JP2005109098A - Thin film forming device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, in the case of a film forming operation for a plurality of semiconductor substrates 3, there is a limitation in an accurate measurement of an aging change of radiation heat by a thermocouple 8 embedded in a susceptor 4 shielded from the radiation heat under the semiconductor substrate 3. <P>SOLUTION: A CVD device 101 comprises a reaction tube 2, the susceptor 4, an infrared lamp 5, a gas inlet 7a for flowing a mixed gas 6 onto the semiconductor substrate 3 and a gas outlet 7b for exhausting the mixed gas 6, the thermocouple 8 which is embedded in a dummy member 102 composed of the same material with the semiconductor substrate 3 on the susceptor 4 near the semiconductor substrate 3, and a heating temperature control unit 9 for controlling the heating output of the infrared lamp 5 on the basis of a measured temperature of the thermocouple 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, an object to be processed is placed on a susceptor disposed in a reaction tube, and a thin film is formed while controlling the temperature of the object to be processed. For example, a CVD (chemical vapor deposition) apparatus or a PVD (physical vapor deposition) is used. The present invention relates to thin film formation such as (chemical vapor deposition) equipment.

  FIG. 2 shows a sectional view of a CVD apparatus as an example of a conventional thin film forming apparatus.

    As shown in FIG. 2, the CVD apparatus 1 includes a reaction tube 2 as a thin film formation processing chamber, a susceptor 4 for placing a semiconductor substrate 3 as an object to be processed in the reaction tube 2, a semiconductor substrate 3, An infrared lamp 5 that heats the susceptor 4 to maintain a predetermined process temperature, and a mixed gas 6 (for example, a mixture of a carrier gas such as hydrogen and a reactive gas in order to deposit a silicon layer on the surface of the semiconductor substrate 3 by a chemical reaction) A gas supply port 7a that flows over the semiconductor substrate 3 and a gas exhaust port 7b that exhausts the mixed gas 6 are configured.

  Further, a thermocouple 8 is embedded in the susceptor 4, and a heating temperature control unit 9 that controls the heating output of the infrared lamp 5 based on the measured temperature of the thermocouple 8 is provided.

  Here, when a silicon layer is formed using this CVD apparatus 1, in order to ensure a desired film thickness and film quality, the temperature of the semiconductor substrate 3 is accurately grasped and temperature control is performed so as to keep the process temperature optimal. This is very important. For this purpose, it is important to obtain the measured temperature of the thermocouple 8 fed back to the heating temperature control unit 9 that controls the infrared lamp 5 as close to the actual temperature of the semiconductor substrate 3 as possible.

  For this reason, in the CVD apparatus 1 described above, an error between the measurement temperature of the thermocouple 8 embedded in the susceptor 4 in the initial state and the temperature of the semiconductor substrate 3 is measured in advance, and the infrared lamp 5 The difference between the temperature of the susceptor 4 and the actual temperature of the semiconductor substrate 3 is corrected by controlling the heating output.

  However, such correction alone is not sufficient when a large number of semiconductor substrates 3 are formed. This is because an undesired reaction product (not shown) gradually adheres to the surface of the reaction tube 2 or the susceptor 4 as the film forming operation is repeated, and accordingly the reaction tube 2 or the susceptor. 4 Since the radiant heat from the surface to the semiconductor substrate 3 gradually changes from the initial state, the correction is shifted only by the correction based on the temperature difference in the initial state. Then, there is a limit to accurately measuring such a chronological change of radiant heat with the thermocouple 8 embedded under the semiconductor substrate 3 and shielded from the radiant heat.

  That is, the measurement temperature closer to the actual semiconductor substrate 3 temperature including the change of radiant heat that changes with the deposition of reaction products (not shown) that gradually adhere to the surfaces of the reaction tube 2 and the susceptor 4 is set. In order to obtain, it is desirable that the thermocouple 8 is not embedded in the susceptor 4 but is embedded in a member made of the same material as that of the semiconductor substrate 3 or a material having the same heat absorption rate and disposed in the vicinity of the semiconductor substrate 3.

