KR100391225B1 - Apparatus and Method for Treatment a Surface of Semiconductor Substrate - Google Patents

Abstract

An apparatus and method for surface treatment of a semiconductor substrate using a laser beam radiated from a laser beam irradiation device and isopropyl alcohol (IPA) are provided.

The surface treatment apparatus of the semiconductor substrate includes a cleaning chamber filled with pure water, a substrate transfer means installed at the bottom of the cleaning chamber to transfer the semiconductor substrate up and down, a substrate holder installed on the substrate transfer means, a gas injection hole provided above the cleaning chamber, and a laser beam. It includes a laser beam irradiation port provided on at least one side of the cleaning chamber so that the laser beam radiated from the irradiation apparatus can be irradiated on the semiconductor substrate. The isopropyl alcohol thin film is formed on the surface of the semiconductor substrate for surface treatment of the semiconductor substrate, and the laser beam is irradiated on the surface of the semiconductor substrate before the isopropyl alcohol thin film evaporates. When the semiconductor substrate is completely exposed from pure water, the irradiation of the laser beam is stopped and nitrogen gas is continuously introduced so that the semiconductor substrate is completely dried while preventing particle reattachment.

According to the present invention, cleaning and drying of the semiconductor substrate can be unified, and both surfaces of the semiconductor substrate can be cleaned and dried at the same time with a laser, thereby improving process efficiency.

Description

Apparatus and Method for Treatment a Surface of Semiconductor Substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for a substrate, and more particularly, to a surface treatment method for a semiconductor substrate capable of simultaneously cleaning and drying the semiconductor substrate.

In order to form a device on a semiconductor substrate, several steps must be performed. Since unnecessary thin films and various contaminants are generated on the surface of the semiconductor substrate where the process is performed in each of these process steps, the process of cleaning and drying the semiconductor substrate for a predetermined time before and after forming the device should be performed.

In addition, the manufacturing technology of semiconductor devices is gradually becoming more integrated and miniaturized. Therefore, even the ultra-fine foreign matter attached to the substrate during the process has a great influence on the reliability and the unit cost of the device, such as causing malfunction of the device and lowering the yield. The importance of is newly recognized and is required to improve the cleaning performance.

In general, the cleaning of the semiconductor substrate is proceeding in a wet manner using various chemicals. However, as the device becomes finer, wet cleaning alone does not completely remove contaminants attached to the substrate, and there is a problem in that water marks occur after cleaning.

In order to solve the problem of the wet cleaning method, a cleaning method using a laser has been actively studied. In the cleaning technique using a laser, a laser beam is irradiated to remove fine particles attached to the surface of the substrate. In order to further enhance the cleaning effect, a liquid thin film must be formed on a semiconductor substrate before irradiating the laser beam. As a method of forming a thin film, a method of flowing a liquid to the substrate surface, a method of spraying heated steam to form a thin film having a constant thickness, and the like are used.

However, when the liquid flows to the substrate surface, it is difficult to uniformly control the thickness of the liquid thin film formed on the semiconductor substrate surface and a large amount of liquid is used. In addition, in the case of spraying the heated steam, the heating steam and the precise control of the liquid should be controlled so that a certain thin film is formed on the substrate by spraying the heated steam immediately before the laser beam irradiation and all liquids are evaporated after the laser beam irradiation. Is required, the system is complicated, and there is a risk that the liquid layer remains after the laser beam irradiation, thereby reducing the reliability of the device.

In addition, as the device becomes smaller, particles on the back side of the semiconductor substrate must be removed. In the current dry cleaning technology, only one side of the substrate can be cleaned by one cleaning process, so two cleaning processes are required for two-sided cleaning. There is a disadvantage that the efficiency is lowered.

On the other hand, the cleaning step must be followed by a step of drying the substrate. As a method for drying the substrate, a high speed rotation method, a method using isopropyl alcohol (IPA) vapor, or the like is used. The high-speed rotation method is a method of drying a substrate while dropping DI water onto the substrate while rotating the substrate. The pure water that has been separated from the carrier and the substrate during the rotation of the substrate is adsorbed to the substrate, and the substrate is loaded and unloaded. There are disadvantages such as damage to the substrate in the process. Therefore, in recent years, as wafers have been large-sized, a drying method using IPA steam has been widely used instead of a high speed rotation drying method.

By the way, the cleaning and drying process is a necessary process in order to improve the reliability and yield of the semiconductor device, but there is a disadvantage that the process and the time is required as the cleaning and drying process is divided into two parts. In addition, when the cleaned substrate is transferred from the cleaning chamber to the drying chamber, contaminants may be reattached to the substrate, thereby reducing the cleaning effect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and there is a technical problem in shortening the time required for surface treatment of a substrate by unifying the cleaning and drying processes of the semiconductor substrate.

