 22 is in contact with the frame 34 of the flow channel 27. Therefore, the relative height of the substrate with respect to the flow channel 27 is always constant. Since it is a lateral flow, the state of thin film formation is sensitive to the height of the substrate flow, but the substrate height is constant and the same relationship can be maintained with respect to the gas flow. The first feature of the present invention is that the height of the substrate can be determined strictly.

  A heat insulating material 33 is provided at the bottom of the flow channel 27 facing the window 34. This is in the flow channel 27 for reflecting the radiant heat from the substrate and maintaining a high heat state in the internal space of the flow channel 27. For example, PG or the like is used.

  Since the substrate is provided face down, the heater 23 is provided immediately above the substrate 20 and generates heat downward to heat the substrate 20. The heater 23 is a resistance heater. A resistor such as PG, PG coated carbon, Mo, conductive BN, or TaC coated carbon is used. A plurality of Mo reflectors 24 are provided on the heater 23. In a molecular beam cell or the like, a thin tantalum (Ta) plate is used as a reflector. However, Ta is weak in a hydrogen atmosphere (reducing atmosphere) and deteriorates. Therefore, a thin Mo plate is used. Mo is hard and difficult to process, but can be made thin.

  A thermocouple 25 that measures the temperature of the heater 23 through the reflector 24 is provided. The thermocouple 25 is a tungsten rhenium (W-Re) wire and uses a Mo sheath thermocouple. The heater temperature is measured by a thermocouple, and the heater power is increased or decreased by increasing or decreasing the current, so that it can be set to an arbitrary temperature. The heater case 26 is made of Mo. The entire heater mechanism including the heater case 26, the reflector 24, and the heater 23 is movable in the vertical direction. The distance S between the substrate and the heater is variable. When replacing the substrate, the entire heater mechanism is pulled up. When the substrate heating thin film is generated, the heater 23 is lowered to a distance of about 5 mm (S = 5 mm) with respect to the substrate 20.

  Since the heater 23 heats the flow channel 27 from the top to the bottom, the upper temperature is high and the lower temperature is low in the flow channel space. In the present invention, the temperature distribution is opposite to that of the conventional example. In this case, the temperature distribution is stable and no convection occurs. Convection occurs because the bottom is hot and the top is cold. In the present invention, convection does not occur, and the gas flow is close to a stable laminar flow. Therefore, the conditions for thin film formation are also stable. In addition, since there is no convection, the source gas emitted from the nozzle goes straight and easily reaches the substrate.

  Gas nozzles 28 and 29 are provided in the opening at the left end of the flow channel 27. Since the nitride semiconductor thin film is grown by the organic metal CVD method, the source gas is ammonia and an organic metal diluted with hydrogen, such as trimethylgallium (TMG), trimethylaluminum (TMA), trimethylindium (TMI), or the like. Organometallics are easily decomposed even at low temperatures, and are generally thermally decomposed at 400 ° C to 450 ° C. Ammonia does not pyrolyze to higher temperatures. It decomposes only after it reaches 900 ° C.

  Therefore, it is normal to install the ammonia blowing nozzle on the high temperature side and the organometallic gas blowing nozzle on the low temperature side. In the conventional example of FIG. 1, since the heater is on the lower side, the lower side of the flow channel is hot and the upper side is colder. In this case, the ammonia blowing nozzle is provided on the lower side, and the TMG (trimethylgallium) blowing nozzle is provided on the upper side.

  However, in the case of the present invention, the heater 23 is above the flow channel 27, and in the internal space of the flow channel 27, the upper is high and the lower is low. Therefore, the upper gas nozzle 28 blows out ammonia, and the lower gas nozzle 29 blows out organic metal (TMA). Such a gas nozzle is a metal such as stainless steel, but the stainless steel nozzle may be deteriorated due to the high temperature of the flow channel. In addition, the gas is already heated inside the stainless steel pipe. There is also the possibility of thermal decomposition immediately after leaving the nozzle tip 35. If the source gas reacts without reaching the substrate, it is wasted.

