KR102140722B1 - Dry clean apparatus and method using atmospheric plasma and steam - Google Patents

Abstract

The present invention relates to a dry cleaning apparatus and method using atmospheric plasma and steam.
The device according to the present invention is a chuck on which a silicon substrate on which silicon oxide and silicon nitride are formed, a RF electrode to which RF power is applied for plasma generation, and a shower installed to be spaced apart between the RF electrode and the plasma generation region. It includes a steam supply device for supplying a high temperature cleaning gas to the head and the shower head, the reaction gas supplied to the plasma generating region is plasma-treated by the RF power supply to the silicon substrate by supplying the silicon oxide and the silicon nitride The reaction layer comprising ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ) is changed, and the high temperature cleaning gas supplied by the steam supply device is sprayed to the reaction layer through the shower head to the reaction layer It is characterized by being removed.
According to the present invention, the overall process time can be shortened by reducing the time required for removing the reaction layer in the dry cleaning process.

Description

Dry cleaning device and method using atmospheric plasma and steam {DRY CLEAN APPARATUS AND METHOD USING ATMOSPHERIC PLASMA AND STEAM}

The present invention relates to a dry cleaning apparatus and method using atmospheric plasma and steam. More specifically, the present invention relates to a dry cleaning apparatus and method using atmospheric pressure plasma and steam, which can shorten the overall process time by reducing the time required for removing the reaction layer in the dry cleaning process.

As semiconductor device circuits are increasingly highly integrated and highly refined, etching and cleaning techniques that exhibit high selectivity characteristics between heterogeneous patterns such as polysilicon, silicon oxide, and silicon nitride are required.

The wet etching technology has excellent particle removal ability, but has a problem in that it is difficult to control the selectivity for fine etching of atomic level (Atomic level) and deterioration of cleaning ability by surface tension in a high aspect ratio pattern. In addition, in the dry etching technology, a damage layer is formed after etching due to ion bombardment incident on the wafer, and subsequent processes for removing it are additionally required.

Recently, as an alternative technique to solve this problem, a hexafluoroammonium silicate ((NH ₄ ) ₂ SiF ₆ ) solid layer is generated by a gas reaction or a radical reaction, and the solid layer thus produced is heated. Dry clean technology to remove is spreading, and this technology has an advantage of selectively removing heterogeneous patterns without damaging the substrate depending on reaction conditions.

1 is a view showing the timing of supply of RF power and gas in a general dry cleaning process, and FIG. 2 is a view showing a reaction mechanism of a general dry cleaning process.

As disclosed in FIG. 1, in order to remove silicon oxide or silicon nitride having a specific thickness, Reaction and Annealing are repeatedly performed. In general, a process for Reaction is as shown in FIG. 2. A solid layer of ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ) is produced during the saturation time generated by the reaction of fluorine and hydrogen radicals to a maximum thickness.

The solid layer of ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ) is removed through heat treatment, and the reaction and heat treatment process is repeated in a repetitive cycle until the removal of silicon oxide or silicon nitride is completed. Due to the time required for heat treatment, there is a problem in that the overall process time is increased.

Republic of Korea Patent Publication No. 10-2009-0071368 (published date: July 01, 2009, name: substrate processing method, substrate processing apparatus and storage medium) Republic of Korea Registered Patent Publication No. 10-0784661 (Registration Date: December 05, 2007, Name: Method of manufacturing a semiconductor device)

An object of the present invention is to provide a dry cleaning apparatus and method using atmospheric plasma and steam, which can shorten the overall process time by reducing the time required to remove the reaction layer from the dry cleaning process.

In order to solve these technical problems, the dry cleaning apparatus using atmospheric pressure plasma and steam according to the present invention is a chuck on which a silicon substrate on which silicon oxide and silicon nitride are formed is disposed, and an RF electrode to which RF power for plasma generation is applied. , A shower head installed to be spaced apart between the RF electrode and the plasma generating region, and a steam supply device for supplying high temperature cleaning gas to the shower head, and the reaction gas supplied to the plasma generating region is supplied by the RF power source. Plasma treatment to be supplied to the silicon substrate to change the silicon oxide and the silicon nitride into a reaction layer containing ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ), and high temperature cleaning supplied by the steam supply device Gas is injected into the reaction layer through the shower head, so that the reaction layer is removed.

