JPH08203840A - Device and method for diffusing aluminum into semiconductor wafer - Google Patents

Abstract

(57) [Summary] (Modified) [Object] To provide an Al diffusion device and method for forming a deep diffusion layer in a semiconductor wafer, which enables Al diffusion excellent in mass productivity and reproducibility. . [Structure] Semi-sealed open end on one side and gas inlet tube 1 on the other
A diffusion container 18 made of quartz and equipped with a plurality of semiconductor wafers 20 is stored in an airtight process pipe 11 having a gas exhaust pipe. The diffusion container gas introduction pipe 16 penetrates the process pipe and is connected to an aluminum gas supply container 17 provided outside the process pipe. The gas exhaust pipe of the process pipe is connected to the vacuum exhaust systems 13 and 14, and the diffusion system is first forcibly exhausted to a vacuum degree of 1 × 10 ⁻⁶ mmHg or less, and then the process pipe is heated to a predetermined temperature. The aluminum gas flux is introduced into the diffusion container from the aluminum gas supply container 17 heated at a temperature to diffuse Al.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffusion device and a diffusion method of aluminum into a semiconductor wafer for forming a mold region.

[0002]

2. Description of the Related Art Boron (B) and gallium (Ga), which are easy to control thermal diffusion from the vapor phase, have been used as acceptor impurities for group IV semiconductors. However, recently, as the capacity and the breakdown voltage of the power semiconductor element have increased, it has become necessary to form a deep p-type region with a low concentration in the n-type substrate. By lowering the concentration, the surface electric field strength can be reduced, and a deep junction can increase the breakdown voltage.

Aluminum (Al) has a diffusion rate higher than that of other acceptors B and Ga, and has an ionic radius of S.
Since it is close to i, it is an impurity suitable for obtaining a uniform deep junction by reducing the introduction of strain and defects in the diffusion process, especially for a silicon wafer. On the other hand, Al is chemically active, and in the diffusion process, it binds to residual oxygen and water in the atmosphere and permeates through the SiO ₂ tube, which is the diffusion container, so the Al vapor pressure in the system does not rise and it is stable. It has the property of being difficult to diffuse into.

Conventionally, as a method of diffusing Al into a semiconductor wafer, an ion implantation method, a closed tube method and an open tube method have been used. The ion implantation method is a method of implanting Al atoms accelerated by an electric field to a predetermined position in a semiconductor wafer and then annealing at high temperature to form a pn bond. The Al diffusion method based on this method is disclosed, for example, in Japanese Patent Laid-Open Nos. 54-101663 and 61-251130.

The closed tube method is a method in which a semiconductor wafer and an Al source are heated to a predetermined temperature in the same vacuum sealed quartz tube to diffuse Al. This method is disclosed, for example, in Japanese Patent Laid-Open No.
No. 73557 and Japanese Patent Laid-Open No. 57-10229. The open-tube method is a method in which a quartz tube containing a semiconductor wafer and an Al source is heated in an inert gas atmosphere or while being evacuated by a vacuum device to diffuse Al. Among them, Japanese Patent Laid-Open No. 54-112473 discloses a method of using Al ₂ O ₃ as an Al source and heating and diffusing it in an inert gas while arranging it in proximity to a semiconductor wafer. The vacuum tube opening method is a method in which an Al source and a semiconductor wafer are housed in a semi-sealed inner tube, which is placed in the outer tube and the outer tube is evacuated and heated.
No. 30 publication.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Although each has advantages, it has the following problems. That is, the ion implantation method of aluminum is an excellent technique for forming a steep impurity distribution in a relatively shallow region, but out diffusion occurs when heat treatment is performed to form a deep junction. For example, a Si wafer has a depth of 80 μm and a surface concentration of 1 to 10 × 10 ¹⁶ ato.
When forming a p-region of ms / cm ³ , thermal heating is performed, but since Al atoms lost from the wafer surface due to out-diffusion have a considerably high concentration, Al ions are initially added at a concentration much higher than the above required amount. Need to dose. As a result, there is a problem that high-concentration crystal defects are introduced in the vicinity of the surface and annealing is not performed even by heat treatment.

