JPH07201876A - Method and apparatus for heating and manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To provide a method and an apparatus for heating wherein a workpiece is uniformly heated in a remarkably shorter time than in conventional short-time heating methods. CONSTITUTION:The title heating method is as follows: The surroundings of a workpiece is turned into a decomposable gas atmosphere or the atmosphere of a mixture of two or more reactable gases, and then the workpiece is directly heated by heat generated through the decomposition or reaction of the gas or mixed gas. The title heating apparatus consists of (a) a heating chamber 10, (b) a gas feed system 20-26 for supplying the heating chamber with decomposable gas or a mixture of two or more reactable gases, and (c) an energy supply device 30 that supplies the gas or mixed gas filled in the heating chamber with energy for decomposing or reacting it so that the workpiece in the heating chamber will be directly heated by heat generated through such decomposition or reaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating method and a heating apparatus capable of heating an object to be heated uniformly and in a short time, and a manufacturing method of a semiconductor device to which the heating method is applied.

[0002]

2. Description of the Related Art In manufacturing a semiconductor device, various processes such as activation treatment of an impurity injection layer formed on a semiconductor substrate, thermal oxidation treatment of a semiconductor substrate or the like, or crystallization treatment of an amorphous layer or a polycrystalline layer are performed. A heat treatment (heating) step is indispensable for process treatment. For this reason, 100
A heating method in which a high temperature of about 0 ° C. and a long time of about 30 minutes to 1 hour are widely used. Further, as a heating method for a shorter time, a short-time heating method by infrared irradiation using a lamp or the like has been developed. Alternatively, as a heating method for a shorter time, a heating method using a pulsed laser beam of visible light or ultraviolet rays has been studied. In this heating method, by using a pulse laser beam having a pulse width of 100 nsec or less, heating can be performed in a short time of 1 μsec or less.

[0003]

With the recent miniaturization and high density of semiconductor devices, for example, there is a demand for a technique for forming an impurity injection layer extremely shallow (for example, 0.5 μm or less) on a semiconductor substrate. However, in the conventional heating method using an electric furnace, it is difficult to control the diffusion of impurities due to the heating of the semiconductor substrate. For this reason, a short-time heating method using infrared irradiation has been developed as a shorter-time heating method. However, even in this heating method, it takes about 10 seconds for heating, so that it is necessary to completely suppress abnormal diffusion of impurities. Has not arrived.

The heating method using a pulse laser beam is 1 μm
Since heating can be performed in a short time of less than a second, diffusion of impurity atoms during heating can be suppressed to be extremely small (for example, 0.1 μm or less). However, there is a problem that heating becomes non-uniform due to non-uniformity of energy in the laser beam and temporal fluctuation of laser energy.

Therefore, an object of the present invention is to provide a heating method and a heating apparatus capable of uniformly heating an unheated material in a much shorter time than a short-time heating method, and a semiconductor device to which such a heating method is applied. It is to provide a manufacturing method.

[0006]

In the heating method of the present invention for achieving the above object, the surroundings of the object to be heated are made into a decomposable gas atmosphere or an atmosphere of two or more kinds of gas mixtures capable of reacting. After that, the object to be heated is directly heated by heat generated by decomposition or reaction of gas. In this case, for example, oxygen is used as the reactable gas in the gas mixture, and the partial pressure ratio of the oxygen gas is 0.04 or more and 0.94 or more.
Below, the partial pressure of oxygen gas can be set to 3 torr or more and 10 atm or less. Furthermore, a gas mixture containing oxygen and hydrogen is used as a reactable gas in the gas mixture, the partial pressure ratio of oxygen gas is 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas is 3 torr or more and 10 atm. It can be:

The above-mentioned objects are further (a) a heating chamber, (b) a gas supply system for supplying a decomposable gas or a mixture of two or more kinds of reactable gases to the heating chamber, and (c) In order to directly heat the object to be heated in the heating chamber by the heat generated by the decomposition or reaction of the gas filled in the heating chamber, the energy for decomposing or reacting the gas filled in the heating chamber is supplied to the heating chamber. It can be achieved by a heating device, characterized in that it comprises an energy supply device for supplying the gas filled therein.

In this case, for example, a gas mixture containing oxygen and hydrogen is used as a reactive gas in the gas mixture, the partial pressure ratio of oxygen gas is set to 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas is set to The pressure can be set to 3 torr or more and 10 atm or less. The product after the reaction of the gas mixture containing oxygen and hydrogen is water, which is preferable because it is easily removed from the object to be heated and does not remain as an impurity on the surface of the object to be heated.

