JPH0755000Y2 - Heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a heat treatment apparatus for thermally oxidizing a semiconductor wafer or the like used for manufacturing a semiconductor integrated circuit.

(Prior Art) A heat treatment apparatus used in an oxidation process for forming an oxide film on the surface of a semiconductor wafer supplies hydrogen gas and oxygen gas to the inside of a furnace core tube, and supplies hydrogen gas inside the furnace core tube. There are an internal combustion type that combusts to generate steam, and an external combustion type that a combustion unit is provided outside the furnace core tube and hydrogen gas is combusted in the combustion unit to generate steam, and this steam is supplied to the furnace core tube. There is.

The internal combustion type fuel treatment device is disclosed in, for example, Japanese Patent Laid-Open No. 62-432.
As shown in Japanese Patent Publication No. 4, a furnace core tube is composed of a large-diameter processing section and a small-diameter combustion section. A semiconductor wafer as an object to be processed is installed in the processing section, and a hydrogen ejection nozzle for ejecting hydrogen gas as a combustion fluid and an oxygen ejection nozzle for ejecting oxygen gas as a combustion supporting fluid are provided in the combustion section. There is.

The hydrogen jet nozzle is provided so as to jet in the tube axis direction of the furnace core tube, and the oxygen jet nozzle is provided so as to jet along the tube wall.

Therefore, the hydrogen gas ejected from the hydrogen ejection nozzle and the oxygen gas ejected from the oxygen ejection nozzle are mixed, ignited by the heat of the infrared lamp or the heater, and burned inside the combustion section. Then, the steam generated by this combustion is guided to the processing section.

(Problems to be solved by the invention) However, since the nozzle portion of the oxygen ejection nozzle of the conventional heat treatment apparatus is provided behind the nozzle portion of the hydrogen ejection nozzle, it ejects hydrogen gas behind the combustion portion. The oxygen concentration around the nozzle is high. Therefore, there is a drawback that combustion flame is generated in the nozzle portion of the hydrogen ejection nozzle, and the nozzle portion of the hydrogen ejection nozzle and the heat collecting plate are melted by the combustion flame.

This invention has been made in view of the above circumstances, and the purpose thereof is to be able to guide the combustion flame to the processing section by the combustion-supporting fluid that advances while swirling in a spiral shape, and to process the processing space of the processing section. While making the temperature distribution in the inside uniform,
It is an object of the present invention to provide a heat treatment apparatus capable of preventing generation of a combustion flame in the vicinity of a nozzle portion of a hydrogen jet nozzle, improving ignitability, and safely igniting hydrogen gas diluted with an inert gas.

[Constitution of device]

(Means and Actions for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides
A combustion fluid ejection nozzle for ejecting combustion fluid in the axial direction of the furnace core tube and a combustion-supporting fluid ejection nozzle for ejecting combustion-supporting fluid along the tube wall are provided, and the nozzle portion of this combustion-supporting fluid ejection nozzle is also provided. Is located closer to the processing portion than the nozzle portion of the combustion fluid ejection nozzle.

Hydrogen gas generated from the combustion fluid ejecting nozzle follows the oxygen gas in front of it, and progresses and uniformly mixes.

According to a second aspect of the present invention, the nozzle portion of the combustion fluid ejecting nozzle is formed by a small diameter hole opening in the pipe axis direction at the tip of the nozzle body, and a heat collecting plate is provided at the tip of the nozzle body, and is separated from the nozzle portion. This is because the combustion flame was formed in the front.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the whole heat treatment apparatus, and 1 is a furnace core tube. The furnace core tube 1 is made of cylindrical quartz glass, and a heater 2 for heating the inside of the furnace core tube 1 is provided around the furnace core tube 1 so as to surround the furnace core tube 1. The furnace core tube 1 is provided with a small-diameter combustion section 3 at one end and a large-diameter processing section 4 at the other end. Further, the combustion section 3 and the processing section 4 are communicated with each other through a tapered section 5 having a diameter gradually larger than that of the combustion section 3, and the internal volume is gradually increased from the combustion section 3 toward the processing section 4. . Therefore, a gap 2a is provided between the small-diameter combustion section 3 and the heater 2. Further, in the processing space 6 of the processing unit 4, semiconductor wafers a ...
Are placed in alignment with the jig b, and an oxide film is formed on this surface.

