JP4112654B2 - Method for manufacturing silicon wafer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides an excellent silicon single crystal in which an insulating oxide film manufactured by the Czochralski method (hereinafter referred to as CZ method) has excellent withstand voltage characteristics (hereinafter referred to as oxide film breakdown voltage) and oxygen precipitation is suppressed, and its manufacture Regarding the method.
[0002]
[Prior art]
CZ silicon single crystals have been widely used as LSI materials because of their excellent characteristics such as high crystal strength. However, it is known that the oxide breakdown voltage of a silicon single crystal varies greatly depending on the fundamental difference in the manufacturing method. The oxide breakdown voltage of a CZ silicon single crystal is different from that of a silicon single crystal or CZ silicon manufactured by the floating zone method. This is significantly lower than that of a wafer obtained by epitaxially growing a silicon thin film on a wafer. However, with the recent increase in MOS device integration, it is strongly desired to improve the reliability of the gate oxide film, and the oxide breakdown voltage is one of the important material characteristics that determine its reliability. Development of manufacturing technology for CZ silicon single crystals with excellent withstand voltage characteristics was emphasized.
[0003]
On the other hand, a silicon single crystal produced by the CZ method contains supersaturated oxygen. These supersaturated oxygen atoms are precipitated during the heat treatment in the LSI manufacturing process, generating oxygen precipitates. When this precipitate is generated in the element forming region, it causes element characteristic deterioration such as junction leakage, and plays a harmful role for the element. Therefore, it is important to suppress oxygen precipitation in order to manufacture LSIs with high yield.
[0004]
As a method for producing a CZ silicon single crystal having an excellent oxide film withstand voltage, a method for producing a silicon single crystal having a diameter of 100 mm or more by the CZ method of Japanese Patent Application Laid-Open No. 2-267195 has a crystal growth rate of 0.8 mm / min or less. Disclosed is a method characterized by: However, this method is not practical due to poor productivity.
[0005]
In Japanese Patent Publication No. 3-67994, the silicon single crystal being pulled is pulled slowly from 1100 ° C to 900 ° C over 3 hours to reduce oxygen precipitate nuclei in the semiconductor device process. And a method for suppressing the occurrence of defects is shown. However, this method can suppress oxygen precipitation, but rather deteriorates the oxide film breakdown voltage.
[0006]
Japanese Patent Application Laid-Open No. 7-223893 discloses a method of forming a temperature region in which a crystal cooling rate is 1.0 ° C./min or less in a crystal temperature region of 1200 ° C. to 1000 ° C. when a silicon single crystal is manufactured. ing. However, in the case of a silicon single crystal manufactured by this method, there are many oxygen precipitations that are harmful to device characteristics. Further, the publication discloses that when a silicon single crystal is produced, a temperature region in which a cooling rate is 1.0 ° C./min or less is formed in a crystal temperature region of 1200 ° C. to 1000 ° C., and a crystal of 1000 ° C. to 500 ° C. A method of adding cooling at a cooling rate of always 1.0 ° C./min or more in the temperature region is shown. However, in this method, since it is necessary to realize slow cooling and rapid cooling within a narrow temperature range with a boundary of 1000 ° C., a special structure is required in the silicon single crystal pulling furnace, which increases the manufacturing cost. It was.
[0007]
In addition, the initial oxygen concentration and precipitation of silicon single crystals with a superior oxide breakdown voltage manufactured by the method of forming a temperature range where the crystal cooling rate is 1.0 ° C / min or less in the crystal temperature range of 1200 ° C to 1000 ° C. A clear relationship of oxygen concentration was not shown.