  Therefore, in the present invention, the gas nozzles 28 and 29 are provided with a water cooling jacket 32. Because it is water cooled, the stainless steel of the nozzle is not damaged by heat. In addition, the source gas is kept at a sufficiently low temperature inside the pipe. When the source gas exits from the nozzles 28 and 29, it passes through the flow channel in the horizontal direction through the upstream side 36 of the flow channel 27, directly below the substrate 37, and downstream side 38 to the outlet 39. Since the source gas is cooled, it takes time for heating after it blows out from the tips 35 and 35 of the nozzles 28 and 29, so that the gas can reach the substrate as it is. As a result, the source gas meets and reacts for the first time on the substrate surface. The raw material gas can be used effectively. Although the distance W between the tip 35 of the nozzles 28 and 29 and the end of the substrate 20 is as short as about 50 mm, the source gas reaches the substrate 20 without being decomposed between them.

  There was concern about installing a water-cooled jacket. Since the substrate is heated to 1800 ° C. to 1900 ° C., the power of the heater is intense. Since the heater power is strong, the flow channel is heated strongly, and the vicinity of the nozzle becomes very hot. So isn't the water in the water cooling jacket boiling immediately and can't be cooled? I was worried. However, in practice, it was found that the water does not boil immediately and the water temperature at the outlet of the water cooling jacket is much lower than 100 ° C. and can be maintained at a sufficiently low temperature near the tips of the nozzles 28 and 29. That is something that you can't understand without actually making it and examining it. If the nozzle does not withstand heat even in the water-cooled jacket, the distance W between the nozzle and the substrate must be set to 100 mm to 200 mm. However, most of the source gas is decomposed and wasted before reaching the substrate. Instead, according to the present invention, the nozzle is brought close to the substrate by cooling with water (up to about 50 mm), so that consumption of the source gas can be efficiently prevented.

The quartz tube is used as the flow channel, the substrate is held upward by the susceptor, the substrate is heated by a resistance heater, the susceptor is raised and lowered, the substrate is replaced, and a raw material gas is blown into the flow channel from the lateral direction to form a thin film. The schematic block diagram of the horizontal type MOCVD apparatus concerning a prior art example.

The flow channel is one of carbon, Mo, and PG, and the resistance heater that holds the substrate downward and heats the substrate from above can be moved up and down in the window provided in the flow channel, and the source gas is blown from the water-cooled source gas nozzle 1 is a schematic view of a horizontal high-temperature CVD apparatus of the present invention in which a thin film is formed on a substrate by reaching a substrate without being thermally decomposed in a flow channel.

Explanation of symbols

1 Substrate
2 Board holder
3 Resistance heater
4 reflectors
5 Thermocouple
6 Susceptor
7 Flow channel
8 Gas nozzle
20 Base substrate
22 Substrate holder
23 Resistance heater
24 reflector
25 Thermocouple
26 Heater case
27 Flow channel
28 Raw material gas nozzle
29 Raw material gas nozzle
32 Water-cooled jacket
33 Insulation
34 windows
35 Nozzle tip
36 Flow channel upstream
37 Directly under the flow channel substrate
38 Flow channel downstream
39 Flow channel exit
S Distance between heater and substrate
W Distance from nozzle tip to substrate edge

Claims (1)

A horizontal flow channel made of carbon (C), molybdenum (Mo), pyrolytic graphite (PG), PG coated carbon, TaC coated carbon, or conductive BN and having a window on the upper wall for holding the substrate; A heater made of PG, PG coated carbon, TaC coated carbon or conductive BN, which can be moved up and down above the window for heating the substrate held downward in the window to a temperature of 1300 ° C. to 1900 ° C., and the flow channel side A flow channel on a substrate heated downward by a flow channel window and heated by a heater, including a raw material gas nozzle for introducing a raw material gas into the flow channel at a side opening and a water cooling jacket for cooling the raw material gas nozzle. A thin film is grown on the substrate by contacting the source gas that has passed through High temperature CVD and wherein the door.

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