KR20120090344A - Chemical vapor deposition apparatus and temperature control method for the same - Google Patents

Abstract

PURPOSE: A chemical vapor deposition apparatus and a temperature control method thereof are provided to simplify structure by using one temperature sensor for measuring susceptor temperature and substrate temperature. CONSTITUTION: A susceptor(30) comprises a heater installed in inside. A gas spray unit(20) sprays process gas to substrates. A temperature sensor(40) is arranged at the upper side of the susceptor. A controller(50) compartmentalizes the temperature measured by the temperature sensor into susceptor temperature and substrate temperature. The controller controls the heater based on a result comparing one of the temperature and the substrate temperature with preset temperature.

Description

Chemical vapor deposition apparatus and temperature control method {CHEMICAL VAPOR DEPOSITION APPARATUS AND TEMPERATURE CONTROL METHOD FOR THE SAME}

The present invention relates to a vapor deposition apparatus and a temperature control method thereof, and more particularly, to a chemical vapor deposition apparatus and a temperature control method thereof.

Chemical vapor deposition apparatus is used to deposit a thin film on the surface of the semiconductor substrate. Process gas is supplied into the chamber through the gas supply unit to deposit a desired thin film on the substrate loaded on the susceptor. The proper internal temperature is very important in the deposition of thin film because it greatly affects the quality of thin film. In particular, in the case of an organometallic chemical vapor apparatus (MOCVD), temperature control must be effectively performed to obtain a high efficiency light emitting device. For effective temperature control, the temperature distribution on the top of the susceptor must be accurately known. This is because the accurate temperature distribution must be known to determine the amount of power to be supplied to the heater. There may be a predetermined temperature difference between the plurality of substrate surface temperatures loaded on the susceptor upper surface and the susceptor surface temperature. According to the prior art, temperature control is performed without distinguishing the difference between the surface temperature of the susceptor and the substrate. In order to produce high-efficiency, high-quality thin films, it is necessary to accurately grasp even the difference in surface temperature and precisely control the temperature. However, in order to grasp the difference in temperature, there is a problem that additionally complicated and expensive equipment must be installed.

In order to produce high quality thin films, a method for accurately determining the temperature distribution on the upper surface of the susceptor is required.

More specifically, even a temperature difference between the susceptor surface and the substrate surface can be distinguished, and a temperature control method capable of reflecting the temperature difference is required.

Also, there is a need for a method that can determine the temperature difference between the susceptor surface and the wafer surface without any complicated or expensive equipment.

Technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

Chemical vapor deposition apparatus according to the present invention for solving the above problems is a chamber; A susceptor positioned inside the chamber and including a heater installed therein to heat the plurality of substrates mounted on the upper surface; A gas injection unit for injecting a process gas toward the substrates; A temperature sensor positioned above the susceptor such that a measurement area passes through both the susceptor and the substrate while the susceptor or the gas injection unit rotates; And a controller for dividing the temperature measured by the temperature sensor into a susceptor temperature and a substrate temperature, and controlling the heater based on a result of comparing at least one of the divided susceptor temperature and the substrate temperature with a set temperature. It includes.

In addition, the temperature sensor may be installed above the gas injection unit as a non-contact temperature sensor, the observation hole may be formed in the gas injection unit so that the non-contact temperature sensor can measure the susceptor temperature and the substrate temperature.

The heater may include a plurality of sub heaters, and the controller may be configured to control the plurality of sub heaters, respectively.

In addition, the upper surface of the susceptor is arranged to form a plurality of concentric circles, the temperature sensor is composed of a plurality, each temperature sensor can measure the temperature of any one concentric circles.

In addition, the controller may be configured to control the plurality of sub-heaters respectively based on the temperature measured by each of the temperature sensors.

The temperature control method of the chemical vapor deposition apparatus according to the present invention for solving the above problems, a susceptor including a chamber, a heater installed therein to heat a plurality of substrates located in the chamber and mounted on the upper surface; A gas injection unit for injecting a process gas toward the substrates, and a temperature sensor positioned above the susceptor so that the measurement region passes through both the susceptor and the substrate while the susceptor or the gas injection unit is rotated. A temperature control method of a chemical vapor deposition apparatus comprising: (a) dividing a temperature measured by the temperature sensor into a susceptor temperature or a substrate temperature; (b) comparing at least one of the susceptor temperature and the substrate temperature with a set temperature; And (c) controlling the heater based on a result of the comparison.

