JP5837290B2 - Epitaxial wafer manufacturing method and epitaxial growth apparatus - Google Patents

Description

  The present invention relates to an epitaxial wafer manufacturing method and an epitaxial growth apparatus.

In the semiconductor manufacturing field, a thin film growth process for accurately vapor-depositing a single crystal thin film or a polycrystalline thin film on a semiconductor substrate is an extremely important process.
An example of a conventionally used epitaxial growth apparatus is shown in FIG. In the case of the epitaxial growth apparatus 11 that circulates the source gas substantially parallel to the main surface of the substrate W, the substrate mounting table 12 is usually provided horizontally, and the substrate W is placed at the center of the substrate mounting table 12. In addition, a preheating member 16 is disposed around the substrate mounting table 12 so that the main surface of the substrate mounting table 12 is flush with the surface of the substrate mounting table 12 so as to reach a temperature suitable for the epitaxial reaction before the source gas touches the substrate W. It is often written.

  The source gas is introduced by the source gas introduction means 13 from one end of the surface formed by the substrate W, the substrate mounting table 12 and the preheating member 16 at a flow rate commanded from the main control system M ′ of the epitaxial growth apparatus 11, toward the other end. Flowing. At this time, since the source gas having almost the same concentration of the source gas supplied from the source gas introduction means 13 reaches the upstream portion of the source gas, the source gas concentration is high and the epitaxial growth rate is high. On the other hand, since the gas after the components necessary for epitaxial growth are consumed in the upstream portion reaches the downstream portion, the concentration is low and the growth rate is slow.

  This phenomenon is unavoidable in an epitaxial growth apparatus that circulates a source gas substantially parallel to the main surface of the substrate W. Therefore, generally, as shown in FIG. 5, the motor 15 is rotated at a rotational speed commanded from the main control system M ′. Thus, a method is adopted in which the substrate mounting table 12 is rotated to average the growth rate of the epitaxial film.

  Further, in order to eliminate the difference in film thickness between the central portion and the peripheral portion with respect to the film thickness distribution that is axially symmetric by the rotation of the substrate mounting table 12, the flow rate of gas flowing near the center of the substrate W and the peripheral portion are set. A method of giving a distribution to the flowing gas flow rate is also known (Patent Document 1).

  As described above, the rotation of the substrate mounting table 12 has a significant effect on uniforming the film thickness distribution. However, there is a problem that the effects of all film thickness control parameters (factors for varying the film thickness) are also axisymmetric. For example, as shown in FIG. 2B, which often occurs in actual epitaxial growth, in the case of a distribution with an inclination such that one of the substrates is thin and the other is thick, it can be solved by any film thickness control parameter. could not.

  The cause of the distribution having an inclination as shown in FIG. 2B may be a shift between the geometric center of the substrate platform 12 and the center of rotation. If the geometric center of the substrate platform 12 and the center of rotation do not coincide with each other, the substrate platform 12 rotates eccentrically, and a large or small difference is generated in a gap with a member surrounding the substrate platform 12.

  The gap between the substrate mounting table 12 and the member surrounding the substrate mounting table 12 has a function of escaping a part of the gas in the concentration boundary layer generated by the epitaxial growth reaction to the back side of the substrate mounting table 12, and affects the growth rate of the epitaxial layer. However, since the size of the gap rotates together with the substrate mounting table 12, it is not averaged by the rotation of the substrate mounting table 12, and a film thickness distribution as shown in FIG.

Conventionally, in order to eliminate such a film thickness distribution, there is no other method than replacing the component that rotates the substrate mounting table 12 with a component having good dimensional accuracy. It took a lot of time to clean up the reaction chamber contamination.
In addition, although the geometric center of the substrate mounting table 12 and the center of rotation coincide with each other, the film thickness distribution may be inclined, and the cause is unknown and the conventional method has such a film thickness. There was no way to eliminate the distribution.

JP 2000-68215 A

  The present invention has been made in view of the above problems, and provides an epitaxial wafer manufacturing method and an epitaxial growth apparatus capable of forming an epitaxial film in which the inclination of the film thickness distribution is eliminated.

