JPS62279642A - Method for heat treatment of wafer - Google Patents

Abstract

PURPOSE:To enable the efficient and uniform heat treatment by inserting a wafer into a heat treatment furnace under the condition that an oxygen gas is included in a tube containing the wafers. CONSTITUTION:By introducing an oxygen gas from gas inlets 2 and 5, the atmosphere inside a heat treatment furnace 1 and that inside a conveying tube 6 are made as an oxygen gas atmosphere respectively. Wafers 4 are inserted into the furnace together with the tube 6. As a result, when a heat treatment starts, the atmosphere inside the tube 6 and that inside the furnace 1 have been made an oxygen gas atmosphere respectiveiy and step of removing impurities due to an oxygen gas is unnecessary, thereby contriving the improvement in productivity. Thus, the efficient and uniform heat treatment can be effected without leaving an inert gas such as nitrogen gas among the wafers 4.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a wafer heat treatment method for forming an oxide film or the like on the wafer surface.

(Prior Art) A wafer heat treatment method for forming an oxide film or the like on the surface of a wafer constituting a semiconductor device has conventionally been carried out, for example, by a method as shown in FIG.

That is, in the same figure, the reference numeral 1 indicates a heat treatment furnace formed in a tube shape with one or more gas inlets 2 at one end and an opening 3 at the other end, and a plurality of wafers 4 are placed in one or more gas inlet ports 2 and an opening 3 at the other end. It is placed on a holding stand (shell boat) 7 placed inside a transport tube 6 equipped with a gas inlet 5 .

For example, when forming an oxide layer on the wafer 4,
First, an inert gas such as nitrogen gas is introduced from the gas inlet 2 and the gas inlet 5 to cover the inside of the heat treatment furnace 1 and the JIG feeding duplex 6 with an inert gas atmosphere (a>.

Thereafter, the wafer 4 is inserted into the heat treatment furnace 1 through the opening 3 together with the general feed tube 6, and oxygen gas is introduced through the gas inlet 2 and the gas inlet 5 to fill the inside of the heat treatment furnace 1 and the inside of the heat treatment furnace 1.
Impurities such as nitrogen gas in the fG feeding tube 6 are removed (b).

Next, oxygen gas and hydrogen gas or oxygen gas are introduced from the nozzle inlet 2 to create a combination gas (containing oxygen gas) or oxygen gas atmosphere inside the heat treatment furnace 16 and the transport tube 6, and form the desired film. A heat treatment is performed for a predetermined time depending on the thickness to form an oxide film. At this time, gas from the gas inlet 5 is shut off (C).

Thereafter, an inert gas such as nitrogen gas is introduced from the gas inlet 2 and the gas inlet 5 to create an inert gas atmosphere inside the heat treatment furnace 1 and the transport tube 6 (d).

Thereafter, the transport tube 6 and the wafer 4 are taken out from the heat treatment furnace 1 (e).

(Problems to be Solved by the Invention) However, in the conventional wafer heat treatment method described above, a large number of wafers are processed at the same time, so the wafers are placed close to each other with an interval of about 3,716 inches, for example. During this time, inert gas such as nitrogen gas, which was filled in the transport tube when it was introduced into the heat treatment furnace, may remain. For this reason, the surroundings of the wafer are not in an atmosphere of oxygen gas or a mixed gas containing oxygen gas, resulting in a problem that, for example, an oxide film is not formed uniformly, and uniform heat treatment cannot be performed. In addition, in order to avoid such problems, it is necessary to carry out a process of introducing oxygen gas and removing impurities for a long time, resulting in a problem that productivity suffers.

The present invention has been made in response to such conventional circumstances, and it is an object of the present invention to provide a wafer heat treatment method that can perform uniform heat treatment and improve productivity.

[Structure of the Invention] (Means for Solving the Problems) That is, the method of the present invention accommodates a wafer in a transport duplex, inserts this transport tube into a heat treatment furnace, and
In the wafer heat treatment method, the wafer is heat-treated in an atmosphere of oxygen gas or a mixed gas containing oxygen gas, wherein the wafer is heated in a state where a gas containing at least oxygen gas flows into the transport tube containing the wafer. Insert into heat treatment furnace.

(Function) According to the wafer heat treatment method of the present invention, when the wafer is inserted into the heat treatment furnace together with the transport duplex and heat treatment is started, the inside of the transport tube and the heat treatment furnace are filled with oxygen gas. The atmosphere does not require an impurity removal process using oxygen gas, and no inert gas such as nitrogen gas remains between these f-quenchers, allowing for efficient and uniform heat treatment. .

(Example) The details of the method of the present invention will be described below with reference to the drawings.

FIG. 1 shows the steps of a method according to an embodiment of the present invention. In the figure, reference numeral 1 indicates one or more gas inlets 2 at one end.
, shows a tube-shaped heat treatment furnace with a frontage 3 at the other end, and a plurality of wafers 4, one or two. ! Transport tube 6 equipped with two nozzle inlets 5
It is placed on a holding table 7 made of a material with high heat resistance and high cleanliness, such as quartz.