[0008]
[Problems to be solved by the invention]
  Excellent silicon single crystal with excellent breakdown voltage and suppressed oxygen precipitation produced by CZ methodCrystalAn object is to provide a manufacturing method.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, in the present invention,,
(1) In silicon single crystals manufactured by the Czochralski method, the cooling rate in the crystal temperature range of 1200 ° C or lower and 1000 ° C or higher is 1.0 ° C / min or lower, the cooling rate in the crystal temperature range of less than 1000 ° C and 800 ° C or higher is There is a region where the temperature is 1.0 ° C / min or less, and rapid cooling is started in the crystal temperature range of less than 800 ° C and 700 ° C or more, and in the temperature range from the rapid cooling start temperature to 600 ° C, the cooling rate is 20 ° C / min or more. A method for producing a silicon wafer, characterized by slicing and polishing a produced silicon single crystal,
(2) (1), In addition, in a temperature range of less than 600 ° C. and 500 ° C. or more, a cooling method having a cooling rate of 10 ° C./min or more,
(Three) (2), In addition, in a temperature range of less than 500 ° C. and 400 ° C. or more, the cooling rate is 8 ° C./min or more, a silicon wafer production method,
(Four) (ThreeIn addition, in a temperature range of less than 400 ° C. and 300 ° C. or more, the method for producing a silicon wafer, wherein the cooling rate is 5 ° C./min or more,
It is.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The withstand voltage characteristic of the insulating oxide film is that the upper layer is made of aluminum and the lower layer is made of polycrystalline silicon doped with 20mm area.²2 layer gate electrode, the electrode area is 20mm²Then, a MOS diode with an insulating oxide film thickness of 25.0 nm is mounted on the entire surface of the silicon wafer cut out from the silicon single crystal, and a DC voltage having a polarity in which majority carriers are injected from the substrate silicon is applied to each MOS diode. It is evaluated by the voltage ramping method. Current density flowing through the oxide film is 1mA / cm²The region where the average electric field applied to the oxide film at this time is 8.0 MV / cm or more is called an intrinsic breakdown region or C-mode region, and indicates that there are no crystal defects in the silicon crystal that degrade the breakdown voltage characteristics. It is. In addition, the average electric field applied to the oxide film is 1.0 MV / cm to 8.0 MV / cm, and the current density flowing through the oxide film is 1 mA / cm.²The electric field region is referred to as a B mode region, and indicates that a defect that degrades the breakdown voltage exists in the silicon crystal. In conventional CZ silicon crystals, the percentage of the total number of MOS diodes that break down in the C mode region is about 10-30% per wafer, and the percentage of the total number of MOS diodes that break down in the B mode region. Is also big. Therefore, a CZ silicon single crystal whose ratio to the total number of MOS diodes that cause dielectric breakdown in the C mode region is 40% or more is a CZ silicon crystal having excellent oxide breakdown voltage characteristics. Furthermore, the percentage of the total number of MOS diodes that break down in the C mode region is 50% or more, and the percentage of the number of MOS diodes that break down in the B mode region is small or the minimum breakdown electric field value is high (for example, 6.0 A CZ silicon single crystal such as a diode that breaks down at MV / cm or less (less than 20%) is a CZ silicon crystal with more excellent oxide breakdown voltage characteristics.
[0011]
Oxygen precipitation is determined by the magnitude of the precipitated oxygen concentration. The precipitated oxygen concentration is expressed as the difference in oxygen concentration before and after heat treatment at 1000 ° C. for 16 hours in a nitrogen gas atmosphere (hereinafter referred to as oxygen precipitation heat treatment) in addition to 800 ° C. for 4 hours in a nitrogen gas atmosphere.
[0012]
The evaluation method of oxygen precipitation of the silicon single crystal produced according to the present invention was performed as follows. Measure the initial oxygen concentration at each point (total 39 points) obtained by dividing the two orthogonal diameters into 20 equal parts of a silicon wafer sample that has been mirror-finished using the Fourier transform infrared absorption method (FT-IR method). did. The wafer was subjected to an oxygen precipitation heat treatment at 1000 ° C. for 16 hours in a nitrogen gas atmosphere in addition to 800 ° C. for 4 hours in a nitrogen gas atmosphere, and then the 39 oxygen concentrations at the same position as the initial oxygen concentration were measured. The difference between the oxygen concentration and the initial oxygen concentration was determined as the precipitated oxygen concentration. The oxygen concentration was calculated based on the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association.
[0013]
The inventors of the present invention set the solid solution oxygen concentration in the silicon single crystal before the oxygen precipitation heat treatment (hereinafter referred to as initial oxygen concentration) to A × 10.^{1 7}atoms / cm^Three(Calculated based on the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association) and the oxygen concentration after the oxygen precipitation heat treatment was B × 10^{1 7}atoms / cm^ThreeAs a result of examining silicon wafers manufactured by the CZ method under various conditions,
B = 48-11.9 × A + 0.74 × A²
We found that the device characteristics changed greatly with the relationship of. And for silicon wafers obtained by conventional manufacturing technology, B> 48-11.9 × A + 0.74 × A²
Thus, the device characteristics represented by PN junction leakage were inferior.
[0014]
In addition, the inventors of the present invention, when manufacturing a silicon single crystal, the oxide film withstand voltage manufactured by a method of forming a temperature range in which the crystal cooling rate in the crystal temperature range of 1200 ° C. to 1000 ° C. is 1.0 ° C./min or less. As a result of examining silicon wafers with excellent characteristics,
B = 26-7.6 × A + 0.55 × A²
We found that the device characteristics changed greatly with the relationship of. In a conventional silicon wafer with excellent oxide breakdown voltage characteristics manufactured by a method of forming a temperature range in which the crystal cooling rate in the crystal temperature range of 1200 ° C. to 1000 ° C. is 1.0 ° C./min or less, B> 26-7.6 × A + 0.55 × A²Thus, the device characteristics represented by PN junction leakage were inferior.
