JPH07301592A - Method for manufacturing semiconductor device and method for measuring hydrogen concentration in gas - Google Patents

Abstract

(57) [Summary] [Purpose] Regarding the method of monitoring the heat treatment atmosphere, the purpose is to monitor the hydrogen concentration in the high-temperature gas without contamination. A method of manufacturing a semiconductor device having a heat treatment step includes a monitor step of heat-treating a silicon crystal by the heat treatment step to obtain a monitor crystal 1, and a step of measuring a hydrogen concentration in the monitor crystal 1. Then, the hydrogen partial pressure in the atmosphere of the heat treatment step is monitored based on the hydrogen concentration in the monitor crystal 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device having a step of performing heat treatment by monitoring the hydrogen concentration in an atmosphere and a method for measuring hydrogen concentration in a gas.

Hydrogen has a high permeability into a substance and diffuses into a wiring or a semiconductor even at a low temperature. Therefore, in the process of handling the thin film, for example, the manufacturing process of the semiconductor device, the residual hydrogen in the atmosphere has a great influence on the characteristics of the thin film.

For example, the presence of hydrogen causes holes inside the wiring due to hydrogen precipitation, acceleration of oxygen precipitation in silicon, electrical inactivation of dopants, electrical activation of neutral impurities, and crystal defects due to hydrogen. As a result, it is known that the device characteristics are destabilized or deteriorated. These problems are remarkable especially in the heat treatment process in the manufacture of semiconductor devices.

Therefore, it is necessary to monitor the hydrogen concentration in the atmosphere during the manufacturing process, and a simple method for measuring the hydrogen concentration in the gas is required for that purpose. In particular, the hydrogen concentration in the heat treatment atmosphere is measured and monitored. There is a need for a method of manufacturing a semiconductor device.

[0005]

2. Description of the Related Art Conventionally, as a method for detecting hydrogen in a gas, a gas heat conduction type, a catalytic combustion type or a hot wire type semiconductor type detector has been used.

However, each of these detectors has 10
It cannot be used at high temperatures above 0 ° C. Therefore, these detectors cannot be installed in the heat treatment furnace to directly measure the high temperature heat treatment atmosphere. Further, since these detectors require a metal heater, a combustion gas, or an adsorption gas, they may contaminate the heat treatment furnace if they are installed in the heat treatment atmosphere.

Therefore, the conventional detector draws the heat treatment atmosphere gas outside the heat treatment furnace or at a low temperature portion to measure the hydrogen concentration. Therefore, at the actual heat treatment temperature, the hydrogen partial pressure in the vicinity of the object to be heat treated cannot be directly measured,
The heat treatment process could not be precisely monitored.

[0008]

As described above, the conventional hydrogen detector has a drawback that the hydrogen concentration in the high temperature heat treatment furnace cannot be directly measured because the operating temperature is low. Moreover, there is a possibility that the hydrogen concentration near the object to be heat-treated cannot be measured because the inside of the heat-treatment furnace may be contaminated. For this reason, it has been difficult to monitor the hydrogen concentration in the heat treatment atmosphere in the semiconductor device manufacturing process.

According to the present invention, a silicon crystal is placed in a heat treatment furnace as a monitor, and the concentration of hydrogen diffused in the monitored silicon crystal is measured to know the hydrogen concentration in the heat treatment atmosphere. Method of measuring hydrogen concentration in gas without contamination and capable of measuring hydrogen concentration in high temperature atmosphere, and semiconductor capable of precisely monitoring hydrogen concentration in heat treatment atmosphere in the vicinity of an object to be processed using this method An object is to provide a method for manufacturing a device.

[0010]

FIG. 1 is a process chart of an embodiment of the present invention, showing a process of measuring and monitoring the hydrogen concentration in a heat treatment atmosphere in a semiconductor device manufacturing process.