Further, in the heating apparatus of the present invention, when using two or more kinds of gas mixtures which can react with each other, it is desirable to equip the gas supply system with a gas mixer in order to mix the gases in advance. At least one gas supply port for supplying gas to the heating chamber may be provided in the heating chamber, and at least one energy supply device may be provided.
Examples of energy include electric energy and light energy, and examples of the energy supply device include a discharge electrode and a laser irradiation means.

The above-mentioned object is further obtained by subjecting the substrate to a heating step for activating the impurity-containing region formed on the substrate or crystallizing the amorphous region or the polycrystalline region formed on the substrate. This can be achieved by a method for manufacturing a semiconductor device, which uses the heating method of the present invention as a heated product.

Alternatively, the above object is to use a gas mixture containing hydrogen and oxygen as a reactive gas, wherein the partial pressure ratio of oxygen gas is 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas is This can be achieved by a method for manufacturing a semiconductor device, which is characterized in that the heating method of the present invention is performed by using the substrate as an object to be heated in an atmosphere having a pressure of 3 Torr or more and 10 atm or less, and an oxide film is formed on the substrate. .

[0012]

In the present invention, the surroundings of the object to be heated are made into a decomposable gas atmosphere or an atmosphere of a mixture of two or more kinds of gases that can react. Then, the object to be heated is directly heated by the heat generated by the gas chain reaction. That is, the gas filled in the heating chamber is locally decomposed or reacted by electric energy such as electric discharge. The decomposition heat or reaction heat generated by this reaction causes the gas filled in the heating chamber to decompose or react in a chain reaction to generate a large amount of decomposition heat or reaction heat. The heat generated in this way directly heats the object to be heated placed in the heating chamber. The amount of heat generated by the gas chain reaction or the heating time can be controlled by the type of gas, the mixing ratio, or the pressure of the gas. Furthermore, by locally supplying energy from the outside, a gas chain reaction phenomenon is caused, heating can be applied to the entire heating chamber in an extremely short time, and uniform heating can be performed.

In the method of manufacturing a semiconductor device of the present invention, by applying the heating method of the present invention capable of uniformly heating an object to be heated in a short time, impurities in the impurity-containing region are activated. Can be suppressed, or uniform crystallization of amorphous regions or polycrystalline regions can be achieved. Furthermore, it is possible to form a very thin and uniform oxide film.

It is well known that the object to be heated is directly or indirectly heated by utilizing the heat of reaction generated by the reaction of gas or the like. However, after heating the atmosphere around the object to be heated to a gas that can be decomposed or a mixture of two or more kinds of gases that can react, the object to be heated is directly heated by the heat generated by the chain reaction of the gas. The characteristics of the method are unknown as far as the inventor investigated.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

(Heating Device) The heating device of the present invention is a heating device to which a gas chain reaction is applied. A schematic diagram of the heating device is shown in FIG. This heating device comprises a heating chamber 10, a gas supply system, and an energy supply device.

From the gas supply system, a decomposable gas or a mixture of two or more kinds of reactable gases is supplied to the heating chamber 10.
Is supplied to. The gas supply system includes gas sources 20A, 20B,
Mass flow controllers 22A, 22B, gas mixer 2
4, a mass flow controller 25, and pipes and valves 21A, 21B, 23 and 26 arranged between them. In this example, oxygen gas and hydrogen gas were used as the reactable gas (gas that causes a chain reaction). Control of the mixing ratio and supply amount of these gases is
This can be performed by the mass flow controllers 22A, 22B, 25.

The heating chamber 10 is provided with an object holder 11, a gas supply port 12, and an exhaust valve 13. The gas in the heating chamber 10 is exhausted to the outside of the system by the vacuum pump 14 via the exhaust valve 13.

In order to directly heat the object to be heated in the heating chamber 10 by the heat generated by the decomposition or reaction of the gas filled in the heating chamber 10, the gas filled in the heating chamber 10 has energy. Supplied by the energy supply device. In the heating device of this example, electric energy was used as energy. In particular,
The energy supply device is composed of a discharge electrode 30 attached to the heating chamber 10, and a high voltage is supplied to the discharge electrode 30 from a high voltage generator 31.