  In order to solve the above-described problem, in the present invention, the substrate mounting table and the substrate mounted on the substrate mounting table are rotated, and the source gas is circulated on the main surface of the substrate, whereby the main surface of the substrate is An epitaxial wafer manufacturing method for forming an epitaxial film on the substrate, wherein the epitaxial film is formed by changing a film thickness control parameter in accordance with a position in a rotation direction of the substrate mounting table. I will provide a.

  In this way, by changing the film thickness control parameter (a factor for changing the film thickness) according to the position (θ) in the rotation direction of the substrate mounting table, an epitaxial film is formed, for example, a conventional epitaxial growth apparatus. The thickness of the portion where the film thickness is reduced (the portion where the film thickness is desired to be increased) can be increased. That is, the growth rate can be adjusted for each portion of the substrate (for each rotation position), and therefore, an epitaxial film in which the deviation (tilt) of the film thickness distribution is eliminated can be formed. Note that the position (θ) in the rotation direction may be any reference position, but the position of the notch on the substrate is preferably the reference position.

  At this time, it is preferable that the epitaxial film is formed by changing a rotation speed of the substrate mounting table as the film thickness control parameter in accordance with a position in a rotation direction of the substrate mounting table.

  Thus, it is preferable to select the rotation speed of the substrate mounting table as the film thickness control parameter. The rotation speed of the substrate mounting table is changed in accordance with the position of the substrate mounting table in the rotation direction. For example, the portion where the film thickness of the epitaxial film tends to be thin (the portion where the film thickness is to be increased) is near the upstream of the source gas. In some cases, the rotation speed of the substrate mounting table is slow, and conversely if it is near the downstream of the source gas, the rotation speed of the substrate mounting table is increased to increase the average growth rate of the part where the film thickness is to be increased. The film thickness can be increased. Therefore, as a result, an epitaxial film in which the unevenness (tilt) of the film thickness distribution is eliminated can be formed.

  At this time, it is preferable that the epitaxial film is formed by increasing or decreasing the flow rate of the source gas as the film thickness control parameter in accordance with the position of the substrate mounting table in the rotation direction.

  Thus, it is also preferable to select the flow rate of the source gas as the film thickness control parameter. Increase or decrease the flow rate of the source gas according to the position of the substrate mounting table in the rotational direction. For example, if the portion where the thickness of the epitaxial film tends to be thin (the portion where the film thickness is to be increased) is near the upstream, If the flow rate is reduced and, conversely, in the vicinity of the downstream, the flow rate of the source gas can be increased to increase the thickness of the portion where the film thickness is desired to be increased. Therefore, as a result, an epitaxial film in which the unevenness (tilt) of the film thickness distribution is eliminated can be formed.

  Further, in the present invention, there is provided an epitaxial growth apparatus having a substrate mounting table for mounting a substrate and a source gas introducing means for circulating a source gas on the main surface of the substrate, the epitaxial growth apparatus further comprising: There is provided an epitaxial growth apparatus comprising means for obtaining positional information in the rotation direction of the substrate mounting table and changing a film thickness control parameter in accordance with the position in the rotation direction of the substrate mounting table.

  Thus, if the epitaxial growth apparatus has means for obtaining positional information in the rotation direction of the substrate mounting table and changing the film thickness control parameter in accordance with the position in the rotation direction of the substrate mounting table, the rotation direction of the substrate mounting table. Depending on the position of the film thickness, the film thickness control parameter that can change the film thickness can be changed. For example, when a conventional epitaxial growth apparatus is used, the portion where the film thickness becomes thin (would like to increase the film thickness) The thickness of the portion) can be increased. That is, the growth rate can be adjusted for each portion (rotation position) of the substrate, and therefore, an apparatus capable of forming an epitaxial film in which the deviation (tilt) of the film thickness distribution is eliminated.

  At this time, it is preferable that the means for changing the film thickness control parameter is for changing the rotation speed of the substrate mounting table in accordance with the position of the substrate mounting table in the rotation direction.

  Thus, if the epitaxial growth apparatus has means for changing the rotation speed of the substrate mounting table as a film thickness control parameter in accordance with the position in the rotation direction of the substrate mounting table, the growth speed of the portion where the film thickness is to be increased is increased. The film thickness can be increased.

  At this time, it is preferable that the means for changing the film thickness control parameter increases or decreases the flow rate of the source gas in accordance with the position of the substrate mounting table in the rotation direction.