With reference to FIG. 1, the first structure of the present invention for solving the above-mentioned problems is to perform a monitor step of heat-treating a silicon crystal in a gas to obtain a monitor crystal 1, and then to a monitor crystal 1 in the monitor crystal 1. And a step of measuring a hydrogen concentration, wherein the hydrogen partial pressure in the gas is monitored based on the hydrogen concentration in the monitor crystal 1, and the second configuration comprises
A method of manufacturing a semiconductor device having a heat treatment step, which comprises a monitor step of heat-treating a silicon crystal by the heat treatment step to obtain a monitor crystal 1, and a step of measuring a hydrogen concentration in the monitor crystal 1. The hydrogen partial pressure in the atmosphere of the heat treatment step is monitored based on the hydrogen concentration in the monitor crystal 1, and the third configuration is the semiconductor device of the first or second configuration. In the manufacturing method, in the step of measuring the hydrogen concentration in the monitor crystal 1, the monitor crystal 1 and a plurality of hydrogen-doped silicon crystals 2 having different known hydrogen concentrations are heat-treated under the same condition to generate a thermal donor. A heat treatment step for forming a donor, and a step for measuring the thermal donor concentration,
Then, the step of interpolating or extrapolating the thermal donor concentration in the monitor crystal 1 to obtain the hydrogen concentration in the monitor crystal 1 in the relationship between the hydrogen concentration in the hydrogen-doped silicon crystal 2 and the thermal donor concentration. And a fourth structure is the method for manufacturing a semiconductor device having the third structure, wherein the hydrogen-doped silicon crystal 2 is obtained by heat treating the silicon crystal in a hydrogen-containing atmosphere 4. When the pressure of the hydrogen-containing atmosphere 4 is P _dT , the hydrogen partial pressure in the hydrogen-containing atmosphere 4 is P _d , the heat treatment temperature in the hydrogen-containing atmosphere 4 is T _d , and the Boltzmann constant is k, the constant C ⁰ = 4.9
Using 6 × 10 ²¹ cm ⁻³ and the constant ε = 1.86 eV, C _d = C ⁰ · exp (−ε / kT _d ) · (P _d / P _dT ).
Characterized by being manufactured by a process including a process of forming the hydrogen-doped silicon crystal having a hydrogen concentration of ^1/2 , and a fifth structure is a semiconductor device of the third or fourth structure. In the manufacturing method, the donor heat treatment step includes 41
And a heat treatment temperature of 0 to 450 ° C. for a period of 10 to 60 minutes. In the step of obtaining the hydrogen partial pressure of C, the hydrogen concentration in the monitor crystal 1 is C, the heat treatment temperature in the monitor step is T _a , the gas pressure is P _T , and the Boltzmann constant is k, the constant C ⁰ = 4.96 × 10 ²¹ cm ^-3 and constant ε =
It is characterized by including a step of calculating a hydrogen partial pressure P _a in the gas _as P _a = P _T · (C / C ⁰ ) ² · exp (2ε / kT _a ), using 1.86 eV. And, in the seventh configuration, in the method for measuring hydrogen concentration in a gas, a monitor step of heat-treating a silicon crystal in a gas to obtain a monitor crystal 1, and then measuring a hydrogen concentration in the monitor crystal 1. and a step, when the hydrogen concentration of the monitor in the crystal to C, and the heat treatment temperature of the monitoring step T _a, the pressure of the gas P _T, the Boltzmann constant and k, the constant C ⁰ =
4.96 × 10 ²¹ cm ^-3, and with a constant epsilon = 1.86 eV, the hydrogen partial pressure P _a in the _{gas, P a = P T · (} C / C 0) 2 · exp (2ε / The feature is that it is calculated as kT _a ).