A platinum thin film thermometer 50 was used to monitor the reaction. The platinum thin film thermometer 50 was produced by forming a platinum thin film on the object to be heated 40 made of a quartz glass substrate by a vapor deposition method. An object to be heated 40 having a platinum thin film thermometer 50 formed thereon was placed on the object to be heated 11 in the heating chamber 10. A load resistor 51 was connected in series to the platinum thin film thermometer 50. Then, a voltage is applied to the platinum thin film thermometer 50 from the voltage generator 52. When the platinum thin film is heated by the heat generated by the chain reaction of the gas, the resistance of the platinum thin film increases and the voltage applied to the load resistor 51 decreases. The voltage change of the load resistor 51 was measured using the oscilloscope 53.

A pressure sensor 54 was attached to the heating chamber 10 to measure the change in pressure inside the heating chamber 10 during the reaction of gas.

The heating device of the present invention is not limited to the heating device shown in FIG. In the gas supply system shown in FIG. 1, two kinds of gas can be supplied to the heating chamber 10, but the gas supply system may be configured to supply three or more kinds of gas to the heating chamber 10. Further, the shape, size, position, etc. of the gas supply port may be appropriately designed according to the heating chamber. The gas mixer 24 can be omitted in some cases. Further, with respect to the energy supply device for inducing the decomposition or reaction of gas, it is possible to use a laser irradiation means or the like, in addition to the structure including the discharge electrode 30. In this case, for example, the heating chamber 10 is provided with a window for irradiation.

(Heating Method) Object to be heated 4 in this embodiment
The heating of 0 can be performed by the following procedure.

First, the exhaust valve 13, the valves 26 and 23
And the valves 21A and 21B are closed, the vacuum pump 14 is operated to exhaust the residual gas in the heating chamber 10, the mass flow controller 25, the gas mixer 24, and the mass flow controllers 22A and 22B. After exhausting the residual gas, all valves are closed and the mass flow controller 22 is operated so that a predetermined hydrogen gas / oxygen gas mixture ratio is achieved.
Set A and 22B. Next, the valves 21A and 21
B and 23 are opened, and the gas mixer 24 is filled with hydrogen gas and oxygen gas. Thereafter, the mass flow controller 25 is set so that the gas mixture of hydrogen gas and oxygen gas in the heating chamber 10 has a predetermined pressure, and the valve 21
A, 21B, 23 are closed and valve 26 is opened to fill heating chamber 10 with the gas mixture. As a result, the atmosphere around the object to be heated 40 becomes a reactive gas atmosphere of hydrogen and oxygen. The total pressure of the gas mixture in the heating chamber 10 at this time is called the initial gas pressure for convenience.

After the inside of the heating chamber 10 is filled with a gas mixture having a predetermined pressure (initial gas pressure), the valve 26 is closed.
Then, a high voltage is applied to the discharge electrode 30 from the high voltage generator 31 to generate a spark. As a result, energy is supplied to the gas mixture filled in the heating chamber 10, oxygen and hydrogen in the heating chamber 10 react with each other to generate reaction heat, and further, due to a chain reaction of gas based on the reaction heat. The reaction between oxygen and hydrogen proceeds rapidly. The object to be heated is directly heated by the heat generated by this gas chain reaction.

After the heating process of the object to be heated is completed, the exhaust valve 13 and the valves 26 and 23 are opened to open the valves 21A and 2A.
With 1B closed, the vacuum pump 14 is operated again, and the heating chamber 10, the mass flow controller 25,
Gas mixer 24, mass flow controller 22A, 22
The residual gas in B is exhausted.

The procedure of the heating method of the present invention is not limited to the procedure described above, and can be changed as appropriate.
In addition, the heating method needs to be appropriately changed depending on the configuration of the heating device used.

The process of heating the object 40 to be heated in the heating chamber 10 was measured by using the platinum thin film thermometer 50, and the measurement result was observed by the oscilloscope 53 to estimate the temperature change of the object 40 to be heated. Furthermore, the pressure sensor 54 measured the change in pressure in the heating chamber 10 during the gas chain reaction.