In the dry cleaning device using atmospheric pressure plasma and steam according to the present invention, the steam supply device is an induction heating supplying a cleaning solution supply device for supplying a cleaning solution and the cleaning solution in an induction heating method to supply high temperature cleaning gas to the shower head It characterized in that it comprises a device.

In the dry cleaning apparatus using atmospheric pressure plasma and steam according to the present invention, it is installed between the cleaning liquid supply device and the induction heating device to control the supply pressure of the cleaning solution and between the first pump and the induction heating device and the shower head It characterized in that it further comprises a second pump that is installed in the control of the supply pressure of the high temperature cleaning gas.

In the dry cleaning apparatus using atmospheric pressure plasma and steam according to the present invention, the shower head is characterized in that the plasma-treated reaction gas and the supply path of the high-temperature cleaning gas are separated from each other.

In the dry cleaning apparatus using atmospheric pressure plasma and steam according to the present invention, the plasma-treated reaction gas passes through the shower head, the ionic component is suppressed, and the reactive radicals in which the ionic component is suppressed are the silicon oxide and the silicon. The reaction layer is formed by reacting with nitride.

In the dry cleaning apparatus using atmospheric pressure plasma and steam according to the present invention, the RF electrode is characterized in that it is a DBD (Dielectric Barrier Discharge) or capillary type electrode.

The dry cleaning method using atmospheric pressure plasma and steam according to the present invention is provided by plasma processing a reaction gas reacting with the silicon oxide and the silicon nitride on a silicon substrate disposed inside the chamber and having silicon oxide and silicon nitride formed thereon. By doing so, the reaction step of changing the silicon oxide and the silicon nitride into a reaction layer containing ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ) and the supply of the plasma-treated reaction gas was stopped and the reaction layer was formed. And removing the reaction layer by spraying a high temperature cleaning gas to the silicon substrate.

In the dry cleaning method using atmospheric pressure plasma and steam according to the present invention, in the reaction layer removal step, the cleaning liquid is heated in an induction heating method to generate the high temperature cleaning gas, and the high temperature cleaning gas is reacted through the shower head. It is characterized in that the reaction layer is removed by spraying with a layer, and the high-temperature cleaning gas is injected into the reaction layer through a supply channel that is separate from the supply path of the plasma-treated reaction gas provided in the shower head. .

According to the present invention, a technical problem is to provide a dry cleaning apparatus and method using atmospheric pressure plasma and steam, which can shorten the overall process time by reducing the time required for removing the reaction layer in the dry cleaning process.

1 is a view showing a conventional dry cleaning cycle,
2 is a view showing a conventional dry cleaning reaction mechanism,
3 is a view showing a dry cleaning apparatus using atmospheric pressure plasma and steam according to an embodiment of the present invention,
4 is a view showing an exemplary configuration of a steam supply device in an embodiment of the present invention,
5 is a view showing a dry cleaning cycle applied to an embodiment of the present invention,
6 is a view showing a dry cleaning method using atmospheric pressure plasma and steam according to an embodiment of the present invention.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification are exemplified only for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention It can be implemented in various forms and is not limited to the embodiments described herein.

Embodiments according to the concept of the present invention can be applied to various changes and can have various forms, so the embodiments will be illustrated in the drawings and described in detail herein. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosure forms, and includes all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

Terms such as first or second may be used to describe various components, but the components should not be limited by the terms. The above terms are only for the purpose of distinguishing one component from other components, for example, without departing from the scope of rights according to the concept of the present invention, the first component can be referred to as the second component and similarly the second The component may also be referred to as a first component.

When a component is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but there may be other components in between. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle. Other expressions describing the relationship between the components, such as "between" and "just between" or "neighboring to" and "directly neighboring to" should be interpreted as well.

The terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “include” or “have” are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described herein exists, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, actions, components, parts or combinations thereof are not excluded in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined herein. Does not.

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

3 is a view showing a dry cleaning apparatus using atmospheric pressure plasma and steam according to an embodiment of the present invention, and FIG. 4 is a view showing an exemplary configuration of a steam supply apparatus in one embodiment of the present invention, FIG. 5 is a view showing a dry cleaning cycle applied to an embodiment of the present invention.

3 to 5, the dry cleaning apparatus using atmospheric pressure plasma and steam according to an embodiment of the present invention includes a chamber 10, a chuck 20, a chuck heating unit 30, an RF electrode 60, It includes a shower head 70 and a steam supply device 80.

The chamber 10 provides a space in which the entire process of removing silicon oxide and silicon nitride formed on the silicon substrate 40 is performed.

The chuck 20 is provided inside the chamber 10 and is a component on which the silicon substrate 40 to be processed is disposed.

The chuck heating unit 30 is a means for heating the chuck 20 and is a component that can be omitted.

The RF electrode 60 is disposed in an upper region inside the chamber 10 and an RF power source 50 for plasma generation is applied and a first gas supply path 62 is provided.

For example, the RF electrode 60 may be a DBD (Dielectric Barrier Discharge) or a capillary electrode.

The shower head 70 is electrically connected to the ground terminal of the RF power source 50 and is spaced apart from the RF electrode 60 with the plasma generation region therebetween, and the second gas supply path 72 and the second gas supply A third gas supply path 74 physically separated from the furnace 72 is provided.

For example, the shower head 70 may be configured to be connected to the ground terminal of the RF power supply 50 to be grounded. According to this configuration, the ion component injected into the silicon substrate 40 is suppressed as much as possible. Only reactive radical components can be passed.

When the RF power supply 50 is applied, the reaction gas injected into the RF electrode 60 and the shower head 70 is radicalized by a plasma reaction to generate a second gas supply path 72 provided in the shower head 70. It is supplied to the silicon substrate 40 through.

The steam supply device 80 is a component that supplies hot cleaning gas injected through the shower head 70 to the reaction layer formed on the silicon substrate.

For example, the steam supply device 80 is a cleaning liquid supply device 810 for supplying a cleaning solution, a first pump installed between the cleaning solution supply device 810 and the induction heating device 830 to adjust the supply pressure of the cleaning solution ( 820) is installed between the induction heating device 830 and the induction heating device 830 and the shower head 70 to supply the high temperature cleaning gas to the shower head 70 by heating the cleaning solution in an induction heating method. It may be configured to include a second pump 840 for adjusting the supply pressure.

Under this configuration of a dry cleaning apparatus using atmospheric pressure plasma and steam according to an embodiment of the present invention, the silicon substrate 40 is heated in response to the heating temperature of the chuck 20 heated by the chuck heating unit 30. .

In addition, the reaction gas that has passed through the first gas supply path 62 is plasma-processed by the RF power supply 50 and is supplied to the silicon substrate 40 through the second gas supply path 72 to form silicon oxide and silicon nitride. At least a portion is changed to a reaction layer comprising ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ).

In addition, the high temperature cleaning gas heated by the steam supply device 80 is sprayed onto the silicon substrate 40 through the third gas supply path 74 provided in the shower head 70 to vaporize ammonium hexafluorosilicate. It is removed, and provided in the first gas supply path 62 and the shower head 70 independently of the supply path of the high-temperature cleaning gas supplied through the third gas supply path 74 provided in the shower head 70 The plasma-treated reaction gas may be supplied through the second gas supply passage 72.

The dry cleaning process through removal of the reaction layer will be described in more detail as follows.

Regarding generation of the reaction layer, by supplying a reaction gas reacting with silicon oxide and silicon nitride to the silicon substrate 40 disposed inside the chamber 10 to induce the reaction, at least a part of the silicon oxide and silicon nitride is hexafluoro The process of changing to a reaction layer containing ammonium silicate ((NH ₄ ) ₂ SiF ₆ ) is performed. That is, after the reaction layer generation process is performed, all or part of silicon oxide and silicon nitride existing on the surface of the silicon substrate 40 is replaced with a reaction layer containing ammonium hexafluorosilicate.

