JP6707676B2 - Method of manufacturing semiconductor device - Google Patents

Description

Embodiments according to the present invention relate to a method of manufacturing a semiconductor device.

A film forming apparatus such as a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus decomposes a group V source gas and a group III source gas and causes them to react on a semiconductor wafer to form a crystal film of metal nitride or the like on the semiconductor wafer. Form a film.

However, in order to thermally decompose the group V source gas on the substrate, a high temperature exceeding 1000° C. is required, and the group III-V crystal film formed at such a high temperature is cooled by the difference in thermal stress from the substrate. It will be distorted later. When the group V source gas is decomposed and supplied by a method such as plasma discharge without relying on the thermal decomposition by the substrate temperature, a shower head arranged between the source of the group V source gas and the stage is used. , Group V source gas and group III source gas are respectively supplied, the showerhead interferes with the group V source gas ions and radicals, making it difficult for the group V source gas ions and radicals to reach the substrate. On the other hand, if an attempt is made to supply the group III source gas with a nozzle, the film thickness and quality of the crystal film will fluctuate on the surface of the semiconductor wafer, although it will not disturb the ions and radicals of the group V source gas.

JP, 2003-142404, A US Patent Publication No. 2014/0037865

(EN) Provided is a method for manufacturing a semiconductor device, which is capable of easily forming a material film having less distortion and more uniform film thickness and film quality.

The semiconductor device manufacturing method according to the present embodiment includes a stage on which a substrate can be mounted, and a stage extending from the central portion to the end portion of the substrate along the radial direction of the substrate and extending in the direction of the substrate, respectively. A semiconductor manufacturing apparatus comprising: a plurality of first supply units each having one hole for supplying a Group III element-containing gas, and a second supply unit for supplying radicals or ions of a Group V element-containing gas onto a substrate. It is a manufacturing method of the used semiconductor device. In the method, the substrate on the stage is rotated. The plurality of first supply units periodically supply the Group III element-containing gas to the substrate at different flow rates in synchronization with the rotation cycle of the substrate , or alternatively, supply the Group III element-containing gas at different flow rates to the rotation cycle of the substrate. It is supplied at a supply amount based on. The second supply unit supplies radicals or ions of the group V element-containing gas to the substrate.

1 is a schematic diagram showing an example of the configuration of a MOCVD apparatus 1 according to the first embodiment. The figure which shows an example of a structure of the 1st supply part 30. The graph which shows the supply amount of the III group element containing gas in the 1st supply part 30. 3 is a flowchart showing an example of a film forming method according to the first embodiment. FIG. FIG. 6 is a timing chart showing the supply operation of trimethylgallium and the supply operation of nitrogen radicals or nitrogen ions. The schematic diagram showing an example of the composition of MOCVD device 2 according to a 2nd embodiment. The figure which shows an example of a structure of the 1st supply part 30 by 2nd Embodiment. The graph which shows the supply amount of the III group element containing gas in the 1st supply part 30. 6 is a graph showing a supply amount of trimethylgallium as a group III element-containing gas and a supply amount of nitrogen radicals or nitrogen ions as a group V element. The figure which shows the 1st supply part 30 according to the modification 2 of 1st Embodiment. The figure which shows the 1st supply part 30 according to the modification 2 of 2nd Embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
FIG. 1 is a schematic diagram showing an example of the configuration of a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus 1 (hereinafter, also simply referred to as apparatus 1) according to the first embodiment. The device 1 includes a chamber 10, a stage 20, a first supply unit 30, a second supply unit 40, a heater 50, a drive unit 55, and a controller 60.

The inside of the chamber 10 is evacuated to a reduced pressure by a vacuum pump (not shown). The chamber 10 houses the stage 20, the first supply unit 30, the second supply unit 40, the heater 50, and the like.

The substrate W can be mounted on the stage 20, and the substrate W can be rotated. The substrate W may be, for example, a silicon substrate, a sapphire substrate, a SiC substrate, or the like.

The first supply unit 30 supplies the group III element-containing gas onto the substrate W. The group III element-containing gas is, for example, an organometallic gas containing a group III element such as aluminum (Al), gallium (Ga), and indium (In). The organometallic gas is, for example, a gas such as trimethylaluminum, trimethylgallium, trimethylindium and the like. In the present embodiment, the first supply unit 30 is, for example, a hollow nozzle, and extends from the central portion of the substrate W to the end portion of the substrate W. The first supply unit 30 has a plurality of holes extending from the center of the substrate W to the end of the substrate W toward the substrate W. The holes have a size, number, or opening area that is substantially proportional to the distance from the center of the substrate W to the edges. A more detailed configuration of the holes of the first supply unit 30 will be described later with reference to FIGS. 2(A) to 2(C).

By supplying the group III element-containing gas to the first supply unit 30, the group III element-containing gas is supplied to the substrate W through the holes. As a result, the first supply unit 30 supplies the group III element-containing gas to the substrate W from the center to the end of the substrate W at a flow rate substantially proportional to the distance from the center. That is, the first supply unit 30 increases the supply amount of the Group III element-containing gas between the central portion and the end portion of the substrate W as the distance from the central portion of the substrate W increases. The group III element-containing gas is thermally decomposed on the substrate W, and the group III element adheres to the surface of the substrate W. The first supply unit 30 is arranged closer to the stage 20 and the substrate W than the second supply unit 40 (position lower than the second supply unit 40). Thereby, the group III element is attached to the substrate W before being combined with the group V element from the second supply unit 40. The group III element is attached to the substrate W and then combined with the group V element to form a crystal film of a group III-V compound.

The second supply unit 40 supplies the radicals or ions of the group V element-containing gas onto the substrate W.
The group V element-containing gas is a gas containing radicals or ions of a group V element such as nitrogen (N), phosphorus (P), and arsenic (As). In the present embodiment, the second supply unit 40 is, for example, a plasma source that brings a group V element into a plasma state. Therefore, the group V element-containing gas is introduced into the second supply unit 40 to be converted into plasma and supplied into the chamber 10 as radicals or ions. Radicals or ions of the group V element-containing gas are supplied onto the substrate W and combine with the group III element on the surface of the substrate W. As a result, crystals of the III-V group compound are formed on the surface of the substrate W.

The heater 50 may be a hot plate built in the stage 20 as shown in FIG. 1, or a lamp or the like provided above the stage 20 (not shown). The heater 50 can heat the substrate W on the stage 20 to about 1000° C.