  As described above, if the epitaxial growth apparatus has a means for increasing / decreasing the flow rate of the source gas according to the position in the rotation direction of the substrate mounting table as the film thickness control parameter, it is possible to increase the film thickness of the portion where the film thickness is to be increased. it can.

  As described above, according to the present invention, when an epitaxial film is grown, a portion where the film thickness is likely to be thin (a portion where the film thickness is desired to be increased) can be grown thick, and as a result, the slope of the film thickness distribution is increased. It is possible to form an epitaxial film in which the above is eliminated.

It is the schematic of the epitaxial growth apparatus of this invention. Film thickness distribution diagram (a) of an epitaxial wafer manufactured using the epitaxial wafer manufacturing method of the present invention and film thickness distribution diagram (b) of an epitaxial wafer manufactured using a conventional epitaxial wafer manufacturing method (constant rotation speed) ). It is the schematic which shows another example of the epitaxial growth apparatus of this invention. Film thickness distribution chart (a) of an epitaxial wafer manufactured using the epitaxial wafer manufacturing method of the present invention and film thickness distribution chart of an epitaxial wafer manufactured using a conventional epitaxial wafer manufacturing method (constant raw material gas flow rate) b). It is the schematic of the conventional epitaxial growth apparatus.

Hereinafter, the present invention will be described more specifically.
As described above, a method of manufacturing an epitaxial wafer that can eliminate the inclination of the film thickness distribution and form an epitaxial film with a uniform film thickness even when the inclination of the film thickness distribution of the epitaxial film has conventionally occurred. There is also a need for an epitaxial growth apparatus.

  Therefore, as a result of various studies by the present inventors, the substrate mounting table and the substrate mounted on the substrate mounting table are rotated, and the raw material gas is circulated on the main surface of the substrate, whereby the main surface of the substrate is An epitaxial wafer manufacturing method for forming an epitaxial film on the substrate, wherein the epitaxial film is formed by changing a film thickness control parameter in accordance with a position in a rotation direction of the substrate mounting table. Then, it has been found that an epitaxial film having a uniform film thickness in which the inclination of the film thickness distribution is eliminated can be formed.

  In the present invention, the film thickness control parameter is a factor that affects the film thickness during the epitaxial growth reaction, and the rotation speed of the substrate mounting table, the flow rate of the source gas, the temperature, the substrate mounting table as described later And the flow rate of the purge gas on the back side of the substrate mounting table.

  The most suitable parameter as the film thickness control parameter is the rotation speed of the substrate mounting table. Specifically, when the substrate mounting table is rotated at a constant speed, when the portion where the thickness of the epitaxial film becomes thin is near the upstream where the growth rate is high, the rotation time is reduced and the residence time is reduced. On the other hand, if it is near the downstream where the growth rate is slow, the rotation speed is increased to shorten the staying time. As a result, the average growth rate of the portion where the film thickness is to be increased is increased, and the film thickness can be increased.

The epitaxial growth apparatus of the present invention will be described in detail below with reference to FIG.
As shown in FIG. 1, an epitaxial growth apparatus 1 of the present invention includes a substrate mounting table 2 for mounting a substrate W, and a source gas introducing means 3 for circulating a source gas such as trichlorosilane on the main surface of the substrate W. And have.
Further, there is provided means 4 for obtaining position information in the rotation direction of the substrate mounting table 2 and changing the film thickness control parameter in accordance with the position of the substrate mounting table 2 in the rotation direction.
Means 4 for obtaining position information in the rotation direction of the substrate mounting table and changing the film thickness control parameter in accordance with the position in the rotation direction of the substrate mounting table is shown in FIG. 1 (a) when developing a new epitaxial growth apparatus. In this way, the control system (main control device) M for the entire apparatus may be incorporated.

Here, as the means 4 for changing the film thickness control parameter, it is preferable to change the rotation speed of the substrate mounting table 2 in accordance with the position of the substrate mounting table 2 in the rotation direction. In this case, the means 4 for changing the film thickness control parameter is obtained, for example, by obtaining positional information in the rotational direction of the substrate mounting table 2 from a sensor (not shown) for examining the rotational position of the substrate mounting table 2. It is preferable that a rotation speed command corresponding to the position of the substrate mounting table 2 in the rotation direction is transmitted to the motor 5 or the like that can finely control the rotation speed to change the rotation speed of the substrate mounting table 2.
A commercially available servo motor is suitable for this condition. The servo motor can specify the rotation speed arbitrarily and has a built-in rotation position sensor, so it can easily grasp the position of the substrate mounting table in the rotation direction by combining with the reference position sensor attached to the substrate mounting table. can do.

