JPH0964028A - Method and apparatus for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely selectively oxidize silicon by introducing specific mixed gas into a treating vessel containing a base to be treated having the exposed part of the silicon, setting the partial pressure H2 gas in the vessel to less than specific value, and setting the temperature of the base to be treated to a specific value or more. SOLUTION: A base to be treated having the exposed part of silicon is contained in a treating vessel 115, and non-oxidative gas different from H2 gas, H2 O gas and H2 gas is introduced into the vessel 115. The partial pressure of the H2 gas in the vessel 115 is set to less than 4%, the temperature of the base to be treated is set to 600 deg.C or higher, and the exposed part of the silicon is selectively oxidized. For example, the non-oxidative gas different from the H2 gas is N2 gas, and the H2 O gas is supplied from a bubbler 123 with N2 gas as carrier gas. The H2 gas partial pressure in the vessel 115 is controlled by flow controllers 104 to 106, and the H2 O gas in the entire atmosphere is monitored by a moisture meter 113.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a semiconductor device characterized by oxidation of silicon.

[0002]

2. Description of the Related Art Large-scale integrated circuits (LSIs) formed by connecting a large number of transistors, resistors, etc. to an electric circuit in important parts of a computer, communication equipment, etc. ) Is often used. For this reason, the performance of the entire device is greatly related to the performance of the LSI alone. The performance of the LSI alone can be improved by increasing the degree of integration, that is, by miniaturizing the elements.

However, with the high integration of semiconductor integrated circuits due to the miniaturization of elements in recent years, there is a problem that the operation speed of the element is limited by RC delay of electrodes such as gate electrodes and wiring such as gate wiring. It has turned into.

This type of delay can be suppressed by reducing the resistance of the electrodes and wiring. For example, in the case of a gate electrode of a MOS transistor or the like, a two-layer structure gate (polycide gate) of a metal silicide film and a polycrystalline silicon film is used instead of the polycrystalline silicon gate which has been conventionally used. Can be suppressed by.

However, after the 0.25 μm generation, a gate electrode having a resistance lower than that of a polycide gate is required, and recently, a three-layer structure gate (polymetal film) of a refractory metal film, a reaction preventive layer and a polycrystalline silicon film has been demanded. The gate) is drawing attention.

[0006] Here, the use of tungsten (W) as a high melting point metal, since the specific resistance of the tungsten was about one order of magnitude smaller than the tungsten silicide (WSi _x), R
The C delay time can be greatly shortened. It also has the advantage that many of the techniques used for polycide gates can be inherited.

On the other hand, in the LSI manufacturing process,
After forming a gate such as a polycrystalline silicon gate, a polycide gate, and a polymetal gate, a step of post-oxidation is performed for the purpose of improving the characteristics and reliability of the device.

For example, in the case of a polycrystalline silicon gate, as shown in FIG. 9, a polycrystalline silicon film is formed on a silicon substrate 901 and patterned to form a gate electrode 90.
2 is formed, an oxidized portion 904 having a film thickness called bird's beak is formed at the end of the gate oxide film 903. As a result, the lower end portion of the gate electrode 902 is rounded and the electric field in the gate portion is relaxed, so that the characteristics and reliability of the device can be improved.

This kind of post-oxidation is used as a metal silicide for W
When applied to a polycide gate using Six, WSi
Since x having a Si composition higher than the normal composition x = 2.0 is usually used as x, excess silicon in WSix is oxidized in the post-oxidation step, and SiO ₂ is also formed on the WSix surface.
Are formed, and similar effects can be obtained in the same manner as in crystalline silicon.

On the other hand, when this kind of post-oxidation is applied to a polymetal gate using W as a refractory metal, W is also oxidized in a normal oxidation step, so that WO _{3 in} a normal oxidation step is used.
Is formed. At this time, because of the large deposition expansion,
The peeling of the film or the like occurs, and the subsequent steps cannot be continued.

Further, an oxidizing agent such as O ₂ or H ₂ O mixed from the atmosphere may oxidize W before starting the oxidation step, and the same problem may occur.

Therefore, in the case of a polymetal gate, a technique (selective oxidation method) of oxidizing only the silicon without oxidizing the refractory metal is required in the post-oxidation step.

