JP2006013326A - Temperature control method of semiconductor manufacturing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature control method of semiconductor manufacturing equipment which can control temperature of a chamber internal surface of the semiconductor manufacturing equipment by using a simple method without enlarging and complicating the equipment. <P>SOLUTION: In the temperature control method of semiconductor manufacturing equipment wherein materials gas MG and rectifying gas SG are supplied in a chamber 1 and depositing of a semiconductor thin film is performed, at least two kinds of gases whose thermal conductivity is different are used as the rectifying gas SG, component proportion of them is adjusted, and temperature of the chamber internal surface 1a is controlled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a temperature control method for a semiconductor manufacturing apparatus, and more particularly to a temperature control method for a semiconductor manufacturing apparatus for forming a semiconductor thin film by supplying a source gas and a rectifying gas into a chamber.

In a semiconductor manufacturing apparatus in which a raw material gas and a rectifying gas are supplied into a chamber to form a semiconductor thin film, the raw material gas reacts to form gallium nitride (GaN), aluminum nitride (AlN) on a substrate made of sapphire or the like. An epitaxial film of indium nitride (InN) or a mixed crystal thereof is grown by a MOCVD (Metal Organic Chemical Vapor Deposition) method to form a film, but when the raw material gas reacts, nitriding is performed on the inner wall surface of the chamber. By-products such as gallium adhere and grow and fall on the substrate, there is a problem that the yield of the film-formed product is remarkably reduced.
This problem is particularly noticeable when the temperature of the inner wall surface of the chamber is high. Conventionally, the inner wall surface of the chamber has been cooled by circulating a cooling medium in the chamber wall (patented). Reference 1).
However, in this temperature control method for a semiconductor manufacturing apparatus, since the responsiveness is poor, the time delay becomes large, and it is difficult to perform the temperature control with high accuracy.
Further, when the cooling medium is circulated in the chamber wall, there is a problem that the apparatus becomes large and complicated.
JP-A-60-262418

  In view of the problems of the temperature control method of the conventional semiconductor manufacturing apparatus, the present invention can control the temperature of the inner wall surface of the chamber of the semiconductor manufacturing apparatus with a simple method without increasing the size and complexity of the apparatus. An object of the present invention is to provide a temperature control method for a semiconductor manufacturing apparatus which can be used.

  In order to achieve the above object, a temperature control method for a semiconductor manufacturing apparatus according to the present invention provides a temperature control method for a semiconductor manufacturing apparatus in which a raw material gas and a rectifying gas are supplied into a chamber to form a semiconductor thin film. The temperature of the inner wall surface of the chamber is controlled by adjusting the component ratio using two or more kinds of gases having different thermal conductivities.

  In this case, hydrogen and nitrogen can be used as the rectifying gas component.

  Further, the flow angle of the rectifying gas can be set to an angle of 45 degrees or less with respect to the upper surface of the substrate placed in the chamber.

According to the temperature control method of the semiconductor manufacturing apparatus of the present invention, by using two or more kinds of gases having different thermal conductivities for the rectifying gas supplied together with the raw material gas in the chamber, and adjusting the component ratio thereof, Since the temperature is controlled, the temperature of the inner wall surface of the chamber can be controlled without increasing the size and complexity of the apparatus.
And, by suppressing the adhesion of by-products such as gallium nitride to the inner wall surface of the chamber when the source gas reacts, the yield of the film-formed product is improved and the frequency of cleaning inside the chamber is greatly reduced. it can.
In addition, unlike the temperature control method in which a cooling medium is circulated in the chamber wall, the adjustment of the rectifying gas component ratio can be easily and instantaneously controlled by the mass flow controller. The temperature of the inner wall surface of the chamber can be kept constant with high responsiveness even when the substrate temperature is changed rapidly.

  Further, by using hydrogen and nitrogen as the rectifying gas component, the temperature of the inner wall surface of the chamber can be controlled by appropriately setting the component ratio between hydrogen having high thermal conductivity and nitrogen having low thermal conductivity.

  In addition, by setting the blowing angle of the rectifying gas to an angle of 45 degrees or less with respect to the upper surface of the substrate placed in the chamber, rectification is performed with respect to the ceiling surface of the inner wall of the chamber where gallium nitride and other byproducts are likely to adhere A gas can be made to act effectively.

