KR101110905B1 - Megasonic cleaning using supersaturated cleaning solution - Google Patents

Abstract

A method and system of megasonic cleaning of one or more substrates to reduce damage from megasonic energy to the substrate is disclosed. The substrate is supported in the process chamber and contacts the cleaning solution including the cleaning liquid having carbon dioxide gas dissolved in the cleaning liquid in an amount that is supersaturated with respect to the conditions in the processing chamber. Megasonic energy is then transferred to the substrate. The cleaning solution provides protection from damage by the application of megasonic / acoustic energy. In another aspect, the present invention is a system for performing the method. The present invention is not limited to carbon dioxide, and can be used in combination with any gas that protects the substrate from damage by the application of megasonic / acoustic energy when dissolved in the cleaning liquid.

Description

Megasonic cleaning with supersaturated cleaning solution {MEGASONIC CLEANING USING SUPERSATURATED CLEANING SOLUTION}

This application is claimed by US Provisional Application 60 / 477,602, filed June 11, 2003, the contents of which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION The present invention generally relates to methods, apparatuses, and systems for substrate processing / manufacturing, and more particularly, to methods, apparatuses, and systems for cleaning semiconductor wafers using applied megasonic energy.

In the manufacture of semiconductors, semiconductor devices are created on thin disk-like objects called wafers. In general, each wafer includes a plurality of semiconductor devices. The importance of minimizing impurities on the surface of such wafers during the production process has been recognized since the beginning of the semiconductor industry. In addition, as semiconductor devices become smaller and more complex as the end product demands, the demand for cleanliness has increased. This is for two reasons.

First, as the device becomes smaller, impurity particles on the wafer will occupy a large proportion in the surface area of the device. This increases the probability of the device failing. Thus, in order to maintain the proper degree of output of a normally functioning device per wafer, increased cleanliness requirements will have to be implemented and achieved.

Secondly, as devices become more complex, the raw materials, time, equipment, and processes required to make such devices also become more complex and more expensive. As a result, the cost required to make each wafer increases. In order to maintain adequate profitability, it is essential for manufacturers to increase the number of devices that operate normally per wafer. One way to increase this output is to minimize the number of devices that are not operated by impurities. Thus, increased cleanliness requirements are required.

One method of increasing the cleanliness of wafers in the process in the semiconductor industry is to apply megasonic energy on the surface of the wafer during the cleaning process. Application of megasonic energy improves the removal of particles during the cleaning process. However, it has been found that the applied megasonic energy can also damage the semiconductor device being cleaned. The composition of the cleaning solution, including the amount and composition of the gas dissolved in the cleaning solution, used in the megasonic cleaning process can affect the cleaning effect and the degree of damage to the wafer. The prior art says that cleaning solutions containing gas at supersaturation levels are unsuitable for wafer cleaning processes.

For example, US Pat. No. 5,800,626 (the '626 patent) states that the cleaning solution must be unsaturated with, for example, 60-98% of gas to obtain optimal cleaning results. The '626 patent requires a low degree of saturation of 60% to maintain a good cleaning effect. The '626 patent also says that too much gas in solution can create flaws in the silicon surface. Therefore, the cleaning solution should not be saturated more than 98%.

U.S. Patent No. 6,167,891 ('891 Patent) states that 100% saturated solution provides the optimal cleaning effect. According to the '891 patent, unsaturated or supersaturated solutions provide a very reduced cleaning effect. The '891 patent sees low cleaning efficiency under supersaturation conditions due to the formation of excess gas bubbles in the solution that are absorbed before megasonic energy reaches the wafer surface. The '891 patent also states that for a heated cleaning solution, it must be partially degassed at low temperatures before the solution is heated to avoid supersaturation at increased temperatures.

U.S. Patent No. 5,849,091 ('091 Patent) states that the air / liquid interface at the wafer surface is important for improving the cleaning rate. However, the inventor of the '091 patent says that the best way to form an air / liquid interface is to inject gas directly into the cleaning solution across the wafer surface.

US Pat. No. 6,039,814 ('814 patent) states that small bubbles in the cleaning solution interfere with the propagation of sound waves, resulting in low cleaning efficiency. The '814 patent also says that bubbles create scratches on the wafer surface. The cause of the bubbles is the gas dissolved in the cleaning solution. Thus, the '814 patent states that the concentration of gas dissolved in the cleaning solution should be at least 5 ppm, and preferably 3 ppm or less.

It is therefore an object of the present invention to provide a method and system for cleaning a substrate.

Another object of the present invention is to provide a method and system for cleaning a substrate that reduces and / or eliminates damage from acoustic energy.

It is yet another object of the present invention to provide a method and system for cleaning a substrate using megasonic energy that can be used in sensitive lines and trench structures of materials including polysilicon, metals or dielectrics.