FIG. 2 shows a platinum thin film thermometer 5 when directly heated by the heat generated by the reaction of the gas according to this embodiment.
The relationship between the temperature change (ΔT) of 0 and the partial pressure ratio of oxygen gas is shown. When the partial pressure ratio of the oxygen gas, that is, the ratio of the partial pressure of the oxygen gas / the total pressure of the gas mixture (the total pressure is constant at 150 Torr) is 0.23 or more and 0.55 or less, a chain reaction of the gas occurs and heating is performed. It became clear that things were heated. The maximum temperature rise was 90 ° C when the partial pressure ratio of oxygen gas was 0.375. The range of the ratio of the partial pressure of the oxygen gas / the total pressure of the gas mixture depends on the heating device. Generally, when the partial pressure ratio of the oxygen gas is 0.04 or more and 0.94 or less, the gas Chain reaction occurs, and the object to be heated is heated.

FIG. 3 shows the relationship between the temperature rise (ΔT) of the platinum thin film thermometer 50 and the initial gas pressure when the partial pressure ratio of oxygen gas is 0.375. The higher the initial gas pressure (total pressure of the gas mixture), the higher the temperature. Initial gas pressure is 2
At 00 torr, the temperature rise (ΔT) was 220 ° C.

The reaction heat generated by the reaction between oxygen and hydrogen induces a reaction between oxygen and hydrogen in the vicinity in a chain reaction. When the pressure of the gas is low, the density of the gas is low, so that the chain reaction does not easily occur. As shown in the measurement results of the initial gas pressure and the temperature increase in FIG. 3, the gas chain reaction did not occur at the initial gas pressure of 20 Torr or less. The minimum value of this initial gas pressure depends on the heating device, and generally, if the partial pressure of oxygen gas is less than 3 torr, the gas chain reaction does not occur.

In FIG. 4, the partial pressure ratio of oxygen gas is 0.375,
Platinum thin film thermometer 50 when initial gas pressure is 200 Torr
The time change of the temperature rise of is shown. The platinum thin film thermometer 50
After energizing the gas mixture, the maximum temperature was reached after about 1 millisecond and dropped to about half the maximum temperature after about 5 milliseconds. From this result, it became clear that the object to be heated can be heated in an extremely short time of 10 milliseconds or less by the heating method of the present invention using the gas chain reaction.

FIG. 5 shows the time variation of the pressure in the heating chamber during the gas chain reaction when the partial pressure ratio of oxygen gas is 0.5 and the initial gas pressure is 100 torr. The pressure in the heating chamber increased from an initial gas pressure of 100 torr to a maximum of 550 torr.

This pressure increase occurs because the gas generated in the heating chamber 10 by the gas chain reaction (for convenience, referred to as the generated gas) is heated to a high temperature. From the Boyle-Charles law (PV = nRT), it is estimated that the temperature of the gas in the case of FIG. 5 has risen to about 1.5 × 10 ³ ° K. However, P is gas pressure, V is volume, n is the number of moles of gas, R is a gas constant, and T is an absolute temperature.

On the other hand, when the pressure of the gas is increased, the gas density is increased, so that the reaction is promoted by the heat of reaction and the speed of the gas chain reaction transmitted through the gas mixture is increased. By the way, when the generated gas reaches the object to be heated, heat is transferred to the object to be heated. At this time, the generated gas in the region near the object to be heated can efficiently and quickly reach the object to be heated and transfer heat. On the other hand, the product gas in a region far from the object to be heated must reach the object to be heated through the product gas that has already transferred heat to the object to be heated and cooled. Therefore, the product gas in the region far from the object to be heated reaches the object to be heated while being cooled by the cooled product gas and slowing down. As described above, it is the high-temperature generated gas in the vicinity of the heated object that can heat the heated object most efficiently, and the higher the density of the generated gas,
In other words, the higher the initial gas pressure of the decomposable gas in the atmosphere around the object to be heated or the two or more kinds of gas mixtures capable of reacting, the higher the temperature of the object to be heated.

FIG. 6 shows the relationship between the time from the rise of the temperature of the platinum thin film thermometer 50 to the maximum temperature and the initial gas pressure (total pressure of the gas mixture). The partial pressure ratio of oxygen gas was 0.375. The higher the initial gas pressure is, the faster the chain reaction is transmitted, so that the platinum thin film thermometer 50 reaches the maximum temperature in a short time. That is, the heating time can be controlled by determining the initial gas pressure.