The drive unit 55 rotates the stage 20 as indicated by the arrow. The controller 60 controls the drive unit 55 and controls the rotation speed (rotation cycle) of the stage 20. The controller 60 can also control the flow rates of the raw material gases from the first and second supply units 30 and 40.

2A to 2C are diagrams illustrating an example of the configuration of the first supply unit 30. In the present embodiment, the first supply unit 30 is an elongated hollow nozzle. FIG. 2A to FIG. 2C show the first supply unit 30 viewed from the substrate W side, and shows an example of the configuration of the holes provided at the bottom of the first supply unit 30. The first supply unit 30 is positioned above the center portion of the substrate W (the front end portion of the first supply unit 30 corresponding to the center portion of the substrate W) C and above the end portion of the substrate W. A plurality of holes H are provided between the edge side portion (the intermediate portion of the first supply unit 30 corresponding to the end portion of the substrate W) E1.

In FIG. 2A, the opening area of the hole H is relatively small in the central portion C of the first supply portion 30 and gradually increases as it approaches the edge portion E1. For example, the hole H has a size (opening area) approximately proportional to the distance from the center to the end of the substrate W. Accordingly, the first supply unit 30 can supply the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center. In other words, the first supply unit 30 can supply the group III element-containing gas to the fan-shaped region of the substrate W at a certain central angle θa.

In FIG. 2B, the opening areas of the plurality of holes H are substantially equal to each other, but the number of holes H differs between the center side portion C and the edge side portion E1 of the first supply unit 30. That is, in FIG. 2B, the number of the holes H is relatively small in the center side portion C of the first supply portion 30, and gradually increases as it approaches the edge side portion E1. That is, the holes H are provided from the central portion of the substrate W to the end portions in a number substantially proportional to the distance from the central portion. Accordingly, the first supply unit 30 can supply the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center. In other words, the first supply unit 30 can supply the group III element-containing gas to the fan-shaped region of the substrate W at a certain central angle θb.

Similar to FIG. 2B, in FIG. 2C, the number of the holes H differs between the center side portion C and the edge side portion E1 of the first supply unit 30. 2C, the opening area of the hole H is smaller than that of the hole H of FIG. 2B, and the number of holes H continuously changes between the center side portion C and the edge side portion E1. is doing. Therefore, in terms of the density of the holes H, the density of the holes H is relatively small in the center side portion C of the first supply portion 30 and gradually increases as it approaches the edge side portion E1. That is, the density of the holes H increases from the center of the substrate W to the edge thereof in proportion to the distance from the center. Accordingly, the first supply unit 30 can supply the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center. In other words, the first supply unit 30 can supply the group III element-containing gas to the fan-shaped region of the substrate W having a certain central angle θc.

The configuration of the first supply unit 30 may be any of FIG. 2(A) to FIG. 2(C). The structure of the holes H of the first supply unit 30 may be arbitrary as long as the Group III element-containing gas can be supplied to the substrate W at a flow rate substantially proportional to the distance from the center of the substrate W.

FIG. 3 is a graph showing the supply amount of the group III element-containing gas in the first supply unit 30.
The first supply unit 30 supplies the group III element-containing gas to the substrate W at a flow rate substantially proportional to the distance from the center side portion C between the center side portion C and the edge side portion E1.

The first supply unit 30 is provided over the radius of the substrate W. Therefore, when the substrate W rotates, in the central portion of the substrate W, the circumference length of the substrate W to which the first supply unit 30 is supplying the Group III element-containing gas is short, and the end portion (outer periphery) of the substrate W is short. ), the length of the circumference gradually becomes longer. Therefore, as shown in FIG. 3, the first supply unit 30 supplies the group III element-containing gas to the substrate W at a flow rate substantially proportional to the distance from the center to the end of the substrate W. Thereby, the supply amount of the group III element-containing gas is small in the central portion of the substrate W, and the supply amount of the group III element-containing gas gradually increases as the outer periphery of the substrate W approaches. As a result, the group III element-containing gas is supplied to the entire surface of the substrate W substantially uniformly, and the group III element adheres to the surface of the substrate W substantially uniformly. A crystal film of a group V compound can be formed on the substrate W.

In addition, as described with reference to FIGS. 2A to 2C, the first supply unit 30 includes the group III element-containing gas in the fan-shaped region of the central angle θa, θb, or θc of the surface of the substrate W. May be considered to supply. In the fan-shaped region having the central angle θa, θb, or θc, the group III element is supplied in a much larger amount than the group V element. Therefore, in this case, the group V element-containing gas is supplied to the region of the surface of the substrate W other than the fan-shaped region of the central angle θa, θb, or θc (region of the central angle 2π−θa, 2π−θb, or 2π−θc). It can be said that it will be done. When the substrate W rotates, the group III element-containing gas is supplied in the fan-shaped region of the central angle θa, θb, or θc, and the group V element-containing gas is supplied in the region of the central angle 2π-θa, 2π-θb, or 2π-θc. Supplied. Thereby, as described later, it is possible to form a good quality III-V compound crystal film on the substrate W.

Such a crystal of a III-V group compound semiconductor or a III group nitride semiconductor is composed of a III group metal element and a V group element, but the III group metal element is a crystal having a relatively low melting point, The element is a gas at room temperature or has a relatively high vapor pressure. However, when the group III metal element and the group V element are bonded, the bond between the group III element and the group V element is strong and highly ionic. That is, the group III element and the group V element each have a weak bond and a high vapor pressure in a single element state. On the other hand, when a compound is ionically bonded to form a III-V group compound semiconductor, the group III element and the group V element are strongly bonded and the vapor pressure is low (the melting point is high).

When such a III-V compound semiconductor crystal film is epitaxially grown on the underlayer, the crystal structure and lattice length of the underlayer are preferably relatively close to the crystal structure and lattice length of the III-V compound semiconductor. .. Group III-V compound semiconductors are formed by epitaxial growth on such an underlayer. For example, when a group III nitride semiconductor is grown on an underlayer, a sapphire substrate, a SiC substrate, a silicon substrate having a (111) plane as a surface, or the like is used as the underlayer. The group III raw material is supplied onto the underlayer in an atmosphere in which the vapor of the group V raw material is excessively supplied. The group III raw material reaching the surface of the underlayer is combined with the group V raw material, and a thin film crystal layer of a group III nitride semiconductor such as gallium nitride is epitaxially grown on the underlayer.