[0012]

In the first configuration of the present invention, referring to the monitoring step of FIG. 1, there is a monitoring step of heat-treating the silicon crystal in the gas 3 whose hydrogen concentration is to be measured. The heat treatment in this monitoring step is performed until the hydrogen concentration in the silicon crystal reaches thermal equilibrium with the hydrogen partial pressure in the gas, for example, 700 ° C.
It is processed at 1200 ° C. for 30 minutes. As a result, the silicon crystal is converted into the monitor crystal 1 having a hydrogen partial pressure of the measured gas 3 and a hydrogen concentration in thermal equilibrium.

Next, the hydrogen concentration of the monitor crystal is measured.
It should be noted that the measurement of the hydrogen concentration in the present specification means that, in addition to the measurement of the absolute value of the hydrogen concentration, relative comparison with the reference hydrogen concentration is performed by some means. The hydrogen concentration in the monitor crystal can be measured by a usual hydrogen concentration measuring method in silicon, for example, an infrared absorption method or a secondary electron mass spectrometry method. Furthermore, convenient concrete means will be described later.

As a result of the measurement of the hydrogen concentration, the absolute value of the hydrogen concentration in the monitor crystal is measured or compared with the reference hydrogen concentration. The hydrogen concentration in the monitor crystal is in thermal equilibrium with the hydrogen partial pressure in the gas during the monitoring process. Therefore, by measuring the hydrogen concentration in the monitor crystal, the hydrogen partial pressure in the gas that is in thermal equilibrium in the monitoring process can be known. Therefore, with the hydrogen concentration measuring method of this configuration, the hydrogen partial pressure in the gas used in the manufacturing process of the semiconductor device can be monitored.

The second configuration of the present invention relates to a method of monitoring the hydrogen partial pressure in the atmosphere of the heat treatment performed in the semiconductor device manufacturing process with reference to the monitoring process of FIG. In this configuration, a silicon crystal is put together with an object to be heat-treated, for example, a wafer in a heat treatment atmosphere performed in the manufacturing process to perform heat treatment, and this heat treatment is used as a monitor process to produce a monitor crystal.

According to this structure, the hydrogen partial pressure in the atmosphere of the heat treatment performed in the semiconductor device manufacturing process is monitored by measuring the hydrogen concentration of the monitor crystal as in the first structure.
In the above-described first and second configurations of the present invention, the hydrogen partial pressure in the atmosphere at the temperature when the monitor crystal is heat-treated is measured. Therefore, according to the first and second configurations, the hydrogen partial pressure at a high heat treatment temperature can be directly measured.

Further, since the monitor crystal is a silicon crystal, it can be made extremely high in purity. Therefore, even if the monitor crystal is put in a heat treatment furnace together with an object to be treated, for example, a silicon wafer, and heat-treated, the object to be treated or the heat treatment furnace is not contaminated.

In the sixth configuration, from the hydrogen concentration C in the monitor crystal 1, the hydrogen partial pressure P _a in the gas, which is the heat treatment atmosphere in the monitoring step in FIG.

[0019]

## EQU1 ## Calculation is performed by P _a = P _T · (C / C ⁰ ) ² · exp (2ε / kT _a ). Here, C is the hydrogen concentration in the monitor crystal 1, T _a is the heat treatment temperature in the monitoring step, P _T is the gas pressure, k is the Boltzmann constant, and C ⁰ is the constant 4.96 × 10 4.
²¹ cm ^-3 and ε are constant 1.86 eV.

This equation 1 is derived as follows. The hydrogen concentration C in the monitor crystal 1 is determined by the heat treatment temperature T in the monitor process.
_{It is} in thermal equilibrium at a. In this equilibrium state, when the hydrogen partial pressure of the atmosphere is 1 atm, the hydrogen concentration C in the monitor crystal 1 is

[0021]

[Equation 2] C = C ⁰ · exp (−ε / kT _a ), is given by Hydrogen in Semiconductors: Se
It is disclosed in miconductors and Semimetals vol.34. On the other hand, by Fukai Yuru
To

[0022]