In the case where an exposed portion of silicon and an exposed portion of a refractory metal such as W coexist on the same substrate as in the case of a polymetal gate, the exposed portion of the refractory metal is not oxidized and only silicon is exposed. A selective oxidation method of selectively oxidizing is known (JP-A-60-9166).

[0014] The selective oxidation method, when performing oxidation in a mixed atmosphere of H ₂ is between H ₂ O reducing agent is an oxidizing agent, to set the partial pressure ratio of H ₂ O / H ₂ in a predetermined range It is to do it. The inventors have actually confirmed that this selective oxidation can be applied to the post-oxidation step of the polymetal gate.

However, this type of H ₂ O gas and H ₂ O
The selective oxidation method using a mixed gas with a gas has the following problems.

H ₂ gas, which is a reducing agent, has a concentration of 4% to 75%.
Explodes at temperatures above 600 ° C in the range of%. On the other hand, the oxidation of silicon is usually performed at a high temperature of 600 ° C. or higher. Therefore, the selective oxidation method using a mixed gas of H ₂ O gas and H ₂ gas has a safety problem.

For example, when 60% of hydrogen completely burns, the temperature rise is 3500 ° C., and the expansion of deposition at that time is 4.3 times. Therefore, not only is the oxidation apparatus itself damaged, but also the surrounding environment. Will be in a dangerous situation.

Therefore, when the above selective oxidation method is used, an apparatus equipped with a safety mechanism is required. As a safety mechanism, a mechanism for maintaining a state in which the reaction chamber does not explode and a mechanism for maintaining a safe state even if oxygen is mixed in for some reason are required.

Therefore, in order to actually use the above-mentioned selective oxidation method, the above-mentioned safety mechanism is required, which causes a problem that the apparatus becomes complicated and the cost becomes high.

[0020]

As described above, in the conventional selective oxidation method of silicon, since H ₂ gas is used as the reducing agent, there is a danger of explosion or the like. Therefore, the device for carrying out the selective oxidation method requires a safety mechanism for preventing the risk of explosion or the like, which makes the device configuration complicated and the device cost high. There was a problem.

The present invention has been made in consideration of the above circumstances, and an object thereof is to avoid complication of the manufacturing method and structure of a semiconductor device capable of safely performing selective oxidation of silicon, and high cost. Another object is to provide a semiconductor manufacturing apparatus capable of safely performing selective oxidation of silicon.

[0022]

[Means for Solving the Problems]

[Summary] In order to achieve the above object, a method for manufacturing a semiconductor device according to the present invention (claim 1) includes a substrate to be processed having an exposed portion of silicon in a processing container, and H in the processing container. ₂ gas, H ₂ O gas and a non-oxidizing gas different from H ₂ gas are introduced, the partial pressure of the H ₂ gas in the processing container is set to less than 4%, and the temperature of the substrate to be processed is set. Is set to 600 ° C. or higher to selectively oxidize the exposed portion of the silicon.

The semiconductor manufacturing apparatus according to the present invention (claim 2) includes a processing container for accommodating a substrate to be processed and performing an oxidation treatment, and H ₂ gas, H ₂ O gas and gas introducing means for introducing a different non-oxidizing gas and H ₂ gas, and the partial pressure control means for setting the partial pressure of the H ₂ gas in the processing chamber to less than 4%, 600 ° C. the target substrate It is characterized by comprising heating means for heating at the above temperature.

Furthermore, it is desirable that the above-described semiconductor device manufacturing method and semiconductor manufacturing device have the following features. (1) Oxidizing treatment is performed while maintaining the pressure inside the processing container at a negative pressure rather than atmospheric pressure. (2) The inside of the processing container is once depressurized to 1 Pa or less, and then an oxidation treatment is performed.

[Operation] According to the method for manufacturing a semiconductor device of the present invention (claim 1), the temperature of the substrate is 6 or more above the oxidation limit.
Since the partial pressure of H ₂ gas is set to a low pressure (low concentration) below the explosion limit in a state of being set to a temperature of 00 ° C. or higher,
You can safely perform selective oxidation of silicon.