[0015]
Furthermore, as a result of detailed investigation of the cooling conditions during the growth of crystals having various oxide film breakdown voltage characteristics, the present inventors have found the following relationship between the cooling conditions and the formation of minute defects that cause dielectric breakdown. Found that there is. In the process of growing a silicon single crystal by the CZ method, defect generation nuclei that cause deterioration of the oxide film breakdown voltage are introduced from the solidification interface. In the temperature range of 1200 ° C. to 1000 ° C., the defect generation nuclei are decomposed and the density is reduced by decreasing the crystal cooling rate and gradually cooling. In the temperature range of 1000 ° C. to 800 ° C., an Ostwald type growth reaction occurs, and defect generation nuclei of a certain size or more grow as crystal defects, but defect generation nuclei of a certain size or less dissolve and disappear. Regarding the growth of crystal defects, the growth of defects is promoted mainly by the diffusion of point defects such as oxygen, atomic vacancies and silicon interstitial atoms, which are impurity elements contained in the silicon crystal. When the temperature range of 1000 ° C to 800 ° C is gradually cooled without slow cooling of the temperature range of 1200 ° C to 1000 ° C, the size of the defect-generating nuclei is large, so it grows as a crystal defect and degrades the oxide film breakdown voltage. However, when the temperature range of 1200 ° C to 1000 ° C is gradually cooled and then the temperature range of 1000 ° C to 800 ° C is gradually cooled, the defect generating nuclei decompose during the slow cooling of the temperature range of 1200 ° C to 1000 ° C, Defect generation nuclei become smaller in size and further dissolve during slow cooling in the temperature range of 1000 ° C to 800 ° C. Therefore, in order to suppress the growth of defect-generating nuclei that cause deterioration of the oxide film breakdown voltage, the cooling rate at 1200 ° C. to 1000 ° C. is reduced, and the passage time in the temperature region is increased, and further 1000 ° C. to It is effective to reduce the cooling rate of 800 ° C and increase the transit time in that temperature range.
[0016]
On the other hand, by slowly cooling the temperature range of 1200 ° C. to 1000 ° C., the decomposed defect-producing nuclei become extremely minute oxygen precipitation latent nuclei. In the crystal temperature range below 700 ° C, oxygen precipitation latent nuclei grow as oxygen precipitation nuclei. As for the growth of oxygen precipitation nuclei, oxygen in the silicon crystal is mainly responsible for promoting the growth of oxygen precipitation nuclei. Therefore, in order to suppress the growth of oxygen precipitation latent nuclei, it is effective to rapidly cool from a higher temperature range including 700 ° C. or lower (for example, a temperature range of 700 ° C. or higher and lower than 800 ° C.). In addition, more oxygen precipitation nuclei are formed at lower temperatures in the temperature range of 700 ° C. or lower. Therefore, in order to reduce the density of precipitation nuclei, the effect becomes greater as the lower temperature side in the temperature range of 700 ° C. or lower is quenched.
[0017]
The silicon single crystal manufacturing apparatus used in the present invention is not particularly limited as long as it is used for silicon single crystal manufacturing by a normal CZ method. In this embodiment, a manufacturing apparatus as shown in FIG. 1 is used. It was. This CZ method silicon single crystal manufacturing apparatus is composed of a crucible 6 composed of a quartz crucible 6a containing a silicon melt M and a graphite crucible 6b protecting the silicon crucible 6a, and a crystal drawing containing a grown silicon single crystal ingot S. Upper furnace 1 The side surface of the crucible 6 is installed so as to surround the heater 4 and the heat insulating material 3 to prevent the heat from the heater 4 from escaping outside the crystal pulling furnace, and this crucible 6 is not shown in the drawing. The crucible 6 is connected to the apparatus by a rotating jig 5 and rotated at a predetermined speed by the driving device, and the crucible 6 is adjusted to compensate for a decrease in the silicon melt liquid level as the silicon melt in the crucible 6 decreases. It is designed to move up and down. A hanging pulling wire 7 is installed in the pulling furnace 1, and a chuck 9 for holding a seed crystal 8 is provided at the lower end of the wire. The upper end side of the pulling wire 7 is wound around a wire winding machine 2 and provided with a pulling device configured to pull up the silicon single crystal ingot. Then, Ar gas is introduced into the pulling furnace 1 from the gas inlet 10 formed in the pulling furnace 1, flows through the pulling furnace 1, and is discharged from the gas outlet 11. The reason why Ar gas is circulated in this way is to prevent SiO 2 generated in the pulling furnace 1 from melting into the silicon melt from being mixed into the silicon melt. The temperature controller 20 was installed so that the temperature at which the cooling rate was minimized in the crystal pulling furnace 1 was in the crystal temperature range of 1200 ° C to 1000 ° C. In addition, the temperature controller 25 was installed so as to include a portion where the cooling rate was 1.0 ° C./min or less in the crystal temperature region of 1000 ° C. to 800 ° C. in the crystal pulling furnace 1. As the temperature control device, a heat insulating heat insulating material such as graphite or a heater installed so as to surround the silicon single crystal ingot S to be raised and grown is effective. In addition, an internal cooling device 30 was installed so that the crystal could be rapidly cooled in the crystal pulling furnace 1 from 700 ° C. or higher. As the internal cooling device, a graphite material or a gas spraying device installed so as to surround the silicon single crystal to be raised and grown is effective. In order to rapidly cool the crystal from 700 ° C. or higher, it is also effective to release the pulling furnace 1 to the atmosphere immediately after the pulling is completed and cool the crystal in the air. In addition, an external cooling device 40 is installed outside the crystal pulling furnace 1 in order to rapidly cool the crystal from 700 ° C. or higher. As the external cooling device, the silicon single crystal taken out after the pulling is completed is rapidly cooled. A gas spraying device, a mist spraying device, and a water-cooled soot can be used.