## EQU3 ## It is disclosed that C∝ (P _a / P _T ) ^1/2 . From Equations 2 and 3, the hydrogen concentration C in the monitor crystal that is in thermal equilibrium with the atmosphere gas is

[0023]

## EQU4 ## C = C ⁰ · exp (−ε / kT _a ) · (P _a /
P _T ) ^1/2 , from which the equation 1 is derived. According to this configuration,
By using a monitor crystal, the absolute value of the hydrogen partial pressure in the gas at high temperature can be measured. In addition, by measuring the hydrogen concentration in the monitor crystal in the same manner as the third to fifth configurations, it is possible to simply perform the heat treatment and the electrical characteristic measurement without using a device for directly measuring the hydrogen concentration in the monitor crystal. The hydrogen concentration in the gas can be measured by various methods.

Next, a method for measuring the hydrogen concentration in the monitor crystal will be described. In the third configuration, referring to the donor generation heat treatment step of FIG. 1, a plurality of hydrogen-doped silicon crystals 2 having a known hydrogen concentration are subjected to donor heat treatment to generate thermal donors. With reference to the step of obtaining the hydrogen concentration, the relationship between the hydrogen concentration in the hydrogen-doped silicon crystal 2 and the thermal donor concentration generated in the hydrogen-doped silicon crystal 2 is obtained as shown by the solid line in FIG. 1, for example. That is, this configuration utilizes the fact that the thermal donor concentration depends on the hydrogen concentration, and the dependency was clarified by the inventor of the present invention.

On the other hand, the monitor crystal 1 is heat-treated to generate donors under the same conditions. As a result, the thermal donor concentration (indicated by a in FIG. 1) generated in the monitor crystal 1 is interpolated into the relationship between the hydrogen concentration in the hydrogen-doped silicon crystal 2 and the thermal donor concentration with reference to FIG. Alternatively, extrapolate to obtain the corresponding hydrogen concentration C.

In the configuration of the present invention, the monitor crystal 1 and the hydrogen-doped silicon crystal 2 are manufactured as silicon crystals having substantially the same properties in relation to the generation of thermal donors. Such a silicon crystal can be manufactured, for example, by cutting the same ingot from positions close to each other. Further, a high temperature solution heat treatment may be performed to erase the thermal history of the silicon crystal. The relationship between the hydrogen concentration and the thermal donor concentration in the monitor crystal 1 and the hydrogen-doped silicon crystal 2 manufactured as described above is the same when the thermal donor generation conditions are the same. Therefore, the results of the monitor crystal can be applied to the relationship of the hydrogen-doped silicon crystal.

In this structure, it is not necessary to directly measure the hydrogen concentration in the monitor crystal by preparing a hydrogen-doped silicon crystal having a known hydrogen concentration. Therefore, a device for measuring the hydrogen concentration in the silicon crystal is not required.

In the fourth structure of the present invention, referring to the hydrogen-doped silicon crystal manufacturing process of FIG. 1, the silicon crystal is heat-treated in the hydrogen-containing atmosphere 4 having a known hydrogen partial pressure to obtain the hydrogen-doped silicon crystal 2. And The hydrogen-doped silicon crystal 2 has a hydrogen concentration in thermal equilibrium with the hydrogen-containing atmosphere 4. The hydrogen concentration C _d of this hydrogen-doped silicon crystal 2 is
When the heat treatment temperature in the hydrogen-containing atmosphere 4 is T _d and the Boltzmann constant is k in thermal equilibrium with the hydrogen partial pressure P _{d in} the hydrogen-containing atmosphere 4 having a pressure of P _dT , , Constant C ⁰ = 4.96 × 10 ²¹ cm ⁻³ , and constant ε =
Using 1.86 eV, C _d = C ⁰ · exp (−ε / kT _d ) · (P _d / P _dT ).
^It is expressed as ^1/2 .