  Further, when incorporated in an existing epitaxial growth apparatus, as shown in FIG. 1B, the main control device M of the epitaxial growth apparatus 1 sends a signal for instructing the motor 5 to the rotational speed (number of rotations) as PLC (Power Line Communications) or the like. Is transmitted once to the motor 5 after being increased or decreased according to the position of the substrate mounting table 2 in the rotational direction. In this case, the sub-control device S serves as means 4 for changing the film thickness control parameter (that changes the rotation speed of the substrate mounting table 2).

In addition, the epitaxial growth apparatus 1 of the present invention may have the preheating member 6 around the substrate mounting table 2 so that the source gas reaches a temperature suitable for the epitaxial growth reaction before it touches the substrate W.
In the epitaxial growth apparatus, when the geometric center of the substrate mounting table and the center of rotation do not coincide with each other, the substrate mounting table rotates eccentrically, resulting in a large or small deviation in the gap with the member surrounding the substrate mounting table. In such a case, an inclined film thickness distribution is likely to occur where one is thick and the other is thin with respect to the center of the substrate. Even in the case where such an uneven film thickness distribution occurs, according to the present invention, it is possible to increase the film thickness of the portion that tends to be thin, and to achieve a uniform film thickness with the inclination of the film thickness distribution eliminated. An epitaxial film having the same can be formed.

Specifically, the range of increase / decrease in the rotational speed is determined by calculating as follows.
First, a substrate is placed on a substrate placing table previously stopped at a reference position, and the inflow direction of the source gas with respect to the notch, that is, the upstream position θ1 is examined. Since this value is fixed to the apparatus, it only needs to be measured once. Next, epitaxial growth is performed with the substrate mounting table stopped rotating, and the upstream growth rate G1 and the downstream growth rate G2 are examined. This value is checked for each growth condition such as the growth temperature and the raw material gas flow rate.

  Next, when epitaxial growth is performed at a constant rotational speed ω1 and a film thickness distribution having an inclination that can be corrected by the technique of the present invention is generated, the thickness T1 of the thick part and the thickness of the thin part are obtained. The thickness T2 and the position θ2 of the thin portion with reference to the notch are examined. In order to obtain these accurately, it is preferable to measure the film thickness of the epitaxial film over the entire substrate, fit a three-dimensional graph consisting of these film thicknesses and measurement positions on a plane, and calculate the thickness from the magnitude and direction of the inclination of the plane. .

Under the above conditions, the rotational speed ω (θ) is ω (θ) = ω1 / (1 + k × sin (θ−θ1 + θ2)) according to the position θ in the rotation direction of the substrate mounting table.
It is good to do. Here, k is a coefficient representing the degree of increase / decrease in the rotational speed, and k = (T1−T2) / (T1 + T2) × (G1 + G2) / (G1−G2) (B)
Determined by

  FIG. 2B shows a tilted film thickness distribution generated when epitaxial growth is performed at a constant rotational speed. It can be seen that the film thickness is thin at a position of 235 degrees counterclockwise from the notch position, and the film thickness of the opposite part is thick. In contrast, it can be seen that the slope of the film thickness distribution is eliminated in the film thickness distribution when the rotational speed is increased or decreased according to the present invention of FIG.

  Further, the flow rate of the source gas is also suitable as the film thickness control parameter. In the vicinity of the downstream of the source gas, the change in the growth rate due to the change in the flow rate of the source gas is larger than in the vicinity of the upstream. Therefore, specifically, when the portion where the thickness of the epitaxial film becomes thin is near the upstream, the flow rate of the source gas is decreased, and conversely, when the portion near the downstream is increased, the flow rate of the source gas is increased. Thus, it is possible to increase the film thickness of the portion where the film thickness is desired to be increased, and it is possible to obtain an epitaxial wafer in which the inclination of the film thickness is eliminated.