Further, a taper rubbing joint 7 is provided at an end of the combustion section 3, and a base 9 of a nozzle unit 8 is removably rubbed and coupled to the taper rubbing joint 7.

Explaining the nozzle unit 8, it is configured as shown in FIGS. That is, the base 9 is formed of quartz glass into a cylindrical shape, both ends of which are closed by end plates 9a and 9b, and is formed into a hollow container containing a heat insulating material 10 such as quartz glass wool. .
Therefore, the opening of the taper butting joint 7 is sealed by the end plate 9a of the base 9. Further, the base 9 is provided with a hydrogen jetting nozzle 11 as a combustion fluid jetting nozzle and an oxygen jetting nozzle 12 as a combustion supporting fluid jetting nozzle, which are made of a quartz pipe penetrating the end plates 9a and 9b and projecting in the axial direction. ing. The hydrogen injection nozzle 11 has a nozzle portion 13 whose tip has a small hole diameter, and injects hydrogen gas in the axial direction of the combustion section 3. Also,
A fixing pin 14 is projectingly provided on an upper portion of the hydrogen injection nozzle 11 located near the nozzle portion 13, and the fixing pin 14 is attached to the center portion of a disk-shaped heat collecting plate 15 made of silicon. The hole 16 is loosely fitted. Further, even if the fixing pin 14 is heated by the combustion flame and thermally expands, the heat collecting plate 15 is prevented from being damaged. Further, the oxygen injection nozzle 12 is longer than the hydrogen injection nozzle 11, and the tip portion is sealed, and a nozzle portion 17 formed of a small hole is provided on the side portion near the tip portion. Therefore, the nozzle portion 17 from which the oxygen gas is ejected is provided in front of the nozzle portion 13 from which the hydrogen gas is ejected, that is, in the processing portion 3 direction. Further, the nozzle portion 17 is opened in a direction of about 90 ° with respect to a vertical line connecting the hydrogen jet nozzle 11 and the oxygen jet nozzle 12, so that the oxygen gas is jetted along the pipe wall of the combustion portion 3. It has become.

Incidentally, the hydrogen injection nozzle 11 and the oxygen injection nozzle 12 are connected by a connecting member 18, a temperature sensor 19 is provided in contact with the heat collecting plate 15 of the hydrogen injection nozzle 11, and the temperature at which ignition is possible is set. It can be monitored at all times.

Next, the operation of the heat treatment apparatus configured as described above will be described.

After the jig b in which the semiconductor wafers a are aligned is installed in the processing unit 3 of the furnace core tube 1, hydrogen gas is supplied from the hydrogen ejection nozzle 11 and oxygen gas is supplied from the oxygen ejection nozzle 12. In this case, hydrogen gas may be mixed with nitrogen gas or an inert gas to supply thin hydrogen gas. The hydrogen gas supplied to the hydrogen ejection nozzle 11 is the nozzle part.
The oxygen gas is ejected from 13 in the axial direction of the combustion section 3, and the oxygen gas supplied to the oxygen injection nozzle 12 is ejected from the nozzle section 17 along the tube wall of the combustion section 3. On the other hand, since the heater 2 surrounding the furnace core tube 1 is heating, the heat collecting plate 15 provided inside the combustion section 4 is heated by the radiant heat, and the hydrogen gas ejected from the nozzle section 13 is converted into hydrogen gas. Ignite and start burning. Moreover, since the heat collecting plate 15 is made of silicon that has a higher temperature rise than that of quartz glass, when hydrogen gas is ejected from the nozzle portion 13, it immediately ignites, so no explosive sound is generated during ignition, and pulsation due to explosive ignition occurs. Therefore, the semiconductor wafers a do not vibrate. Also, the heat collecting plate 15
Since a temperature sensor 19 is provided in contact with the temperature sensor 19 to constantly monitor the temperature at which ignition is possible, the ignition state can be monitored. At this time, the oxygen gas ejected from the nozzle portion 17 of the oxygen ejecting nozzle 12 advances while swirling along the tube wall of the combustion section 4, so that the combustion flame of hydrogen gas does not extend in the tube axis direction. , Follow the swirling and swirling movement of oxygen gas and proceed toward the processing unit 3. Further, the nozzle portion 13 of the hydrogen jet nozzle 11 is formed by a small diameter hole that opens in the tube axis direction at the tip portion of the nozzle body, and a heat collecting plate 15 is provided at the tip portion of the nozzle body and is separated from the nozzle portion 13. Moreover, since the combustion flame is formed in the front, the nozzle portion 13 and the heat collecting plate 15 are not heated by the combustion flame and the melting can be prevented.

