KR20010094349A - Equipment for cleansing of wafer and method for cleansing of wafer - Google Patents

Abstract

PURPOSE: An apparatus and a method for cleaning a wafer are provided to improve cleaning capacity and etching uniformity by performing a cleaning process, a rinsing process, and a dry process within one bath. CONSTITUTION: A single chamber(100) performs all processes such as a cleaning process, a rinsing process, and a dry process. A wafer(101) is installed in the chamber(100). A chemical and DI(DeIonized) supply line(102a) supplies chemicals or DI to the chamber(100). A chemical and DI exhaust line(103a) exhausts the chemicals or DI. A chemical injection module(104) decides a mixing ratio of the injected chemicals. An IPA(IsoPropyl Alcohol) supply module(105) injects heated IPA to the chamber(100) in order to dry the wafer(101) after the cleaning process is completed. An IPA supply line(103a) supplies the IPA from the IPA supply module(105) to the chamber(100). An IPA exhaust portion(102b) exhausts the IPA after the dry process is completed.

Description

Wafer cleaning equipment and its cleaning method {EQUIPMENT FOR CLEANSING OF WAFER AND METHOD FOR CLEANSING OF WAFER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor cleaning, and more particularly, to a wafer cleaning apparatus and a cleaning method thereof.

Referring to the accompanying drawings, a conventional wafer cleaning apparatus and a cleaning method thereof will be described.

1 is a plan view illustrating a cleaning apparatus according to a procedure of performing a conventional wafer cleaning method, and FIG. 2 is a flowchart illustrating a process of moving from a conventional chemical bath to a rinse bath.

Conventional cleaning equipment is largely composed of a chemical bath (bath) for cleaning and etching of the wafer, a rinse bath (bath) for removing the chemical on the wafer, and a drying bath for drying the wafer, respectively.

That is, the conventional wafer cleaning apparatus includes a wafer load unit 10 into which a wafer is loaded as shown in FIG. 1, a first chemical bath 11 for cleaning or etching a wafer, and the cleaning or etching process. A first rinse bath 12 for rinsing the old wafer, a second chemical bath 13 for rinsing or etching the wafer again, and a second rinse bath 14 for rinsing the cleaned or etched wafer ), A dry bath 15 for drying the rinsed wafer, and a wafer unload section 16 for unloading the dried wafer.

As described above, the conventional cleaning method using the conventional cleaning equipment configured to sequentially perform washing and rinsing and drying through the respective baths is as follows.

The wafer is cleaned / etched in the first chemical bath 11 using a wet bench type equipment as shown in FIG. 1 and then rinsed in the first rinse bath 12 by rinsing in the second chemical bath 13. / Etch → The operation of drying in the rinse → draw bath 15 in the second rinse bath 14 is performed step by step. At this time, the movement to each bath is performed by a robot.

That is, the wafer is moved in the mixed chemical bath at a specific ratio, and the cleaning and etching processes are performed.

At this time, the solution in the chemical bath is replaced with a new solution at regular intervals, and the rinse bath between the chemical baths is always supplied with fresh deionized (DI).

As shown in FIGS. 2A and 2B, the wafer 17 is moved to the chemical bath 11 by a robot. At this time, the chemical bath 11 is not filled with all the chemicals.

The wafer 17 then entered into the chemical bath 11 first enters and the portion contacted with the chemical exits the last from the chemical bath 11 as shown in FIG.

Accordingly, there is a fear that a particular portion may be excessively etched.

And when the wafer 17 is moved from the chemical bath 11 to the rinse bath 12, as shown in FIG. An oxide film is formed, which results in a deterioration of quality during the process.

In addition, foreign matter in the atmosphere may be adsorbed onto the wafer surface, thereby degrading the cleaning capability in the rinse bath 12.

Conventional wafer cleaning equipment and the cleaning method as described above has the following problems.

First, since the cleaning process is performed while the wafer is moved between the chemical baths, the wafer is exposed to the air to form a natural oxide film, and the film quality is deteriorated. Also, foreign matters in the air may be adsorbed onto the wafer surface, thereby degrading the cleaning ability.

Second, as the mixing ratio of the chemical in the chemical bath is changed depending on the use time, the cleaning ability is lowered.

Third, since the wafer advancing direction into the chemical bath is a first-in last-out method, the etching uniformity is poor in the same wafer during the etching process.

