JPS6321836A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To omit a labor of disposing unnecessary water and to prevent a peripheral environment from being deteriorated by supplying steam to reevaporating means when a reaction furnace is not used, reevaporating the water to return it to steam, and discharging it together with the remaining steam without condensation by exhausting means out of a chamber. CONSTITUTION:When an oxidation is not executed in a furnace core tube 21, a valve 51 is closed, a valve 52 is opened to feed steam toward a tube 64. In this case, part of the steam is condensed on the inner wall of the tube 64 to return to water, the water flows together in the tube 64, and is discharged into a vessel 42. The remaining steam without condensation flows from an exhaust port 46 to an exhaust conduit 7, and is discharged into an exhaust duct. On the other hand, the water remaining in the vessel 42 is boiled by the heat of a heater 47 to be again steam, and discharged by the conduit 7 into an exhaust duct. At this time, since the vessel 42 is sealed, the steam is not scattered to the periphery. When an oxidation is executed again in the tube 21, the valve 51 is again opened, and the valve 52 is closed. At this time the steam and the water do not flow into the vessel 42.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to improvements in semiconductor manufacturing equipment used for wet oxidation of silicon wafers and the like.

(b) Conventional technology Conventionally, semiconductor manufacturing equipment used for wet oxidation, which oxidizes silicon wafers using water vapor, is
The one shown in the figure is known.

13 is a water vapor supply source, and 12 is a reactor in which silicon wafers are stored. A valve 15a is provided on the conduit 16a (including flexible tubes, hoses, etc.) connecting the steam supply source 13 and the reactor 12, and another conduit 16b is provided on the steam supply source 13 side of the conduit 16a from the valve 15a. are set up in a branched manner. A valve 15b is similarly provided on this conduit 16b.

The conduit 16b extends downward, and its tip is connected to a suitable empty container 1.
It has been introduced in 4.

When performing wet oxidation of silicon wafers in the reactor 12, the valve 15a is opened and the valve 15b is closed.
Steam from a steam supply source 13 is sent into the reactor 12 .

On the other hand, when wet oxidation is not performed in the reactor 12, for example, when a silicon wafer is set in the reactor 12,
Close the valve 15a and open the valve 15b to supply steam. Steam from TA13 is sent to conduit 16b. This is because if the steam supply source 13 itself is stopped, it takes time to stably generate steam again.

The water vapor flowing through the conduit 16b is discharged into the empty container 14, cooled, and returned to water. Further, a part of this water vapor condenses within the conduit 16b and returns to water, but this water also flows down within the conduit 16b. These unnecessary waters are stored in the empty container 14.

(c) Shortcomings to be Solved by the Invention In the above-mentioned conventional semiconductor manufacturing apparatus, the empty container 14
It is necessary to regularly dispose of unnecessary water stored inside the empty container 14, and if this is neglected, there is an inconvenience that water overflows from inside the empty container 14 and spreads on the floor.

In addition, the water vapor released into the empty container 14 from the conduit 16b leaks from the opening of the empty container 14, causing problems such as deterioration of the surrounding environment, such as lowering the insulation of surrounding electrical equipment.

The present invention was made in view of the above-mentioned disadvantages, and an object of the present invention is to provide a semiconductor manufacturing apparatus that eliminates the trouble of disposing of unnecessary water and does not cause deterioration of the surrounding environment due to water vapor.

(d) Means for Solving the Problems As a means for solving the above-mentioned disadvantages, the semiconductor manufacturing apparatus of the present invention includes a reactor, a steam supply means for supplying steam to the reactor, and a steam supply means for supplying steam to the reactor. and the reactor, a switching valve means for switching the flow of water vapor, a reevaporation means connected to the switching valve means, and an exhaust means for discharging the water vapor generated by the reevaporation means outdoors. It is equipped with the following.

(E) Function The semiconductor manufacturing apparatus of the present invention allows steam from the steam supply source to flow into the reevaporation means by the switching valve means when the reactor is not used. The re-evaporation means heats the water produced by condensation of a portion of this water vapor, re-evaporates it back to water vapor, and removes the remaining water vapor, together with the water vapor that has not condensed, to the outside in the form of water vapor by the exhaust means. discharge.

(F) Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing the overall configuration of a semiconductor manufacturing apparatus 1 according to this embodiment. 2 is a reactor.

This reactor 2 includes a furnace core tube 21 made of quartz glass or the like,
It is composed of a heater 22 surrounding this furnace core tube 21. A boat 23 made of quartz glass is housed in the furnace core tube 21, and a silicon wafer 24 is placed on the boat 23.
,...,24 are installed. This boat 23 also includes a cap 26 attached to the left end of the furnace tube 21.
By removing it, it can be taken in and out of the furnace core tube 21.

3 is a water vapor supply means. This water vapor supply means 3 has a mantle heater 31 equipped with a storage container 32 for pure water W. A safety valve 33 and a conduit 61 are connected to the upper part of the storage container 32 .

The conduit 61 is connected to a passage pipe 62 via a valve (switching valve means) 51 operated by compressed air. This conduit 6
2 is connected to the right end of the furnace core tube 21.

Furthermore, another conduit 63 branches off from the conduit 61. This conduit 63 is connected to a flexible tube 64 via a valve (switching valve means) 52 operated by compressed air. This tube 64 is guided downward,
It is introduced into the reintroducing means 4.