  Embodiments of a temperature control method for a semiconductor manufacturing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a temperature control method for a semiconductor manufacturing apparatus according to the present invention.
This semiconductor manufacturing apparatus 20 is an apparatus for manufacturing a compound semiconductor by MOCVD, and includes a chamber 1, source gas MG introduction nozzles (source gas blowing portions) 2 a and 2 b, and an inert gas RG introduction nozzle. 2c, a plurality of rectifying gas SG supply nozzles (rectifying gas blowing portions) 3b, an exhaust port 4, a susceptor 5, a turntable 6, a heater 7, and a tungsten ring (catalyst member) 8 are main components. Have as.

In this case, the organometallic gas OG is introduced from the introduction nozzle 2a, and the ammonia gas NH (NH ₃ ) is introduced from the introduction nozzle 2b.

The chamber 1 can hold a substrate W or the like (for example, a sapphire single crystal substrate, silicon carbide, gallium nitride, silicon, or the like) in an internal reaction chamber.
The susceptor 5 for placing and holding the substrate W is placed on the turntable 6 and is turnable by the turntable 6.
The heater 7 is disposed below the turntable 6, and heats the substrate W to an arbitrary temperature (for example, 800 to 1200 ° C.) at which a film forming reaction occurs through the turntable 6 and the susceptor 5 to control the temperature. Is provided.
A tungsten ring 8 is disposed so as to surround the outer periphery of the susceptor 5 as a catalyst member for decomposing ammonia gas NH by catalytic action.

  The exhaust port 4 is provided to exhaust the used gas that has passed through the upper part of the susceptor 5 and is provided on the side wall of the chamber 1 opposite to the nozzles 2a, 2b, and 2c.

Each of the plurality of rectifying gas supply nozzles 3b injects a rectifying gas SG (for example, a gas such as hydrogen gas or nitrogen gas) flowing through the gas flow path 3a into the chamber 1, and the plurality of rectifying gas supply nozzles 3b Are formed on the inner wall surface 1a of the chamber facing the upper surface of the substrate W.
Each of the plurality of rectifying gas supply nozzles 3b blows the rectifying gas SG in an oblique direction that forms an angle θ with the upper surface of the substrate W, and downstream from the upstream side with respect to the flow of the source gas in the chamber 1. The rectifying gas SG is blown out toward the side.
The angle θ of each rectifying gas supply nozzle 3b with respect to the upper surface of the substrate W is preferably inclined at an angle of 45 ° or less, more preferably 5 to 20 ° (about 10 ° in this embodiment).
The chamber inner wall surface 1a is preferably inclined at substantially the same angle as the rectifying gas supply nozzle 3b, in other words, in parallel with the rectifying gas supply nozzle 3b.

  Examples of the organometallic gas OG include trimethyl gallium (TMG), triethyl gallium (TEG), trimethyl aluminum (TMA), triethyl aluminum (TEA), trimethyl indium (TMI), triethyl indium (TEI), and other impurities. An organic metal containing an element can be used.

  Moreover, it is preferable to form the material of the part which contacts the source gas MG and the rectification gas SG of the chamber 1 with nickel.

The tungsten ring 8 disposed so as to surround the susceptor 5 may be a catalyst member that can decompose ammonia by catalytic action.
In order to facilitate the decomposition of ammonia, ammonia gas NH preheated to about 300 ° C. in advance may be supplied into the chamber 1.

In the above configuration, a substrate W such as single crystal sapphire is placed on the susceptor 5, and the susceptor 5 is heated to 1200 ° C.
The actual temperature of the substrate W is monitored by a radiation thermometer (not shown) provided outside the chamber 1.

  It is left to stand for 10 minutes while maintaining the above gas conditions and temperature conditions. At this time, the susceptor 5 is rotated by the turntable 6 at 5 rpm to 10 rpm. The rotation of the susceptor 5 continues until the film formation is completed. After the standing time has elapsed, the temperature of the susceptor 5 is lowered to 800 ° C.

The ammonia gas NH is supplied into the chamber 1 from the nozzle 2b at a flow rate of 15 liters / minute, and the nitrogen gas is supplied from the nozzle 2c as an inert gas RG at a flow rate of 6 liters / minute. While maintaining the supply state of the ammonia gas NH and the nitrogen gas, the ammonia gas and the nitrogen gas that have passed over the susceptor 5 are exhausted from the exhaust port 4 to the outside of the chamber 1. In this state, nitrogen gas at a flow rate of 6 liters / min is used as a carrier gas, trimethylindium is 9.6 × 10 ⁻⁵ mol / min and trimethylgallium is 8.0 × 10 ⁻⁶ mol / min from the nozzle 2a. Supply into the chamber 1. In this state, the growth of the indium gallium nitride thin film is started on the substrate W, and the indium gallium nitride thin film is grown for 1 hour. As a result, an indium gallium nitride thin film of about 0.3 μm is grown on the substrate W.