In addition, the step (a) is a step of obtaining a measurement data by measuring the temperature a plurality of times by the temperature sensor; Calculating a distribution (frequency distribution or probability distribution) according to the temperature of the measurement data; And dividing a temperature of a relatively hot section from the first peak section and a second peak section in the calculated distribution by a susceptor temperature, and dividing a temperature of a relatively low section by a substrate temperature. have.

In addition, the step (a) is a step of obtaining a measurement data by measuring the temperature a plurality of times by the temperature sensor; Calculating an average temperature based on the measured data; And dividing a temperature of a section that is higher than the average temperature by a susceptor temperature, and dividing a temperature of a section that is lower than the average temperature by a substrate temperature.

In addition, the step (a) is (a1) obtaining a measurement data by measuring the temperature a plurality of times by the temperature sensor; (a2) excluding a temperature change interval appearing in the measurement data as the temperature is changed around the edge of the substrate from the measurement data; (a3) dividing the temperature of the relatively high temperature section periodically appearing by the susceptor temperature after the step (a2), and dividing the temperature of the relatively low temperature section periodically appearing by the substrate temperature.

In addition, the step (b) is a step of comparing any one selected from the susceptor temperature or the substrate temperature with a set temperature, the step (c) is controlling the heater based on the comparison result; (c) inputting information on whether or not the result of performing the chemical vapor deposition satisfies a predetermined criterion; and, if the predetermined criterion does not meet the predetermined criterion, other not selected from the susceptor temperature or the substrate temperature. The method may further include comparing one with a set temperature.

Since there is no need to install a temperature sensor for measuring the susceptor temperature and a temperature sensor for measuring the substrate temperature, the configuration of the device is simplified and the manufacturing cost is reduced.

The technical effects of the present invention are not limited to the above-mentioned effects, and other technical effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a schematic configuration diagram of a chemical vapor deposition apparatus according to an embodiment of the present invention.
2 is a view of projecting the position of the temperature sensor on the plane of the susceptor in order to explain the position and operation of the temperature sensor according to an embodiment of the present invention.
3 is a graph showing an example of the measured value of the temperature sensor over time.
Figure 4 is a flow chart schematically showing a first embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.
5 is a view for explaining a first embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.
Figure 6 is a flow chart schematically showing a second embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.
Figure 7 is a flow chart schematically showing a third embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.
Figure 8 is a flow chart schematically showing a fourth embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present embodiment is not limited to the embodiments disclosed below, but can be implemented in various forms, and only this embodiment makes the disclosure of the present invention complete, and the scope of the invention to those skilled in the art. It is provided for complete information. Shapes of the elements in the drawings may be exaggerated parts for a more clear description, elements denoted by the same reference numerals in the drawings means the same element.

1 is a schematic configuration diagram of a chemical vapor deposition apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the chemical vapor deposition apparatus according to the present embodiment includes a chamber wall 10, a gas injection unit 20, a susceptor 30, a temperature sensor 40, and a controller 50. .

The chamber wall 10 forms the exterior of the chemical vapor deposition apparatus, and the chemical vapor deposition reaction takes place in the reaction chamber 10a therein. The chamber wall 10 has a discharge port 11 for discharging the process gas (G) to the outside.

The gas injection unit 20 supplies the process gas G toward the substrate W loaded on the susceptor 30. An observation hole 20a is formed inside the gas injection unit 20 so that the temperature sensor 40 can measure the temperature of the substrate W and the susceptor 30.

The susceptor 30 is located inside the reaction chamber 10a, and a plurality of substrates W may be loaded on the upper surface. The susceptor 30 may be rotated at a high speed by a motor (not shown). The susceptor 30 includes a susceptor cover 31, a heater 32, and a shaft 33. The substrate W may be mounted on the upper surface of the susceptor cover 31. The heater 32 may be configured in such a manner that a plurality of sub heaters are combined while heating the inside of the reaction chamber 10a and the substrate W loaded on the upper surface of the susceptor cover 31. The shaft 33 is rotatably connected to a motor (not shown) outside the reaction chamber 10a, and thus the susceptor 30 is rotatable.

In another embodiment, a configuration in which the susceptor is fixed and the gas injection unit rotates is also possible.