According to this structure, by changing either one or both of the heat treatment temperature and the hydrogen partial pressure of the hydrogen-containing atmosphere, hydrogen-doped silicon crystals having different and known hydrogen concentrations can be easily manufactured. You can Therefore,
No device for measuring hydrogen concentration is required to produce a hydrogen-doped silicon crystal of known concentration.

The fifth constitution relates to a thermal donor generation heat treatment condition suitable for sensitively measuring the hydrogen concentration according to the present invention. The inventor of the present invention has clarified experimentally the relation between the hydrogen concentration dependence of the thermal donor concentration in the silicon crystal and the heat treatment conditions for donor generation. The experimental results are shown in FIGS. Hereinafter, this experiment and its result will be described.

A wafer having a thickness of 1 mm and a silicon plate having a thickness of 10 mm were cut out from adjacent positions of the same ingot.
This wafer was subjected to a dehydrogenation heat treatment at 750 ° C. for 5 minutes in a nitrogen atmosphere to diffuse and remove hydrogen from the wafer surface to obtain a dehydrogenated silicon crystal having a low hydrogen concentration. on the other hand,
The silicon plate was heat-treated at 1200 ° C. for 30 minutes in a hydrogen-containing atmosphere having a hydrogen partial pressure of 22 Torr to obtain a hydrogen-doped silicon crystal.

Next, the hydrogen-doped silicon crystal and the dehydrogenated silicon crystal were subjected to donor formation heat treatment at 425 ° C. and 500 ° C. to generate a thermal donor. FIG. 3 is a diagram showing the dependence of the thermal donor concentration on the time of donor generation heat treatment. The time of the donor generation heat treatment and the thermal donor generated by the hydrogen-doped silicon crystal and the dehydrogenated silicon crystal having a low hydrogen concentration. It is the experimental result that clarified the relationship with the concentration of.

In FIG. 3, a and b are heat treatments at 425 ° C.,
C and D represent the thermal donor concentration generated corresponding to the heat treatment at 500 ° C., B and C represent hydrogen-doped silicon crystals, and B and D represent dehydrogenated silicon crystals.

Referring to (a) and (b) in FIG. 3, when the heat treatment temperature for donor generation is 425 ° C., the thermal donor concentration b of the dehydrogenated silicon crystal is equal to that of the hydrogen-doped silicon crystal at the beginning of the heat treatment time. Rises slower than Furthermore, a constant thermal donor concentration difference occurred even after long-term heat treatment.

On the other hand, referring to C and D, when the heat treatment temperature for donor generation is 500 ° C., the thermal donor concentrations of both the dehydrogenated silicon crystal and the hydrogen-doped silicon crystal rise rapidly, and the difference is small. .

FIG. 4 is a diagram showing the dependence of the thermal donor concentration ratio on the time of heat treatment for donor generation. The thermal donor concentration generated in the hydrogen-doped silicon crystal after a certain processing time was changed to that in the dehydrogenated silicon crystal at that time. The heat treatment time dependence of the thermal donor concentration ratio expressed based on the generated thermal donor concentration is shown. In addition, in FIG.
(A) and (b) correspond to the donor formation heat treatment at 425 ° C. and 500 ° C., respectively.

FIG. 4 shows that the shorter the heat treatment time for generating the donor,
In particular, it is clarified that the thermal donor concentration ratio increases within 60 minutes, that is, the thermal donor concentration is sensitively affected by the hydrogen concentration. On the other hand, from FIG. 3, when the heat treatment time for generating the donor is short, for example, for 10 minutes or less, the thermal donor concentration is low, and precise measurement of the thermal donor concentration becomes difficult. The increase in the thermal donor concentration ratio that occurs when the processing time is short is 425 at low temperature.
It is remarkable at ℃, and it is small at high temperature of 500 ℃. Therefore,
To measure hydrogen concentration precisely and sensitively, 10
It is preferable to perform the donor formation heat treatment for about 60 minutes.
Note that this time may vary depending on the properties of the silicon crystal, the temperature of the heat treatment for donor generation, the oxygen concentration, and the like.