The timing until the group III raw material is combined with the group V raw material to form a crystal varies depending on the ratio of the supply amount of the group III raw material to the group V raw material (hereinafter, also referred to as V/III ratio). Therefore, the crystal growth method of the group III nitride semiconductor differs depending on the V/III ratio. For example, when the supply amount of the group V raw material is much larger than the supply amount of the group III raw material (when the V/III ratio is very large), the group III atom is strongly bonded to the group V atom on the surface of the underlayer in a short time. Therefore, it is not possible to migrate on the surface of the underlayer. Therefore, the crystal of the group III nitride semiconductor grows in the thickness direction of the underlayer (substrate) according to the supply of the group III raw material.

On the other hand, when the supply amount of the group V raw material is approximately the same as the supply amount of the group III raw material (when the V/III ratio is close to 1), the group III atom is bonded to the group V atom on the surface of the underlayer. Takes a relatively long time. Therefore, the group III atoms can migrate on the surface of the underlayer. Therefore, the group III atom can move to a stable position in the underlayer or the crystal and then bond with the group V atom. In this case, since the group III nitride semiconductor grows at a stable position, the crystal quality can be improved. Preferably the V/III ratio is equal to 1. Further, in this case, the group III nitride semiconductor may form minute steps, or may grow while forming a plane orientation (facet plane) different from the surface of the underlayer. Controlling such a growth mode makes it possible to control defects (dislocations) and the like during the growth and leads to improvement of the crystal quality of the group III nitride semiconductor.

If the V/III ratio is much less than 1, a defective portion without a group V atom is generated in the crystal lattice, and the quality of the group III nitride semiconductor is deteriorated. Further, when the film formation temperature is high, the group V atoms with incomplete bonds may re-evaporate on the crystal surface of the group III nitride semiconductor. Also in this case, there is a possibility that a defective portion without a group V atom is generated in the crystal lattice.

Therefore, in order to suppress the lattice defect of the group V atom while reducing the V/III ratio, a method of alternately supplying the group III raw material and the group V raw material can be considered. In this method, the supply of the group V raw material is stopped or reduced, and the supply of the group III raw material is excessively performed, and the supply of the group III raw material is stopped or reduced, and the supply of the group V raw material is supplied. And a second period of excessively supplying C are alternately repeated. Thus, the excessive supply state of the group III raw material and the excessive supply state of the group V raw material are alternately executed in time. In the first period, a large amount of group III atoms are supplied, so that group III atoms can largely migrate. On the other hand, after that, a large amount of group V atoms are supplied in the second period, so that group III atoms and group V atoms are bonded to each other, and the loss of group V atoms can be suppressed. In this way, by repeating the first period and the second period alternately, it is possible to activate the migration of the group III atom and suppress the lattice defect of the group V atom.

For example, in the first period, the group III raw material having a group III atomic weight or more contained in one atomic layer of the group III-V crystal is supplied in an atmosphere containing almost no group V raw material. As a result, the group III atom stays on the surface of the underlayer due to a weak metallic bond and migrates. In the second period, the group V raw material is supplied in an atmosphere containing almost no group III raw material in an amount approximately equal to 100 times the amount of the group III raw material supplied in the first period. As a result, the group III atom on the underlayer is bonded to the group V atom to form a normal group III-V crystal.

The ratio of the supply amount of the group III raw material in the first period to the supply amount of the group V raw material in the second period is a ratio of the flow rates thereof (the amount of the group V raw material supplied to a unit area per unit time and the group III source). The ratio may be controlled by the ratio of the amount of the raw material) or the ratio of the time between the first period and the second period (the ratio of the supply time). The method of forming a crystal film of a III-V group compound semiconductor by alternately supplying the group III material and the group V material in this way is also called a migration enhanced epitaxy method.

In this embodiment, a migration-enhanced epitaxy method is applied to the MOCVD apparatus 1 to form a crystal film of a III-V group compound semiconductor. The method for forming a III-V compound semiconductor film according to the present embodiment will be described below.

FIG. 4 is a flowchart showing an example of the film forming method according to the first embodiment. First, the substrate W is transferred into the chamber 10 and placed on the stage 20 (S10). Next, the heater 50 heats the stage 20 and the substrate W, and the stage 20 rotates the substrate W (S20). The substrate W is heated to about 1000° C. or lower (eg, about 800° C. to about 1000° C.).

(First period)
Next, the first supply unit 30 periodically supplies the group III element-containing gas to the substrate W in synchronization with the rotation cycle of the substrate W (S30). The first supply unit 30 supplies the group III element-containing gas over the radius of the substrate W from the center to the end of the substrate W. Therefore, in order to share the group III element-containing gas on the entire surface of the substrate W, the first supply unit 30 supplies the group III element-containing gas for a predetermined first period. As a result, the group III element-containing gas is thermally decomposed on the substrate W, and the group III element adheres to the surface of the substrate W. For example, trimethylgallium (Ga(CH ₃ ) ₃ ) is used as the group III element-containing gas.

For example, in the circular silicon substrate W, the first supply unit 30 forms a fan-shaped region (hereinafter, also referred to as “θ region”) having a central angle θ (rad) with an area density j1 (atoms/cm ² ) per unit time of III. It is assumed that a group raw material (group III element-containing gas) is supplied. That is, the supply rate of the group III raw material is j1 (atoms/cm ² ·s). θ may be any of θa, θb or θc.

In the silicon substrate W, a region other than the θ region (fan-shaped region having a central angle of 2π−θ) is also referred to as “(2π−θ) region” hereinafter. The θ region is a region where the first supply unit 30 is arranged above the substrate W, and the (2π−θ) region is arranged above the substrate W without the first supply unit 30 and the second supply unit 40 is arranged. This is the area that was created. The second supply unit 40 continuously supplies the group V raw material, but in the θ region, the group III raw material is supplied in a larger amount than the group V raw material (group V element-containing gas). May be supplied and the group V raw material may not be supplied. On the other hand, since the first supply unit 30 is not provided above the (2π−θ) region, it may be considered that the group V raw material is supplied and the group III raw material is not supplied. That is, in the first period, the first supply unit 30 may supply the group III raw material in the θ region, and the group V raw material may be negligibly small and may not be supplied at all. On the other hand, in the (2π-θ) region, the second supply unit 40 supplies the group V raw material, the group III raw material is so small that it can be ignored, and may be almost not supplied.