The temperature sensor 40 includes a first temperature sensor 40a, a second temperature sensor 40b, a third temperature sensor 40c, and a fourth temperature sensor 40d. The temperature sensor 40 may be installed on the chamber wall 10 and a non-contact temperature sensor may be applied. Non-contact temperature sensors include radiation pyrometers, optical pyrometers, phototube thermometers, and infrared thermometers. The observation hole 20a is formed inside the gas injection unit 20 so that the temperature sensor 40 can measure the temperature inside the substrate W or the reaction chamber 10a. The temperature sensor 40 is positioned above the susceptor so that the measurement area measured by the temperature sensor 40 passes through both the susceptor surface and the substrate surface.

The controller 50 includes a heater controller 51, a temperature sensor controller 52, and a main controller 53. The heater controller 51 may control the heating amount by controlling the power supplied to the heater 32, and may individually temperature control each subheater. The temperature sensor controller 52 may control the operation of the temperature sensor 40 or read data provided by the temperature sensor 40 and transfer the data to the main controller 53. The main controller 53 distinguishes between the temperature of the susceptor cover 31 and the temperature of the substrate W based on the measurement data transmitted from the temperature sensor controller 52, and compares the resultant with a set value. The heater operation amount can be transmitted to the heater control unit 51. The operation and configuration of the main control unit 53 in more detail will be described later in detail. The heater controller 51 may control the heater 32 based on the received heater operation amount.

2 is a view of projecting the position of the temperature sensor on the plane of the susceptor in order to explain the position and operation of the temperature sensor according to an embodiment of the present invention.

As shown in FIG. 2, in the case where the substrates W are arranged to form four concentric circles, the temperature sensors 40 can measure four temperatures 40a and 40b so as to measure the temperatures of the respective concentric circles. , 40c, 40d) may be installed. Accordingly, it is possible to grasp the overall temperature distribution of the substrates (W). The number of temperature sensors is not necessarily limited to four, and as another embodiment, five or more may be installed, or one or two may be installed. In FIG. 2, the position of the temperature sensor is projected on the upper surface of the susceptor cover 31 in order to clearly describe the positions of the temperature sensors 40a, 40b, 40c, and 40d.

Each temperature sensor 40a, 40b, 40c, 40d is shown to be located slightly outside of the circle connecting the center of the substrate W. This is because it may be difficult to accurately measure the temperature of the susceptor when the substrates are disposed adjacent to each other because the upper part of the susceptor that the temperature sensor can measure is small. However, the position of the temperature sensor does not necessarily have to be located slightly outside of the circle connecting the center of the substrate W. In some cases, the temperature sensor may be located inside the circle connecting the center of the substrate W. When the sensitivity of the sensor is high or the rotation speed of the susceptor is low, it may be located in a circle connecting the center of the substrate (W).

3 is a graph showing an example of the measured value of the temperature sensor over time.

As shown in FIG. 3, the temperature of the substrate sections W1, W2, W3, and W4 is generally lower than the temperature of the susceptor sections S1, S2, and S3. In the edge portion of the substrate, a temperature change section (c) may appear, in which the temperature is not constant. In FIG. 3, a relatively high temperature section of 710 degrees or less is represented by T1, and a relatively low temperature region of 710 degrees or less is represented by T2.

Figure 4 is a flow chart schematically showing a first embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention. As an example, each step is listed in order, but may be implemented differently from the order described below unless the order of each step is explicitly defined in the claims.

First, a step (S101) of obtaining a measurement data by measuring a temperature a plurality of times by a temperature sensor may be performed. For example, a pyrometer that measures surface temperature at a frequency of about 700 may be used as the temperature sensor.

Next, a step (S102) of calculating a distribution (frequency distribution or probability distribution) according to the temperature of the measured data may be performed. That is, the temperature sensor controller 52 may transmit the value measured by the temperature sensors 40a, 40b, 40c, and 40d to the main controller 53 to secure the temperature distribution on the upper surface of the susceptor according to time flow.