The heat from the generated gas is transferred to the object to be heated by heat conduction. If the total energy of the generated gas transmitted to the object to be heated is E and the energy is transmitted with the flux W and the pulse width t, then E = W × t (1). Further, assuming that the thermal diffusion coefficient of the object to be heated is D and the specific heat is C, the maximum heating temperature T _MAX of the object to be heated is T _MAX = W × √t / (C × √D) (2) Becomes From the formula (1), W = E / t. Therefore,
The formula (2) is T _MAX = E / C√ (D × t) (3) When the pressure of the produced gas increases, the total energy E increases, and the transmission time of the gas chain reaction decreases, so the pulse width t decreases. Therefore, the higher the initial gas pressure (total pressure of the gas mixture), the more efficient heating of the object to be heated can be realized. From FIG. 6, it is understood that the higher the initial gas pressure, the more efficiently the object to be heated is heated in a short time.

The types of gas for realizing the heating method of the present invention are not limited to oxygen and hydrogen. For example, a gas mixture of hydrogen and nitrous oxide can cause a chain reaction. Further, a large heat of reaction can be obtained by the reaction of hydrocarbon (for example, C ₂ H ₂ ) and oxygen. In addition, a gas mixture composed of a combination of carbon monoxide and oxygen, hydrocarbon and nitrous oxide, carbon monoxide and nitrous oxide, chlorine and hydrogen, and the like can be used. In addition, even if a single gas such as ozone is used, a gas that generates heat of decomposition when decomposed can be used in the heating method of the present invention.

Hereinafter, a method for manufacturing a field effect transistor, a method for manufacturing a bipolar transistor, and a method for manufacturing a semiconductor device related to a method for manufacturing a thin film transistor will be described.

(Method of Manufacturing Semiconductor Device: Method of Manufacturing Field Effect Transistor) Formation of oxide film on the surface of semiconductor substrate,
A method for manufacturing a field effect transistor (FET) in which the heating method of the present invention is applied to activation of an impurity-containing region (impurity injection layer) formed on a semiconductor substrate will be described below. Oxygen gas and hydrogen gas are used as two kinds of gas mixtures which can react. Hereinafter, referring to FIG. 7, FE
A method of manufacturing T will be described.

First, a silicon substrate 60 (corresponding to a base) on which an element isolation region 61 is formed by a conventional method is shown in FIG.
The object to be heated 11 is placed in the heating chamber holder 11 shown in FIG. 1 and the heating chamber 10 is filled with a gas mixture of oxygen and hydrogen. As a result, the surroundings of the silicon substrate 60, which is the object to be heated, are in a reactive atmosphere of two kinds of gas mixture (oxygen and hydrogen). The partial pressure ratio of oxygen gas may be 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas may be 3 torr or more and 10 atmospheres or less.

Next, energy is supplied from the energy supply device to the gas mixture to cause a gas chain reaction of oxygen and hydrogen, and the silicon substrate 60 is directly heated by the generated heat of reaction. At the same time, the surface of the silicon substrate 60 is oxidized by H ₂ O generated by the reaction of oxygen and hydrogen and the heated oxygen existing in the atmosphere. As a result, a very thin and uniform gate oxide film 62 is formed on the surface of the silicon substrate 60 (see FIG. 7A). The gate oxide film 62 is heated at a lower heating temperature than before and in a short time.
Can be formed. As a result, the gate oxide film 62 is uniform and very thin.

After that, the silicon substrate 60 is taken out from the heating device, the gate electrode 63 is formed of, for example, polysilicon, and then a predetermined impurity is implanted into the silicon substrate 60 by an ion implantation method to form an impurity-containing region (impurity implantation). The layer 64 is formed on the silicon substrate 60 (see FIG. 7B). In general, when impurity ions having high energy are implanted, the crystallinity of the silicon substrate in the impurity-containing region 64 is impaired and the silicon substrate becomes amorphous, and the implanted impurities are inactive.

Then, next, the impurity-containing region 64 is activated by the heating method of the present invention. for that reason,
The silicon substrate 60 (corresponding to an object to be heated) on which the impurity-containing region 64 is formed is used as the heating chamber 10 shown in FIG.
It is mounted again on the object to be heated 11 inside and the heating chamber 10 is filled with a gas mixture of oxygen and hydrogen. As a result, the surroundings of the silicon substrate 60, which is the object to be heated, are in a reactive atmosphere of two kinds of gas mixture (oxygen and hydrogen). The partial pressure ratio of oxygen gas may be 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas may be 3 torr or more and 10 atmospheres or less.