Further, since the substrate W rotates with respect to the first and second supply units 30 and 40, when the first supply unit 30 is supplying the group III raw material, the group III raw material is in the θ region of the substrate W. It is supplied every time it passes and is supplied to the entire surface of the substrate W. On the other hand, since θ<<(2π−θ), it can be considered that the group V raw material is supplied to the entire surface of the substrate W when the first supply unit 30 does not supply the group III raw material. That is, the group III raw material is supplied to the entire surface of the substrate W in the first period, and the group V raw material is supplied to the entire surface of the substrate W in the second period described later.

Assuming that the areal density j0 of the group III atoms (for example, gallium atoms) in the (0001) plane of the group III-V crystal (for example, gallium nitride) is j0, when the substrate W is stopped, it is supplied from the first supply unit 30. It is assumed that the areal density j1 of the group III atoms is j1=α·j0.
In this case, when α=1, the areal density j1 of the group III raw material supplied to the surface of the substrate W per unit time becomes equal to the areal density j0 of the group III atoms in the group III-V crystal (j1=j0). .. Therefore, when α=1, the amount of the group III raw material corresponding to the amount of the group III atoms contained in one atomic layer of the group III-V crystal was supplied per unit time. On the other hand, when α<1, it means that the supply amount of the group III raw material per unit time is less than the amount of group III atoms contained in one atomic layer of the group III-V crystal. When α>1, it means that the supply amount of the group III raw material per unit time is larger than the amount of the group III atom contained in one atomic layer of the group III-V crystal (excess supply).

When the substrate W rotates at the rotation speed ω (rad/s), the time for the substrate W to pass through the θ region of the first supply unit 30 becomes θ/ω(s). Therefore, the first supply unit 30 supplies the group III raw material to (α·θ/ω)·j0 each time the substrate W makes one rotation (every time the first supply unit 30 passes over the θ region). Supply with an areal density of (atoms/cm ² ).

Here, the first period is n1·2π/ω(s). n1 is the number of rotations of the substrate W during the first period. In this case, the areal density j1 of the group III raw material supplied to the substrate W during the first period is n1·(α·θ/ω)·j0 (atoms/cm ² ). Therefore, when n1·(α·θ/ω) is larger than 1, the supply amount of the group III raw material becomes larger than the amount of group III atoms contained in one atomic layer in the III-V crystal, resulting in excessive supply. .. That is, the areal density j1 of the group III raw material supplied exceeds j0 (atoms/cm ² ). When n1·(α·θ/ω) is equal to 1, the supply amount of the group III raw material becomes equal to the amount of group III atoms contained in one atomic layer in the group III-V crystal. That is, the areal density of the supplied group III raw material becomes equal to j0. Further, when n1·(α·θ/ω) is smaller than 1, the supply amount of the group III raw material is smaller than the amount of group III atoms contained in one atomic layer in the group III-V crystal. That is, the areal density of the supplied group III raw material becomes smaller than j0. In this embodiment, by setting n1·(α·θ/ω)≧1 in the first period, the supply of the group III raw material is excessively supplied to activate the migration of the group III atoms on the surface of the substrate W.

(Second period)
The first supply unit 30 stops the supply of the group III raw material, and the second supply unit 40 continues to supply the radicals or ions of the group V element-containing gas toward the substrate W in the chamber 10 (S40). As a result, the radicals or ions of the group V element-containing gas are supplied onto the substrate W and are combined with the group III element attached to the surface of the substrate W. As a result, crystals of the III-V group compound are formed on the surface of the substrate W. For example, when nitrogen (N ₂ ) and hydrogen (H ₂ ) are supplied to the second supply unit 40 as the group V element-containing gas, the second supply unit 40 converts the nitrogen and hydrogen gas into plasma to generate a nitrogen radical (N 2). ^* ), nitrogen ions (N ⁺ ), hydrogen radicals (N ^* ), hydrogen ions (N ⁺ ), hydrogen nitride radicals (NH ^* ) and hydrogen nitride ions (NH ⁺ ) are generated, and these are supplied to the substrate W. .. As a result, gallium nitride (GaN) crystals are formed on the surface of the substrate W.

For example, it is assumed that the second supply unit 40 supplies the group V source material to the (2π−θ) region of the substrate W at an area density j2 (atoms/cm ² ) per unit time. That is, the supply rate of the group V raw material is j2 (atoms/cm ² ·s). At this time, when the surface density j0 of the group III atom (eg, gallium atom) in the (0001) plane of the group III-V crystal (eg, gallium nitride) is j0, when the substrate W is stopped, the second supply unit 40. It is assumed that the areal density j2 of the group V atoms supplied by the relation of 2=β·j0.

When the substrate W rotates at the rotation speed ω (rad/s), the time for the substrate W to pass through the (2π−θ) region is (2π−θ)/ω(s). Therefore, the second supply unit 40 supplies the group V raw material (β·(2π) every time the substrate W makes one rotation (every time the first supply unit 30 passes over the (2π−θ) region). Supply at an areal density of −θ)/ω)·j0 (atoms/cm ² ).

Here, the second period is n2/2π/ω(s). n2 is the rotation speed of the substrate W during the second period. In this case, the areal density j2 of the group V raw material supplied to the substrate W during the second period is n2·(β·(2π−θ)/ω)·j0 (atoms/cm ² ). Therefore, when n2·(β·(2π−θ)/ω) is larger than n1·(α·θ/ω), the supply amount of the group V raw material becomes larger than the supply amount of the group III raw material, and excessive supply Becomes When n2·(β·(2π−θ)/ω) is equal to n1·(α·θ/ω), the supply amount of the group V raw material becomes equal to the supply amount of the group III raw material. Further, when n2·(β·(2π−θ)/ω) is smaller than n1·(α·θ/ω), the supply amount of the group V raw material becomes smaller than the supply amount of the group III raw material.

In the present embodiment, the group V raw material is supplied more than the group III raw material by setting n2·(β·(2π−θ)/ω)≧n1·(α·θ/ω) in the second period. Suppressing lattice defects in group V atoms.