It is yet another object of the present invention to provide a method and system for cleaning a substrate that increases the yield of semiconductor devices operating per wafer.

These and other objects are met by the present invention, and in one aspect the present invention is a method of cleaning at least one substrate, comprising: (a) having a substrate having a first temperature and a first partial pressure with respect to the first gas; Positioning in a process chamber in a gaseous environment; (b) supplying a solution comprising a cleaning liquid and the first gas to the process chamber to be in contact with the substrate; And (c) applying acoustic energy to the substrate to clean the substrate while the substrate is in contact with the solution, wherein the first gas is supersaturated for the first temperature and the first partial pressure. To at least one substrate dissolved in the cleaning liquid.

It is preferable that a 1st gas is a gas which protects a board | substrate from the damage by acoustic energy like carbon dioxide. The cleaning solution may be a commonly used semiconductor solution such as deionized water, RCA solution, diluted acid, diluted base or semi-water soluble solvent. The solution preferably further comprises a second gas dissolved in the cleaning liquid that facilitates the removal of particles from the substrate, such as nitrogen (N ₂ ), oxygen, helium, and argon. The second gas may or may not be dissolved in the cleaning liquid to such an extent that it is a supersaturated concentration relative to the temperature and partial pressure of the second gas in the process chamber.

In a preferred embodiment, the first gas is carbon dioxide and the cleaning liquid is deionized water. The solution can be produced in an environment other than the process chamber by dissolving CO ₂ in deionized water as a membrane contactor. While dissolving CO ₂ in deionized water in this embodiment, the gaseous environment in the membrane contactor is such that the amount of CO ₂ dissolved in deionized water in the membrane contactor is at or below the saturation concentration relative to the temperature and partial pressure in the membrane contactor. It is preferred to be maintained for temperature and partial pressure for _two . The amount of carbon dioxide dissolved in the cleaning liquid may range from 50 to 2000 ppm, most preferably about 1000 ppm.

Film despite the amount of dissolved CO ₂ in a saturated concentration or less of deionized water for the partial pressure and the temperature of the CO ₂ in the contactor and for the partial pressure and the temperature of the CO ₂ in the amount of the deionized water and CO ₂ process chambers supersaturated Concentration.

Once produced at the proper concentration in the membrane contactor, the solution is fed into the process chamber to contact the substrate being cleaned. Since the amount of CO _{2 in} the solution is at supersaturation relative to the partial pressure and temperature of the gaseous environment in the process chamber, the CO ₂ will tend to escape from the solution into the gaseous environment in the process chamber. Thus, completing the step of applying acoustic energy to the substrate before the CO ₂ has been sufficiently released from the solution and the concentration of CO ₂ dissolved in deionized water is lowered to saturation with respect to the temperature and partial pressure of CO _{2 in} the process chamber desirable.

The environment in the process chamber is preferably a gaseous environment containing air or N ₂ and at room temperature and atmospheric pressure. It is also preferred that the acoustic energy applied to the substrate is megasonic energy and the substrate is a semiconductor wafer.

It is also desirable for acoustic energy to be delivered to the substrate through the solution. Due to the protective effect of CO ₂ , the method of the present invention applies megasonic energy with minimal damage to a wafer comprising trenches and sensitive lines of material comprising polysilicon, metal or dielectric during the cleaning process of the semiconductor wafer. Can be used to

The method of the invention can also be used to clean substrates in both non-immersion and immersion process chambers, and can be used in single or batch substrate processing. When implemented in a non-immersion process chamber, the substrate may be supported in a substantially horizontal direction. In this embodiment, the solution is preferably supplied to the process chamber to form a layer of the solution on at least one surface of the substrate. The acoustic energy is then preferably delivered to the substrate through the solution. In comparison, when immersed, the substrate will be submerged in solution.

In another aspect, the present invention provides a method of cleaning at least one semiconductor wafer, comprising: (a) placing a semiconductor wafer in a process chamber; (b) supplying a solution comprising a cleaning liquid and first and second gases dissolved in the cleaning liquid into the process chamber to contact the wafer; And (c) applying acoustic energy to the wafer through the solution to clean the wafer, wherein the first gas promotes particle removal from the wafer and the second gas is caused by acoustic energy. A method of cleaning at least one semiconductor wafer that protects the wafer from damage.