Further, according to the semiconductor manufacturing apparatus according to the present invention (Claim 2), since the H ₂ gas partial pressure can be set to explosion limit or lower pressure (low density), H ₂ gas an inert gas Can be treated the same as. Therefore, the selective oxidation of silicon can be safely performed without complicating the device structure and increasing the cost.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a schematic view showing a schematic configuration of a semiconductor manufacturing apparatus according to the first embodiment of the present invention.

In the figure, reference numeral 115 denotes a processing container for accommodating a substrate to be processed such as a Si wafer and performing an oxidation process. In the processing container 115, H ₂ gas and H ₂ O are contained.
Gas is introduced together with N ₂ gas (non-oxidizing gas).

The H ₂ gas contains a valve 102, a flow rate controller 105, a valve 108, an inlet pipe 111, and a moisture meter 11.
3. Introduced into the processing container 115 via the valve 114. At this time, the first N ₂ gas is the valve 101, the flow rate controller 104, the valve 107, the introduction pipe 111, the moisture meter 1
13. It is introduced into the processing container 115 via the valve 114. That is, the H ₂ gas is introduced into the processing container 115 using the first N ₂ gas as the carrier gas.

On the other hand, as the H ₂ O gas, pure water vapor sealed in the bubbler 123 using the second N ₂ gas as a carrier gas is introduced into the processing container 115 through the valve 110 and the introduction pipe 112. Supplied by Second N
₂ gas, valve 103, flow controller 106, valve 1
09, it is introduced into the bubbler 123 via the flow rate controller 124.

The H ₂ gas concentration (H ₂ gas partial pressure) in the processing container 115 is controlled by the flow rate controllers 104, 105 and 106. That is, the flow rate controllers 104, 105 and 106 control the flow rates of the H ₂ gas and the N ₂ gas so that the H ₂ gas concentration becomes a predetermined value. Also, the processing container 1
The H ₂ O gas concentration in the entire atmosphere in 15 is monitored by the moisture meter 113.

A heater 116 is provided in the processing container 115. The heater 116 sets the substrate to be processed to a predetermined temperature. Further, the processing container 115 includes the valve 120.
It is connected to the vacuum pump 122 via. The processing container 115 is evacuated by the vacuum pump 122. The pressure inside the processing container 115 is a pressure gauge 11.
It can be monitored by 7.

In the figure, 118 is a valve, 119 is a dilution gas introduction line, 121 is a vacuum reference line, and 125 is an exhaust line.

The present inventors have examined the oxidation of Si and W using the semiconductor manufacturing apparatus configured as described above.

First, with the H ₂ gas concentration fixed at less than 4% (less than the combustion limit), the partial pressure ratio (P _H2O / P _H2 ) of H ₂ gas and H ₂ O gas was changed to change Si and W. Experiments were carried out to examine the oxidation of.

In this experiment, the substrate temperature was 800 ° C., the oxidation time was 30 minutes, and the total pressure was about 1 × 10 ⁵ Pa (1 at).
fixed to m).

The oxidation of the W surface was judged by the shift of the W peak in XPS (X-ray photoelectron spectroscopy) and the shape of the W surface by SEM. The amount of Si oxidation was measured by an ellipsometer.

FIG. 2 shows the resulting partial pressure ratio P _H2O / P _H2
FIG. 3 is a characteristic diagram showing the relationship between the film thickness (oxide film thickness) of a silicon oxide film formed on Si and Si.

When the partial pressure ratio P _H2O / P _H2 is 0.3 or less, W
The surface is kept smooth without being oxidized, and _PH2O / _PH2
It was found that a silicon oxide film having a thickness of about 3 nm can be formed on Si at 0.22.

On the other hand, it was found that when the partial pressure ratio P _H2O / P _H2 exceeds 0.3, the W surface becomes rough. It was also confirmed that the higher the temperature of the substrate to be treated (substrate temperature), the higher the partial pressure ratio P _H2O / P _{H2 at} which the W surface begins to roughen. It is advisable to set appropriate conditions depending on the temperature so that the partial pressure ratio P _H2O / P _H2 is 0.2 to 0.4 or less.

FIG. 3 shows that P _H2 = 4000Pa (0.04a
tm), P _H2O / P _H2 = 0.2, and the time dependence of the oxide film thickness at a substrate temperature of 800 ° C. Also,
The hydrogen concentration is below the combustion limit (4% or less).