[0018]
In the present invention, a temperature control function is installed in the crystal pulling furnace, and the temperature at which the cooling rate is minimized is gradually cooled so that it falls within the temperature range of 1200 ° C to 1000 ° C. Promote and improve the oxide film breakdown voltage. In addition, by installing another temperature control function in the crystal pulling furnace, or by changing the cooling method of the crystal after pulling, the temperature at which quenching is started from a temperature lower than 800 ° C and 700 ° C or higher, and the rapid cooling starts. By controlling the cooling rate within the temperature range of ˜600 ° C. to 20 ° C./min or more, growth of oxygen precipitation latent nuclei is suppressed and oxygen precipitation is suppressed. In this case, the ratio that the dielectric breakdown electric field of the silicon wafer indicates 8.0 MV / cm or more is 40% or more, and the initial oxygen concentration of the silicon wafer is A × 10^{1 7}atoms / cm^Three, The oxygen concentration of silicon wafer by oxygen precipitation heat treatment^{1 7}atoms / cm^ThreeAverage value (A,B) But,B<26-7.6 ×A+0.55 ×A ²It is possible to produce a silicon single crystal that satisfies the above condition and has an excellent oxide film withstand voltage and little oxygen precipitation.
[0019]
In addition, oxygen precipitation is further suppressed by adjusting the cooling rate of 600 ° C. to 500 ° C. to 10 ° C./min or more. In this case, at any position on the silicon wafer, the precipitated oxygen concentration B is B <26-7.6 × A + 0.55 × A with respect to the initial oxygen concentration A.²It is possible to produce a silicon single crystal that has an excellent oxide film withstand voltage and little oxygen precipitation.
[0020]
In addition, oxygen precipitation is further suppressed by adjusting the cooling rate of 500 ° C. to 400 ° C. to 8 ° C./min or more. In this case, the initial oxygen concentration of the silicon wafer is A × 10^{1 7}atoms / cm^Three, The oxygen concentration of silicon wafer by oxygen precipitation heat treatment^{1 7}atoms / cm^ThreeAverage value (A,B) But,B<48-11.9 ×A+0.74 ×A ²It is possible to produce a silicon single crystal that has an excellent oxide film withstand voltage and little oxygen precipitation.
[0021]
In addition, oxygen precipitation is further suppressed by setting the cooling rate of 400 ° C. to 300 ° C. to 5 ° C./min or more. In this case, the precipitated oxygen concentration B at any position on the silicon wafer is B <48-11.9 × A + 0.74 × A with respect to the initial oxygen concentration A.²It is possible to produce a silicon single crystal that has an excellent oxide film withstand voltage and little oxygen precipitation.