Next, energy is supplied to the gas mixture from the energy supply device to cause a chain reaction of oxygen and hydrogen, and the silicon substrate 60 is directly heated by the generated heat of reaction. The silicon substrate is sufficiently heated to activate the impurity-containing region 64 and form the source / drain regions 65 (see FIG. 7C). The heating time is on the order of milliseconds. The heating time is remarkably shorter than that of a short-time heating method using infrared irradiation, for example, diffusion of impurities during heating can be sufficiently suppressed, and the shallow source / drain regions 65 can be formed.
Can be formed.

Then, the silicon substrate 60 is taken out from the heating device, an insulating layer 66 is formed on the source / drain regions 65 and the gate electrode 63 formed on the silicon substrate 60, and an opening 67 is formed in the insulating layer 66. After that, the metal wiring material 68 is embedded in the opening 67 (see FIG. 7D) to complete the field effect transistor.

(Manufacturing Method of Semiconductor Device: Manufacturing Method of Bipolar Transistor) A manufacturing method of a bipolar transistor in which the heating method of the present invention is applied to activation of an impurity-containing region (impurity implantation layer) will be described below. . Oxygen gas and hydrogen gas are used as two kinds of gas mixtures which can react. Hereinafter, a method for manufacturing a bipolar transistor will be described with reference to FIGS.

First, after forming the protective film 71 on the silicon substrate 70, predetermined impurities are implanted into the collector formation planned region 72A of the silicon substrate 70 by the ion implantation method. Further, predetermined impurities are sequentially implanted into the base formation planned area 73A and the emitter formation planned area 74A by the ion implantation method. Thus, as shown in FIG.
Impurity containing regions 72A, 73A and 74A are formed.

Next, the heating method of the present invention is applied to activate the impurity-containing regions 72A, 73A and 74A. Therefore, the silicon substrate 70 (corresponding to an object to be heated)
Is placed on the object holder 11 in the heating chamber 10 shown in FIG. 1, and the heating chamber 10 is filled with a gas mixture of oxygen and hydrogen. As a result, the surroundings of the silicon substrate 60, which is the object to be heated, are in a reactive atmosphere of two kinds of gas mixture (oxygen and hydrogen). The partial pressure ratio of oxygen gas may be 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas may be 3 torr or more and 10 atmospheres or less.

Next, energy is supplied from the energy supply device to the gas mixture to cause a chain reaction of oxygen and hydrogen, and the silicon substrate 70 is directly heated by the generated heat of reaction. The silicon substrate is sufficiently heated. The heating time is on the order of milliseconds. As a result, the impurity-containing region 7
2A, 73A, 74A are activated, and collector region 7
2, a base region 73 and an emitter region 74 are formed (see FIG. 8B). The heating time is remarkably short as compared with, for example, a short-time heating method using infrared irradiation, diffusion of impurities during heating can be sufficiently suppressed, and a shallow emitter region 74 and a narrow base region 73 can be formed.

Then, the silicon substrate 70 is taken out of the heating device, an insulating layer 75 is formed on the protective film 71, an opening is formed in the insulating layer 75 and the protective film 71, and the collector electrode 72B, The base electrode 73B and the emitter electrode 74B are formed (see FIG. 8C) to complete the bipolar transistor.

(Manufacturing Method of Semiconductor Device: Manufacturing Method of Thin Film Transistor) The heating method of the present invention is applied to crystallization of a polycrystalline layer (polycrystalline region) made of polysilicon and activation of an impurity-containing region (impurity implantation layer). A method of manufacturing a field effect type thin film transistor (TFT) applied to the above is shown below. Oxygen gas and hydrogen gas are used as two kinds of gas mixtures which can react. Hereinafter, a method for manufacturing a TFT will be described with reference to FIG.

First, a polysilicon layer 81 is formed on an insulating substrate 80 such as glass by the CVD method (FIG. 9).
(A)).

Next, the polysilicon layer 81 is crystallized by the heating method of the present invention. Therefore, the substrate 80 on which the polysilicon layer 81 is formed (corresponding to an object to be heated)
Is placed on the object holder 11 in the heating chamber 10 shown in FIG. 1, and the heating chamber 10 is filled with a gas mixture of oxygen and hydrogen. As a result, the surroundings of the silicon substrate 60, which is the object to be heated, are in a reactive atmosphere of two kinds of gas mixture (oxygen and hydrogen). The partial pressure ratio of oxygen gas may be 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas may be 3 torr or more and 10 atmospheres or less.