The epitaxial growth apparatus 1 of the present invention when the flow rate of the source gas is increased or decreased as the film thickness control parameter will be described in detail below with reference to FIG.
In developing a new epitaxial growth apparatus, means 4 for obtaining positional information in the rotational direction of the substrate mounting table 2 and changing the film thickness control parameter in accordance with the rotational position of the substrate mounting table, that is, the substrate mounting table. What increases or decreases the flow rate of the raw material gas in accordance with the position in the rotation direction may be incorporated into the control system (main controller) M of the entire apparatus as shown in FIG.

Specifically, the means 4 for changing the film thickness control parameter (which increases or decreases the flow rate of the source gas according to the position of the substrate mounting table in the rotation direction) examines the position of the substrate mounting table 2 in the rotation direction. The position information of the rotation direction of the substrate mounting table 2 is obtained from a sensor (not shown), the flow rate of the source gas corresponding to the obtained position of the substrate mounting table 2 in the rotation direction is instructed to the mass flow controller 7, It is preferable to increase or decrease the flow rate.
In order to obtain position information in the rotation direction of the substrate mounting table 2, the current position may be calculated simply from the reference position passing time detected by a photo interrupter or the like, the current time, and the rotation speed. In order to detect an accurate position, a rotary encoder may be attached to the rotating shaft or the motor 5 that supports the substrate mounting table 2 in addition to the reference position sensor.

Further, when incorporated in an existing epitaxial growth apparatus, as shown in FIG. 3B, the main controller M of the epitaxial growth apparatus once receives a signal for instructing the material gas flow rate to the mass flow controller 7 by the sub-control apparatus S such as PLC. Then, after increasing / decreasing according to the position of the substrate mounting table in the rotation direction, it is transmitted to the mass flow controller 7. In this case, the sub-control device S serves as means 4 for changing the film thickness control parameter (that increases or decreases the flow rate of the source gas).
Here, as shown in FIGS. 3A and 3B, in the apparatus and method of the present invention, the flow rate of the source gas is increased or decreased according to the position of the substrate mounting table in the rotation direction, and the rotation speed of the substrate mounting table is increased. May also be changed. Thereby, the film thickness distribution can be made uniform with higher accuracy.

The range of increase / decrease in the raw material gas flow is determined by calculating as follows.
First, epitaxial growth is performed at a normal source gas flow rate F1 in a state where the rotation of the substrate mounting table is stopped in advance, and the upstream growth rate G1 and the downstream growth rate G2 are examined. Next, epitaxial growth is performed at a raw material gas flow rate F2 slightly different from the raw material gas flow rate F1 while the rotation of the substrate mounting table is stopped, and the upstream growth rate G3 and the downstream growth rate G4 are examined. Next, the substrate mounting table is rotated so that the source gas flow rate is maximum when the substrate mounting table is at the reference position and the source gas flow rate is minimized when the substrate mounting table is rotated 180 degrees from the reference position. Epitaxial growth is performed while increasing or decreasing the source gas flow rate, and the direction θ1 in which the film thickness with respect to the notch of the substrate becomes the largest is examined.

  Next, when epitaxial growth is performed at the raw material gas flow rate F1 and a sloped film thickness distribution that can be corrected by the technique of the present invention is generated, the thickness T1 of the thick part and the thickness of the thin part are obtained. T2 and the position θ2 of the thin portion with reference to the notch are examined. In order to obtain these accurately, it is preferable to measure the film thickness of the epitaxial film over the entire substrate, fit a three-dimensional graph consisting of these film thicknesses and measurement positions on a plane, and calculate the thickness from the magnitude and direction of the inclination of the plane. .

Under the above conditions, the source gas flow rate F (θ) is F (θ) = F1 × (1 + k × sin (θ−θ1 + θ2)) (C) according to the position θ in the rotation direction of the substrate mounting table.
It is good to do. Here, k is a coefficient representing the degree of increase / decrease in the raw material gas flow rate, and k = (T1-T2) / (T1 + T2) × (G1 + G2) / (G4-G3-G2 + G1) / 2 × (F2-F1) / F1 ( D)
Determined by

  FIG. 4B shows an inclined film thickness distribution generated when epitaxial growth is performed at a constant raw material gas flow rate. It can be seen that the film thickness is thin at a position of 235 degrees counterclockwise from the notch position, and the film thickness of the opposite part is thick. On the other hand, it can be seen that the slope of the film thickness distribution is eliminated in the film thickness distribution when the flow rate of the source gas is increased or decreased according to the present invention of FIG.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to this.

