JPH06124936A - Surface treatment device - Google Patents

Abstract

PURPOSE:To perform treatment such as washing of the sample surface of a large area in a short time and at low cost in a friendly way to environment by spraying a small quantity of fluid for surface treatment together with a carrier fluid on a low temperature sample inside an airtight container for performing surface dew condensation by washing. CONSTITUTION:An airtight container 2 having an interior finished sample 1 to be subjected to surface treatment is provided with a cooling part 2a and a drain part 2b. A pure water supply 3, an inert gas supply 4, a fluid mixer 5 and a heated and compressed vapor supply 6 are connected to the airtight container 2 through piping and the switching valves a, b, c, d. To a plurality of inlet port of the fluid mixer 5, connected are a surface treatment fluid supply 7 and a pure water supply 3 through a valve e1, the heated and compressed vapor supply 6 through a valve f.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductors, particularly silicon wafers, liquid crystal display devices, electronic parts such as printed wiring boards,
The present invention relates to a surface treatment device for cleaning, rinsing, removing an oxide film, and drying various objects used in the manufacturing process of optical components such as lenses and prisms and precision mechanical components such as gears and lead frames.

[0002]

2. Description of the Related Art Conventionally, for wet and dry surface treatments such as cleaning, rinsing, oxide film removal, and drying of various objects, a batch system in which treatment tanks and treatment devices are installed in parallel and sequentially sent for each process Also, the single-wafer method in which the object to be processed is fed at a constant speed by a belt conveyor and sequentially processed is mainly used.

[0003]

However, these methods require a large apparatus and require a large installation area. In order to maintain the cleanliness of the apparatus and the large volume space in which the apparatus is installed, a large size is required. High-purity water, gas, chemicals and other expensive substances required for energy-consuming processing are used in large amounts, and in many cases they are disposable, which is uneconomical and requires a large amount of waste liquid / gas treatment. Equipment and processing cost are high. Especially in batch type dipping treatment, treatment liquid such as chemicals and water is repeatedly used, so deterioration of the treatment liquid with time cannot be avoided, which tends to cause deterioration of treatment quality with time. There was a problem.

According to the present invention, in order to eliminate the above-mentioned problems, a low temperature sample in a closed container is sprayed with a small amount of a surface treatment fluid together with a carrier fluid to cause dew condensation on the surface, and then washed with water to form a large area. The purpose is to subject the surface of the sample to a treatment such as cleaning in a short time at a low cost and environmentally friendly.

[0005]

The above-mentioned object of the present invention is to provide a cooling part and a drain part in a closed container (hereinafter simply referred to as a container) containing a sample to be surface-treated, and to provide the closed container. Is connected to each outlet side of a pure water source, an inert gas source, a fluid mixer, and a heating and pressurized steam source through an on-off valve, respectively, and a plurality of inflow ports of the fluid mixer are respectively connected to the surface via switching valves. This can be achieved by connecting the heated and pressurized steam source through a pipe through a processing fluid source, a pure water source, and an opening / closing valve.

[0006]

In order to carry out a surface treatment such as cleaning of a silicon wafer using the above-mentioned apparatus, first, ammonia water and hydrogen peroxide solution (H2O2) are stored in a silicon wafer at a temperature below room temperature stored in a container. Ammonia and H2 O2 can be condensed into a silicon wafer by introducing it into a container together with a medium (carrier) by heating and pressurized steam.

Next, after spray rinsing the sample with cooled pure water, introducing heated steam, expelling the air in the container to fill the container with high temperature steam, and then sealing the container, and then the container By cooling a part of the inside, the inside of the container can be brought into a state close to a vacuum, and water can be rapidly evaporated and removed from the surface of the silicon wafer.

It is possible to remove the silicon oxide film by introducing hydrogen fluoride into the container together with a carrier gas of nitrogen gas while keeping the container closed.

Finally, after introducing nitrogen gas into the container to return it to normal pressure, the lid can be opened to take out the surface-treated silicon wafer. During these operations, the silicon wafer has a structure in which it slowly rotates about once every two seconds through a support frame supported by an airtight bearing with a mechanical seal from the outside, and / or the spray nozzle itself has an airtight bearing. It is preferable to adopt a structure that rotates by rotating.