Next, energy is supplied from the energy supply device to the gas mixture to cause a chain reaction of oxygen and hydrogen, and the silicon substrate 80 is directly heated by the generated reaction heat. The silicon substrate is sufficiently heated and the polysilicon layer 81 is crystallized to form the single crystal silicon layer 82 (see FIG. 9B). The heating time is on the order of milliseconds. Since the substrate 80 is heated uniformly, a uniform single crystal silicon layer 82 can be formed.

After that, the substrate 80 is taken out of the heating device, the gate oxide film 83 is formed by the conventional method, and the gate electrode 84 is further formed. Then, a predetermined impurity is injected into the single crystal silicon layer 82 by an ion injection method to form an impurity-containing region (impurity injection layer) 85 (see FIG. 9C). Then, again, by using the heating device shown in FIG. 1, the impurity-containing region 85 is activated by the same heating method as the activation of the impurity-containing region in the method for manufacturing the FET to form the source / drain regions 86. (See (D) of FIG. 9).

Then, the substrate 80 is taken out from the heating device, an insulating layer 87 is formed on the source / drain regions 86 and the gate electrode 84 formed on the substrate 80, and an opening 88 is formed in the insulating layer, and then an opening is formed. A metal wiring material 89 is embedded in the portion 88 (see FIG. 9E) to complete a field effect thin film transistor.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments. For example, the energy required for activation and crystallization in the semiconductor device manufacturing method depends on the number of implanted impurity ions, the thermal conductivity of the substrate, and the like, so the partial pressure ratio of the gas and the initial gas pressure are appropriately optimized. There is a need to.

Further, the heat treatment by the heating method of the present invention is 1
It doesn't stop at heating once. That is, when heating a plurality of times gives an optimum result, the optimum number of times of heating may be appropriately determined. For example, in the case where the optimum result is obtained by heating the object to be heated to 1000 ° C in the first heat treatment and subsequently heating it to 800 ° C in the second heat treatment, the gas mixing conditions may be changed as appropriate. Also, heating may be performed by changing the initial gas pressure.

Further, the object to be heated is not limited to silicon. In addition to polycrystalline silicon and amorphous silicon, the heating method and the heating method of the present invention can be applied to various heating processes for manufacturing a semiconductor device including single crystal silicon germanium, polycrystalline silicon germanium, and amorphous silicon germanium. The device can be applied. Further GaA
The present invention can be applied to various heating processes for manufacturing a semiconductor device composed of a compound semiconductor such as s and ZnSe.

The method of forming an oxide film to which the heating method of the present invention is applied is not limited to the formation of an oxide film on the surface of single crystal silicon, but can also be used for the formation of an oxide film on the surface of polycrystalline silicon or amorphous silicon. it can. Furthermore,
In manufacturing a semiconductor device, a gate oxide film may be formed from a laminated structure of an oxide film formed according to the present invention and an insulating film formed by another method. For example, thermal decomposition CVD
Method or plasma decomposition CVD method, and further it is possible to stack with SiO ₂ or SiN formed by a sputtering method.

In the examples, the heating method of the present invention is applied to the manufacturing method of the semiconductor device, but the heating method and the heating device of the present invention can be applied to, for example, metal materials, plastic materials, fiber materials and the like. It can be applied to fields such as surface treatment, surface processing, and surface processing of cutting tools.

[0063]

In the heating apparatus of the present invention, it is possible to uniformly and quickly heat the inside of the heating chamber to a high temperature by using the gas chain reaction. Further, in the heating method of the present invention, it is possible to uniformly heat the object to be heated over a large area in a short time, activation of the impurity-containing region capable of suppressing the diffusion of impurities, and amorphous regions and It is possible to uniformly crystallize the polycrystalline region and to form a uniform and thin oxide film. In particular, by using the heating method and the heating apparatus of the present invention for manufacturing an electronic device such as a field effect transistor, a bipolar transistor, or a thin film transistor, it is expected that the device process steps will be remarkably improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a heating device of the present invention using a gas chain reaction.

FIG. 2 is a diagram showing the relationship between the partial pressure ratio of oxygen gas and the temperature rise of a platinum thin film thermometer in a gas mixture of hydrogen and oxygen.

FIG. 3 is a diagram showing the relationship between the temperature rise of the platinum thin film thermometer and the initial gas pressure of the gas mixture when the partial pressure ratio of oxygen gas in the gas mixture of hydrogen and oxygen is 0.375.