[0022]
Further, in the present invention, a temperature control function is installed in the crystal pulling furnace, and there is a region where the cooling rate in the temperature region of 1200 ° C to 1000 ° C at which the cooling rate is minimized is 1.0 ° C / min or less, In addition, by pulling up under a condition where the cooling rate in the crystal temperature range of less than 1000 ° C. and 800 ° C. or more is 1.0 ° C./min or less, decomposition of defect-generating nuclei is promoted and the oxide film breakdown voltage is improved. In addition, by installing another temperature control function in the crystal pulling furnace, or by changing the cooling method of the crystal after pulling, the temperature at which quenching is started from a temperature lower than 800 ° C and higher than 700 ° C, and the rapid cooling starts. By controlling the cooling rate in the temperature range of 600 ° C to 20 ° C / min or more, the growth of oxygen precipitation latent nuclei is suppressed and oxygen precipitation is suppressed. In this case, the rate at which the dielectric breakdown electric field of the silicon wafer is 8.0 MV / cm or more is 50% or more, the rate at which 6.0 MV / cm or less is less than 20%, and the initial oxygen concentration of the silicon wafer is A × 10^{1 7}atoms / cm^Three, The oxygen concentration of silicon wafer by oxygen precipitation heat treatment^{1 7}atoms / cm^ThreeAverage value (A,B) But,B<26-7.6 ×A+0.55 ×A ²It is possible to produce a silicon single crystal that satisfies the above condition and has an excellent oxide film withstand voltage and little oxygen precipitation.
[0023]
In addition, oxygen precipitation is further suppressed by adjusting the cooling rate of 600 ° C. to 500 ° C. to 10 ° C./min or more. In this case, at any position on the silicon wafer, the precipitated oxygen concentration B is less than the initial oxygen concentration A, B <26-7.6 × A + 0.55 × A²It is possible to produce a silicon single crystal that has an excellent oxide film withstand voltage and little oxygen precipitation.
[0024]
In addition, oxygen precipitation is further suppressed by adjusting the cooling rate of 500 ° C. to 400 ° C. to 8 ° C./min or more. In this case, the initial oxygen concentration of the silicon wafer is A × 10^{1 7}atoms / cm^Three, The oxygen concentration of silicon wafer by oxygen precipitation heat treatment^{1 7}atoms / cm^ThreeAverage value (A,B) But B <48-11.9 ×A+0.74 ×A ²It is possible to manufacture a silicon single crystal that has excellent oxide breakdown voltage and little oxygen precipitation.
[0025]
In addition, oxygen precipitation is further suppressed by setting the cooling rate of 400 ° C. to 300 ° C. to 5 ° C./min or more. In this case, the precipitated oxygen concentration B at any position on the silicon wafer is B <48-11.9 × A + 0.74 × A with respect to the initial oxygen concentration A.²It is possible to produce a silicon single crystal that has an excellent oxide film withstand voltage and little oxygen precipitation.
[0026]
【Example】
Examples of the present invention will be described below, but it goes without saying that the present invention is not limited by the description of these examples.
[0027]
  (referenceExample 1)
  Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the temperature range of 1200 ° C to 1000 ° C is the pulling condition as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C is the pulling condition as shown in Fig. 3, that is, the temperature at which the rapid cooling starts is 710 ° C, and the crystal cooling rate within the temperature range of 710 ° C to 600 ° C is 20.0 ° C / min or more. Five silicon single crystals were grown under these conditions.
[0028]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 10 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0029]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The proportions of the C mode region are all 40% or more, which indicates that the wafer cut from the silicon single crystal ingot manufactured by the method of the present invention has a good oxide film breakdown voltage. Further, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured, and are shown in FIG. The average value of the precipitated oxygen concentration B of these silicon wafers is
B<26-7.6 ×A+0.55 ×A ²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0030]
  (reference(Example 2)
  Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the temperature range of 1200 ° C to 1000 ° C is the pulling condition as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C is the pulling condition as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate in the temperature range of 720 ° C to 600 ° C is The crystal cooling rate in the temperature range of 20.0 ° C./min or higher and 600 ° C. to 500 ° C. is 10.00 ° C./min or higher. Five silicon single crystals were grown under these conditions.
  The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (phosphorus-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 2 Ω · cm, oxygen concentration: 8.0-0.5 × 10¹⁷atoms / cm^Three(Calculated using the oxygen concentration conversion factor by Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10¹⁷atoms / cm^Three(Calculated using the carbon concentration conversion factor by the Japan Electronics Industry Promotion Association).
[0031]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (phosphorus-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 2 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0032]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The proportions of the C mode region are all 40% or more, which indicates that the wafer cut from the silicon single crystal ingot manufactured by the method of the present invention has a good oxide film breakdown voltage. Further, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. These silicon wafers are measured at all measurement points.
B <26-7.6 × A + 0.55 × A²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0033]
  (reference(Example 3)
  Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the temperature range of 1200 ° C to 1000 ° C is the pulling condition as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C is the pulling condition as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate in the temperature range of 720 ° C to 600 ° C is The crystal cooling rate in the temperature region of 20.0 ° C./min or higher, 600 ° C. to 500 ° C. is 10.0 ° C./min or higher, and the crystal cooling rate in the temperature region of 500 ° C. to 400 ° C. is 8.0 ° C./min or higher. Five silicon single crystals were grown under these conditions.