The reevaporation means 4 includes a metal cover 41 as shown in FIG.
A cup-shaped container 42 is housed in a case 41 whose inner surface is equipped with a heat insulating material 41b. A lid 44 is screwed onto the upper opening of the container 42 .

A ring-shaped packing 43 is sandwiched between this M44 and the upper opening of the container 42, and the container 42 is hermetically sealed.

The M44 shaft has an inlet 4 through which the tube 64 is introduced.
5 is provided. The inlet 45 is composed of a sleeve 45'a that stands up from the center of the lid 44, and a ring cap 45C that is screwed onto the sleeve 45a. The tip of the tube 64 is introduced into the container 42 through the ring cap 45c and the communication hole 45b of the sleeve 45a. At this time, the inner surface of the communication hole 45b and the outer surface of the tube 64 are brought into close contact with each other due to the tightening force of the ring cap 45c, and the container 42 is kept airtight.

In addition, an exhaust port 46 is provided in 1ii44.

An exhaust conduit (exhaust means) 7 is connected to the exhaust port 46 . The tip of this exhaust conduit 7 is guided into an exhaust duct (not shown).

On the other hand, a heater 47 and a thermocouple 48 are provided on the bottom of the container 42 . This thermocouple 48 is for detecting the temperature of the bottom surface of the container 42, and is connected to a power control circuit of a heater 47 (not shown).

Next, the operation of the semiconductor manufacturing apparatus 1 of this embodiment will be explained below.

First, when the wafers 24, ... ζ, 24 are being oxidized in the reactor 2, the valve 52 is closed and the valve 5
1 is open. Due to the heat of the mantle heater 31,
The water vapor created by evaporating the pure water W in the container 32 is transferred to the conduit 6.
1, it flows through the valve 51 and the conduit 62 and is supplied into the reactor core tube 21.

The inside of the furnace tube 21 is heated to a high temperature by a heater 22, and an oxidation reaction takes place between the water vapor and the wafers 24, . . . , 24. The steam flows leftward inside the reactor core tube 21 and passes through an exhaust port 26 provided in the cap 26.
It is discharged from a.

If oxidation is not performed in the furnace tube 21, for example, the wafer 24
. When water vapor flows inside the tube 64, a part of it turns back to water on the inner wall surface of the tube 64, but this water also flows inside the tube 64 together with the water vapor.

Water and steam flowing within tube 64 are discharged into container 42 . The remaining uncondensed water vapor flows from the outlet 46 to the exhaust conduit 7 and is discharged into the exhaust duct. On the other hand, the water remaining in the container 42 is boiled by the heat of the heater 47 and is turned into water vapor again. This water vapor is also discharged into the exhaust duct via the exhaust conduit 7. At this time, since the inside of the container 42 is sealed, water vapor does not scatter around.

When oxidation is performed in the furnace core tube 21 again, the valve 5 is closed again.
1 and close the valve 52. At this time tube 6
No water vapor flows into the container 42, and neither water vapor nor water flows into the container 42. During this time, if all the water in the container 42 has evaporated, the thermocouple 48 detects an abnormal temperature rise, and the heater 47 stops generating heat or reduces the amount of heat generated, thereby preventing the container 42 from being heated dry. Ru.

In the above embodiment, the closed container is equipped with a heater as the re-evaporation means, but the present invention is not limited to this, and the design can be changed as appropriate.

Further, in the above embodiment, two valves operated by compressed air are used as the switching valve means, but the present invention is not limited to this (three-way pulp, etc., design changes can be made as appropriate).

Further, in the above embodiment, an exhaust conduit guided into the exhaust duct is used as the exhaust means, but the exhaust conduit is not limited to this, and the design can be changed as appropriate.

(G) Effects of the Invention The semiconductor manufacturing apparatus of the present invention includes a reactor, a steam supply means for supplying steam to the reactor, and a steam supply means provided between the steam supply means and the reactor to control the flow of steam. Since it is equipped with a switching valve means for switching, a reevaporation means connected to the switching valve means, and an exhaust means for releasing water vapor from the reevaporation means to the outside, there is no need to dispose of unnecessary water. It also has the advantage of being able to prevent unnecessary water overflow accidents.

It also has the advantage of preventing deterioration of the surrounding environment due to water vapor leakage.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a semiconductor manufacturing apparatus according to an embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of a re-evaporation means of the same semiconductor manufacturing apparatus, and FIG. 3 is a conventional semiconductor manufacturing apparatus. FIG. 2 is a diagram briefly showing the configuration of FIG. 2: Reactor, 3: Steam supply means, 4: Reevaporation means, 51 and 52: Valve, 7: Exhaust conduit. Patent applicant ROHM Co., Ltd. agent
Patent Attorney Shigeru Nakamura Figure 1: 20,000 Lira Figure 2

Claims (2)

[Claims] (1) A reactor, a steam supply means for supplying steam to the reactor, a switching valve means provided between the steam supply means and the reactor for switching the flow of steam, and a switching valve means for switching the flow of steam. A semiconductor manufacturing apparatus comprising a reevaporation means connected to the reevaporation means and an exhaust means for discharging water vapor from the reevaporation means to the outside. (2) The semiconductor manufacturing apparatus according to claim 1, wherein the reevaporation means is a closed container equipped with a heater and connected to the switching valve means.