From FIG. 3, the substrate temperature is 800 ° C. and the oxidation time is 1
It can be seen that an oxide film of about 4 to 5 nm can be formed by oxidizing for about 20 minutes. At this time, it was found by XPS and SEM observation that W was not oxidized and its surface was kept smooth.

FIG. 4 is a characteristic diagram showing the relation between the substrate temperature and the oxide film thickness when the substrate temperature is 800 to 950 ° C. and the oxidation time is 30 min under the same gas conditions as in FIG.

From FIG. 4, for example, in the case of oxidation at a substrate temperature of 900 ° C. and an oxidation time of 30 min, without oxidizing W,
It can be seen that a silicon oxide film having a thickness of about 12 nm can be formed.

From the above results, it was found that Si can be selectively oxidized while keeping the W surface flat even when the hydrogen concentration is below the combustion limit. Therefore, according to the present embodiment, the hydrogen gas can be treated in the same manner as a normal noncombustible gas,
Selective oxidation of silicon can be performed safely.

Although the above experiment was conducted when the substrate temperature was 800 ° C. or higher, the substrate temperature was 600 ° C. or higher, that is, the temperature at which silicon was oxidized (above the oxidation limit).
Then, it was confirmed that similar results could be obtained.

Further, such selective oxidation is performed by a semiconductor manufacturing apparatus having a simple structure as shown in FIG. 1, that is, in addition to the conventional structure, N ₂ gas (non-oxidizing gas) which is a carrier gas is used.
Since it can be performed by a semiconductor manufacturing apparatus having a configuration in which the above-mentioned supply system is added, there is no problem that the apparatus price rises.

FIG. 5 shows photomicrographs of the polymetal gate before and after the selective oxidation method of this embodiment.

FIG. 5A shows a case where polycrystalline Si is formed on a Si substrate.
A film, a WSiN film, and a W film are sequentially formed, and then this laminated film is patterned by RIE to form a polymetal gate.

FIG. 5B shows a state in which a silicon oxide film having a thickness of 4 nm is formed by the selective oxidation method of the present embodiment, and FIG. 5C shows a thickness of 12 nm by the selective oxidation method of the present embodiment. The silicon oxide film of FIG.

From FIGS. 5B and 5C, it is confirmed that SiO ₂ is selectively formed on the Si surface without damaging the shape of the W film. (Second Embodiment) FIG. 6 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus according to a second embodiment of the present invention. This is an improvement of the semiconductor manufacturing apparatus of FIG.

In the figure, reference numeral 606 denotes a processing container in which a substrate 608 to be processed, such as a Si wafer, is housed and subjected to an oxidation process. In this processing container 606, a plurality of substrates 6 to be processed are placed.
A support 607 capable of simultaneously supporting 08 is provided. The support 607 is made of an insulating material such as quartz or SiC.

The equipment systems on the right and left sides of the processing container 606 correspond to the gas introduction system and the gas exhaust system of the semiconductor manufacturing apparatus of FIG. 1, respectively. The gas introduction system has almost the same configuration except that the H ₂ O gas is supplied without using the bubbler 123.

That is, the valves 618 to 620 correspond to the valves 101 to 103 in FIG. 1, the flow rate controllers (MFC) 615 to 617 correspond to the flow rate controllers 104 to 106 in FIG. 1, and the valves 612 to 614. 1 corresponds to the valves 107 to 109 of FIG.
0 corresponds to the valve 114 in FIG. 1, and the hydrogen supply line 62
Reference numeral 5 corresponds to the hydrogen supply line 111 in FIG. As shown in this figure, N ₂ gas is introduced to dilute the H ₂ gas. The H ₂ O gas may also be diluted with N ₂ gas.

On the other hand, the gas exhaust system has been improved. First, as in a normal low pressure CVD apparatus, a vacuum pump 601 such as a dry pump and a pressure control apparatus 604 are provided, whereby the inside of the reaction vessel 600 is about 1 Pa. The pressure can be reduced to. Furthermore, conductance valve 6
No. 05 is provided, and the pressure can be controlled at a quasi-normal pressure of about 0.8 atm. In addition, 624 is a pressure gauge,
Reference numeral 602 represents an exhaust line, and 603 represents a dilution line with an inert gas.