As described above, in the present embodiment, by setting n1·(α·θ/ω)≧1 in the first period, the supply of the group III raw material is excessively supplied to activate the migration of the group III atoms on the surface of the substrate W. And satisfying n2·(β·(2π−θ)/ω)≧n1·(α·θ/ω) in the second period, the group V raw material is supplied in excess of the group III raw material and V Suppresses lattice defects in group atoms. By repeating the first period and the second period, it is possible to form a good quality III-V crystal film on the substrate W. In this case, the supply amount of the group III element-containing gas can be controlled by the length of the first period. The supply amount of the group V element-containing gas can be controlled by the length of the second period.

When steps S30 (first period) and S40 (second period) are repeated (NO in S50) and the crystal film of the III-V group compound is formed to a desired film thickness (YES in S50), the device 1 The supply of the group III element-containing gas and the group V element-containing gas are both stopped (S60).
As a result, a crystal film (for example, a gallium nitride crystal film) of a III-V group compound having a good quality is formed on the surface of the substrate 1 with a desired film thickness.

For example, FIGS. 5A and 5B are timing charts showing a supply operation of trimethylgallium as a group III element-containing gas and a supply operation of nitrogen radicals or nitrogen ions as a group V element. The vertical axis of FIG. 5A shows the supply amount of trimethylgallium, and the vertical axis of FIG. 5B shows the supply amount of nitrogen radicals or nitrogen ions. The horizontal axis of FIG. 5(A) and FIG. 5(B) is time.

For example, in FIG. 5A, f1_1, f2_1, f3_1... Are the first periods, and f1_2, f2_2, f3_2... are the second periods. The controller 60 rotates the stage 20 together with the substrate W during the first and second periods f1_1 to f3_2. For example, the controller 60 rotates the stage 20 at about 800 rpm. The first supply unit 30 supplies trimethylgallium in the first periods f1_1, f2_1, f3_1... And stops the supply thereof in the second periods f1_2, f2_2, f3_2. As shown in FIG. 5B, nitrogen radicals and nitrogen ions are continuously supplied in the first and second periods f1_1 to f3_2. It can be considered that the nitrogen radicals and the nitrogen ions are substantially supplied in the second period f1_2, f2_2, f3_2,... While the supply of trimethylgallium is stopped. As a result, gallium adheres to the entire surface of the substrate W in the first period f1_1, f2_1, f3_1... And a gallium nitride crystal film is formed on the substrate W in the second period f1_2, f2_2, f3_2. It As described above, the first supply unit 30 repeatedly supplies and stops the supply of trimethylgallium for each of the first and second periods, so that the crystal film of gallium nitride is gradually formed on the substrate W (for example, 1 to 10 atomic layers). Formed).

Note that the lower the atmospheric pressure in the chamber, the longer the mean free path of the raw material gas, the higher the directivity of the raw material gas, and the more easily the deposited film thickness varies. However, according to this embodiment, the first supply unit 30 supplies the group III element-containing gas to the entire surface of the substrate W substantially uniformly, and the group III element adheres to the surface of the substrate W substantially uniformly. As a result, the device 1 forms a flat III-V compound crystal film having a substantially equal film thickness on the substrate W even in a low-pressure (for example, about 100 Pa or less) atmosphere having a high degree of vacuum. You can

Further, according to this embodiment, the first supply unit 30 supplies the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center. Supply.
Thereby, the group III atoms can be attached to the surface of the substrate W substantially uniformly. Further, radicals or ions of the group V element generated by the plasma are supplied from the second supply unit 40 and are bonded to the group III atoms attached to the surface of the substrate W. Accordingly, a crystal film of a III-V group compound having a substantially uniform film thickness and good film quality can be formed on the substrate W.

For example, when a III-V group compound crystal film is formed on the substrate W by thermally decomposing both the Group III element-containing gas and the Group V element-containing gas on the substrate W, the temperature of the substrate W is about 1000° C. ~ Need to be heated at high temperature of about 1100 degrees. In this case, due to the difference in thermal stress between the substrate W (for example, a silicon substrate) and the crystal film of the III-V group compound, when the substrate W is cooled, the substrate W is distorted, cracked, or broken.

On the other hand, in the present embodiment, the group III element-containing gas is thermally decomposed near the surface of the substrate W, but the group V element-containing gas is decomposed by plasma in the second supply unit 40. Thereby, the temperature of the substrate W can be relatively low (for example, about 800° C. to about 1000° C.). Thereby, the difference in thermal stress between the substrate W and the crystal film of the III-V group compound can be relaxed, and distortion, cracks, breakage, and the like of the substrate W can be suppressed.

When the group V element-containing gas is decomposed by plasma and the group III element-containing gas is thermally decomposed near the surface of the substrate W, the first supply unit 30 is arranged closer to the substrate W than the second supply unit 40. Preferably. Accordingly, the first supply unit 30 can supply the group III element-containing gas near the substrate W. However, if the first supply unit 30 is a shower head having a large area, it becomes an obstacle to radicals and ions of the group V element-containing gas, and the radicals and ions of the group V element-containing gas remain on the substrate W in the active state as described above. Hard to reach. On the other hand, if the first supply unit 30 is simply in the shape of a nozzle, it is difficult to evenly deposit the group III atoms on the surface of the substrate W. In this case, it becomes difficult to form the crystal film of the III-V group compound on the substrate W with a uniform film thickness.

On the other hand, in the present embodiment, the first supply unit 30 is an elongated nozzle that extends from the central portion of the substrate W to the end portion thereof over the radius of the substrate W. The first supply unit 30 supplies the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center. As a result, the group III element-containing gas is supplied to the entire surface of the substrate W substantially uniformly, and the group III element can be attached to the surface of the substrate W substantially uniformly. As a result, the device 1 can form a crystal film of a III-V group compound on the substrate W with little distortion and a substantially uniform film thickness and film quality.

(Modification 1)
In the first embodiment, a first period for supplying the group III raw material and a second period for stopping the supply of the group III raw material are set while continuously supplying the group V raw material, and the first period and the second period are set. The III-V group crystal film is formed on the substrate W by repeating the period.

In the first modification, the first and second supply units 30 and 40 continuously supply the group III raw material and the group V raw material, respectively. On the other hand, by setting the rotation speed ω of the substrate W, or by setting the supply amount (supply rate) of the group III raw material and the group V raw material from the first and second supply units 30 and 40, III− A group V crystal film is formed on the substrate W.