On the other hand, a closed tube ampoule is designed to uniformly generate a predetermined Al vapor partial pressure in a closed space so as to give a uniform Al surface concentration to a plurality of semiconductor wafers and diffuse it. This is an excellent Al diffusion method, but the workability is poor because the semiconductor wafer and Al source are held in the same quartz tube and vacuum sealed, and the cost is increased because it is necessary to break the quartz ampoule after diffusion to take out the sample. Therefore, there is a problem that mass productivity is low.

Among the open-tube methods, the Al diffusion method using an Al ₂ O ₃ source and an inert gas atmosphere has a problem of contamination of impurities such as heavy metals contained in the Al ₂ O ₃ source and shortens the life of minority carriers. It is not preferable. On the other hand, in the vacuum tube opening method of the double quartz tube structure using the semi-sealed diffusion tube,
Since the Al source is held together with the semiconductor wafer in the semi-sealed diffusion tube, the occupation rate of the source storage location cannot be ignored, and if the number of wafers increases, the diffusion tube length increases and the temperature distribution inside the tube deteriorates. As a result, there is a problem in that the dispersion of the impurity concentration within the wafer surface after diffusion and between lots becomes large.
An object of the present invention is to provide an apparatus and a method that enable Al diffusion with excellent mass productivity and uniformity.

[0009]

According to the present invention, a quartz tube (diffusion vessel) having a semi-sealed open end on one side and a gas introduction tube on the other side and containing a plurality of semiconductor wafers therein, and this diffusion vessel are built in. Airtight process pipe having a gas exhaust pipe, an aluminum gas generation source connected to the gas introduction pipe penetrating the process pipe and outside the process pipe, an exhaust device connected to the gas exhaust pipe, and the process pipe Disclosed is an apparatus for diffusing aluminum into a vacuum open tube type semiconductor wafer, which comprises a resistance heating apparatus for heating the aluminum wafer, and a heating apparatus for holding the aluminum gas generation source and the gas introduction tube at a predetermined temperature.

Further, according to the present invention, a semiconductor wafer is placed on a diffusion container, an aluminum source is stored in an aluminum gas supply source container, and then the diffusion container is stored at a predetermined position in the process pipe, and the gas exhaust pipe of the process pipe is installed. The first step of driving the connected exhaust device to forcibly exhaust the process tube, the diffusion container, and the aluminum gas supply source container and the gas introduction pipe to the diffusion container to a predetermined vacuum degree, and the process tube were housed. The resistance heating device is driven to raise the temperature of the process tube and the diffusion container to a first predetermined temperature, and then the aluminum gas supply source container and the gas introduction pipe are heated to a predetermined temperature so that a predetermined partial pressure of aluminum gas is supplied. A second step of introducing into the diffusion container, and after a predetermined time elapses, only the temperature of the process and the diffusion container is raised to a second predetermined temperature higher than the first predetermined temperature. A third step of diffusing aluminum on the conductor wafer, and a predetermined time after which the temperature of the aluminum gas supply container and the gas introduction pipe is lowered, and then the process pipe and the diffusion container are lowered to finish the diffusion process. And a method of diffusing aluminum into a semiconductor wafer comprising the steps of.

The predetermined degree of vacuum is 1 × 10 ^-6 mmHg
The following is preferred. Further, it is preferable that the first predetermined temperature is a suitable temperature between 950 and 1000 ° C. and the second predetermined temperature is a suitable temperature between 1010 and 1100 ° C. Further, the aluminum gas supply source container may be a quartz container including a silicon or tantalum board containing metallic aluminum.

[0012]

By separating the aluminum gas generation source from the diffusion container and connecting the two with a quartz gas introduction pipe, a large number of semiconductor wafers can be efficiently housed in the diffusion container. As a result, the length of the diffusion container can be shortened, it becomes easy to diffuse all the semiconductor wafers in the soaking zone, and the workability can be improved.

High-purity metallic aluminum housed in a boat made of high-melting point high-purity silicon or tantalum is used as a diffusion source, and aluminum gas generated by heating is removed at 1100 ° C. in order to remove residual gas and moisture and avoid condensation.
Since it reaches the semiconductor wafer under reduced pressure in a high-purity quartz tube heated to a high temperature, it is difficult to be affected by residual impurities.
It is possible to obtain a deep p-type region having a long minority carrier lifetime.