By the way, in the present embodiment, in order to control the temperature of the inner wall surface 1a of the chamber, the component ratio of the rectifying gas SG blown from the rectifying gas supply nozzle 3b is adjusted.
Specifically, the rectifying gas SG uses two or more kinds of gases having different thermal conductivities and adjusts the component ratio thereof to control the temperature of the chamber inner wall surface 1a.

At this time, it is preferable to use hydrogen having a high thermal conductivity (thermal conductivity 17.53) and nitrogen having a low thermal conductivity (thermal conductivity 2.38) as components of the rectifying gas SG. Is appropriately set, the temperature of the chamber inner wall surface 1a can be controlled.
As a component of the rectifying gas SG, argon, helium, neon, or the like can be used in addition to hydrogen and nitrogen. Argon having a thermal conductivity of 1.63 is lower than the thermal conductivity of nitrogen 2.38, and can be suitably used as an alternative gas for nitrogen when the temperature of the chamber inner wall surface 1a needs to be raised. .

FIG. 2 shows the relationship between the rectifying gas concentration (hydrogen gas concentration) and the wall surface temperature.
When the temperature of the substrate W is 1091 ° C. and the rectifying gas SG of hydrogen gas 0% and nitrogen gas 100% is used, the wall temperature is 161 ° C., the rectifying gas SG of hydrogen gas 50% and nitrogen gas 50% is used. When used, the wall surface temperature was 126 ° C., and the wall temperature was 91 ° C. when the rectified gas SG of hydrogen gas 100% and nitrogen gas 0% was used.
As is clear from this result, the relationship between the hydrogen concentration and the wall surface temperature is proportional.

The temperature measuring instrument 10 for measuring the temperature of the chamber inner wall surface 1a is disposed in the vicinity of the chamber inner wall surface 1a. As shown in FIG. You may comprise so that it may take.
Usually, when the temperature of the inner wall surface 1a of the chamber exceeds 200 ° C., the organic matter is decomposed and deposited on the inner wall surface 1a of the chamber.
Therefore, the mass ratio of the hydrogen component and the nitrogen component of the rectifying gas SG blown out from the rectifying gas supply nozzle 3b so as to keep the temperature of the chamber inner wall surface 1a measured by the temperature measuring instrument 10 from 100 to 200 ° C. Adjust by control of (omitted).
That is, when it is necessary to lower the temperature of the chamber inner wall surface 1a, the hydrogen concentration is raised and the nitrogen concentration is lowered. Conversely, when it is necessary to raise the temperature of the chamber inner wall surface 1a, the hydrogen concentration is lowered and the nitrogen concentration is raised.

  As mentioned above, although the temperature control method of the semiconductor manufacturing apparatus of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, In the range which does not deviate from the meaning, it is appropriate. The configuration can be changed.

  As described above, the temperature control method of the semiconductor manufacturing apparatus of the present invention can control the temperature of the inner wall surface of the chamber by a simple method of adjusting the component ratio of the rectifying gas without increasing the size and complexity of the apparatus. Therefore, the present invention can be applied not only to a new semiconductor manufacturing apparatus but also to an existing semiconductor manufacturing apparatus.

It is sectional drawing which shows roughly the structure of the semiconductor manufacturing apparatus to which the temperature control method of the semiconductor manufacturing apparatus of this invention is applied. It is a graph which shows the relationship between rectification gas concentration (hydrogen gas concentration) and wall surface temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chamber 1a Chamber inner wall surface 2 Raw material gas introduction nozzle 2a Raw material gas (organic metal gas) introduction nozzle 2b Raw material gas (ammonia gas) introduction nozzle 2c Inert gas introduction nozzle 3a Gas flow path 3b Rectification gas supply nozzle 4 Exhaust port 5 Susceptor 6 Turntable 7 Heater 8 Tungsten ring (catalyst member)
20 Semiconductor manufacturing equipment MG Source gas SG Rectification gas

Claims (3)

  In a temperature control method of a semiconductor manufacturing apparatus in which a raw material gas and a rectifying gas are supplied into a chamber to form a semiconductor thin film, two or more kinds of gases having different thermal conductivities are used as the rectifying gas and the component ratio is adjusted. And controlling the temperature of the inner wall surface of the chamber.   2. The temperature control method for a semiconductor manufacturing apparatus according to claim 1, wherein hydrogen and nitrogen are used as the rectifying gas component.   3. The temperature control method for a semiconductor manufacturing apparatus according to claim 1, wherein the flow angle of the rectifying gas is set to an angle of 45 degrees or less with respect to the upper surface of the substrate placed in the chamber.

Images