In this embodiment, the same effect as that of the previous embodiment can be obtained, and further, the above-mentioned improvement provides another 2
One effect is obtained.

First, it is possible to check the airtightness under a reduced pressure as in the case of using a low pressure CVD apparatus, so that the airtightness of the apparatus can be confirmed at the start of the oxidation step.

Therefore, it is possible to surely perform the oxidation while ensuring the sufficient airtightness. As a result, the possibility that oxygen will be mixed becomes extremely low, and even if the hydrogen concentration may increase, the oxidation can be safely performed.

Oxidizing agents such as oxygen and water mixed in the apparatus at the time of releasing the atmosphere or oxidizing agents such as oxygen and water adsorbed in the apparatus are temporarily reduced to about 1 Pa,
Most can be discharged. Therefore, it becomes possible to start the oxidation process under more controlled conditions.

The other is that the oxidation can be carried out at a pressure slightly lower than the atmospheric pressure, and even if the hydrogen concentration slightly exceeds the lower limit of combustion, even if the hydrogen is burned, damage to the device due to pressure increase and danger to the surroundings can be avoided. It is possible.

An example of the trial calculation will be shown below.

Hydrogen burns according to the following reaction formula,
At 800 ° C. and atmospheric pressure, about 249 kJ of heat is released per mol.

2H ₂ + O ₂ → 2H ₂ O + 249 × ₂ kJ If the volume of the processing container 606 is 50 l, the volume of 4% H ₂ is 2 l. Total pressure is 8 × 10 ⁴ Pa (0.8 at
m) and when this is converted into the number of moles, it becomes about 0.07 mol. The energy generated at this time is 17.4 kJ.

When the specific heat of the gas filling the inside of the processing container 606 is considered to be about the isochoric specific heat of N ₂ , V _{V, N 2} = 0.74J
Therefore, the temperature rise is about 470 ° C.

The pressure rise at that time is about 1.4 times, and the initial state is 8 × 10 ⁴ Pa, so the pressure is about 1.14 × 1.
It becomes 0 ⁵ Pa (1.14 atm).

Therefore, if the positive pressure is about 0.14 atm with respect to the atmospheric pressure, even a vacuum system of ordinary strength will not be damaged. (Third Embodiment) FIG. 7 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus (cold wall type heating apparatus) according to a third embodiment of the present invention.

This cold wall type heating device is roughly divided into a vacuum chamber, a processing container 711 in which a substrate 722 to be processed is housed and subjected to an oxidation process, and an N ₂ gas whose flow rate is accurately controlled. It is composed of a gas introduction system 712 of diluted H ₂ O gas, a gas introduction system 713 of H ₂ gas diluted with N ₂ gas whose flow rate is precisely controlled, and a substrate holder 714 also serving as a heating source. There is. The heating source is composed of, for example, a resistance heater.

When the cold wall type heating device is used, the temperature of the inner wall of the processing container 711 becomes about room temperature, so that when the selective oxidation is performed in the atmosphere used in the previous embodiment, water vapor is generated on the inner wall of the processing container 711. Condensation is likely to occur, and it may be difficult to control the water vapor partial pressure depending on the gas introduction route. Therefore, in the present embodiment, the heating plate 715 heated to 50 ° C. or higher is provided inside the processing container 711.

Next, selective oxidation of Si using this cold wall type heating device, specifically, W / WSiN / Si
The selective oxidation of Si of the laminated film (polymetal gate) will be described.

First, the substrate 722 to be processed on which the W / WSiN / Si laminated film is formed is introduced into the processing container 711.

Next, the valve 719 is opened to open the dry pump 7.
After the inside of the processing container 711 is evacuated by 20, the valve 719 is closed and the valves 716 and 718 are opened, and the inside of the processing container 711 is evacuated by the turbo molecular pump 717.

Next, H diluted with N ₂ gas to 4% or less
₂ gas is introduced into the processing container 711 from the gas introduction system 713, and then H ₂ O gas diluted with N ₂ gas is caused to flow from above the substrate 722 to be processed from the gas introduction system 712 to selectively oxidize Si. Do. At this time, the substrate 722 to be processed is set to a temperature of 600 ° C. or higher.