Next, a step of dividing the temperature of the relatively hot section of the first peak section and the second peak section appearing in the calculated distribution by the susceptor temperature, and the temperature of the relatively low section by the substrate temperature (S103) Can be performed. In other words, two peaks appear in the probability distribution, one for the susceptor section and the other for the substrate section. In other words, the probability distribution is calculated based on the temperature, the peak range above the predetermined probability (or frequency) is filtered from the calculated probability distribution, and the average temperature (or the highest temperature and the lowest temperature) of the filtered peak interval is susceptor. It can be determined by the temperature or the substrate temperature.

Next, a step (S104) of comparing at least one of the susceptor temperature or the substrate temperature with the set temperature may be performed. That is, the susceptor temperature may be compared with the set temperature, or the substrate temperature may be compared with the set temperature. Alternatively, the susceptor temperature and the substrate temperature may be compared with the first set temperature for the susceptor and the second set temperature for the substrate, respectively.

Next, controlling the heater (S105) may be performed based on the comparison result. In other words, when the temperature is lower than the reference temperature, the amount of heat generated by the heater may be increased by increasing the power supplied to the heater, and when the temperature is higher than the reference temperature, the amount of heat generated by the heater may be reduced by reducing the power supplied to the heater.

5 is a view for explaining a first embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.

FIG. 5 (a) shows a temperature distribution over time, and FIG. 5 (b) shows a probability distribution over temperature. In order to specify the relative high temperature part H and the low temperature part L shown in FIG. 5A, a probability distribution of the temperature measurement value is calculated. Then, the probability distribution is assumed to be a normal distribution for the high temperature part and a normal distribution for the low temperature part to calculate an average in each normal distribution. The predetermined standard deviation range may be determined as the high temperature portion H or the low temperature portion L. FIG. That is, the low temperature portion L and the high temperature portion H may be determined in the T2a to T2b sections of FIG. 5C. And a heater can be controlled based on the result of comparing the average value T1m of the high temperature part H or the average value T2m of the low temperature part L with a setting value.

Figure 6 is a flow chart schematically showing a second embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.

First, a step of obtaining a measurement data by measuring a temperature a plurality of times by a temperature sensor may be performed.

Next, calculating the average temperature based on the measured data (S202) may be performed.

Next, a step (S203) of dividing the temperature of the section higher than the average temperature by the susceptor temperature and the temperature of the section lower than the average temperature by the substrate temperature may be performed. That is, the boundary values of T1 and T2 of FIG. 3 may be calculated and classified into the high temperature section and the low temperature section based on the boundary values. The method of calculating the boundary value between T1 and T2 may be a method of calculating the calculated average of the entire interval.

Next, a step (S204) of comparing at least one of the susceptor temperature or the substrate temperature with the set temperature may be performed. Here, the susceptor temperature and the substrate temperature are the average temperatures (or maximum temperatures) of the susceptor sections (S1, S2, S3 ...) and the average temperatures (or minimums) of the substrate sections (W1, W2, W3, W4 ...). Temperature). Then, the average temperature and the reference temperature are compared, and the heater can be controlled based on this. The mean temperature may be a calculated mean, a geometric mean, a harmonic mean, a weighted average, a cut average, a quadrant average, or the like.

Next, a step (S205) of controlling the heater may be performed based on the comparison result.

Figure 7 is a flow chart schematically showing a third embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.

First, a step of obtaining a measurement data by measuring a temperature a plurality of times by a temperature sensor may be performed.

Next, as the temperature is changed around the edge of the substrate, the step S302 of excluding the temperature change section appearing in the measurement data from the measurement data may be performed.

Next, a step (S303) of dividing the temperature of the relatively high temperature section periodically shown by the susceptor temperature and the temperature of the relatively low temperature section periodically appearing by the substrate temperature may be performed. As shown in FIG. 3, the W1, W2, W3, and W4 sections except for the temperature change section c may be divided into substrate sections, and the S1, S2, and S3 sections may be divided into susceptor sections.

Next, a step (S304) of comparing at least one of the susceptor temperature or the substrate temperature with the set temperature may be performed.

Next, the step of controlling the heater (S305) may be performed based on the comparison result.

Figure 8 is a flow chart schematically showing a fourth embodiment of the temperature control method of the chemical vapor deposition apparatus according to the present invention.

First, a step S401 of dividing the temperature measured by the temperature sensor into a susceptor temperature and a substrate temperature may be performed.

Next, comparing the susceptor temperature with the set temperature (S402) may be performed.

Next, a step (S403) of controlling the heater may be performed based on the comparison result.