An example of the device operation related to the generation of the reaction layer will be described in more detail as follows.

First, a process of placing the silicon substrate 40 on the chuck 20 inside the chamber 10 is performed. For example, the silicon substrate 40 may be transferred to the chuck 20 inside the chamber 10 by a transfer device (not shown) and disposed. For example, the silicon substrate 40 may be in a normal temperature or a heated state, and as a configuration for this, the chuck 20 on which the silicon substrate 40 is disposed using the chuck heating unit 30 is room temperature-100° C. It can be controlled to have a temperature of. Since the silicon substrate 40 is disposed in contact with the chuck 20, it may be heated to a temperature corresponding to the heating temperature of the chuck 20.

Next, a process of injecting the reaction gas into the plasma generating region is performed. For example, the reaction gas may include one or more of NF ₃ , O ₂ , He, Ar, NH ₃ , and H ₂ . For example, the reaction gas may be injected into the plasma generation region from the top of the chamber 10, and for this purpose, the RF electrode 60 disposed in the upper region of the chamber 10 provides an injection path of the reaction gas The first gas supply passage 62 may be provided.

Next, a process of generating plasma in the plasma generation region by applying the RF power source 50 is performed. For example, an RF electrode 60 may be disposed on the upper side of the chamber 10 with a plasma generation region therebetween, and a shower head 70 to be described below may be disposed on the lower side, and the anode of the RF power source 50 may be disposed. The silver electrode may be electrically connected to the RF electrode 60 and the cathode may be electrically connected to the shower head 70. When the RF power supply 50 is applied, the injected reaction gas is radicalized by a plasma reaction and supplied to the silicon substrate 40 through the second gas supply path 72 provided in the shower head 70.

For example, in addition to the second gas supply path 72 that provides a path for the radicalized reaction gas to pass through the shower head 70 disposed under the plasma generation region, a high-temperature cleaning gas to be described later is injected. A third gas supply path 74 providing a passage may be provided, and the second gas supply path 72 and the third gas supply path 74 may be configured to have independent paths physically separated.

A process in which the plasma-treated reaction gas reacts with silicon oxide and silicon nitride formed on the silicon substrate 40 to generate hexafluoroammonium silicate as a reaction product. For example, ammonium hexafluorosilicate may be formed as a solid layer, and all or part of silicon oxide and silicon nitride existing on the surface of the silicon substrate 40 may be replaced with a solid layer of ammonium hexafluorosilicate. .

For example, when silicon oxide is formed on the silicon substrate 40, the process of converting silicon oxide to ammonium hexafluorosilicate by radical components contained in the reaction gas supplied through plasma treatment will be described in the following scheme. Same as

2NH ₄ F(g) + 4HF(g) + SiO ₂ = (NH ₄ ) ₂ SiF ₆ (g) + 2H ₂ O

Next, the reaction layer containing ammonium hexafluorosilicate by spraying the hot cleaning gas supplied by the steam supply device 80 to the silicon substrate 40 on which ammonium hexafluorosilicate was generated through the shower head 70. The process of removing them is performed.

The heating temperature of the high-temperature cleaning gas may be 200-1000°C. When the heating temperature of the high-temperature cleaning gas is configured in this way, ammonium hexafluorosilicate can be effectively vaporized and removed.

For example, a process in which ammonium hexafluorosilicate is vaporized and removed by a high-temperature cleaning gas is described as a reaction scheme as follows.

(NH ₄ ) ₂ SiF ₆ (g) = SiF ₄ (g) + 2NH ₃ (g) + 2HF(g)

For example, in the process of removing the reaction layer containing ammonium hexafluorosilicate, the chuck 20 in which the silicon substrate 40 is placed in contact may be heated, and accordingly, the silicon substrate 40 is Since it is heated to a temperature corresponding to the heating temperature of the chuck 20, the removal efficiency of ammonium hexafluorosilicate can be increased.