The above gas introduction sequence prevents the H ₂ O gas concentration from becoming higher than the desired set value at which selective oxidation occurs. Therefore, if the order of gas introduction is reversed,
In the initial stage of gas introduction, the oxidation of W occurs because it exceeds the equilibrium water vapor partial pressure with the oxides of W and WSiN.

Further, the total gas pressure is set to about 0.1 to 0.9 atm so that the processing container 711 is not destroyed even when the combustion reaction of H ₂ gas occurs inside the processing container 711.

The exhaust gas is exhausted from the exhaust port of the dry pump 720 through the pipe 721. At this time, N ₂ gas is introduced from the pipe 723 in order to further dilute the H ₂ gas concentration.

When the selective oxidation is completed, the introduction of H ₂ O gas from the gas introduction system 712 is stopped, and subsequently the introduction of H ₂ gas diluted with N ₂ gas from the gas introduction system 713 is stopped. The substrate 722 to be processed is unloaded from the processing container 711.

This sequence of stopping gas introduction prevents the H ₂ gas concentration from becoming higher than the desired set value at which selective oxidation occurs. Therefore, if the order is reversed, oxidation of W occurs because the equilibrium water vapor partial pressure with the oxides of W and WSiN is exceeded at the stage of gas introduction termination.

In the present embodiment, the substrate holder 714 also serves as the heating source for the substrate 722 to be processed. In this case, however, the heater of the heating source must be always on. In order to prevent the oxidation of WSiN, it is indispensable that the substrate 722 to be processed before being carried out and the processing container 711 before being carried out are vacuum chambers. (Fourth Embodiment) FIG. 8 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus (cold wall type heating apparatus) according to a fourth embodiment of the present invention.

The cold wall type heating apparatus of this embodiment is different from that of the third embodiment in that a lamp 823 capable of high-speed temperature rising / falling is used as a heating source, and it is provided on the outer periphery of the substrate 822 to be processed. This is because a gas is caused to flow from the shower head 825 to the surface of the substrate 822 to be processed, and the substrate holder 814 is rotatable.

The lamp 823 and the shower head 825 are
It constitutes a part of the gas introduction part 824. That is, the gas inlet 824, a gas introduction system 812 for flow to introduce H ₂ O gas diluted with precisely controlled N ₂ gas, is diluted with N ₂ gas flow rate is precisely controlled A gas introduction system 813 for introducing H ₂ gas, a lamp 823, and a shower head 825 are included.

The other structure is basically the same as that of the third embodiment. That is, the valves 816, 818,
819 are valves 716, 718, and 719 of FIG. 7, respectively.
7, the turbo molecular pump 817 corresponds to the turbo molecular pump 717 of FIG. 7, the dry pump 820 corresponds to the dry pump 720 of FIG. 7, and the pipes 821 and 826 correspond to the pipes 721 and 723 of FIG. 7, respectively. ing.

In this embodiment, the same effect as that of the third embodiment can be obtained. Further, in the present embodiment, the semiconductor substrate 8
Since the holding table 814 holding the 22 is rotatable, it is possible to improve the uniformity of the gas flow and the heating of the lamp 823.

Specifically, the temperature distribution on the surface of the substrate 822 to be processed is highly uniform within 800 ° C. ± 2 ° C. (6σ), and the distribution of the oxide film thickness on the Si surface is 7 nm ± 0. The uniformity is as high as 0.1 nm (6σ). (Fifth Embodiment) When the cold wall type heating device described above is used as a multi-chamber with another process device, manufacturing efficiency can be improved and reliability can be improved by a vacuum continuous process.

The other process equipment is, specifically, a reactive ion etching equipment for etching a laminated film or the like to be a gate electrode or a gate wiring of a polymetal structure, and a resist for peeling the resist used in the etching. It is a resist stripping device such as an oxygen plasma ashing device, and a device for performing alkaline etching or treatment using HF vapor, followed by washing and drying.

A multi-chamber type apparatus is constructed by arranging these process apparatuses so that they can be continuously processed with any of the above cold wall type heating apparatuses.

By adopting such a multi-chamber, the construction period was shortened by 30% or more, the LSI manufacturing efficiency was improved, the space occupied by the clean room was reduced to about half, and COO (cost of ownership) could be reduced. .