The aluminum flux generated by heating the aluminum gas supply source container has a long diffusion length because it is under reduced pressure, and reaches the diffusion container in a short time, but the diffusion device container is held at a relatively low first predetermined temperature. 4Al (g) + 3SiO ₂ (s) → 2Al ₂ O ₃ (s) +
According to the reaction of 3Si (s) 2, a brown film made of alumina and silicon is formed on the surface. When this film is completely formed, the film blocks the contact between the quartz and the aluminum flux, so that the reaction does not proceed any further and the gas partial pressure of aluminum in the diffusion container increases. Therefore, by raising the temperature to a relatively high second predetermined temperature, a high concentration A up to the solid solubility limit can be stably obtained in the n-type semiconductor wafer under quasi-saturated vapor pressure.
l diffusion can be performed.

The aluminum gas partial pressure (aluminum flux concentration) in the semiconductor wafer region under reduced pressure is determined by the balance between the aluminum flux supply rate from the aluminum gas generation source and the exhaust rate. Therefore, the semi-encapsulation degree (openness) of the open end of the diffusion container is set to 2 to 1
It is possible to adjust the diffusion concentration to the semiconductor wafer by controlling the temperature and area of the aluminum gas generation source while suppressing the concentration to about 0%.

[0016]

【Example】

(First Embodiment) The present invention will be described in more detail based on the embodiments. FIG. 1A shows a schematic sectional view of a lateral Al diffusion device according to an embodiment. Figure 1 (B) shows the diffusion container K
The figure seen from the side is shown. In FIG. 1A, 10 is a cylindrical resistance heating furnace. The resistance heating furnace 10 is divided into three electrically independent zones, and by controlling the temperature of each zone, the uniform heating zone in the longitudinal direction is lengthened. In this embodiment, the soaking zone in the range of ± 0.5 ° C. is 900
mm. A liner tube 12 made of silicon carbide is installed inside the opening of a cylindrical resistance heating furnace 10. This is because it is necessary to prevent contamination and impact due to the lengthening of the soaking zone. Further, in order to prevent direct contact with the resistance heating furnace 10, the outer surface of the liner tube 12 is coated with a mullite film.

Reference numeral 11 is a process tube, usually a quartz tube. Diameter 210mm, wall thickness 8mm, length 2120mm
Then, a gas exhaust pipe with a diameter of 30 mm is attached to one end,
It is connected to the vacuum exhaust systems 13 and 14. A quartz lid 15 is attached to the other end by a flange. A 12 mm gas introduction pipe 16 penetrates the quartz lid 15 and is connected to an aluminum gas supply container 17. The container 17 of the aluminum gas supply source is made of, for example, quartz, the inside of which is coated with alumina and the outside of which is 120
Heater 24 so that the temperature can be controlled up to 0 ℃
Is wound. The gas inlet pipe 16 always has a temperature of 1100 ° C.
A ribbon heater is wound on the outside of the quartz lid in order to keep it warm.

A gas introducing pipe 16 is connected to one end of the process pipe 11, and a diffusion container (ampule pipe) 18 in which a quartz container lid 25 is semi-sealed is installed at the other end. There is. The diffusion container 18 is made of transparent quartz and has a wafer holder 19 and a diameter of 1 mm.
A 50 mm silicon wafer 20 is installed. The wafer holder 19 is made of polycrystalline silicon and is coated with a silicon nitride film by the CVD method. Figure 1 (B)
It is the figure which looked at the diffusion container 18 from the K direction of FIG. 1 (A).
As shown in FIG. 1B, the diffusion container 18 and the container lid 25.
Is to prevent a sudden outflow of gas when removing oxygen in the diffusion container 18 by vacuuming before diffusion, and to prevent the aluminum gas partial pressure during diffusion from being reduced by vacuum exhaustion to prevent high-concentration diffusion. A gap 18a is provided and is in a semi-sealed state.