In still another aspect, the present invention provides a system for cleaning at least one substrate, comprising: a process chamber having a gaseous environment of a first temperature and a first partial pressure of a first gas; A support for supporting at least one substrate in the process chamber; Dissolving means for dissolving the first gas in a cleaning liquid to form a solution; Supply means for supplying a layer of the solution to at least one surface of the substrate supported by the support; An acoustic energy source for delivering acoustic energy through the layer of solution to a substrate supported by the support; And (1) controlling the dissolution means such that the first gas is dissolved in the cleaning liquid at a supersaturation concentration with respect to the first temperature and the first partial pressure, and (2) a substrate is placed in the support and the layer of the solution is And a controller for activating an acoustic energy source when supplied to the substrate, wherein the acoustic energy is such that the concentration of the first gas dissolved in the cleaning liquid due to the sufficient outflow of the first gas from the solution is determined by the first temperature and the first temperature. A system for cleaning at least one substrate that passes through a layer of solution to the substrate before being lowered to saturation with respect to partial pressure.

The above-described embodiment of the megasonic cleaning method of the present invention has various characteristics and cannot bring desired properties by itself. Without limiting the scope of the invention, which is represented by the following claims, very prominent features will be discussed.

Effective cleaning of semiconductor wafers with applied megasonic energy requires an appropriate concentration of dissolved gas in the cleaning solution. However, contrary to the teachings of the prior art, optimal cleaning without wafer damage is obtained using a cleaning solution having a supersaturated concentration of dissolved gas. The method of the present invention described herein is effective for cleaning wafers using both immersion and non-immersion cleaning techniques. The wafer to be cleaned will be submerged in the cleaning solution or, optionally, the cleaning solution will be applied to the wafer surface in a thin film by spraying means.

1 is a schematic diagram of a megasonic cleaning system according to an embodiment of the present invention.

2 is a left side view of a non-soaked single wafer megasonic cleaning apparatus according to an embodiment of the present invention.

3 is a left side cross-sectional view of the device shown in FIG. 2;

4A is a microscopic image of a damaged semiconductor wafer surface with etch lines cleaned using the prior art megasonic cleaning process.

4B is a microscopic image of an undamaged semiconductor wafer surface with cleaned etch lines in accordance with an embodiment of the present invention.

Referring to FIG. 1, a megasonic cleaning system 10 is shown in accordance with an embodiment of the present invention. The megasonic cleaning system 10 includes a CO ₂ gas source 20, a nitrogen (N ₂ ) gas source 30, a cleaning liquid source 40, a membrane contactor 50, a process chamber ( 60), and megasonic energy source 70. Although megasonic energy source 70 is shown coupled to the bottom of process chamber 60, megasonic energy source 70 delivers megasonic energy to a semiconductor wafer (not shown) supported within process chamber 60. As long as it can supply, the present invention is not limited to any particular arrangement of megasonic energy sources 70 relative to the process chamber 60.

In order to clean semiconductor wafers according to embodiments of the present invention using the megasonic cleaning system 10, commonly used deionized water, RCA solutions, diluted acids, diluted bases or semi-aqueous solvents are used. A cleaning liquid, such as a semiconductor solution, is first supplied from the cleaning liquid source 40 to the membrane contactor 50 via a fluid line 41. Other cleaning solutions may be used in the present invention, including but not limited to other RCA cleaning solutions. At the same time CO ₂ Gas is CO ₂ via fluid line 21 Supplied from the gas source 20 to the membrane contactor 50, N ₂ Gas is passed through the fluid line 31 N ₂ It is supplied from the gas source 30 to the membrane contactor 50. Membrane contactor 50 is a CO ₂ gas and N ₂ It operates to dissolve the gas to form a cleaning solution. CO ₂ and N ₂ Although described with respect to dissolving the gas in the cleaning liquid, the present invention is not limited thereto. The gas is preferably a gas in a manner that promotes particle removal, such as nitrogen (N ₂ ), oxygen (O ₂ ), helium (He), argon (Ar) and others. In addition, the gas is preferably a gas that protects the semiconductor wafer from damage caused by megasonic energy exposure. Preferred examples of such gases are CO ₂ to be. In addition, although the gas may be dissolved in the cleaning liquid using a membrane contactor, other known methods or apparatuses for dissolving the gas in the liquid may be used.

A gaseous environment with controlled temperature and pressure is CO ₂ And N ₂ It is held in the membrane contactor 50 while dissolving the gas. CO ₂ in the gaseous environment at the membrane contactor 50 And partial pressures of N and N ₂ are more CO ₂ than in the gaseous environment maintained in the process chamber 60. And N ₂ The gas is controlled to dissolve in the cleaning liquid in the membrane contactor. Accordingly, CO ₂ dissolved in the cleaning liquid in the membrane contactor 50 relative to the temperature and partial pressure of the gaseous environment in the membrane contactor 50. And N ₂ The amount of gas is at or below the saturation concentration, but CO ₂ dissolved in the cleaning liquid relative to the temperature and partial pressure of the gaseous environment within the process chamber 60. And N ₂ The amount of gas will be above the saturation concentration.