For example, when forming an oxide film on the wafer 4, oxygen gas is first introduced from the gas inlet 2 to create an oxygen gas atmosphere in the heat treatment furnace 1. Further, a gas containing oxygen gas, for example, oxygen gas, is introduced from the gas inlet 5 to create an oxygen gas atmosphere in the transport duplex 6 (a). Note that nitrogen (N2) gas may be mixed with the oxygen gas at this time.

Thereafter, the wafer 4 and the transport tube 6 are inserted into the heat treatment furnace 1 through the opening 3, and oxygen gas and hydrogen gas or oxygen gas are introduced from the gas inlet 2 to fill the heat treatment furnace 1 and the transport tube 6 with oxygen. Gas mixture containing gas or oxygen/
An oxide film is formed by heat treatment for a predetermined time period depending on the desired film thickness in a J-sulfur atmosphere. At this time, gas inlet 5
Cut off gas from. In addition, under an oxygen gas atmosphere,
An oxide film is formed on the wafer even at finger temperature, so in order to form an oxide film of the desired thickness, the time the wafer stays in the heat treatment furnace 1, that is, the heat treatment time, is shorter than in the conventional method. need to (mouth).

Next, an inert gas such as nitrogen gas is introduced from the gas inlet 2 and the nozzle inlet 5 to create an inert gas atmosphere inside the heat treatment furnace and the one-way feed tube 6 (c).

Thereafter, the transport tube 6 and the wafer 4 are taken out from the heat treatment furnace 1 (d).

In the method of this embodiment described above, oxygen gas is introduced from the gas inlet 2 and the gas supply port 5 to create an oxygen gas atmosphere in the heat treatment furnace 1 and the transfer tube 6, and then the wafer is transferred together with the transfer tube 6. 4 is inserted into the heat treatment furnace 1, the inside of the transport tube 6 and the inside of the heat treatment furnace 1 are already in an oxygen gas atmosphere at the time the heat treatment is started, and an impurity removal process using oxygen gas is not necessary. Therefore, productivity can be improved. Further, since no inert gas such as nitrogen gas remains between the wafers, uniform heat treatment can be performed.

Furthermore, in this embodiment method, when the wafer 4 and the transport duplex 6 are taken out from the heat treatment furnace 1 after the heat treatment is completed,
Although the inside of the transport duplex 6 and the heat treatment furnace 1 are set to an inert gas atmosphere such as nitrogen gas, for example, when heat treatment is performed under an oxygen gas atmosphere, the inside of the transport duplex 6 and the heat treatment furnace 1 are set to an oxygen gas atmosphere. The wafer 4 and the transport tube 6 may be taken out as they are. In this case, in order to form an oxide film with a desired thickness, it is necessary to make the heat treatment time for the wafer 4 and the transport tube 6 in the heat treatment furnace 1 even shorter than in the method of this embodiment. In addition, an inert gas (J argon gas, etc.) may be used, and oxygen gas may be
Gas, 03 gas, or a mixture thereof may also be used.

In addition, in the apparatus used in these embodiment methods, for example, as shown in FIG. The gas and the like introduced between the 1fffl feeding tube 6 and the tube-shaped heat treatment furnace 1 flow as shown by arrows and are discharged from the discharge pipe 8.

Further, in these embodiment methods, a horizontal heat treatment furnace in which the transport tube 6 is inserted horizontally into the heat treatment furnace 1 has been described, but the method of the present invention is not limited to such embodiments, and for example, As shown in FIG. 3, a general feeding tube 6a, which is formed into a tube shape from below, is provided with a holding table 7a for holding a plurality of wafers 4a between three or more columnar bodies. In a vertical heat treatment furnace inserted into the heat treatment furnace 1a, it can be carried out in the same manner as in the above-mentioned embodiment, and the same effect can be obtained 1q.

[Effects of the Invention] As described above, in the wafer heat treatment method of the present invention, heat treatment is not performed with inert gas such as nitrogen gas remaining between the wafers, and uniform heat treatment can be performed. There is no need for a step to remove impurities from the gas, and productivity can also be improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the steps of an embodiment of the method of the present invention, Fig. 2 is a vertical sectional view showing the main parts of the apparatus shown in Fig. 1, and Fig. 3 is an explanatory diagram showing a vertical heat treatment furnace. 4 are explanatory diagrams showing the steps of the conventional method. 1... heat] Jl furnace, 4... wafer, 6
...Transportation tube. Applicant Tokyo Electron Co., Ltd. Agent Patent Attorney Sasa Suyama - (A) ↓ 1 ↓ (D) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) A wafer heat treatment method in which a wafer is housed in a transfer tube, the transfer tube is inserted into a heat treatment furnace, and the wafer is heat treated in an atmosphere of oxygen gas or a mixed gas containing oxygen gas, A method for heat processing a wafer, comprising inserting the wafer into the heat treatment furnace while a gas containing at least oxygen gas flows into the transport tube containing the wafer.