Furthermore, since the combustion section 4 is formed to have a smaller pipe diameter than the processing section 3, the combustion flame is effectively swirled, and the combustion section 4 has a tapered section 5 whose diameter gradually increases. It is guided to the processing unit 3 and diffused into the processing space 6.
Therefore, the temperature distribution in the processing space 6 can be made uniform, and a uniform oxide film is formed on the surface of the semiconductor wafers a due to the water vapor generated by the combustion of hydrogen gas.

[Advantage of Invention] As described above, according to this invention, Claim 1 is
A combustion fluid ejection nozzle for ejecting combustion fluid in the axial direction of the furnace core tube and a combustion-supporting fluid ejection nozzle for ejecting combustion-supporting fluid along the tube wall are provided, and the nozzle portion of this combustion-supporting fluid ejection nozzle is also provided. Is projected forward from the nozzle portion of the combustion fluid ejection nozzle.

Therefore, the hydrogen gas generated from the combustion fluid jet nozzle follows the oxygen gas in front of it, and the combustion flame is guided to the processing unit while swirling in a spiral shape, so that the temperature distribution in the processing space of the processing unit is made uniform. be able to. Moreover, it is possible to prevent the generation of combustion flame near the nozzle portion of the hydrogen ejection nozzle, improve the ignitability, and safely ignite even hydrogen gas diluted with an inert gas, so that a thin oxide film can be formed. effective.

Further, claim 2 is the nozzle portion of the combustion fluid jet nozzle,
The nozzle body is formed with a small-diameter hole that opens in the tube axis direction, and a heat collecting plate is provided at the tip of the nozzle body so that a combustion flame is formed in front of the nozzle portion. This has an effect of preventing melting of the heat collecting plate and the heat collecting plate.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a vertical sectional side view of a heat treatment apparatus, FIG. 2 is a partially cutaway plan view of a nozzle unit, and FIG. 3 is a nozzle unit. FIG. 4 is a vertical cross-sectional side view, and FIG. 4 is a front view of the nozzle unit. 1 ... Furnace core tube, 3 ... Combustion part, 4 ... Treatment part, 5 ... Tapered part, 11 ... Hydrogen ejection nozzle (combustion fluid ejection nozzle), 12 ... Oxygen ejection nozzle (combustion fluid ejection nozzle) ),
13, 17 ... Nozzle part, 15 ... Heat collecting plate.

Claims (2)

[Scope of utility model registration request] 1. An inside having a furnace core tube provided with a processing section for setting an object to be processed and a combustion section for supplying a combustion fluid and a combustion-supporting fluid to internally generate a combustion reaction to process the object to be processed. In a combustion type heat treatment apparatus, a combustion fluid jet nozzle for jetting a combustion fluid in the axial direction of the furnace core tube and a combustion fluid jet nozzle for jetting a combustion supporting fluid along the tube wall are provided, and A heat treatment apparatus, wherein the nozzle portion of the combustion-supporting fluid ejection nozzle is located closer to the processing unit than the nozzle portion of the combustion fluid ejection nozzle. 2. A nozzle portion of a combustion fluid jetting nozzle is formed by a small diameter hole opening in the tube axis direction at the tip of the nozzle body, and a heat collecting plate is provided at the tip of the nozzle body. The heat treatment apparatus according to claim 1.