[0034]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 8 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0035]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The proportions of the C mode region are all 40% or more, which indicates that the wafer cut from the silicon single crystal ingot manufactured by the method of the present invention has a good oxide film breakdown voltage. Further, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and are shown in FIG. The average value of the precipitated oxygen concentration B of these silicon wafers is
B<48-11.9 ×A+0.74 ×A ²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0036]
  (reference(Example 4)
  Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the temperature range of 1200 ° C to 1000 ° C is the pulling condition as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C is the pulling condition as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate in the temperature range of 720 ° C to 600 ° C is 20.0 ° C / min or more, crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min or more, 400 ° C to 300 ° C The crystal cooling rate in the temperature range of ℃ is 5.0 ℃ / min or more. Five silicon single crystals were grown under these conditions.
[0037]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 10 Ω · cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0038]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The proportions of the C mode region are all 40% or more, which indicates that the wafer cut from the silicon single crystal ingot manufactured by the method of the present invention has a good oxide film breakdown voltage. In addition, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. At all measurement points of these silicon wafers,
B <48-11.9 × A + 0.74 × A²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0039]
(Example 5)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range include the pulling conditions as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the 1200 ° C to 1000 ° C temperature range. In the temperature range of 1000 ° C to 800 ° C, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less. In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 710 ° C, and the crystal cooling rate within the temperature range of 710 ° C to 600 ° C is 20.0 ℃ / min or more. Under these conditions, five silicon single crystals were grown.
[0040]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 10 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0041]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The ratio of the C mode region is 50% or more, and the ratio of 6.0 MV / cm or less is less than 20%. A wafer cut from a silicon single crystal ingot manufactured by the method of the present invention is excellent. It shows that the oxide film has a breakdown voltage. Further, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured, and are shown in FIG. The average value of the precipitated oxygen concentration B of these silicon wafers is
B<26-7.6 ×A+0.55 ×A ²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0042]
(Example 6)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range include the pulling conditions as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the 1200 ° C to 1000 ° C temperature range. In the temperature range of 1000 ° C to 800 ° C, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less. In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate within the temperature range of 720 ° C to 600 ° C is The crystal cooling rate in the temperature range of 20.0 ° C./min or higher and 600 ° C. to 500 ° C. is 10.0 ° C./min or higher. Under these conditions, five silicon single crystals were grown.
[0043]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (phosphorus-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 2 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0044]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The ratio of the C mode region is 50% or more, and the ratio of 6.0 MV / cm or less is less than 20%. A wafer cut from a silicon single crystal ingot manufactured by the method of the present invention is excellent. It shows that the oxide film has a breakdown voltage. Further, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. These silicon wafers are measured at all measurement points.
B <26-7.6 × A + 0.55 × A²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0045]
(Example 7)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range include the pulling conditions as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the 1200 ° C to 1000 ° C temperature range. In the temperature range of 1000 ° C to 800 ° C, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less. In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate within the temperature range of 720 ° C to 600 ° C is The crystal cooling rate in the temperature region of 20.0 ° C / min or higher, 600 ° C to 500 ° C is 10.0 ° C / min or higher, and the crystal cooling rate in the temperature region of 500 ° C to 400 ° C is 8.0 ° C / min or higher. Under these conditions, five silicon single crystals were grown.
[0046]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 8 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0047]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The ratio of the C mode region is 50% or more, and the ratio of 6.0 MV / cm or less is less than 20%. A wafer cut from a silicon single crystal ingot manufactured by the method of the present invention is excellent. It shows that the oxide film has a breakdown voltage. Further, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and are shown in FIG. The average value of the precipitated oxygen concentration B of these silicon wafers is
B <48-11.9 × A + 0.74 × A²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0048]
(Example 8)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range include the pulling conditions as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the 1200 ° C to 1000 ° C temperature range. In the temperature range of 1000 ° C to 800 ° C, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less. In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 3, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate within the temperature range of 720 ° C to 600 ° C is 20.0 ° C / min or more, crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min or more, 400 ° C to 300 ° C The crystal cooling rate in the temperature region of ℃ is 5.0 ℃ / min or more. Under these conditions, five silicon single crystals were grown.
[0049]
The five silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 10 Ω · cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0050]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The ratio of the C mode region is 50% or more, and the ratio of 6.0 MV / cm or less is less than 20%. A wafer cut from a silicon single crystal ingot manufactured by the method of the present invention is excellent. It shows that the oxide film has a breakdown voltage. In addition, the initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. At all measurement points of these silicon wafers,
B <48-11.9 × A + 0.74 × A²
The wafer cut out from the silicon single crystal ingot produced by the method of the present invention shows that oxygen precipitation is suppressed.