The present invention has been made in order to solve the above problems, and in particular, an object of the present invention is to provide a wafer cleaning apparatus and a method for cleaning the same, which can increase the cleaning capacity and achieve uniform etching.

1 is a plan view showing a cleaning apparatus according to a procedure of proceeding a conventional wafer cleaning method

2 is a flowchart illustrating a process of moving from a conventional chemical bath to a rinse bath.

3 is a plan view illustrating a wafer cleaning apparatus according to the present invention.

4 is a process flow diagram for performing a chemical cleaning / etching process and a rinse process according to the present invention.

Explanation of symbols for the main parts of the drawings

100 chamber 101 wafer

102a: chemical and DI supply path 102b: dry gas outlet

103a: chemical and DI outlet 103b: dry gas supply passage

104: chemical supply module 105: dry gas (IPA) supply module

The wafer cleaning equipment of the present invention for achieving the above object is a single chamber in which both wafer cleaning / etching and drying processes are performed, and a chemical or die (DI) in the top direction at the bottom of the chamber. A first supply path for supplying de-ionized, a first discharge port for discharging the chemical or DI injected into the chamber, and a mixing ratio of the chemical to be injected is determined and the first supply A chemical supply module for supplying chemical to the furnace, a second supply path for supplying dry gas from a top of the chamber to a bottom direction for drying the wafer, and injection into the chamber And a dry gas supply module for supplying dry gas to the second supply path and a second outlet for discharging the dried gas.

In the wafer cleaning method of the present invention having the above configuration, the first step of cleaning the wafer by filling a deionized (DI) in a top direction from the bottom of the chamber in which the wafer is embedded, the chamber A second step of cleaning and etching the wafer by injecting chemical in a bottom direction at a bottom of the wafer, and filling the DI in a top direction at a bottom of the chamber. A third step of cleaning the second step, a fourth step of repeating the second step and the third step N times, and a drying gas is injected from the top of the chamber to the bottom direction to dry the wafer; It characterized in that it comprises a fifth step.

Referring to the accompanying drawings, a wafer cleaning apparatus of the present invention and a cleaning method thereof will be described.

3 is a plan view illustrating a wafer cleaning apparatus according to the present invention, and FIG. 4 is a process flowchart of performing a chemical cleaning / etching process and a rinse process according to the present invention.

In the present invention, the cleaning, rinsing and drying processes are performed in a bath without moving the wafer during the cleaning process.

As described above, the wafer cleaning equipment according to the embodiment of the present invention in which cleaning, rinsing and drying are performed in a bath through a series of processes, as shown in FIG. 3, cleaning, rinsing, and drying of the wafer are all performed. A single chamber 100, a wafer 101 embedded in the chamber 100, and a chemical and DI supply path for supplying chemical or De Ionized (DI) to the chamber 100 (102a), a chemical injection to determine the mixing ratio of the chemical and DI (outlet) (103) for discharging the chemical and DI (DI) injected into the chamber 100, and the chemical to be injected Module 104, a dry gas (IPA) supply module 105 for injecting heated IPA into the chamber 100 to dry the wafer 101 after the cleaning process is finished, and the dry gas (IPA) supply A dry gas (IPA) supply passage 103b for supplying dry gas (IPA) from the module 105 to the chamber 100, After the manufacturing process consists of the end of the drying gas (IPA) outlet (102b) for discharging the dry gas (IPA).

In the above, the chemical and De Ionized (DI) supply passage 102a is configured to supply the chemical or DI from the bottom of the chamber 100 to the top, and the dry gas (IPA) supply passage. 103b is configured to inject dry gas (IPA) from the top of the chamber 100 to the bottom.

And the chemical and DI supply path (102a) is composed of a plurality of supply for supplying the chemical and one supply for supplying the DI.

The dry gas (IPA) outlet 102b is connected to each other at one end of the chemical and DI supply path 102a.

The dry gas (IPA) supply path 103b and the chemical and DI outlets 103a are located at both sides of the chamber 100 and are connected to each other.

In FIG. 3, the solid arrows indicate the flow direction of DI and chemical during the cleaning process after the chamber 101 is closed after the movement of the wafer 101 into the cleaning chamber 100 is completed.

After the cleaning process is completed, the dotted arrow indicates that the dry gas (IPA) is supplied from the dry gas (IPA) supply module 105 to the chamber 100 to dry the wafer 101, and then the dry gas (IPA) is stored in the chamber ( 100) shows the process of discharging to the outside.