For example, assuming that the supply rate of the group III raw material is j1 (atoms/cm ² ·s), the area density of the group III atom (for example, gallium atom) in the (0001) plane of the group III-V crystal (for example, gallium nitride) is As j0, j1 has a relationship of j1=α·j0 with respect to j0.

Further, it is assumed that the second supply unit 40 supplies the group V raw material to the (2π−θ) region with an areal density j2 (atoms/cm ² ) per unit time. That is, the supply rate of the group V raw material is j2 (atoms/cm ² ·s). At this time, j2 has a relationship of j2=β·j0 with respect to j0.

In the θ region, the group III raw material is supplied, but the group V raw material is hardly supplied, and in the (2π−θ) region, the group V raw material is supplied, but the group III raw material is hardly supplied. To do so.

When the substrate W rotates at the rotation speed ω (rad/s), the time for the substrate W to pass through the θ region of the first supply unit 30 becomes θ/ω(s). Therefore, the first supply unit 30 supplies the group III raw material to (α·θ/ω)·j0 each time the substrate W makes one rotation (every time the first supply unit 30 passes over the θ region). Supply with an areal density of (atoms/cm ² ). When α·θ/ω≧1, the amount of the group III raw material in excess of the amount of the group III atoms contained in one atomic layer of the group III-V crystal is supplied to the θ region. This allows the group III atoms to migrate on the surface of the substrate W.

Further, the time taken for the substrate W to pass through the (2π−θ) region is (2π−θ)/ω. Therefore, the second supply unit 40 supplies the group V raw material (β·(2π) each time the substrate W makes one rotation (every time the first supply unit 30 passes over the (2π−θ) region). Supply at an areal density of −θ)/ω)·j0 (atoms/cm ² ). Here, in the case of β·(2π−θ)/ω≧α·θ/ω, the group V raw material is supplied in excess of the supply amount of the group III raw material. This makes it possible to suppress the lattice defect of the group V atom.

That is, if the rotation speed ω of the substrate W is set so as to satisfy α·θ/ω≧1, and β·(2π−θ)/ω≧α·θ/ω, or the first and second supply By setting the supply amount (supply rate) of the group III raw material and the group V raw material from the parts 30 and 40, a state in which migration of group III atoms on the surface of the substrate W is active and a state in which lattice defects of group V atoms are suppressed And can be repeated for each rotation of the substrate W. As a result, a good quality III-V crystal film can be formed on the substrate W.

In the apparatus 1 shown in FIG. 1, the group V raw material from the second supply part 40 may be mixed with the group III raw material from the first supply part 30, and the supply amount of the group V raw material in the θ region may not be ignored. is there. In this case, as the areal density of the group III raw material supplied to the θ region per unit time, j1-j2 may be used instead of j1. On the contrary, the group III raw material may be mixed in the (2π-θ) region, and the supply amount of the group III raw material may not be ignored. In this case, j2-j1 may be used as the areal density of the group V raw material supplied to the (2π−θ) region per unit time instead of j2.

(Second embodiment)
FIG. 6 is a schematic diagram showing an example of the configuration of the MOCVD apparatus 2 according to the second embodiment.
In the second embodiment, the first supply unit 30 is a nozzle that extends over the diameter of the substrate W from one end of the substrate W through the central portion to the other end of the substrate W. Other configurations of the second embodiment may be similar to the corresponding configurations of the first embodiment.

7A to 7C are diagrams showing an example of the configuration of the first supply unit 30 according to the second embodiment. The 1st supply part 30 is an elongate hollow nozzle similarly to that of 1st Embodiment. 7A to 7C show the first supply unit 30 viewed from the substrate W side, and shows an example of the configuration of the holes provided at the bottom of the first supply unit 30. The first supply unit 30 has a plurality of holes H between a first end E10 located above one end of the substrate W and a second end E20 located above the other end of the substrate W.

The holes H are provided substantially symmetrically between the first end E10 and the second end E20 with the central portion C10 (the central portion of the substrate W) as a boundary. The configuration of the hole H from the central portion C10 to the first end E10 and the configuration of the hole H from the central portion C10 to the second end E20 are the same as those of the central portion C of the first supply unit 30 of the first embodiment. The configuration of the hole H up to the edge side portion E1 may be the same.

Therefore, in FIG. 7(A), the opening area of the hole H is relatively small in the central portion C10 of the first supply portion 30 and gradually increases as it approaches the first and second end portions E10, E20. That is, the hole H has a size (opening area) substantially proportional to the distance from the central portion C10 from the first end portion E10 to the second end portion E20 of the first supply portion 30. Accordingly, the first supply unit 30 can supply the group III element-containing gas to the substrate W from one end of the substrate W to the other end of the substrate W at a flow rate substantially proportional to the distance from the center. ..

In FIG. 7B, although the opening areas of the plurality of holes H are substantially equal to each other, the number of holes H is between the first and second end portions E10 and E20 of the first supply portion 30 and the central portion C10. Differ in. That is, in FIG. 7B, the number of the holes H is relatively small in the central portion C10 and gradually increases as the first and second end portions E10, E20 of the first supply portion 30 are approached. That is, the holes H are provided from the central portion of the substrate W to the end portions in a number substantially proportional to the distance from the central portion. Accordingly, the first supply unit 30 can supply the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center.

7C, the number of the holes H is different between the first and second end portions E10 and E20 of the first supply unit 30 and the central portion C10, as in FIG. 7B. However, in FIG. 7C, the opening area of the hole H is smaller than that of the hole H of FIG. 7B, and the number of holes H is the first and second end portions E10 and E20 and the central portion C10. Continuously changing between. Therefore, in terms of the density of the holes H, the density of the holes H is relatively small in the central portion C10 of the first supply portion 30 and gradually increases as the distance approaches the first and second end portions E10, E20. That is, the density of the holes H increases from the one end to the other end of the substrate W substantially in proportion to the distance from the center. Accordingly, the first supply unit 30 can supply the group III element-containing gas to the substrate W from the center of the substrate W to the end of the substrate W at a flow rate substantially proportional to the distance from the center.

The configuration of the first supply unit 30 may be any of FIG. 7(A) to FIG. 7(C). If the group III element-containing gas can be supplied to the substrate W from one end to the other end of the substrate W at a flow rate substantially proportional to the distance from the center, the configuration of the holes H of the first supply unit 30 will be described. May be arbitrary.