Another technical problem of the present invention is to simplify the cleaning process and minimize the influence of particles on the back side of the substrate by simultaneously cleaning both sides of the substrate.

1 is a view for explaining a surface treatment apparatus and a preparation state for the surface treatment of a semiconductor substrate according to the present invention.

2A and 2B are views for explaining a surface treatment progress process by the surface treatment apparatus of the semiconductor substrate according to the present invention.

3 is a view for explaining a state in which the surface treatment is completed by the surface treatment apparatus of the semiconductor substrate according to the present invention.

<Description of the symbols for the main parts of the drawings>

10 cleaning chamber 12 substrate transfer means

14 semiconductor substrate 16 substrate holder

18: pure water 20: gas nozzle

22: beam irradiation port (Quartz Window) 24: laser beam irradiation device

26: liquid outlet 28: IPA thin film

30 laser light source 32 first mirror

34: second mirror

According to an aspect of the present invention, there is provided a surface treatment apparatus for controlling particles of a semiconductor substrate using a laser beam emitted from a laser beam irradiation apparatus, the cleaning chamber being loaded with a semiconductor substrate and filled with pure water. A substrate transfer means installed at the bottom of the cleaning chamber to move the semiconductor substrate up and down, a substrate holder installed on the substrate transfer means to fix the semiconductor substrate, and installed at one side of the cleaning chamber to inject cleaning gas and dry gas And a laser beam irradiator provided on at least one side of the cleaning chamber so that a gas injection hole for the laser beam and the laser beam radiated from the laser beam irradiation device are irradiated into the cleaning chamber.

Here, the substrate holder is composed of a vacuum chuck or an edge gripper, the laser beam irradiator is provided on opposite sides of the cleaning chamber, respectively, and may further include a liquid discharge port for discharging the pure water to the bottom of the cleaning chamber.

In addition, the present invention for achieving the above technical problem is a surface treatment method of a semiconductor substrate for controlling the particles of the semiconductor substrate using a laser beam radiated from the laser beam irradiation apparatus, the semiconductor substrate into a cleaning chamber filled with pure water Loading and fixing the semiconductor substrate by a substrate holder installed on a substrate transfer device installed at the bottom of the cleaning chamber, injecting cleaning gas into the cleaning chamber to form a liquid thin film by the cleaning gas on the pure surface. Step, irradiating a laser beam radiated from the laser beam irradiation apparatus, and spraying a dry gas into the cleaning chamber, the semiconductor substrate is exposed from the pure water to the exposed semiconductor substrate surface liquid phase thin film by the cleaning gas Allowing it to extend, phase from the pure When the semiconductor substrate is completely exposed and a step and a step of unloading the semiconductor substrate from the cleaning chamber to the step of stopping the irradiation of the laser beam, stopping the supply of the drying gas.

Here, the semiconductor substrate is fixed horizontally or vertically by a vacuum chuck or edge gripper, and the method of exposing the semiconductor substrate from the pure water is by moving the substrate transfer device or by discharging the pure water from the cleaning chamber. Then, the exposure rate of the semiconductor substrate should be controlled so that the laser beam is irradiated onto the semiconductor substrate before the liquid thin film of the cleaning gas formed on the surface of the semiconductor substrate evaporates. When the laser beams are irradiated from both sides of the cleaning chamber, the semiconductor substrate Both sides of can be cleaned simultaneously. In addition, it is preferable to use isopropyl alcohol vapor as the cleaning gas and nitrogen gas as the dry gas.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view of a surface treatment apparatus for a semiconductor substrate according to the present invention, showing a state of preparation for surface treatment.

In the cleaning chamber 10 provided with the substrate transfer means 12 at the bottom, the semiconductor substrate 14 is transported from the cassette into the cleaning chamber 10 by the robotic system, and then the substrate holder 16 on the substrate transfer means 12. It is fixed vertically with respect to the bottom of the cleaning chamber 10 by the (), it is movable up and down by the substrate transfer means (12).

A sufficient amount of DI water 18 is filled in the cleaning chamber 10 so that the semiconductor substrate 14 is submerged, and a gas injection hole into which the gas necessary for cleaning and drying may flow into the cleaning chamber 10. 20 is provided.