[0010]

EXAMPLES Examples will be described with reference to the drawings. First, as shown in FIG. 1, the basic structure of the present invention is that a sample 1 such as a silicon wafer to be subjected to surface treatment such as cleaning and removal of an oxide film is supported in a known heat-conductive closed container 2 by a known hermetic bearing. A cooling unit 2a and a drain unit 2b are provided at the bottom of the closed container 2 while being arranged via a support frame or the like.

Further, the closed container 2 includes a low temperature pure water source 3 of about 15 ° C., an inert gas source 4 such as nitrogen gas, a fluid mixer.
5 and the respective outlet sides of the heated pressurized steam source 6 by the heater 8 and the like are connected to fluid-operated on-off valves a, b, c,
Pipe connection via d.

Further, a plurality of surface treatment fluid sources 7, such as ammonia water, H2 O2 and Hcl, are provided at a plurality of inlets of the fluid mixer 5 via switching valves e1, e2, e3, respectively.
7, the heating / pressurizing steam source 6 is connected by piping through the pure water source 3 and the open / close valve f to form a basic part of the surface treatment apparatus according to the present invention.

A water cooling pipe 9 is wound around the cooling part 2a of the container 2 to circulate cold water from a well-known cooler 10 via a valve g, and an opening / closing valve h is connected to the drain part 2b. It can be drained when desired, and the container 2
The gas inside can be exhausted by opening the upper and lower open / close valves j individually or simultaneously when desired.

The container 2 may be sealed by a well-known means such as an airtight packing type opening / closing lid. Further, as the airtight bearing, a chemical resistant rubber O-ring seal may be adopted, and the pressure in the container 2 is a pressure. The total PG can be used for inspection.

The basic structure of the surface treatment apparatus according to the present invention is as described above.
Intermediate closing type fluid operated switching valves are used for 1, e2, e3, and as a concrete example of the piping, a surface treatment fluid source 7 is provided at one of the two inlets i1 of each switching valve. In addition to the communication connection, the pure water source 3 is connected to the other inflow port i2.
A total of three outlets O, one each of 1, e2, and e3, are individually connected to the three inlets of the fluid mixer 5 for piping.

In the case of this example, the sample 1 is suitable for the surface treatment of an object such as a silicon wafer which requires a severe surface treatment, and the intervals of a plurality of different surface treatments for the same sample are aimed at and the inside of each communication pipe is examined. Drain the remaining fluid by operating the three-way selector valves e1, e2, and e3 together with pure water so that it does not hit the sample in container 2 and discharge it.
After draining from 2b to wash and remove the residual fluid in each pipe, the next surface treatment is performed.

The present invention has the above-described specific structure, and the procedure for cleaning a silicon wafer with the structure shown in the figure will be described below. First, the sample 1 made of a silicon wafer is housed in the closed container 2, and the sample is structured so as to slowly rotate by the support frame supported from the outside through the mechanical seal as described above. In this state, all the valves a, b, c, d, e1, e2, e3, g, h, j are closed.

Next, a treatment fluid from a surface treatment fluid source 7 such as aqueous ammonia or hydrogen peroxide is introduced into the fluid mixer 5 by opening the valve e1, and the valves f and c are opened to heat the fluid. The above-mentioned processing fluid is introduced into the container 2 using pressurized steam as a medium (carrier). The processing fluid introduced into the container condenses on the surface of the sample 1 such as a silicon wafer along with water vapor.

Here, after closing the valve f and switching the switching valve e1, the valve h is opened and the valve a is opened to about 1
Pure water at 5 ° C is put into the container 2 for about 10 seconds from the nozzle n to the sample 1
The sample 1 is sprayed and rinsed onto the surface of the sample 1, and the deionized water that has passed through the switching valve e1 gradually flows into the container 2 through the fluid mixer 5 and the opening / closing valve c to remove the residual surface treatment fluid remaining in the piping. After flowing out with pure water and draining from the drain valve h, the valves a and h are closed and the switching valve e1 is returned to its original state.

Next, another surface treatment fluid such as hydrochloric acid is introduced into the fluid mixer 5 through the switching valve e2, the valves f and c are opened, and the pressurized steam is introduced into the container 2 as a medium. The processing fluid introduced into the container 2 condenses on the surface of the sample 1 such as a silicon wafer together with water vapor.