FIG. 8 is a graph showing the supply amount of the group III element-containing gas in the first supply unit 30.
The first supply unit 30 supplies the group III element-containing gas to the substrate W between the first end E10 and the second end E20 at a flow rate substantially proportional to the distance from the center C10.

The operation of the MOCVD apparatus 2 according to the second embodiment is basically the same as that of the apparatus 1 according to the first embodiment. However, in the second embodiment, since the first supply unit 30 supplies the group III element-containing gas over the diameter of the substrate W, the cycle of supplying the group III element-containing gas to the substrate W is the first embodiment. It becomes half of.

For example, FIGS. 9A and 9B are graphs showing the supply amount of trimethylgallium as the group III element-containing gas and the supply amount of nitrogen radicals or nitrogen ions as the group V element. The 1st supply part 30 makes the 1st period which supplies trimethyl gallium half of that of 1st Embodiment.

For example, in FIG. 9A, f11_1, f12_1,... Are the first period, and f11_2, f12_2 are the second period. The stage 20 rotates the substrate W in the first and second periods f11_1 to f12_2. The first supply unit 30 supplies trimethylgallium in the first periods f11_1, f12_1... And stops the supply in the second periods f11_2, f12_2. As shown in FIG. 9B, the nitrogen radicals and the nitrogen ions are continuously supplied in the first and second periods f11_1 to f12_2. It can be considered that the nitrogen radicals and the nitrogen ions are substantially supplied in the second period f1_2, f2_2, f3_2,... While the supply of trimethylgallium is stopped. As a result, gallium adheres to the entire surface of the substrate W in the first periods f11_1, f12_1... And a gallium nitride crystal film is formed on the substrate W in the second periods f11_2, f12_2. In this way, the first supply unit 30 repeatedly executes the supply and the stop of the supply of trimethylgallium for each of the first and second periods. In the second embodiment, since the first supply unit 30 is provided over the diameter of the substrate W, the first and second periods may be half of those in the first embodiment. In the second embodiment, as in the first embodiment, a crystal film of a III-V group compound can be formed on the substrate W, and the same effect as in the first embodiment can be obtained.

The second embodiment may be a combination of the first modification. In this case, the first and second supply units 30 and 40 may continuously supply the group III element-containing gas and the group V element-containing gas, respectively, and set the rotation speed ω of the substrate W appropriately.

In the above-described embodiment, the first supply unit 30 has a plurality of holes H provided in one nozzle and supplies the group III element-containing gas substantially uniformly over the entire surface of the substrate W. However, the first supply unit 30 may supply the group III element-containing gas to the surface of the substrate W with a plurality of nozzles as described below.

(Modification 2 of the first embodiment)
For example, FIG. 10 is a diagram showing the first supply unit 30 according to the second modification of the first embodiment. The first supply unit 30 includes a plurality of nozzles 30_1 to 30_5. The nozzles 30_1 to 30_5 are arranged along the radius of the substrate W from the central portion to the end portion of the substrate W, and supply the group III element-containing gas to the substrate W in synchronization with the rotation cycle of the substrate W. Each of the nozzles 30_1 to 30_5 has an opening at its tip, and as shown by an arrow, emits a Group III element-containing gas from the tip. The nozzles 30_1 to 30_5 may supply the group III element-containing gas according to the supply amount shown in FIG. Therefore, the nozzles 30_1 to 30_5 supply the group III element-containing gas to the substrate W at a flow rate substantially proportional to the distance from the center Cw of the substrate W. Other configurations of the second modification may be the same as the configurations of the first embodiment.

The flow rate of the group III element-containing gas supplied from the nozzles 30_1 to 30_5 may be adjusted by changing the size (area) of the openings of the nozzles 30_1 to 30_5 and/or the thickness of the nozzles 30_1 to 30_5. Good. Alternatively, the flow rate of the group III element-containing gas may be adjusted by making the nozzles 30_1 to 30_5 have the same configuration and changing the pressure of the group III element-containing gas in each of the nozzles 30_1 to 30_5.

Further, in FIG. 10, the nozzles 30_1 to 30_5 are arranged along the radius of the substrate W from the center to the end of the substrate W. However, the nozzle 30_2 may supply the group III element-containing gas to any position on the circumference C2. The nozzle 30_3 may be provided so as to correspond to any position on the circumference C3. The nozzle 30_4 may be provided so as to correspond to any position on the circumference C4. The nozzle 30_5 may be provided corresponding to any position on the circumference C5. That is, the nozzles 30_2 to 30_5 do not necessarily need to be linearly arranged along the radius of the substrate W as long as the group III element-containing gas is supplied to arbitrary positions along the circumferences C2 to C5.
Since the substrate W rotates around the central portion Cw, if the nozzles 30_2 to 30_5 supply the group III element-containing gas at any position of the circumferences C2 to C5, the supply as shown in FIG. The Group III element-containing gas can be supplied in an amount. The operation of the second modification may be the same as the operation of the first embodiment. Therefore, the second modification can obtain the same effect as that of the first embodiment.

(Modification 2 of the second embodiment)
For example, FIG. 11 is a diagram showing the first supply unit 30 according to the second modification of the second embodiment. The first supply unit 30 includes a plurality of nozzles 30_1 to 30_9. The nozzles 30_1 to 30_9 are arranged along the diameter of the substrate W from one end to the other end of the substrate W, and supply the group III element-containing gas to the substrate W in synchronization with the rotation cycle of the substrate W. The first supply unit 30 may supply the group III element-containing gas according to the supply amount shown in FIG. Therefore, the nozzles 30_1 to 30_9 supply the group III element-containing gas to the substrate W at a flow rate substantially proportional to the distance from the center Cw of the substrate W. The other configuration of the second modification may be the same as the configuration of the second embodiment.

The flow rate of the group III element-containing gas supplied from the nozzles 30_1 to 30_9 may be adjusted by changing the size (area) of the openings of the nozzles 30_1 to 30_9 and/or the thickness of the nozzles 30_1 to 30_9. Good. Alternatively, the flow rate of the group III element-containing gas may be adjusted by making the nozzles 30_1 to 30_9 have the same configuration and changing the pressure of the group III element-containing gas in each of the nozzles 30_1 to 30_9.