In addition, at least one side surface of the cleaning chamber 10 is provided with a beam irradiation port 22 to which a laser beam for cleaning the semiconductor substrate 14 is irradiated, so that the laser beam radiated from the laser beam irradiation device 24 is cleaned. To be irradiated into the chamber 10. The laser beam irradiation device 24 is a device that reflects a laser beam emitted from the laser light source 30 through a plurality of optical mirrors 32 and 34 and lenses (not shown) and emits the light.

On the other hand, the liquid discharge port 26 is provided at the bottom of the cleaning chamber 10 to discharge the pure water 18 from the cleaning chamber 10 to expose the semiconductor substrate 14.

As a preparatory step for cleaning the semiconductor substrate 14, the cleaning chamber 10 filled with pure water 18 is opened and the semiconductor substrate 14 to be processed is transported to the substrate holder 16 on the substrate transfer means 12. Fix it.

When loading the semiconductor substrate 14 into the cleaning chamber 10, a robot system is used. If the semiconductor substrate 14 is to be installed perpendicularly to the bottom of the cleaning chamber 10, a rotation function is added to the robot system. . That is, the semiconductor substrate to be processed is removed from the cassette in which the plurality of semiconductor substrates are stored in a horizontal state, and the semiconductor substrate 14 is vertically rotated by 90 °, and then the standing semiconductor substrate 14 is placed vertically. When mounted on the substrate holder 16, the laser beam can be irradiated while the semiconductor substrate is installed vertically. In this case, the substrate holder 16 is constructed using a vacuum chuck.

In a preferred embodiment of the present invention, the edge portion of the semiconductor substrate is formed by the substrate holder 16, which is vertically erected in the vertical direction by adding a rotation function to the robot system and constituted by an edge gripper as described above. In the state where only the fixed state is held, the laser beams are irradiated from both beam irradiation holes 22 of the cleaning chamber 10 so that both surfaces of the semiconductor substrate 14 can be cleaned simultaneously.

2A and 2B are views for explaining a surface treatment progress process by the surface treatment apparatus of the semiconductor substrate according to the present invention.

In the state where the semiconductor substrate 14 loaded into the cleaning chamber 10 filled with pure water 18 is fixed with the substrate holder 16, isopropyl alcohol (IPA) vapor is injected through the gas injection port 20 to obtain pure water 18 The IPA thin film 28 is formed on the surface of the substrate. Subsequently, the laser beam is irradiated through the beam irradiation port 20, while the nitrogen substrate is sprayed through the gas injection port 20 so that the semiconductor substrate 14 is gradually exposed out of the pure water 18 from the upper side thereof. Here, the laser beam should be emitted by adjusting the energy and angle of the laser beam according to the characteristics of the device formed on the semiconductor substrate 14.

The method of exposing the semiconductor substrate 14 includes a method of moving the substrate transfer means 12 upward and a method of discharging the pure water 18 in the cleaning chamber 10 through the liquid discharge port 26. When the semiconductor substrate 14 is exposed by moving the substrate transfer means 12 upward as shown in FIG. 2A, scanning is performed by the movement of the semiconductor substrate 14 in a state where the laser beam irradiation position is fixed. Is done.

On the other hand, when the semiconductor substrate 14 is exposed by the discharge of the pure water 18 as shown in FIG. 2B, the second mirror of the laser beam irradiator 24 is fixed while the substrate transfer device 12 is fixed. 34 is moved downward to adjust the position where the laser beam is irradiated, thereby scanning the surface of the semiconductor substrate 14 exposed as the pure water 18 is discharged.

Meanwhile, the IPA vapor introduced through the gas injection port 20 exists as a liquid IPA thin film 28 on the surface of the pure water 18, and the semiconductor substrate 14 begins to be exposed, thereby exposing the exposed surface of the semiconductor substrate 14. Extends accordingly. Since the IPA thin film 28 formed on the surface of the pure water 18 is coated on the surface of the semiconductor substrate 14 with a uniform thickness as the semiconductor substrate 14 is exposed, the IPA thin film 28 is spread over the entire surface of the semiconductor substrate 14 when the laser beam is irradiated. Uniform scanning effect can be obtained. As such, by forming an IPA thin film using a small amount of IPA, environmental pollution due to excessive chemical use, which is a disadvantage of wet cleaning, can be minimized.

Particles of the exposed semiconductor substrate 14 are attracted toward the IPA thin film 28 formed on the pure water by the difference in the surface tension of the pure water and the IPA, and also through the beam injection hole 22 from the laser beam irradiation device 24. Particles on the surface of the semiconductor substrate 14 are removed by the laser beam scanned on the surface of the substrate 14. It uses the Marangoni principle to remove moisture and contaminants on the substrate using surface tension, thereby effectively removing water spots generated during wet cleaning as well as particles on the substrate.

