JP2001269634A - Treatment method for semiconductor material or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment method for semiconductor materials or the like capable of further effectively removing the impurities sticking to the surfaces of media to be treated and completely removing even the impurities intruding into surface grooves known as trenches and confined by air. SOLUTION: The media W to be treated are housed in a hermetically closed process chamber 1 and, while the treating liquid in the chamber is boiled under reduced pressure during the water washing treatment by the treating liquid sent into the chamber from its bottom, the water washing treatment is executed, by which the impurities sticking to the surface of the media W to be treated are effectively removed and further, even the impurities in the surface grooves 6, etc., known as the trenches are effectively flushed away and are completely removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing semiconductor materials and the like. The present invention relates to a processing method for washing and removing impurities such as dust, organic residues, and inorganic residues attached to a medium to be processed after being washed.

[0002]

2. Description of the Related Art Conventionally, as a water washing process for washing impurities such as dust, organic residues or inorganic residues from a semiconductor material, a process in which a processing solution is continuously fed from the bottom of a processing chamber for storing a semiconductor material. A method is well known in this kind of semiconductor material manufacturing process (for example, it is known in Japanese Patent Application Laid-Open No. 6-326073).

By the way, a large number of small surface grooves called trenches exist on the surface of a semiconductor material, and impurities often enter these surface grooves and the like, and air is often contained therein.

[0004]

However, in the conventional processing method in which water is fed from the bottom of the processing chamber to wash away impurities, impurities adhering to the surface of the medium to be processed can be removed by washing. However, it is not possible to remove air present in the surface groove or the like. In other words, since impurities trapped in the surface grooves and the like by air cannot be washed out from the grooves, the production yield is extremely poor, and an improvement has been required.

In view of such circumstances, as a result of numerous studies, the inside of a closed processing chamber in which the medium to be processed is immersed is evacuated to a reduced pressure, and the processing liquid is boiled under reduced pressure. Focusing on the fact that bubbles are also generated from the surface portion or surface groove of the medium to which the impurities are attached, and that the generation of the bubbles has an excellent effect of washing off the impurities from the medium to be processed, the present invention has been achieved. The purpose is to remove impurities such as dust, organic residues or inorganic residues adhering to the surface more effectively, and impurities entering the surface grooves and the like and trapped by air. It is an object of the present invention to provide a method for treating a semiconductor material or the like which has been developed so as to completely remove the same.

[0006]

In order to achieve the object, the present invention provides a processing solution comprising pure water or a processing solution in a sealed processing chamber in which a medium to be processed is immersed in the processing solution. That is, the medium to be treated is washed with water while boiling under reduced pressure. Further, the boiling of the processing solution under reduced pressure is performed during the water washing process in which the processing solution is continuously fed from the bottom of the processing chamber. Further, the reduced pressure in the processing chamber is set within a range of -720 to -30 mmHg. The setting of the degree of pressure reduction is appropriately selected depending on the water temperature (for example, 10 to 95 ° C.) of the processing liquid to be used. In the present invention, a treatment liquid having a low water temperature is used in the initial stage of the water treatment of the medium to be treated, and the water is washed while the treatment liquid is boiled under reduced pressure.
Then, after an appropriate time has elapsed from the start of the water washing process using the low processing solution, the water washing process is performed while gradually switching the processing solution to a high water temperature and boiling the processing solution under reduced pressure to obtain a surface called a trench. The grooves and the like are effectively washed with water. According to such a configuration, the pressure in the chamber is reduced by suction to a reduced pressure (mmHg) range in which the processing liquid in the processing chamber is boiled under reduced pressure. Then, bubbles are generated from the surface portion of the medium to which the impurities are attached, and small surface grooves called trenches existing on the surface. The final washing (rinsing treatment) of the medium to be treated is performed by the generation of the bubbles and the flow of the treatment liquid forming a rising water flow from the bottom to the top of the chamber. As a result, cleaning for removing impurities from the surface of the medium to be processed is more effective, and
Impurities are reliably washed away from the surface grooves and the like by physical force due to the generation of bubbles from the grooves.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a processing apparatus for performing the processing method of the present invention.
2 is a processing liquid generating unit, 3 is a drainage / vacuum suction unit, 4 is a steam generating unit, 5 is a gas supply unit, and a processing liquid in a closed processing chamber 1 in which the medium to be processed W is immersed. The structure is such that the final washing process of the medium to be dried W is performed while boiling under reduced pressure. However, the processing chamber 1 is provided by the drainage / vacuum suction unit 3.
The inside of the chamber is suctioned and depressurized to a reduced pressure (mmHg) range in which the processing liquid in the inside boils under reduced pressure. Then, bubbles are generated from the surface portion of the medium to which the impurities adhere and the small surface grooves 6 called trenches existing on the surface (FIG. 2).
(See the enlarged cross-sectional view of (b).) The final washing (rinsing treatment) of the medium to be treated is performed by the generation of the bubbles and the flow of the treatment liquid forming a rising water flow from the bottom to the top of the chamber 1.