Further, in FIG. 11, the nozzles 30_1 to 30_9 are arranged along the diameter of the substrate W from one end to the other end of the substrate W. However, the nozzles 30_2 to 30_5 do not necessarily need to be linearly arranged along the radius of the substrate W as long as the group III element-containing gas is supplied to arbitrary positions along the circumferences C2 to C5. The nozzles 30_6 to 30_9 also do not necessarily need to be linearly arranged along the radius of the substrate W as long as the group III element-containing gas is supplied to arbitrary positions along the circumferences C2 to C5. The operation of the second modification may be the same as the operation of the second embodiment. Therefore, the second modification can obtain the same effect as that of the second embodiment.

The above embodiment can be applied not only to MOCVD but also to MBE (Molecular Beam Epitaxy) having a high degree of vacuum.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The embodiments and their modifications are included in the scope of the invention and the scope thereof, and are included in the invention described in the claims and the scope of equivalents thereof.

DESCRIPTION OF SYMBOLS 1... MOCVD apparatus, 10... Chamber, 20... Stage, 30... 1st supply part, 40... 2nd supply part, 50... Heater, 55... Drive part, 60... Controller, W... Board

Claims (9)

A stage on which a substrate can be mounted and arranged along the radial direction of the substrate from the center to the end of the substrate, each extending in the direction of the substrate, and supplying a Group III element-containing gas onto the substrate Method for manufacturing a semiconductor device using a semiconductor manufacturing apparatus including a plurality of first supply units each having one hole for supplying the radicals or ions of the group V element-containing gas onto the substrate And
Rotating the substrate on the stage,
The plurality of first supply units periodically supply the Group III element-containing gas to the substrate at different flow rates,
The second supply unit supplies radicals or ions of a group V element-containing gas to the substrate ,
The plurality of first supply units supply the group III element-containing gas to a region having a central angle θ on the surface of the substrate,
The second supply unit supplies the group V element-containing gas to a region having a central angle (2π−θ) on the surface of the substrate,
In the first period, the plurality of first supply units supply the Group III element-containing gas so as to satisfy n1·(α·θ/ω)j0≧j0.
In the second period, the second supply unit supplies the group V element-containing gas so as to satisfy n2·(β·(2π−θ)/ω)j0≧n1·(α·θ/ω)j0. ,
j0 is the areal density of the group III atoms of the III-V crystal, ω is the rotation speed of the substrate, n1 is the rotation speed of the substrate in the first period, and n2 is the rotation number in the second period. It is the number of rotations of the substrate, and α is j1/j0, where j1 is the areal density of the group III atoms supplied from the plurality of first supply parts, and α is j1/j0. A method of manufacturing a semiconductor device , wherein β is j2/j0, where areal density is j2 . 2. The group III element-containing gas is supplied to the substrate from the central portion of the substrate to an end portion of the substrate at a flow rate substantially proportional to a distance from the central portion, the plurality of first supply portions. A method for manufacturing a semiconductor device as described above. The plurality of first supply units repeatedly supply and stop the supply of the Group III element-containing gas,
The method of manufacturing a semiconductor device according to claim 1, wherein the second supply unit continuously supplies the group V element-containing gas. The plurality of first supply units supply the group III element-containing gas to the substrate at a flow rate substantially proportional to a distance from the center of the substrate from one end of the substrate to the other end of the substrate. Item 2. A method of manufacturing a semiconductor device according to item 1. The plurality of first supply units supply group III atoms at an areal density that is equal to or greater than the area density of group III atoms of the group III-V crystal,
The said 2nd supply part supplies a V group atom with the surface density of the III group atom supplied from the said some 1st supply part or more, The any one of Claim 1 to 4 characterized by the above-mentioned. Of manufacturing a semiconductor device of. The plurality of first supply units are configured to change the size or thickness of the opening of each nozzle, or to change the pressure of each Group III element-containing gas, thereby changing the group III element-containing gas. 6. The method for manufacturing a semiconductor device according to claim 1, wherein the gas is supplied to the substrate at different flow rates. The plurality of first supply units supply the group III element-containing gas to a region having a central angle θ on the surface of the substrate,
The second supply unit supplies the group V element-containing gas to a region having a central angle (2π−θ) on the surface of the substrate,
The plurality of first supply units supply the group III element-containing gas so that (α·θ/ω)j0≧j0 is satisfied every time the substrate rotates once,
The second supply unit supplies the group V element-containing gas so that (β·(2π−θ)/ω)j0≧(α·θ/ω)j0 is satisfied every time the substrate rotates once. ,
j0 is the areal density of the group III atoms of the III-V group crystal, ω is the rotation speed of the substrate, and j1 is the surface density of the group III atoms supplied from the plurality of first supply units. is j1 / j0, When j2 the surface density of the group V atoms to be supplied from the second supply unit, beta is j2 / j0, as claimed in any one of claims 6 Method of manufacturing semiconductor device. A stage with a substrate mounted and rotatable ,
The substrate is arranged along the radial direction of the substrate from the central portion to the end portion thereof, extends in the direction of the substrate, has one hole, and supplies the Group III element-containing gas at different flow rates. A plurality of first supply units for supplying the substrate,
A second supply unit for supplying radicals or ions of a group V element-containing gas onto the substrate,
The plurality of first supply units periodically supply the Group III element-containing gas to the substrate at different flow rates,
The second supply unit supplies radicals or ions of a group V element-containing gas to the substrate,
The plurality of first supply units supply the group III element-containing gas to a region having a central angle θ on the surface of the substrate,
The second supply unit supplies the group V element-containing gas to a region having a central angle (2π−θ) on the surface of the substrate,
In the first period, the plurality of first supply units supply the Group III element-containing gas so as to satisfy n1·(α·θ/ω)j0≧j0.
In the second period, the second supply unit supplies the group V element-containing gas so as to satisfy n2·(β·(2π−θ)/ω)j0≧n1·(α·θ/ω)j0. ,
j0 is the areal density of the group III atoms of the III-V crystal, ω is the rotation speed of the substrate, n1 is the rotation speed of the substrate in the first period, and n2 is the rotation number in the second period. It is the number of rotations of the substrate, and α is j1/j0, where j1 is the areal density of the group III atoms supplied from the plurality of first supply parts, and α is j1/j0. The semiconductor manufacturing apparatus in which β is j2/j0, where j2 is the areal density . 9. The semiconductor manufacturing apparatus according to claim 8 , wherein the plurality of first supply units supply the group III element-containing gas at a flow rate substantially proportional to a distance from a portion corresponding to the center of the substrate.

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