(Examples and comparative examples)
As an epitaxial substrate W, a silicon wafer having a diameter of 200 mm, a thickness standard of 725 μm, a P type, and a resistivity of 5 to 10 mΩcm was prepared.

The silicon wafer W is placed on the substrate mounting table 2 previously stopped at the reference position, the position θ1 in the inflow direction of the source gas with respect to the notch is examined, and then the rotation of the substrate mounting table 2 is stopped as shown in FIG. The epitaxial growth apparatus 1 was used for epitaxial growth under the following conditions.
Source gas (trichlorosilane) flow rate: 10 slm
Carrier gas (H ₂ gas) flow rate: 40 slm
Epitaxial growth temperature: 1100 ° C

Next, when epitaxial growth was performed at a constant rotational speed ω1, an uneven film thickness distribution was generated (Comparative Example).
The thickness T1 of the thick part, the thickness T2 of the thin part, and the position θ2 of the thin part on the basis of the notch are obtained and applied to the above general formulas (A) and (B). The rotational speed ω (θ) corresponding to the position θ in the rotational direction of the mounting table 2 was obtained. Each value is shown below.
T1: 12.19 μm T2: 11.87 μm
θ1: 270 ° θ2: 235 ° ω1: 35 rpm
Next, the silicon wafer W is mounted on the substrate mounting table 2 under the same conditions as described above, and the position θ in the rotation direction of the substrate mounting table 2 is grasped by the servo motor while the position θ in the rotation direction of the substrate mounting table 2 is determined. When epitaxial growth was performed by rotating the substrate mounting table 2 at a corresponding rotation speed ω (θ), the thickness of the portion where the film thickness was thick in the comparative example was 12.05 μm, and the film thickness was thin in the comparative example. The thickness of the portion (the portion where the film thickness is to be increased) is 12.01 μm, that is, the average growth rate of the portion where the film thickness is to be increased can be increased, and the film thickness as observed in the comparative example. The inclination of was eliminated (Example).

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

W ... Substrate, 1,11 ... Epitaxial growth apparatus, 2,12 ... Substrate mounting table, 3,13 ... Raw material gas introduction means, 4 ... Means for changing film thickness control parameter, 5,15 ... Motor, 6,16 ... Preheating 7: Mass flow controller, M, M ′: Main control device, S: Sub control device.

Claims (2)

The substrate mounting table and the substrate mounted on the substrate mounting table are rotated in a state where the geometric center of the substrate mounting table and the center of rotation do not coincide with each other , and a source gas is introduced onto the main surface of the substrate. In the epitaxial wafer manufacturing method in which an epitaxial film is formed on the substrate main surface by flowing in parallel with the main surface of the substrate, when the substrate is rotated at a constant rotation speed and epitaxial growth is performed, after examining the position of the portion epitaxial film on the substrate becomes thinner, the rotational speed of the substrate table as a thickness control parameter is changed in accordance with the rotational position of the substrate mounting table, the epitaxial film in the substrate thinning portion, when in the upstream of the raw material gas is to slow the rotational speed of the substrate mounting table, it thin epitaxial film in the substrate Portion, wherein when the downstream of the raw material gas is to increase the rotational speed of the substrate mounting table, method for manufacturing an epitaxial wafer, characterized in that to form the epitaxial layer. The substrate mounting table and the substrate mounted on the substrate mounting table are rotated in a state where the geometric center of the substrate mounting table and the center of rotation do not coincide with each other, and a source gas is introduced onto the main surface of the substrate. An epitaxial growth apparatus for forming an epitaxial film on the main surface of the substrate by flowing in parallel with the main surface of the substrate, wherein the epitaxial growth apparatus further obtains positional information of the rotation direction of the substrate mounting table. It has a means to change a film thickness control parameter according to the position of the substrate mounting table in the rotation direction, and the means to change the film thickness control parameter corresponds to the position of the substrate mounting table in the rotation direction. changing the rotational speed of the substrate mounting table, the epitaxial film in the substrate when performing rotated by epitaxial growth of the substrate at a constant rotational speed portion becomes thin, the If there is upstream of the material gas, a slower rotational speed of the substrate mounting table, parts epitaxial film is thinner in the substrate, when the downstream of the feed gas, the rotational speed of the substrate mounting table An epitaxial growth apparatus characterized by speeding up the process.

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