[0051]
(Comparative Example 1)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range are as shown in Fig. 2, that is, there is no temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 4, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate in the temperature range of 720 ° C to 600 ° C is 20.0 ° C / min or more, crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min or more, 400 ° C to 300 ° C The crystal cooling rate in the temperature region of ℃ is 5.0 ℃ / min or more. Ten silicon single crystals were grown under these conditions.
[0052]
Ten silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 10 Ω-cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0053]
The oxide film breakdown voltage of the wafer cut out from these ingots was measured and shown in FIG. The proportion of the C mode region is less than 40%, indicating that the oxide film breakdown voltage of this wafer is inferior.
[0054]
(Comparative Example 2)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range are as shown in Fig. 2, that is, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 4, that is, the temperature at which rapid cooling starts is 680 ° C, and the crystal cooling rate in the temperature range of 680 ° C to 600 ° C is 20.0 ° C / min or more, crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min or more, 400 ° C to 300 ° C The crystal cooling rate in the temperature region of ℃ is 5.0 ℃ / min or more. Ten silicon single crystals were grown under these conditions.
[0055]
Ten silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 6 Ω · cm, oxygen concentration: 8.0-0.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0056]
The initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. These silicon wafers include
B <26-7.6 × A + 0.55 × A²
This wafer shows that oxygen precipitation is not suppressed.
[0057]
(Comparative Example 3)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range are as shown in Fig. 2, that is, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less within the temperature range of 1200 ° C to 1000 ° C. . In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 4, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate is within the temperature range of 720 ° C to 600 ° C. Including the part that is less than 20.0 ° C / min, the crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, and the crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min or more The crystal cooling rate in the temperature range of 400 ° C. to 300 ° C. is 5.0 ° C./min or more. Ten silicon single crystals were grown under these conditions.
[0058]
Ten silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (phosphorus-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 4 Ω-cm, oxygen concentration: 8.0 to 10.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0059]
The initial oxygen concentration A and precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. These silicon wafers include
B <26-7.6 × A + 0.55 × A²
This wafer shows that oxygen precipitation is not suppressed.
[0060]
(Comparative Example 4)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range include the pulling conditions as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the 1200 ° C to 1000 ° C temperature range. In the temperature range of 1000 ° C to 800 ° C, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less. In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 4, that is, the temperature at which rapid cooling starts is 680 ° C, and the crystal cooling rate in the temperature range of 680 ° C to 600 ° C is 20.0 ° C / min or more, crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min or more, 400 ° C to 300 ° C The crystal cooling rate in the temperature region of ℃ is 5.0 ℃ / min or more. Ten silicon single crystals were grown under these conditions.
[0061]
Ten silicon single crystal ingots grown under these conditions are as follows. Conductive type: p-type (boron-doped), crystal diameter: 160 mm (for 6 inch) and 210 mm (for 8 inch), resistivity: 6 Ω · cm, oxygen concentration: 8.0 to 10.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0062]
The initial oxygen concentration A and the precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. These silicon wafers include
B <26-7.6 × A + 0.55 × A²
This wafer shows that oxygen precipitation is not suppressed.
[0063]
(Comparative Example 5)
Using the apparatus of FIG. 1, a silicon single crystal was grown under the following conditions. The crystal growth rate is 1.0 mm / min. The crystal cooling temperature and rate pattern in the 1200 ° C to 1000 ° C temperature range include the pulling conditions as shown in Fig. 2, that is, the temperature at which the crystal cooling rate is 1.0 ° C / min or less within the 1200 ° C to 1000 ° C temperature range. In the temperature range of 1000 ° C to 800 ° C, there is a temperature at which the crystal cooling rate is 1.0 ° C / min or less. In addition, the crystal cooling temperature and rate pattern after around 700 ° C are as shown in Fig. 4, that is, the temperature at which rapid cooling starts is 720 ° C, and the crystal cooling rate is within the temperature range of 720 ° C to 600 ° C. The crystal cooling rate in the temperature range of 600 ° C to 500 ° C is 10.0 ° C / min or more, including the part that is less than 20.0 ° C / min, and the crystal cooling rate in the temperature range of 500 ° C to 400 ° C is 8.0 ° C / min Min., And the crystal cooling rate in the temperature range of 400 ° C. to 300 ° C. is 5.0 ° C./min or more. Ten silicon single crystals were grown under these conditions.
[0064]
Ten silicon single crystal ingots grown under these conditions are as follows. Conductive type: n-type (phosphorus-doped), crystal diameter: 160 mm (for 6 inches) and 210 mm (for 8 inches), resistivity: 4 Ω-cm, oxygen concentration: 8.0 to 10.5 × 10^{1 7}atoms / cm^Three(Calculated using the oxygen concentration conversion factor by the Japan Electronics Industry Promotion Association), carbon concentration: <1.0 × 10^{1 7}atoms / cm^Three(Calculated using carbon concentration conversion factor by Japan Electronics Industry Promotion Association).