6 is a view showing a dry cleaning method using atmospheric pressure plasma and steam according to an embodiment of the present invention. It is revealed that the description of the dry cleaning apparatus using atmospheric pressure plasma and steam in one embodiment of the present invention described in detail above can be applied to the method.

6 and FIGS. 3 to 5 referenced to describe the apparatus, a dry cleaning method using atmospheric pressure plasma and steam according to an embodiment of the present invention includes a reaction step (S20) and a reaction layer removal step (S30). It includes.

First, in step S10, a process of transferring and disposing a silicon substrate on which silicon oxide and silicon nitride are formed is transferred to the chamber.

In the reaction step (S20), silicon oxide and silicon nitride are hexafluorinated by plasma processing and supplying a reaction gas reacting with silicon oxide and silicon nitride to a silicon substrate disposed inside the chamber and on which silicon oxide and silicon nitride are formed. The process of changing to a reaction layer containing ammonium silicate ((NH ₄ ) ₂ SiF ₆ ) is performed.

In the reaction layer removal step (S30), the process of removing the reaction layer is performed by stopping supply of the plasma-treated reaction gas and spraying hot cleaning gas onto the silicon substrate on which the reaction layer is formed.

For example, in the reaction layer removal step (S30), the cleaning solution is heated in an induction heating method to generate a high temperature cleaning gas, and the high temperature cleaning gas is sprayed to the reaction layer through the shower head 70 to remove the reaction layer, The high-temperature cleaning gas is provided in the shower head 70 and may be configured to be injected into the reaction layer through a supply path that is separated from the supply path of the plasma-treated reaction gas.

As described in detail above, according to the present invention, there is an effect of providing a dry cleaning apparatus and method using atmospheric plasma and steam, which can shorten the overall process time by reducing the time required for removing the reaction layer in the dry cleaning process. .

10: chamber
20: chuck
30: Chuck heating section
40: silicon substrate
50: RF power
60: RF electrode
62: first gas supply path
70: shower head
72: second gas supply path
74: third gas supply path
80: steam supply
810: cleaning liquid supply device
820: first pump
830: induction heating device
840: second pump
S20: reaction step
S30: reaction layer removal step

Claims (8)

As a dry cleaning device using atmospheric plasma and steam,
A chuck disposed in a lower region inside the chamber and on which a silicon substrate on which silicon oxide and silicon nitride are formed is disposed;
An RF electrode disposed in an upper region inside the chamber and having an RF power for generating plasma and having a first gas supply path;
A third gas supply path physically separated from the second gas supply path and the second gas supply path and installed to be spaced apart from the RF electrode and the plasma generation region while being electrically connected to the ground terminal of the RF power. Shower head provided with; And
It includes a steam supply device for supplying a high-temperature cleaning gas to the shower head,
The reaction gas passing through the first gas supply path provided in the RF electrode and supplied to the plasma generation region is plasma-processed by the RF power and supplied to the silicon substrate through the second gas supply path provided in the shower head. By this, the silicon oxide and the silicon nitride are changed into a reaction layer containing ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ),
The high temperature cleaning gas supplied by the steam supply device is sprayed to the reaction layer through a third gas supply path provided in the shower head to remove the reaction layer,
The steam supply device
A cleaning liquid supply device for supplying a cleaning liquid;
An induction heating device that heats the cleaning solution in an induction heating method to supply high temperature cleaning gas to the shower head; And
And a first pump installed between the cleaning solution supply device and the induction heating device to adjust the supply pressure of the cleaning solution.
delete delete delete According to claim 1,
The plasma-treated reaction gas passes through a shower head electrically connected to the ground terminal of the RF power source, and an ion component is suppressed, and a reactive radical in which the ion component is suppressed reacts with the silicon oxide and the silicon nitride to react the reaction layer. A dry cleaning apparatus using atmospheric plasma and steam, characterized in that it is generated.
According to claim 1,
The RF electrode is a DBD (Dielectric Barrier Discharge) or capillary (Capillary) type electrode, characterized in that the dry cleaning apparatus using atmospheric pressure plasma and steam.
delete delete

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