FIG. 5 is a diagram showing the temperature dependence of the thermal donor concentration on the donor formation heat treatment, and shows the thermal donor concentration generated by the donor formation heat treatment for 1 hour.
In addition, FIG. 6 is a diagram showing the temperature dependence of the thermal donor concentration ratio on the donor formation heat treatment. The hydrogen-doped silicon is represented based on the thermal donor concentration in the dehydrogenated silicon crystal after the donor formation heat treatment for 1 hour. The thermal donor concentration in the crystal is defined as the thermal donor concentration ratio.
The dehydrogenated silicon crystal and hydrogen-doped silicon are the same as those used in the experiments of FIGS. 3 and 4. In addition, the donor generation heat treatment was performed at different treatment temperatures for a treatment time of 1 hour.

For the thermal donor concentration, refer to FIG.
When the heat treatment temperature for donor generation is between 410 ° C and 450 ° C, it increases as the temperature rises, and when it exceeds 450 ° C, it becomes constant or decreases. On the other hand, for the thermal donor concentration ratio, refer to FIG.
The lower the temperature for donor heat treatment, the more it increases at 450 ° C or lower. Therefore, the heat treatment temperature for donor generation is preferably 450 ° C. or lower for sensitive measurement of hydrogen concentration. On the other hand, in order to generate a thermal donor having a concentration that does not deteriorate the measurement accuracy of the donor, the temperature is preferably 410 ° C. or higher.

[0040]

The present invention will be described in detail with reference to an embodiment in which the present invention is applied to a heat treatment process in a semiconductor device manufacturing process.

FIG. 1 is a process chart of an embodiment of the present invention, showing a process of monitoring the hydrogen concentration in the atmosphere during the heat treatment process of a wafer in the process of manufacturing a semiconductor device. First, a silicon crystal small piece having a thickness of 10 mm, a width of 12 mm and a length of 20 mm was cut out from substantially the same position of a silicon crystal ingot grown by the Czochralski method.

Next, referring to the monitoring process of FIG.
One of the silicon crystal small pieces to be the monitor crystal 1 was placed on the boat 6 together with the silicon substrate 5 to be the substrate of the semiconductor device, inserted into the heat treatment furnace 3, and heat-treated. This heat treatment corresponds to the monitor process. Into the heat treatment furnace 3, nitrogen gas of 1 atm passing through the nitrogen purifier was introduced from the gas introduction port 7, contacted with the silicon substrate 5, and then discharged from the exhaust port 8.

The heat treatment in this monitor process is performed at a temperature of 1000
After 2 hours at 0 ° C., the silicon crystal pieces were converted into monitor crystals. The monitor crystal was rapidly cooled from 1000 ° C. to 20 ° C. in 10 minutes after the heat treatment in the monitor process was completed. This quenching is done to prevent out-diffusion of hydrogen in the monitor crystal. In this embodiment, the effect of outward diffusion could be ignored at a depth of approximately 1 mm or more from the surface of the monitor crystal.

On the other hand, the remaining silicon crystal pieces are shown in FIG.
The hydrogen-doped silicon crystal 2 was manufactured by referring to the hydrogen-doped silicon crystal manufacturing process of 1), mounting it on a boat 6, inserting it in a hydrogen-containing atmosphere 4 at 1 atm, and performing heat treatment. In the hydrogen atmosphere 4, hydrogen gas was added to a gas having nitrogen gas as a carrier to give a hydrogen partial pressure of 20 Torr. The heat treatment temperature for producing the hydrogen-doped silicon crystal 2 is 800 ° C. to 120 ° C. for each of 10 silicon crystal pieces.
Performed at different temperatures of about 50 ℃ up to 0 ℃, and as a result 10
Hydrogen-doped silicon crystals having different hydrogen concentrations 2
Was manufactured.