Here, the valve f is closed, the switching valve e2 is switched, the valve h is opened, the valve a is opened again, and pure water cooled to about 15 ° C. is put into the container 2 from the nozzle n to the sample 1 for about 10 seconds. The sample 1 is spray-rinsed again with pure water, and the pure water that has passed through the switching valve e2 gradually flows into the container 2 through the fluid mixer 5 and the opening / closing valve c, and the residual fluid that remains in the pipe, etc. Is removed together with pure water and drained from the drain valve h, then the valves a and h are closed and the switching valve e2 is returned to its original state.

Next, the valves d and j are opened to introduce the heated steam directly into the container 2, and the air in the container is expelled from the valve j to the outside to fill the container 2 with steam. Valve d
By closing j and h to close the container and then opening the valves g and g, cooling water is supplied from the cooling source 10 to the water cooling pipe 9 in the container cooling part 2a to cool the lower part of the container 2. After making the inside of the container 2 close to a vacuum and evaporating and removing water from the surface of the sample 1 such as a silicon wafer, the valves g and g are closed.

The valve c is opened and the switching valve e3 is switched to introduce hydrogen fluoride for removing an oxide film into the closed container 2 using nitrogen gas as a medium to remove the silicon oxide film. After that, the switching valve e3 is returned to the original state and the valve c is closed.

Next, the valve b is opened to feed an inert gas such as N 2 gas into the container 2 from the inert gas source 4, and the hydrogen fluoride gas is fed to the well-known exhaust gas treating apparatus from the upper and lower valves j. 2 Replace the inside with inert gas and
After returning the inside pressure to atmospheric pressure, open the airtight lid and take out the surface-treated sample 1 such as silicon wafer.

[0025]

Since the present invention is constructed as described above, it has the following effects. Ammonia water and hydrogen peroxide solution are introduced into the container together with the medium (carrier) by heating and pressurized steam in the silicon wafer housed in the closed container.
Ammonia and H2 O2 can be condensed on a silicon wafer.

After spray rinsing the cooled pure water, introducing heated steam, expelling the air in the container to fill the container with high temperature steam, and then sealing the container,
By cooling a part of the inside of the container, the inside of the container can be brought into a state close to a vacuum, and water can be rapidly evaporated and removed from the surface of the silicon wafer.

Therefore, according to the present invention, all the steps of the surface treatment of the sample 1 can be performed in a clean space in the small airtight container 2, and the environment is not polluted and does not pollute the environment. The first effect is that a compact surface treatment device can be provided at low cost.

Further, according to the present invention, a small amount of the surface treatment fluid such as the cleaning treatment liquid can be used, and since only the novel treatment fluid is used, the treatment quality is not deteriorated and the waste water.
There are second and third effects that the burden on waste gas treatment can be reduced and the running cost can be reduced.

In particular, in the present invention, the unnecessary surface treatment fluid remaining in the piping, the on-off valve, etc. is replaced by the switching valve e1.
The fourth effect is to prevent the mixing of different kinds of treatment chemicals and to surely prevent various troubles due to the mixing because it is possible to drain pure water and the drain to the outside at intervals of a plurality of different kinds of surface treatments on the same sample by the individual operations of ~ e3. There is also.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 Sample to be surface treated 2 Closed container 2a Cooling part 3 Low temperature pure water source 4 Inert gas source 5 Fluid mixer 6 Heated pressurized steam source 7 Surface treatment fluid source a to d, f to j Open / close valve e1, e2, e3 (intermediate closing type) switching valve

Claims (1)

[Claims] 1. A closed container 2 containing a sample 1 to be surface-treated is provided with a cooling part 2a and a drain part 2b, and the closed container 2 has a pure water source 3, an inert gas source 4 and a fluid mixer. 5 and the heating / pressurizing steam source 6 are connected to the fluid mixer 5 through the on-off valves a, b, c and d, respectively.
A surface treatment apparatus in which the heating and pressurized steam source 6 is connected to the plurality of inflow ports via a switching valve e1 through a surface treatment fluid source 7, a pure water source 3 and an opening / closing valve f.