[0065]
The initial oxygen concentration A and precipitated oxygen concentration B at the 39 points in the wafer cut out from the ingot were measured and shown in FIG. These silicon wafers include
B <26-7.6 × A + 0.55 × A²
This wafer shows that oxygen precipitation is not suppressed.
[0066]
【The invention's effect】
  BookThe silicon single crystal produced by the manufacturing method of the present invention has a good oxide film breakdown voltage and suppressed oxygen precipitation, so that the gate oxide film has high reliability and excellent PN junction leakage characteristics, and is a MOS device. Suitable for wafers.
[Brief description of the drawings]
FIG. 1 is a schematic view of a CZ method silicon single crystal manufacturing apparatus used in the present invention.
FIG. 2 showsReference example 1 ~ Four ,ExampleFiveThe figure which shows the relationship between the crystal | crystallization temperature and the cooling rate in the 1400 to 800 degreeC temperature range pulling of ~ 8 and Comparative Examples 1-5.
FIG. 3 showsReference example 1 ~ Four andExampleFiveThe figure which shows the relationship between the crystal | crystallization temperature and the cooling rate during raising of 800 to 300 degreeC temperature range of ~ 8.
FIG. 4 is a graph showing the relationship between the cooling temperature and the crystal temperature during pulling in the 800 ° C.-300 ° C. temperature range of Comparative Examples 1-5.
FIG. 5 (a)Reference example 1 ~ Four ,ExampleFiveThe figure which shows the C mode ratio of the oxide-film pressure | voltage resistant characteristic of -8 and the comparative example 1, (b),Reference example 1 ~ Four ,ExampleFiveThe figure which shows the ratio of 6 MV / cm or less of the oxide film pressure | voltage resistant characteristic of -8 and the comparative example 1. FIG.
FIG. 6 showsreferenceFIG. 6 is a graph showing the relationship between the initial oxygen concentration and the precipitated oxygen concentration in Example 1 and Example 5.
FIG. 7 showsreferenceFIG. 6 is a graph showing the relationship between the initial oxygen concentration and the precipitated oxygen concentration in Example 2 and Example 6.
FIG. 8 showsreferenceFIG. 6 is a graph showing the relationship between the initial oxygen concentration and the precipitated oxygen concentration in Example 3 and Example 7.
FIG. 9 showsreferenceFIG. 6 is a graph showing the relationship between the initial oxygen concentration and the precipitated oxygen concentration in Example 4 and Example 8.
10 is a graph showing the relationship between the initial oxygen concentration and the precipitated oxygen concentration in Comparative Examples 2 and 4. FIG.
11 is a graph showing the relationship between the initial oxygen concentration and the precipitated oxygen concentration in Comparative Examples 3 and 5. FIG.
[Explanation of symbols]
  1 ... CZ silicon single crystal pulling furnace
  2 ... Wire hoisting machine
  3 ... Insulation
  4 ... Heating heater
  5 ... Rotating jig
  6 ... Crucible
    6a Quartz crucible
    6b Graphite crucible
  7 ... Wire
  8 ... Seed crystal
  9 ... Chuck
10 ... Gas inlet
11 ... Gas outlet
20 ... Temperature control device (Slow cooling in the temperature range of 1200 ° C to 1000 ° C)
25 ... Temperature control device (slow cooling in the temperature range of 1000 ° C to 800 ° C)
30 ... Internal cooling device
40 ... External cooling device

Claims (4)

In a silicon single crystal produced by the Czochralski method, 1200 ℃ or less 1000 Cooling rate in the crystal temperature range above ℃ 1.0 ℃ / An area that is less than or equal to minutes, 1000 Less than ℃ 800 Cooling rate in the crystal temperature range above ℃ 1.0 ℃ / There are areas that are less than or equal to minutes, and 800 Less than ℃ 700 Starts rapid cooling in the crystal temperature range above ℃, 600 In the temperature range of ℃, the cooling rate is 20 ℃ / A method for producing a silicon wafer, comprising slicing and polishing a silicon single crystal produced under conditions of more than 5 minutes. 600 Less than ℃ 500 In the temperature range above ℃, the cooling rate is Ten ℃ / Claim or more 1 The manufacturing method of the silicon wafer of description. 500 Less than ℃ 400 In the temperature range above ℃, the cooling rate is 8 ℃ / Claim or more 2 The manufacturing method of the silicon wafer of description. 400 Less than ℃ 300 In the temperature range above ℃, the cooling rate is Five ℃ / Claim or more Three The manufacturing method of the silicon wafer of description.