Next, referring to the donor generation heat treatment step of FIG. 1, the monitor crystal 1 and the 10 hydrogen-doped silicon crystals 2 are placed on the boat 6 and the temperature is set to 450 in a nitrogen atmosphere.
The donor was heat-treated at 30 ° C. for 30 minutes to generate a thermal donor in these crystals. For these thermal donor concentrations, referring to the thermal donor concentration measuring step of FIG. 1, the monitor crystal 1 and the hydrogen-doped silicon crystal 2 are divided into two, and four probes are brought into contact with the polished divided surface. It was obtained from the specific resistance measured using a four-point probe resistance measuring device for measuring the specific resistance.

Next, the thermal donor concentration of the monitor crystal was compared with the thermal donor concentration of the hydrogen-doped silicon crystal 2 as follows. FIG. 2 is a diagram showing the hydrogen concentration dependence of the thermal donor concentration, and shows the relationship between the hydrogen concentration in the hydrogen-doped silicon crystal 2 and the thermal donor concentration generated in the hydrogen-containing silicon crystal 2 as a result of the donor generation heat treatment.

From FIG. 2, the hydrogen concentration and the thermal donor concentration have a relationship in which their logarithms are linear. Figure 2
Has extrapolated the straight line to the low hydrogen concentration region. On the other hand, the thermal donor concentration D _T in the monitor crystal is 2.1
It was × 10 ¹³ cm ^-3 . The thermal donor concentration D _T in this monitor crystal was applied to the straight line in FIG. 2 to obtain the hydrogen concentration C = 3.05 × 10 ¹¹ atoms cm ⁻³ in the corresponding monitor crystal.

Next, referring to the hydrogen partial pressure calculation step in FIG. 1, the hydrogen concentration C in this monitor crystal is C = 3.05.
× 10 ¹¹ atoms cm ⁻³ , heat treatment temperature of monitor process, that is, heat treatment temperature of heat treatment process in semiconductor manufacturing process, T _a = 100
By substituting 0 ° C. and its heat treatment atmosphere pressure P _T = 1 atm into Equation 1, P _a ≈2 × 10 ⁻⁶ atm was obtained. Therefore, the hydrogen concentration in the heat treatment process atmosphere in this semiconductor manufacturing process is
It was confirmed that the concentration was 2 ppm near the silicon substrate that was the object to be processed.

[0049]

According to the present invention, since the hydrogen concentration in the heat treatment atmosphere can be monitored by using the silicon crystal as a monitor, the heat treatment furnace is not contaminated, and the heat treatment object can be used in the high temperature atmosphere and in the high temperature atmosphere. It is possible to provide a method for manufacturing a semiconductor device capable of monitoring the hydrogen concentration in the vicinity, and to measure the hydrogen concentration in a gas in a high temperature atmosphere and near the object to be heat treated without contaminating the heat treatment furnace. Since the measurement method can be provided, it greatly contributes to the performance improvement of the semiconductor device.

[Brief description of drawings]

FIG. 1 is a process chart of an embodiment of the present invention.

FIG. 2 is a diagram showing the hydrogen concentration dependence of the thermal donor concentration.

FIG. 3 is a diagram showing the dependency of thermal donor concentration on the heat treatment for donor generation.

FIG. 4 is a diagram showing the dependency of the thermal donor concentration ratio on the heat treatment time for donor generation.

FIG. 5 is a diagram showing temperature dependence of thermal donor concentration for donor generation heat treatment.

FIG. 6 is a diagram showing a temperature dependence of a donor thermal treatment on a thermal donor concentration ratio.