The present invention is not limited to the above embodiment. For example, in the above embodiment, N ₂ gas was used as the carrier gas and the diluting gas.
Other inert gas such as gas may be used.

Further, in the above embodiment, the selective oxidation of Si of the polymetal gate has been described, but the present invention can be applied to other selective oxidation.

Besides, various modifications can be made within the technical scope of the present invention.

[0090]

As described above in detail, the present invention (Claim 1)
According to the method, the substrate temperature is set to a temperature of 600 ° C. or higher, which is higher than the oxidation limit, and the partial pressure of H ₂ gas is set to a low pressure (low concentration), which is lower than the explosion limit. It becomes possible to perform selective oxidation.

According to the present invention (claim 2), H ₂
Since the partial pressure of the gas can be set to a low pressure (low concentration) below the explosion limit, H ₂ gas can be treated in the same way as an inert gas, which does not complicate the apparatus configuration and raise the cost. Moreover, it becomes possible to realize a semiconductor manufacturing apparatus capable of safely performing selective oxidation of silicon.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the partial pressure ratio P _H2O / P _H2 and the oxide film thickness.

FIG. 3 is a characteristic diagram showing the relationship between oxidation time and oxide film thickness.

FIG. 4 is a characteristic diagram showing a relationship between an oxidation temperature and an oxide film thickness.

FIG. 5 is a micrograph showing a crystal structure.

FIG. 6 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

FIG. 7 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus according to a third embodiment of the present invention.

FIG. 8 is a schematic diagram showing a schematic configuration of a semiconductor manufacturing apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view for explaining post-oxidation of a gate portion.

[Explanation of symbols]

 101-103 ... Valves 104-106 ... Flow controller 107-110 ... Valves 111, 112 ... Introduction pipe 113 ... Moisture meter 114 ... Valve 115 ... Processing container 116 ... Heater 117 ... Pressure gauge 118 ... Valve 119 ... Diluting gas introduction line 120 ... Valve 121 ... Vacuum reference line 122 ... Vacuum pump 123 ... Bubbler 124 ... Flow rate controller 125 ... Exhaust line 600 ... Reaction vessel 601 ... Vacuum pump 602 ... Exhaust line 603 ... Dilution line 605 ... Conductance valve 606 ... Processing vessel 607 ... Support tool 608 ... Substrate to be processed 610 ... Valve 612-614 ... Valve 615-617 ... Flow controller (MFC) 618-620 ... Valve 624 ... Pressure gauge 625 ... Hydrogen supply line 711 ... Processing container 712, 713 ... Gas introduction system 714 ... substrate holding 715 ... Heating plate 716 ... Valve 717 ... Turbo molecular pump 718, 719 ... Valve 720 ... Dry pump 721 ... Piping 722 ... Processing substrate 723 ... Piping 812, 813 ... Gas introduction system 814 ... Substrate support 816 ... Valve 817 ... Turbo Molecular pump 818, 819 ... Valve 820 ... Dry pump 821 ... Piping 822 ... Substrate to be treated 823 ... Lamp 824 ... Gas introducing section 825 ... Shower head 826 ... Piping

Front page continuation (72) Inventor Kiyotaka Miyano 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Corporation Research & Development Center

Claims (2)

[Claims] 1. A substrate to be processed having an exposed portion of silicon is housed in a processing container, and H ₂ gas and H ₂ are stored in the processing container.
A non-oxidizing gas different from O gas and H ₂ gas is introduced, and the partial pressure of the H ₂ gas in the processing container is set to 4
%, And the temperature of the substrate to be treated is 600 ° C.
A method for manufacturing a semiconductor device, which is set as described above and selectively oxidizes the exposed portion of the silicon. 2. A processing container for accommodating a substrate to be processed and performing an oxidation treatment, and a gas for introducing a non-oxidizing gas different from H ₂ gas, H ₂ O gas and H ₂ gas into the processing container. It comprises: introducing means, partial pressure control means for setting the partial pressure of the H ₂ gas in the processing container to less than 4%, and heating means for heating the substrate to be processed at a temperature of 600 ° C. or higher. A semiconductor manufacturing apparatus characterized by the above.