As shown in FIG. 3, a thermocouple 8 covered with a material 3a made of the same material as that of the semiconductor substrate 3 is vacuum sealed in a quartz glass tube 10 made of an infrared transmitting material. The structure arrange | positioned in the reaction tube 2 is proposed (refer patent document 1).
Japanese Patent Laid-Open No. Sho 62-163323

  However, in the above configuration (the configuration described in Japanese Patent Laid-Open No. 62-163323), the thermocouple 8 is vacuum-sealed in the permeable quartz glass tube 10, so that the reaction product (not shown) adheres to it. Although there is a follow-up capability with respect to the time-dependent change of the radiant heat, since the thermocouple 8 is not directly in contact with the susceptor 4 or the mixed gas 6, a measurement temperature including conduction heat from the susceptor 4 or the mixed gas 6 is obtained. There was a problem that I couldn't.

  That is, in order to obtain a measurement temperature including conduction heat from the susceptor 4 and the mixed gas 6, it is desirable that the member is in direct contact with the susceptor 4 and exposed to the mixed gas 6.

  An object of the present invention includes a change in radiant heat that changes with the deposition of reaction products that gradually adhere to the surface of a reaction tube or susceptor as a measured temperature that is closer to the actual temperature of the object to be processed. Another object of the present invention is to provide a thin film forming apparatus and a thin film forming method capable of obtaining a measurement temperature including conduction heat from the atmosphere in the reaction tube and forming a thin film while controlling the heating means based on the measurement temperature.

  The thin film growth apparatus of the present invention is a thin film forming apparatus that forms a thin film on the surface of a target object while heating the temperature of the target object placed on a susceptor disposed in a reaction tube by heating means. The thin film forming apparatus is characterized in that a thermocouple embedded in a dummy member made of the same material as the object to be processed or a material having the same heat absorption rate is disposed in contact with the susceptor in the vicinity of the body.

  In the thin film growth method of the present invention, a thin film is formed on the surface of a target object by placing the target object on a susceptor disposed in a reaction tube and controlling the temperature by heating the target object with a heating means. In the forming method, heating is performed based on the measured temperature of a thermocouple embedded in a dummy member made of the same material as the object to be processed or a material having the same heat absorption rate, which is disposed in contact with the susceptor in the vicinity of the object to be processed. A thin film forming method is characterized in that a thin film is formed while controlling the means.

  According to the thin film growth apparatus and thin film formation method of the present invention, the radiant heat that changes as the reaction product gradually adheres to the reaction tube or susceptor surface is measured as a measurement temperature that is closer to the actual temperature of the object to be processed. In addition, a measurement temperature including the heat of conduction from the susceptor and the mixed gas can be obtained.

  In a thin film forming apparatus, the measurement temperature is closer to the actual temperature of the object to be processed, including a change in radiant heat that changes with the deposition of reaction products that gradually adhere to the reaction tube and susceptor surface, For the purpose of obtaining a measurement temperature including conduction heat from the mixed gas and forming a thin film while controlling the heating means based on the measurement temperature, the same material as the object to be processed is in contact with the susceptor near the object to be processed. Alternatively, it was realized by arranging a thermocouple embedded in a dummy member made of a material having the same heat absorption rate.

  Further, in the thin film forming method, the measurement temperature is closer to the temperature of the object to be processed, including a change in radiant heat that changes with the deposition of reaction products that gradually adhere to the reaction tube and the susceptor surface, An object to be processed placed on a susceptor in the vicinity of the object for the purpose of obtaining a measured temperature including conduction heat from the mixed gas and forming a thin film while controlling the heating means based on the measured temperature. This was realized by forming a thin film while controlling the heating means based on the measured temperature of a thermocouple embedded in a dummy member made of the same material or a material having the same heat absorption rate.

  FIG. 1 shows a cross-sectional view of a CVD apparatus as an example of the thin film forming apparatus of the present invention.

    As shown in FIG. 1, a CVD apparatus 101 includes a reaction tube 2 as a thin film formation processing chamber, a susceptor 4 for placing a semiconductor substrate 3 as an object to be processed in the reaction tube 2, a semiconductor substrate 3, An infrared lamp 5 that heats the susceptor 4 to maintain a predetermined process temperature, and a mixed gas 6 (for example, a mixture of a carrier gas such as hydrogen and a reactive gas in order to deposit a silicon layer on the surface of the semiconductor substrate 3 by a chemical reaction) A gas supply port 7a that flows over the semiconductor substrate 3 and a gas exhaust port 7b that exhausts the mixed gas 6 are configured.