In the present invention, depending on the temperature of the processing solution to be used, when a processing solution having a water temperature of 10 to 95 ° C. is used, the reduced pressure in the processing chamber 1 is reduced to −720 to −3.
It is important to set the range to 0 mmHg in order to realize the present invention. For example, in the case of a processing solution having a water temperature of 15 to 20 ° C., it is preferable to set the reduced pressure in the processing chamber 1 to about −700 mmHg.

The processing chamber 1 has a double structure comprising an inner chamber 1-1 and an outer chamber 1-2 provided with an openable / closable lid 7.

The inner chamber 1-1 has a size capable of accommodating a large number of media W to be processed in parallel, and is formed in a bottomed box shape having an upper surface opening having a depth capable of being immersed in the processing liquid. A processing liquid supply / drain port 8 is formed in the center of the inclined bottom, and the processing liquid generating unit 2 is connected through a water supply flow path 9 so that the chamber 1 is removed from the bottom of the inner chamber 1-1 at the time of final washing. 1
The processing liquid is continuously fed into the chamber (FIG. 2).
(B), (b)). Then, the drainage / vacuum suction unit 3 is connected via the drainage channel 10 branched from the middle of the water supply channel 9 and the header 11 connected to one end of the drainage channel 10, and the final washing is completed. Later inside chamber 1-1
The treatment liquid in the inside is forcibly drained from the bottom (the state shown in FIG. 2C).

The outer chamber 1-2 is formed in the shape of a box with a bottom and an upper opening having a size that allows the inner chamber 1-1 to be freely inserted inside as shown in the figure, and a closed lid 8 is opened and closed at the upper opening. It will be equipped as possible. Then, an overflow port 12 is formed in the inclined bottom, and the overflow port 12 is connected to the drain / vacuum suction unit 5 through the overflow channel 13 over the above-mentioned header 11,
During the final washing process, the processing liquid (so-called overflow water) overflowing from the upper opening of the inner chamber 1-1 is forcibly drained to the outside (the state shown in FIGS. 2A and 2C).
In addition, a steam inlet 14 and a gas supply port 15 are formed on a wall located above the upper opening of the inner chamber 1-1, respectively,
One end of the steam flow path 16 is connected to the steam inlet 14, and after the final washing is completed, the processing liquid in the inner chamber 1-1 is forcibly drained from the bottom, and the organic liquid is placed in the closed chamber 1 which is evacuated. The solvent is sucked and introduced (the state shown in FIG. 2C). In addition, the gas supply port 15
The gas supply unit 5 is connected to the processing chamber 17 through a gas supply unit 17, and after vapor drying of the medium W to be treated with the organic solvent is completed, the organic vapor or moisture remaining in the inner and outer chambers 1-1 and 1-2 is removed. After forcibly evacuating the chambers 1-1 and 1-2, a clean gas (eg, N ₂ ) is fed into the evacuated chambers 1-1 and 1-2 (the state shown in FIG. 2 (d)). The inside of the chambers 1-1 and 1-2 is returned to normal pressure (atmospheric pressure), and thereafter, the closed lid 8 is opened so that the medium to be processed can be taken out (state of FIG. 5 (e)).

An outer chamber having a steam inlet 14 opened.
A suction port 18 is formed in the upper side wall portion of 1-2, and the header 1 described above is formed.
1, the suction chamber 19 is connected, and the drainage / vacuum suction unit 3 suctions and depressurizes the inside of the processing chamber 1 during the final rinsing process, so that the processing target medium W is immersed in the inner chamber 1-1. The processing liquid is boiled under reduced pressure to generate bubbles in the processing liquid (the state shown in FIG. 2B). In addition, bubbles are also generated from the surface portion to which impurities adhere and the surface grooves 6 existing on the surface. 2 (b), and the bubbles adhere to the surface of the medium W to be processed and the surface grooves 6 to be processed by utilizing the physical force generated by the bubbles. The washing effect (rinsing action) at the time of the final washing of the medium W is promoted, so that the final washing process can be performed efficiently and in a short time.