Next, a step (S404) of checking whether the chemical vapor deposition performance results meet the criteria may be performed. That is, the operator may check the quality of the deposited thin film and the like to determine whether it meets a predetermined thin film quality standard, and then input information on the result.

Next, when it is input that the execution result does not meet the criteria, step S405 of comparing the substrate temperature with the set temperature may be performed.

Next, a step (S406) of controlling the heater may be performed based on the comparison result.

The fourth embodiment may be performed to determine which temperature is controlled based on the susceptor temperature and the substrate temperature when the chemical vapor deposition apparatus is initially set.

An embodiment of the present invention described above and illustrated in the drawings should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

Claims (10)

chamber;
A susceptor positioned inside the chamber and including a heater installed therein to heat the plurality of substrates mounted on the upper surface;
A gas injection unit for injecting a process gas toward the substrates;
A temperature sensor positioned above the susceptor such that a measurement area passes through both the susceptor and the substrate while the susceptor or the gas injection unit rotates; And
A controller for dividing the temperature measured by the temperature sensor into a susceptor temperature and a substrate temperature, and controlling the heater based on a result of comparing at least one of the divided susceptor temperature and the substrate temperature with a set temperature; Chemical vapor deposition apparatus comprising.
The method of claim 1,
The temperature sensor is installed on the gas injection unit as a non-contact temperature sensor,
And a observation hole formed in the gas injection unit so that the non-contact temperature sensor can measure the susceptor temperature and the substrate temperature.
The method of claim 1,
The heater includes a plurality of sub heaters,
And the control unit is configured to control the plurality of sub heaters, respectively.
The method of claim 3,
The substrate is arranged on the susceptor upper surface to form a plurality of concentric circles,
The temperature sensor is composed of a plurality, each temperature sensor chemical vapor deposition apparatus, characterized in that for measuring the temperature of any one concentric circles of the substrate.

The method of claim 4, wherein
The control unit is a chemical vapor deposition apparatus, characterized in that configured to control the plurality of sub-heaters respectively based on the temperature measured by each of the temperature sensors.
A susceptor including a chamber, a heater disposed therein to heat a plurality of substrates disposed on the upper surface of the chamber, a gas injection unit for injecting a process gas toward the substrates, the susceptor or the gas In the temperature control method of the chemical vapor deposition apparatus comprising a temperature sensor located above the susceptor so that the measurement region passes through both the susceptor and the substrate while the injection unit is rotating,
(a) dividing the temperature measured by the temperature sensor into a susceptor temperature or a substrate temperature;
(b) comparing at least one of the susceptor temperature and the substrate temperature with a set temperature; And
(c) controlling the heater based on the comparison result; temperature control method of a chemical vapor deposition apparatus comprising a.
The method of claim 6, wherein step (a)
Measuring the temperature a plurality of times by the temperature sensor to secure measurement data;
Calculating a distribution (frequency distribution or probability distribution) according to the temperature of the measurement data; And
A chemical vapor phase comprising dividing a temperature of a section having a relatively high temperature into a susceptor temperature and a temperature of a section having a relatively low temperature by a substrate temperature; Temperature control method of deposition apparatus.
The method of claim 6, wherein step (a)
Measuring the temperature a plurality of times by the temperature sensor to secure measurement data;
Calculating an average temperature based on the measured data; And
And dividing the temperature in the section that is higher than the average temperature by a susceptor temperature, and dividing the temperature in the section that is lower than the average temperature by the substrate temperature.

The method of claim 6, wherein step (a)
(a1) obtaining a measurement data by measuring a temperature a plurality of times by the temperature sensor;
(a2) excluding a temperature change interval appearing in the measurement data as the temperature is changed around the edge of the substrate from the measurement data;
(a3) dividing the temperature of the relatively high temperature section periodically appearing by the susceptor temperature after the step (a2) and dividing the temperature of the relatively low temperature section periodically by the substrate temperature; Temperature control method.
The method of claim 6,
Step (b) is a step of comparing any one selected from the susceptor temperature or the substrate temperature with a set temperature,
Step (c) is a step of controlling the heater based on the comparison result;
(C) inputting information on whether the result of performing chemical vapor deposition satisfies a predetermined criterion;
And comparing the other one which is not selected from the susceptor temperature or the substrate temperature with a set temperature when the predetermined criteria are not met.

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