The silicon wafer 20 used is FZ, n-type conductive, has a resistivity of about 300 Ω-cm, a diameter of 150 mm, and a thickness of about 1000 μm. An aluminum wire having a purity of 99.999% was used as an aluminum gas generation source. The aluminum wire is housed in a Si or Ta boat, and the boat is housed in an aluminum supply container 17.
Since aluminum has a large affinity with oxygen, it is easily oxidized by residual oxygen or moisture in the diffusion system.
Therefore, the aluminum gas source container 17 and the valve 21
After connecting the gas to the gas introduction pipe 16, the valve 21 is opened and the aluminum gas supply container 17 containing the aluminum wire is opened.
The diffusion container 18 accommodating the silicon wafer 20 and the gas introduction pipe 16 and the process pipe 11 are evacuated to a vacuum of 10 ⁻⁶ mmHg to remove residual gas components. After that, the valve 21 is closed, first, the process tube 11, the aluminum gas supply container 17 and the gas introducing pipe 16 are heated, and when the diffusion container 18 reaches 980 ° C., the valve 21 is opened to introduce the aluminum gas. After heat treatment at 980 ° C. for 3 hours, the temperature is raised to 1020 ° C. and diffusion treatment is performed for 10 hours. Next, the valve 21 was closed, the temperature was lowered, the vacuum exhaust system was closed, the quartz lid 15 was opened, and the diffusion container 18 was taken out of the furnace. The container lid 25 was opened, the silicon wafer 20 was taken out, and the diffusion layer sheet resistance of the silicon wafer 20 was measured by the four-point probe method. The measurement result is shown in FIG. Wafer 20
Is the sheet resistance of the aluminum diffusion layer according to this embodiment. FIG. 3 shows the sheet resistance of the aluminum diffusion layer formed by the conventional vacuum tube method. As shown in FIG. 2, according to the aluminum diffusion according to the present invention, the sheet resistance of each wafer in the lot has an average value of 58 ± 2Ω / □. The result by the vacuum open tube method shown in FIG. 3 is 60 ± 5Ω / □. The sheet resistance values shown in FIGS. 2 and 3 show variations in measured values at a total of 25 points at the center and the periphery of a silicon wafer having a diameter of 150 mm for each silicon wafer. This result indicates that the aluminum diffusion method of the present invention can provide more uniform diffusion than the conventional aluminum diffusion method.

(Second Embodiment) FIG. 4 is a schematic sectional view of an Al diffusion device for a silicon wafer according to another embodiment. This embodiment discloses a method of increasing the diffusion concentration by increasing the number of aluminum gas supply sources containing metallic aluminum. Reference numeral 23 in FIG. 4 is a second aluminum gas supply container connected in series to the aluminum gas supply container 17 of the previous embodiment. 22 is the first container 17
It is a valve that connects 23 and.

The silicon wafer 20 used for diffusion is F
Z, n-type conductivity, resistivity about 300 Ω-cm, diameter 150
mm and thickness about 1000 μm. As the aluminum gas source, an aluminum wire having a purity of 99.999% was used as in the previous example. After making the arrangement as shown,
The valves 21 and 22 are opened, and the aluminum gas supply source containers 17 and 23 containing the aluminum wires and the diffusion container 18 containing the silicon wafer are evacuated to a vacuum degree of 1 × 10 ⁻⁶ mmHg. Next, the valve 21 is closed and the process pipe 1
1 and the aluminum gas supply source containers 17 and 23 and the gas introduction pipe 16 are heated, and when the process pipe 11 reaches 980 ° C., the valve 21 is opened to introduce the aluminum gas into the diffusion container 18, and Heat treatment for hours. Next, after further opening the valve 22 and performing heat treatment for 2 hours, 1 is left as it is.
The temperature was raised to 020 ° C. and diffusion treatment was performed for 10 hours. Thereafter, the valve 21 is closed, the temperature is lowered, and the vacuum exhaust system is closed. After this operation, the quartz lid 15 was opened and the diffusion container 18 was taken out. Silicon wafer 2 after removing container lid 25
0 was taken out and the diffusion layer sheet resistance of the silicon wafer was measured by the four-point probe method. The average value of the sheet resistance of all the wafers in the lot obtained by this method was 50 ± 2Ω / □. This value indicates that the diffused Al concentration is higher than in the case of the single aluminum gas supply source of the previous example. Further, the sheet resistance can be reduced by increasing the number of aluminum gas supply containers.
That is, it was shown that it is possible to increase the aluminum gas flux density in the diffusion container 18 by increasing the surface area of the metal aluminum melted at the time of diffusion, thereby increasing the Al diffusion concentration of the semiconductor wafer.