In the drawing, reference numeral 20 denotes a water supply valve provided in the water supply flow path 9 for the treatment liquid, 21 denotes a drain valve provided in the drainage flow path 10, 22 denotes an overflow valve provided in the overflow flow path 13, and 23 denotes an overflow valve. A steam valve arranged in the steam passage 16,
24 is a gas valve provided in the gas flow path 17, 25 is a suction flow path
This is a pressure reducing valve provided at 19.

Next, the processing method of the present invention using the processing apparatus constructed as described above will be briefly described. The medium W to be processed is housed in parallel in the inner chamber 1-1, and the upper surface opening of the outer chamber 1-2 is opened. Is closed by the closed lid 8, the processing liquid generating unit 4 is operated, the water supply valve 19 is opened, and the processing liquid of, for example, about 10 ° C. is supplied into the inner chamber 1-1 at a predetermined flow rate (m / s). Sent in. Then, a rising water flow of the processing liquid that contacts the surface of each processing target medium W is formed in the inner chamber 1-1, and the final rinsing (rinsing processing) of each processing target medium W starts (FIG. 2A). State). At the same time as the start of this final washing process,
At a predetermined timing, the decompression valve 25 is opened and the suction / decompression inside the processing chamber 1 is started by the drain / vacuum suction unit 3 which is continuously operated, and a rising water flow is formed from the bottom of the inner chamber 1-1. The processing liquid flowing to the upper portion is boiled under reduced pressure (the state shown in FIG. 2B). Then, bubbles are generated in the processing liquid, and the bubbles float while physically contacting (colliding) with the surface of the processing target medium W, and a surface portion to which impurities adhere and a small portion called a trench. Bubbles are also generated from the surface grooves 6 and the like. Then, after an appropriate time from the start of the treatment with the treatment liquid at about 10 ° C., the water washing process is performed while the treatment liquid having a water temperature of, for example, about 30 ° C. is fed and the treatment liquid is boiled under reduced pressure. Thereby, impurities adhering to the surface of the processing target medium W are effectively washed away by the bubbles and the rising water flow of the processing solution, and the physical force of the bubbles effectively acts on the surface grooves 6 and the like. The impurities are also peeled off from the surface grooves 6 and the like by the physical force of the bubbles and washed away (see an enlarged sectional view of FIG. 2B). The boiling under reduced pressure of the treatment liquid during the final washing is optional, such as intermittently or continuously performed until the final washing treatment is completed.

The final washing (rinsing treatment) of the medium W to be treated with the rising water flow of the treatment liquid and bubbles generated by the boiling of the treatment liquid under reduced pressure is completed, the water supply valve 20 and the pressure reduction valve 25 are closed, and the inner chamber 1 is closed. When the supply of the processing liquid to the processing chamber 1 is stopped and the suction and pressure in the processing chamber 1 are stopped, the drain valve 21 is opened and the processing liquid in the inner chamber 1-1 is discharged by the drain / vacuum suction unit 3 which is continuously operated. The water is forcibly drained out of the chamber 1-1 from the water supply / drain opening 8 at the bottom,
With this forced drainage, the inside of the outer chamber 1-2 including the inside of the inner chamber 1-1 is gradually evacuated. Then, with the evacuation, the steam valve 23 is opened, and the inner and outer chambers 1-1 and 1-2 are opened.
Organic vapor is introduced into the inner and outer chambers 1-1 and 1-2 from the vapor inlet 14 of the outer chamber 1-2 by the negative pressure due to the internal vacuum so as to be sucked into the inner and outer chambers 1-1 and 1-2 (state of FIG. 2C).

The organic solvent introduced into the inner chamber 1-1 comes into contact with the surface of the processing target medium W which is exposed as the water level L of the processing liquid is lowered, and vapor replacement with water droplets on the surface is performed. You. Thereafter, when the processing liquid in the inner chamber 1-1 is completely forcibly drained, the steam drying of the processing target medium W by the organic vapor is completed, and when the steam valve 23 is closed, the drain / vacuum suction unit that is continuously operated is operated. 3, inner and outer chambers 1-1, 1
-2 The organic vapor and moisture remaining in the
Drain port 8 and overflow port 1 of outer chamber 1-2
It is forcibly exhausted from 2.

After the final washing with the treatment liquid, steam drying with organic vapor is performed, and the organic vapor and moisture are completely forcibly exhausted from the inside and outside chambers 1-1 and 1-2.
1. When the overflow valve 22 is closed, the gas valve 24 is opened and clean gas is sent from the gas inlet port 15 of the outer chamber 1-2 into the inner and outer chambers 1-1 and 1-2, and the vacuum state (under negative pressure) is established. The inside of the chambers 1-1 and 1-2 is returned to the atmospheric pressure (normal pressure) (the state of FIG. 2 (d)). Thereby, the processing target medium W can be taken out from the inner chamber 1 by opening the sealing lid 7 for closing the upper opening of the outer chamber 1-2 (the state of FIG. 2 (e)).