  A thermocouple 8 embedded in a dummy member 102 made of the same material as the semiconductor substrate 3 is disposed in contact with the susceptor 4 in the vicinity of the semiconductor substrate 3. And the heating temperature control part 9 which controls the heating output of the infrared lamp 5 based on the measured temperature of the thermocouple 8 is provided.

  In the method of forming a silicon layer using the CVD apparatus 101 of the present invention, the semiconductor substrate 3 is placed on the susceptor 4 disposed in the reaction tube 2 and the semiconductor substrate 3 and the susceptor 4 are heated by the infrared lamp 5. When the thin film is formed, the infrared lamp 5 is based on the measured temperature of the thermocouple 8 embedded in the dummy member 102 made of the same material as the semiconductor substrate 3 disposed in contact with the susceptor 4 near the semiconductor substrate 3. The thin film is formed while controlling the heating output.

  In this case, since the thermocouple 8 is embedded in the dummy member 102 having the same heat absorption rate as that of the semiconductor substrate 3, the measurement temperature of the thermocouple 8 is affected by almost the same effect with respect to the change with time of the radiant heat. Changes similar to those of the semiconductor substrate 3 are shown. Further, the dummy member 102 is disposed in direct contact with the susceptor 4 in the vicinity of the semiconductor substrate 3 and is exposed to the mixed gas 6. In addition to the fact that the measurement point is close to the semiconductor substrate 3, the dummy member 102 is provided. And the measurement temperature containing the heat of conduction from the mixed gas 6 can be obtained. For this reason, a measurement temperature closer to the actual temperature of the semiconductor substrate 3 is obtained, and the process temperature can be kept optimal because the heating temperature control unit 9 controls the heating output of the infrared lamp 5 based on the measurement temperature, Even when a large number of semiconductor substrates 3 are formed, a desired film thickness and film quality can be secured as a result.

  In the above example, the heating output of the infrared lamp 5 is controlled based on the measured temperature of the thermocouple 8 embedded in the dummy member 102. Further, another thermocouple is used for the susceptor 4. It goes without saying that the heating output of the infrared lamp 5 may be controlled in consideration of the measurement temperature of both thermocouples.

  Measurement temperature closer to the actual temperature of the object to be processed includes changes in radiant heat that change with the deposition of reaction products that gradually adhere to the surface of the reaction tube and susceptor, and from the atmosphere in the susceptor and reaction tube. It can be applied to a thin film forming apparatus and a thin film forming method capable of obtaining a measured temperature including the conduction heat of and forming a thin film while controlling the heating means based on the measured temperature.

Sectional drawing of an example of the thin film forming apparatus of this invention Sectional view of an example of a conventional thin film forming apparatus Sectional drawing of the principal part of another example of a conventional thin film forming apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conventional CVD apparatus 2 Reaction tube 3 Semiconductor substrate 3a Substance made of the same material as the semiconductor substrate 4 Susceptor 5 Infrared lamp 6 Mixed gas 7a Gas supply port 7b Gas exhaust port 8 Thermocouple 9 Heating temperature controller 10 Quartz glass tube 101 Invention CVD apparatus 102 Dummy member

Claims (3)

  In a thin film forming apparatus for forming a thin film on the surface of the object to be processed while controlling the temperature by heating the object to be processed placed on the susceptor disposed in the reaction tube with a heating means, the surface of the susceptor in the vicinity of the object to be processed A thin film forming apparatus characterized in that a thermocouple embedded in a dummy member made of the same material as the object to be processed or a material having the same heat absorption rate is disposed in contact with the object.   The thin film forming apparatus according to claim 1, further comprising a heating temperature control unit that controls the heating unit based on a measured temperature of a thermocouple embedded in the dummy member. In the thin film formation method of placing a target object on a susceptor disposed in a reaction tube and forming a thin film on the target object surface while heating the target object with a heating means and controlling the temperature, the target object The heating means is controlled based on the measured temperature of a thermocouple embedded in a dummy member made of the same material as that of the object to be processed and disposed on the susceptor in the vicinity of the body, or a material having the same heat absorption rate. A thin film forming method characterized in that a thin film is formed.

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