FIG. 4 shows the case where the partial pressure ratio of oxygen gas is 0.375 and the initial gas pressure is 200 Torr in the gas mixture of hydrogen and oxygen.
It is a figure which shows the time change of the temperature rise of a platinum thin film thermometer.

FIG. 5 is a diagram showing the time change of the pressure of the product gas by the gas chain reaction in the case where the partial pressure ratio of oxygen gas is 0.5 and the initial gas pressure is 100 Torr in the gas mixture of hydrogen and oxygen.

FIG. 6 is a diagram showing the relationship between the time from when the temperature of the platinum thin film thermometer rises until it reaches the maximum temperature and the initial gas pressure.

FIG. 7 is a diagram for explaining a method for manufacturing a field effect transistor to which the heating method of the present invention is applied.

FIG. 8 is a diagram illustrating a method for manufacturing a bipolar transistor to which the heating method of the present invention is applied.

FIG. 9 is a diagram for explaining a manufacturing method of a thin film transistor to which the heating method of the present invention is applied.

[Explanation of symbols]

 10 Heating Chamber 11 Heated Object Holder 12 Gas Supply Port 13 Exhaust Valve 14 Vacuum Pump 20A, 20B Gas Source 22A, 22B, 25 Mass Flow Controller 24 Gas Mixer 21A, 21B, 23, 26 Valve 30 Discharge Electrode 31 High Voltage Generation Device 40 Heated object 50 Platinum thin film thermometer 51 Load resistor 52 Voltage generator 53 Oscilloscope 54 Pressure sensor 60, 70, 80 Substrate 61 Element isolation region 62, 83 Gate oxide film 63, 84 Gate electrode 64, 85 Impurity containing region 65,86 Source / drain region 66,75,87 Insulating layer 67,88 Opening 68,89 Metal wiring material 71 Protective film 72 Collector region 73 Base region 74 Emitter region 81 Polysilicon layer 85 Single crystal silicon layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01L 21/336 29/786 (72) Inventor Masato Fujita 1280, Kamizumi, Sodegaura, Chiba Idemitsu Kosan Co., Ltd. Inside the ceremony company (72) Inventor Shimo Shinro Idemitsu Kosan Co., Ltd. 1280 Kamizumi, Sodegaura City, Chiba Prefecture

Claims (7)

[Claims] 1. An object to be heated is directly heated by the heat generated by the decomposition or reaction of the gas after the surroundings of the object to be heated are made into a decomposable gas atmosphere or an atmosphere of a mixture of two or more kinds of gases that can react. A heating method characterized by the above. 2. Oxygen is used as the reactable gas in the gas mixture, and the partial pressure ratio of the oxygen gas is 0.04 or more and 0.94.
The heating method according to claim 1, wherein the partial pressure of oxygen gas is 3 torr or more and 10 atm or less. 3. A gas mixture containing oxygen and hydrogen is used as a reactable gas in the gas mixture, the partial pressure ratio of oxygen gas is 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas is 3 Torr. The heating method according to claim 2, wherein the heating pressure is not less than 10 atm. 4. A heating chamber; (b) a gas supply system for supplying a decomposable gas or a mixture of two or more kinds of reactable gases to the heating chamber; and (c) a heating chamber. Energy for directly heating the object to be heated in the heating chamber with the heat generated by the decomposition or reaction of the filled gas, and supplying the energy for decomposing or reacting the gas filled in the heating chamber to the gas. A heating device comprising a supply device. 5. A gas mixture containing oxygen and hydrogen is used as a reactable gas in the gas mixture, the partial pressure ratio of oxygen gas is 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas is 3 Torr. The heating device according to claim 4, wherein the heating device is at least 10 atm. 6. A heating step for activating an impurity-containing region formed on a substrate or crystallizing an amorphous region or a polycrystalline region formed on a substrate, wherein the substrate is used as an object to be heated. A method for manufacturing a semiconductor device, which uses the heating method according to any one of claims 1 to 3. 7. A gas mixture containing hydrogen and oxygen is used as a reactable gas, the partial pressure ratio of oxygen gas is 0.04 or more and 0.94 or less, and the partial pressure of oxygen gas is 3 Torr or more and 10 Torr or more.
A method for manufacturing a semiconductor device, comprising performing the heating method according to claim 1 as an object to be heated in an atmosphere at a pressure of not more than atmospheric pressure to form an oxide film on the substrate.