[Explanation of symbols]

 1 monitor crystal 2 hydrogen-doped silicon crystal 3 heat treatment furnace 4 hydrogen-containing atmosphere 5 silicon substrate 6 boat 7 gas inlet port 8 exhaust port 9 four-point probe resistance measuring instrument 9a probe

Claims (7)

[Claims] 1. A monitor step of heat-treating a silicon crystal in a gas to form a monitor crystal (1), and a step of measuring a hydrogen concentration in the monitor crystal (1). 1) A method for measuring hydrogen concentration in a gas, which comprises monitoring the hydrogen partial pressure in the gas based on the hydrogen concentration in the gas. 2. A method of manufacturing a semiconductor device having a heat treatment step, wherein a monitor step of heat-treating a silicon crystal in the heat treatment step to obtain a monitor crystal (1), and then a hydrogen concentration in the monitor crystal (1) are set. A method for manufacturing a semiconductor device, comprising: measuring the hydrogen partial pressure in the atmosphere of the heat treatment step based on the hydrogen concentration in the monitor crystal (1). 3. The method of manufacturing a semiconductor device according to claim 1 or 2, wherein the step of measuring the hydrogen concentration in the monitor crystal (1) includes the steps of measuring the hydrogen concentration in the monitor crystal (1) and known hydrogen concentrations different from each other. A plurality of hydrogen-doped silicon crystals (2) having a heat treatment under the same conditions to generate a thermal donor, a donor generation heat treatment step, a step of measuring the thermal donor concentration, and then a hydrogen-doped silicon crystal ( 2) interpolating or extrapolating the thermal donor concentration in the monitor crystal (1) to determine the hydrogen concentration in the monitor crystal (1) in relation to the hydrogen concentration in the monitor crystal (1). A method of manufacturing a semiconductor device, comprising: 4. The method of manufacturing a semiconductor device according to claim 3, wherein the hydrogen-doped silicon crystal (2) is heat-treated in a hydrogen-containing atmosphere (4) to obtain a hydrogen-doped silicon crystal (2). Pressure is P _dT , the hydrogen-containing atmosphere (4)
When the hydrogen partial pressure in the medium is P _d , the heat treatment temperature in the hydrogen-containing atmosphere (4) is T _d , and the Boltzmann constant is k, the constant C ⁰ = 4.96 × 10 ²¹ cm ⁻³ , and the constant ε. = 1.86 eV
By using C _d = C ⁰ · exp (−ε / kT _d ) · (P _d / P _dT ).
^A method of manufacturing a semiconductor device, which is manufactured by a step including a step of forming the hydrogen-doped silicon crystal having a hydrogen concentration of ^1/2 . 5. The method of manufacturing a semiconductor device according to claim 3 or 4, wherein the donor heat treatment step includes steps 410 to 410.
A method of manufacturing a semiconductor device, comprising a step of performing heat treatment for 10 to 60 minutes at a heat treatment temperature of 450 ° C. 6. A method of manufacturing a semiconductor device according to claim 3.
In the step of obtaining the hydrogen partial pressure in the gas,
The hydrogen concentration in the crystal (1) is C, and the heat treatment temperature of the monitoring step is
Degree T_a, The pressure of the gas is P_T, The Boltzmann constant is k
The constant C⁰= 4.96 × 10 ^{twenty one}cm^-3, And constant
Using ε = 1.86 eV, the hydrogen partial pressure P in the gas_aTo_, P_a= P_T・ (C / C⁰)²・ Exp (2ε / kT_a) The semiconductor device including the step of calculating
Manufacturing method. 7. A method for measuring hydrogen concentration in a gas according to claim 1.
In the method, the hydrogen concentration in the monitor crystal (1) is
The heat treatment temperature of the monitor process is T_a, The pressure of the gas is P_T，
When the Boltzmann constant is k, the constant C⁰= 4.96 ×
10 ^{twenty one}cm^-3, And the constant ε = 1.86 eV, the gas
Hydrogen partial pressure P in_aTo_, P_a= P_T・ (C / C⁰)²・ Exp (2ε / kT_a) Is calculated as
Method.