(Third Embodiment) FIG. 5 is a schematic sectional view of an Al vertical diffusion device according to still another embodiment of the present invention. In FIG. 5, reference numeral 41 is a resistance heating furnace, and 42 and 43 are process tubes and diffusion vessels which constitute a reaction chamber provided in the resistance heating furnace 41, respectively, and a fixed flange 44.
It is fixed tightly on top. Reference numeral 45 is a quartz tube boat that is carried in and transported into the diffusion container 43, and a large number of wafers 52 are mounted thereon. Reference numeral 46 denotes a quartz boat support, which is placed on the lifting door portion 47 of the lifting mechanism. Reference numeral 48 denotes a gas introduction port for introducing the reaction gas into the diffusion container 43, which is provided with a quartz gas introduction pipe 49 having a diameter of 12 mm and is connected to the aluminum gas supply source container 50. The aluminum gas supply container 50 is made of quartz, and the inside thereof is coated with aluminum, and the temperature can be controlled up to 1200 ° C. A ribbon heater is wound around the gas introducing pipe 49 so that the temperature can be kept at 1200 ° C. at all times. After the aluminum gas is filled in the diffusion container 43, it is discharged from a large number of sub-holes (not shown) provided in the upper part of the diffusion container 43, and passes through between 42 and 43 to be connected to a vacuum exhaust system (not shown). Forced exhaust from the mouth 51.

The silicon wafer used for diffusion is FZ, n
Mold conductive and resistivity about 300Ω-cm, diameter 150mm,
The thickness is about 1000 μm. An aluminum wire having a purity of 99.999% was used as an aluminum gas generation source.
After storing each silicon wafer 52 in the quartz boat 45,
The raising / lowering mechanism raises / lowers the raising / lowering door portion 47 to raise the quartz boat 45 on the quartz boat support base 46, and a large number of wafers 52 mounted on the quartz tube boat 45 are loaded into the diffusion container 43 and 1 × After forced evacuation to a vacuum degree of 10 ⁻⁶ mmHg, the resistance heating furnace 41 is heated. When the temperature of the process pipe 42 reached 980 ° C., aluminum gas was introduced into the diffusion container 43 through the gas introduction pipe 49, heat-treated at 980 ° C. for 3 hours, then raised to a temperature of 1020 ° C. and subjected to diffusion treatment for 10 hours. Set the temperature of the aluminum gas source to 105
When the temperature was set to 0 ° C., the sheet resistance of the diffusion layer, which was taken out after cooling and measured by the four-point probe method, was almost the same as that in Example 1.

The above-described embodiments have been described only when Al diffusion is applied to a silicon wafer. However, the present invention is not limited to this. For example, n
It can also be applied to type germanium, SiC, or II-VI group compound semiconductor wafers. Further, the aluminum gas supply source of the present invention is not limited to the above-mentioned metallic aluminum. For example, it is possible to use high-purity (purity 5N, 6N) organoaluminum. Since these organoaluminums are liquids, they are filled in a quartz container, and hydrogen or an inert gas is used as a carrier while controlling the temperature thereof, so that an aluminum flake having a desired density can be easily supplied to the diffusion container.

Further, although the process tube 11 is made of quartz in the above embodiment, the high purity alumina tube and the inner wall are coated with alumina (Al ₂ O ₃ ) or aluminum nitride (AlN) or tantalum oxide (Ta ₂ O ₅ ). Quartz tubes can be used. The inner wall of the process pipe is previously made of aluminum compound or A
If it is formed of a compound which is non-reactive with l, it is possible to prevent the process tube from being eroded by the aluminum flux flowing out from the lid of the diffusion container during high temperature diffusion while evacuation. As a result, it is possible to extend the service life of the process tube and to stabilize the aluminum flux density in the diffusion container.

In the present invention, the aluminum flux density supplied to the semiconductor wafer during diffusion is determined by the aluminum gas supply rate, the vacuum exhaust rate, and the opening ratio of the diffusion container. In the above embodiment, the degree of vacuum of the diffusion system is 1 × 10 ⁻⁶ m
Although mHg is used, if it is less than this value, a uniform and flat Al diffusion layer having a relatively low carrier concentration and a deep junction position can be obtained by appropriately selecting these factors.

[0027]

As described above, according to the present invention, (1) the semi-sealed diffusion container is easy to handle and has a large capacity, and the aluminum diffusion source can be separated from the diffusion container. Also, the wafer storability is significantly improved. Therefore, it is possible to diffuse Al with excellent mass productivity. (2) Since it is easy to control the temperature of the aluminum diffusion source independently and adjust the aluminum gas flux density, variation in diffusion concentration is reduced, and Al can be diffused with high reproducibility. In this respect, it is superior to the conventional Al diffusion method. It is considered that the present invention makes it possible to manufacture a high-power semiconductor element having a low aluminum concentration and a deep junction position at a lower cost than ever.