At this time, the exposure speed of the semiconductor substrate 14 is adjusted according to the evaporation rate of the IPA vapor, so that the particles are adsorbed onto the IPA thin film 28 before the IPA thin film 28 on the surface of the semiconductor substrate 14 evaporates. When the laser beam is irradiated, the IPA thin film can be more effectively removed from particles on the substrate surface by instantaneous boiling and explosive evaporation by the energy of the laser beam.

In a preferred embodiment of the present invention, an excimer laser is used as the laser light source. The excimer laser beam directly destroys the molecular bonds of the tissue to be removed to remove the tissue, thereby minimizing damage to the object to be treated. It is effective in this regard, and in the form of a line beam, there is an advantage in terms of scan efficiency.

3 is a view for explaining a state in which the surface treatment is completed by the surface treatment apparatus of the semiconductor substrate according to the present invention.

When all of the semiconductor substrate 14 is exposed and the cleaning process is completed for the entire surface of the substrate, only nitrogen gas flows from the gas injection port 20. By introducing only nitrogen gas, it is possible to improve the drying effect of the semiconductor substrate and to prevent the particles from being reattached to the substrate. When the cleaning and drying process is completed, the semiconductor substrate 14 is unloaded from the cleaning chamber 10.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

In the present invention described above, since the cleaning and drying of the semiconductor substrate are performed at the same time, it is possible to shorten the device manufacturing process step and the processing time. In addition, by introducing a cleaning technique using a laser, even fine particles of an ultrafine element can be controlled, and both surfaces of the semiconductor substrate can be simultaneously cleaned, thereby improving process efficiency.

In addition, since the IPA layer of the thin film is formed on the surface of the substrate, the amount of IPA and expensive chemical materials used in the cleaning process can be reduced, and the temperature of the semiconductor substrate by the laser beam irradiation increases the temperature on the substrate surface after completion of the process. IPA can be prevented from remaining.

Claims (11)

A surface treatment apparatus for controlling particles of a semiconductor substrate using a laser beam radiated from a laser beam irradiation apparatus, A cleaning chamber loaded with a semiconductor substrate and filled with pure water; Substrate transfer means provided at a bottom of the cleaning chamber to move the semiconductor substrate up and down; A substrate holder provided on the substrate transfer means for fixing the semiconductor substrate; A gas injection hole installed at one side of the cleaning chamber to inject cleaning gas and dry gas; And A laser beam irradiator provided on at least one side of the cleaning chamber so that the laser beam radiated from the laser beam irradiation device can be irradiated into the cleaning chamber; Surface treatment apparatus for a semiconductor substrate comprising a. According to claim 1, And the substrate holder is a vacuum chuck or an edge gripper. According to claim 1, And the laser beam irradiator is provided on opposite sides of the cleaning chamber, respectively. According to claim 1, And a liquid discharge port for discharging the pure water to the bottom of the cleaning chamber. A surface treatment method of a semiconductor substrate for controlling particles of the semiconductor substrate using a laser beam radiated from a laser beam irradiation apparatus, Loading the semiconductor substrate into a cleaning chamber filled with pure water, and fixing the semiconductor substrate by a substrate holder provided on a substrate transfer device installed at the bottom of the cleaning chamber; Injecting a cleaning gas into the cleaning chamber to form a liquid thin film by the cleaning gas on the pure surface; Irradiating a laser beam radiated from the laser beam irradiation device, and spraying dry gas into the cleaning chamber; Exposing the semiconductor substrate from the pure water to extend the liquid thin film by the cleaning gas to the exposed semiconductor substrate surface; Stopping irradiation of the laser beam when the semiconductor substrate is completely exposed from the pure water; Stopping supply of the dry gas; And Unloading the semiconductor substrate from the cleaning chamber; Surface treatment method of a semiconductor substrate comprising a. The method of claim 5, And the semiconductor substrate is vertically fixed by a vacuum chuck or an edge gripper. The method of claim 5, And the semiconductor substrate is exposed from the pure water by the vertical motion of the substrate transfer device. The method of claim 5, And said semiconductor substrate is exposed by discharging said pure water from said cleaning chamber. The method of claim 5, And controlling the exposure speed of the semiconductor substrate so that a laser beam is irradiated onto the semiconductor substrate before the liquid thin film of the cleaning gas formed on the semiconductor substrate surface evaporates. The method of claim 5, And the laser beams are irradiated from both sides of the cleaning chamber. The method of claim 5, Isopropyl alcohol vapor is used as the cleaning gas, and nitrogen gas is used as the dry gas.