Therefore, according to the processing method of the present invention, during the final washing of the processing target medium W with the processing liquid forming the rising water flow from the bottom to the upper part of the inner chamber 1-1, bubbles are generated by the reduced pressure boiling of the processing liquid. Is generated, and bubbles are also generated from the surface portion of the processing target medium W to which impurities adhere, the surface groove 6 on the surface, and the like.
The final washing (rinsing treatment) of the medium to be treated is performed by the generation of the bubbles and the flow of the treatment liquid forming a rising water flow from the bottom to the top of the chamber. Thereby, the cleaning for removing impurities from the surface of the medium to be processed W is more effective, and the impurities are also peeled off from the surface grooves 6 and the like by the physical force due to the generation of bubbles from the grooves 6 so as to be surely washed. Dropped.

In the above embodiment, the processing chamber 1 is described as having a double-chamber configuration including the inner and outer chambers 1-1 and 1-2. Good and optional. In this case, an overflow port is provided in the chamber wall so that excess processing liquid is forcibly drained from the upper side where the medium to be processed W is immersed in the final washing,
An overflow channel is connected to the overflow port.

It goes without saying that the medium W to be treated after the final washing treatment may be completely dried using hot air or centrifugal force (spindle dryer).

[0021]

Since the method for treating a semiconductor material or the like according to the present invention is constituted as described above, the following functions and effects are obtained. By boiling the processing solution in a closed processing chamber in which the medium to be processed is immersed in a immersive manner under reduced pressure, bubbles are also generated from the surface portion of the medium to which impurities adhere and small surface grooves called trenches. Then, the medium to be treated can be washed with water using the physical force caused by the generation of the bubbles. As a result, the washing for removing impurities from the surface of the medium to be treated is more effective, and the impurities are peeled off from the surface grooves and the like by the physical force due to the generation of bubbles from the grooves, so that the impurities are surely washed off.

Further, as described above, the synergistic effect of the physical force of the bubbles generated by the boiling under reduced pressure of the processing solution and the flow of the processing solution forming a rising water flow from the bottom to the top of the processing chamber (the cleaning promoting power). Improvement) allows the medium to be treated to be more effectively washed with water. As a result, the processing efficiency is overwhelmingly faster than in the past, and the production yield of semiconductor materials and the like can be expected to be improved, which is beneficial.

Therefore, according to the present invention, impurities such as dust, organic residues and inorganic residues adhering to the surface of the medium to be treated can be more effectively removed. In addition, it is possible to provide an epoch-making treatment method capable of completely removing impurities trapped by air by entering small surface grooves called trenches.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a processing apparatus that performs a processing method of the present invention.

FIGS. 2A and 2B are schematic views showing an example of a manufacturing process of a semiconductor material or the like according to the processing method of the present invention. FIG. 2A shows a state in which a processing liquid is fed into a processing chamber from the bottom to perform a final washing. ) Is to reduce the pressure inside the processing chamber and boil the processing solution under reduced pressure during the final washing process, thereby generating bubbles in the processing solution and performing final washing while generating bubbles also from the grooves on the surface. (C)
After the final washing is completed, the processing liquid is forcibly drained from the bottom after the final washing, and the organic solvent is introduced into the chamber through the vapor introduction pipe by evacuation of the processing chamber,
(D) is a state in which organic vapor or moisture remaining in the processing chamber is forcibly exhausted, and then an inert gas is introduced into the processing chamber to return the inside of the chamber to normal pressure (atmospheric pressure). Opening the sealing lid and removing the completely dried medium from the processing chamber

[Explanation of symbols]

1: processing chamber 2: processing liquid generation unit 3: drainage / vacuum suction unit 4: steam generation unit 5: gas unit 6: surface groove 7: closed lid W: medium to be processed

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B201 AA03 AB45 BB02 BB13 BB82 BB92 CB12 4K030 DA08 5F043 DD05 DD30 EE03 EE27 GG10

Claims (3)

[Claims] 1. A method for processing a semiconductor material or the like, wherein the processing medium is washed with water while the processing liquid in a closed processing chamber in which the medium to be processed is immersed is immersed under reduced pressure. 2. A method for treating semiconductor material or the like, wherein the reduced pressure boiling of the treatment liquid according to claim 1 is performed during a water washing treatment in which the treatment liquid is continuously fed from the bottom of the treatment chamber. 3. A method for processing a semiconductor material or the like, wherein the reduced pressure in the processing chamber according to claim 1 or 2 is in a range of -720 to -30 mmHg.