[Brief description of drawings]

FIG. 1 is a schematic view showing a configuration of a horizontal Al diffusion device according to an example. FIG. 1A is a cross-sectional view of the entire apparatus, FIG.
(B) shows the container lid viewed from the K direction of (A).

FIG. 2 is data showing Al diffusion results in a silicon wafer using the Al diffusion device shown in FIG.

FIG. 3 is data showing Al diffusion results in a silicon wafer using a conventional horizontal vacuum open tube Al diffusion device.

FIG. 4 is a schematic diagram showing a configuration of a horizontal Al diffusion device according to another embodiment.

FIG. 5 is a schematic view showing a configuration of a vertical Al diffusion device according to still another embodiment.

[Explanation of symbols]

 10, 41 Resistance heating furnace 11, 42 Process tube 12 Liner tube 13, 14 Vacuum exhaust system 15 Quartz lid 16, 49 Gas introduction tube 17, 50 Aluminum gas supply source container 18, 43 Diffusion container 19 Wafer holder 20, 52 Silicon wafer 21 , 22 Valve 23 Second Aluminum Gas Supply Container 24 Heater 25 Container Lid 44 Flange 45 Quartz Boat 46 Quartz Boat Support 47 Lifting Door of Lifting Mechanism 48 Gas Inlet 51 Exhaust

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Atsushi Watanabe 7-1-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory

Claims (7)

[Claims] 1. A quartz tube (hereinafter referred to as a diffusion container) having a semi-sealed open end on one side and a gas introduction tube on the other side and containing a plurality of semiconductor wafers, and a gas exhaust pipe including the diffusion container. An airtight process pipe provided, an aluminum gas generation source connected to the gas introduction pipe penetrating the process pipe and the outside of the process pipe, an exhaust device connected to the gas exhaust pipe, and a resistance for heating the process pipe. An apparatus for diffusing aluminum into a semiconductor wafer, comprising: a heating device; and a heating device that holds the aluminum gas generation source and the gas introduction feeling at a predetermined temperature. 2. The aluminum diffusing apparatus according to claim 1, wherein the aluminum source comprises a Si or Ta boat containing metallic aluminum and a quartz container containing the boat. 3. A plurality of semiconductor wafers are placed in a diffusion container made of quartz having a gas introduction pipe so that the open ends thereof are in a semi-sealed state, and the semiconductor wafer is installed outside the diffusion container and is provided with the gas introduction pipe. After filling the aluminum gas supply source container connected to the diffusion container with an aluminum source, the diffusion container is stored at a predetermined position in the process pipe, and an exhaust device connected to the gas exhaust pipe of the process pipe is driven to drive the inside of the process pipe. In the diffusion container, a first step of forcibly exhausting the aluminum gas supply source container and the gas introduction pipe to a predetermined degree of vacuum, and driving the resistance heating device housing the process pipe,
After raising the temperature of the process pipe and the diffusion container to a first predetermined temperature, the temperature of the aluminum gas supply source container and the gas introduction pipe is raised to a predetermined temperature to introduce a predetermined partial pressure of aluminum gas into the diffusion container. Aluminum for a semiconductor wafer comprising a second step, and a fourth step of cooling the aluminum gas supply source container and the gas introduction pipe after a predetermined time has passed, and then cooling the process pipe and the diffusion container to finish the diffusion. How to spread. 4. The predetermined degree of vacuum is 1 × 10 ⁻⁶ mmHg.
The method for diffusing aluminum into a semiconductor wafer according to claim 3, which is as follows. 5. The first predetermined temperature is 950 to 1000.
4. A method for diffusing aluminum into a semiconductor wafer according to claim 3, wherein the temperature is a suitable temperature between 0 ° C. and the second predetermined temperature is a suitable temperature between 1010 and 1100 ° C. 6. The method of diffusing aluminum into a semiconductor wafer according to claim 3, wherein the aluminum gas supply source container is a quartz container including a silicon or tantalum boat containing metal aluminum. 7. A semiconductor device having a semiconductor wafer manufactured by using the aluminum diffusion method according to claim 3.