The wafer cleaning method using the wafer cleaning equipment as described above will be described with reference to FIGS. 3 and 4.

First, a batch unit (25-50 sheets) of wafers are moved to a closed cleaning chamber 100 using a robot.

Thereafter, DI (De Ionized) is flowed to fill the inside of the cleaning chamber 100 with DI. (Before the process of Figure 4)

Then, as shown in (a) and (b) of FIG. 4, the chemicals required to perform the chemical cleaning / etching process are mixed at a constant ratio, and then injected into the cleaning chamber 100 using D.I as a carrier.

In this case, the injection of the DI and the chemical is performed in the top direction at the bottom of the cleaning chamber 100.

Thereafter, as shown in (c) and (d) of FIG. 4, after a predetermined time has passed, DI is flowed into the cleaning chamber 100 to rinse the chamber 100 and the wafer 101.

As described above, DI is introduced into the chamber 100 to perform a rinse process between chemical cleaning steps. In this case, the inflow of DI is made from the bottom to the top and accordingly, first-in first-out is performed.

Thereafter, the desired process (washing / etching and rinse process) is repeatedly performed, followed by drying by injecting dry gas (IPA) into the cleaning chamber.

At this time, the dry gas IPA flows from the top of the chamber 100 to the bottom to dry the wafer in the cleaning chamber 100.

As above, each chemical is pressurized into the chamber 100 with mixing in D.I according to a pre-set ratio at each operation. At this time, ultra sonic wave can be added at the chemical step to maximize the cleaning ability.

Since the cleaning chamber 100 is in a sealed state and the cleaning chamber 100 is filled with DI or chemicals after the cleaning and etching process, the wafer 101 is not exposed to the air.

In addition, the flow of DI and chemicals flows from the bottom of the chamber to the top so that the chemical on the wafer is first-in first-out.

In other words, when the wafer 101 in a batch unit is introduced into the chamber 100 as described above, the chamber 100 is filled with DI to clean the wafer 101.

Thereafter, the chemical is injected into the chamber 100 to clean / etch, and thereafter, DI is again injected to rinse (clean) the wafer 101.

After the chemical is injected into the chamber 100 again, the cleaning / etching process is repeated, and the process of injecting and rinsing by injecting DI again N times is followed by injecting dry gas (IPA) into the chamber 100 and then wafer 101. To dry.

In this case, when the process is repeated N times, the chemical may be fresh (clean), and the mixing rate may be different.

The wafer 101 is then taken out of the chamber 100.

The wafer cleaning equipment of the present invention and the cleaning method as described above have the following effects.

First, since the cleaning / etching and rinsing and drying processes are performed in the closed cleaning chamber, it is possible to prevent the wafer from being exposed to the air, thereby preventing the formation of a natural oxide film or adsorption of foreign matter onto the wafer.

Second, since the chemical is used every time the cleaning / etching, the mixing ratio is changed according to the cleaning time, thereby preventing the cleaning effect from being lowered.

Third, since the chemical contact proceeds in a first-in first-out manner, the same etching in the wafer can be obtained.

Fourth, various chemical mixing ratio can be adjusted according to the DI flow amount, it is easy to apply to various other etching process.

Claims (3)

A single chamber in which both wafer cleaning / etching and drying are performed, A first supply path for supplying a chemical or a deionized (DI) in a top direction at the bottom of the chamber, A first outlet for discharging the chemical or the DI injected into the chamber; A chemical supply module for supplying the chemical to the first supply path by determining a mixing ratio of the chemical to be injected; A second supply passage for supplying a dry gas in a bottom direction from a top of the chamber to dry the wafer; A second outlet for discharging dry gas injected into the chamber; Wafer cleaning equipment comprising a dry gas supply module for supplying a dry gas to the second supply path. The wafer cleaning apparatus according to claim 1, wherein the first supply path is formed by combining a plurality of chemical supply paths and one DI eye supply path. A first step of cleaning the wafer by filling a DI in a top direction at the bottom of the chamber in which the wafer is embedded; A second step of cleaning and etching the wafer by injecting a chemical in a top direction from a bottom of the chamber, A third step of cleaning the wafer by filling a DI in a top direction at a bottom of the chamber; A fourth step of repeating the second step and the third step N times, And a fifth step of injecting a dry gas in a bottom direction from the top of the chamber to dry the wafer.