For example, consider the gaseous environment of the membrane contactor 50 containing only N ₂ and CO ₂ in a volume ratio of 1: 1 and the gaseous environment of the process chamber 60 containing only air. Assuming that both gaseous environments are at atmospheric pressure and room temperature, the partial pressure of CO ₂ in the gaseous environment of the membrane contactor 50 is greater than the partial pressure of CO ₂ in the gaseous environment of the process chamber 60. Thus, the concentration of CO ₂ dissolved in the cleaning liquid exposed to the gaseous environment of the membrane contactor 50 at equilibrium will be greater than the concentration of CO ₂ of the cleaning liquid exposed to the gaseous environment of the process chamber 60. This principle is dissolved N ₂ The same can be applied to the gas.

Preferred amounts of CO ₂ to form the desired cleaning solution And N ₂ After the gas is dissolved in the cleaning liquid, the cleaning solution is applied to the process chamber 60 through the fluid line 51. As it enters the process chamber 60, the cleaning solution contacts the wafer supported there. Process chamber 60 preferably includes air at atmospheric pressure and room temperature. Thus, when the cleaning solution reaches the process chamber 60, the gas dissolved in the cleaning solution (eg, CO ₂₎ Gas or N ₂ One or more of the gases) is above the saturation concentration. Thus, for each part pressure and the temperature of the gas environment of the process chamber 60, dissolved gases above the saturation concentration will tend to exit the cleaning solution. However, it is desirable that the wafer processing / cleaning detailed below be completed before a sufficient amount of gas flows out of the cleaning solution to return the amount of gas in the cleaning solution to the saturation concentration.

In a preferred embodiment, the CO ₂ concentration of the cleaning solution is 1000 ppm, which is more than 1000 times the saturation concentration of CO ₂ in air at atmospheric pressure and room temperature. Experiments have shown that this concentration of CO ₂ can be used in conjunction with applied megasonic energy for very effective cleaning without wafer damage.

Once the cleaning solution is supplied to the process chamber 60 and in contact with the semiconductor wafer in the process chamber 60, the megasonic energy source 70 is activated. Depending on the type of process chamber used, the semiconductor wafer may be submerged in the cleaning solution, or in the case of a single-wafer process chamber, a layer of cleaning solution may be applied to one or more of the surfaces of the wafer. The invention is not limited to any particular kind of process chamber. Optionally, the megasonic energy source is not limited to any particular form and / or arrangement. For example, megasonic energy sources can be plate-shaped, elongated rods, triangles, or other shapes. The present invention may be used by applying ultrasonic and other types of acoustic energy may be used.

When activated, megasonic energy source 70 generates and delivers megasonic acoustic energy to a semiconductor wafer that is cleaned through a cleaning solution. Dissolved CO ₂ (and / or N ₂ ) in the cleaning solution protects the cleaned wafers from damage by the megasonic energy delivered to the wafer surface. As a result, megasonic energy can be applied to the semiconductor wafer in a cleaning process, followed by a wafer in a sensitive state such as after etching of a line or trench of a material comprising polysilicon, metal or dielectric.

4A and 4B show the benefit of using supersaturated amounts of CO ₂ as one of the gases dissolved in the cleaning solution. 4A and 4B show the evaluation of damage to sensitive bitline structures using a microscope. Dark spots in the figure show wafer damage. 4A shows wafer damage when using a cleaning solution with air at saturation concentrations. The cleaning efficiency is about 99%, but the wafer will be severely damaged. 4B shows wafer damage when using a cleaning solution with a supersaturated concentration of CO ₂ in accordance with an embodiment of the present invention. The cleaning efficiency is also about 99%, but the wafer is not damaged. In the process used to clean the wafers shown in FIGS. 4A and 4B, the megasonic conditions are the same, and the cleaning solution is the same except for the concentration of dissolved gas.

As discussed above, the present invention can be realized in combination with various types of process chambers of a single wafer or batch process chamber and / or a immersion or non-immersion process chamber. For illustration purposes, a single wafer non-soak process chamber will be discussed, but the principles of the invention may equally apply to batch, soak process tanks.

2 shows a single wafer non-soaked megasonic energy cleaning apparatus 101 made in accordance with the present invention. The resulting cleaning solution as described in connection with FIG. 1 is supplied to the wafer 106 through the fluid outlet 214 to form a thin film on the wafer surface. Optionally, a cleaning solution may also be applied to the bottom surface of the wafer 106. Fluid outlet 214 may be coupled to fluid line 51 (FIG. 1). The megasonic energy cleaning device 101 includes an extended probe 104 inserted through the wall 100 of the process tank 101. Process tank 101 forms a process chamber within which wafer 106 can be processed in accordance with the present invention. As can be seen, the probe 104 is supported at one end outside the container 101. A suitable O-ring 102 fitted between the probe 104 and the tank wall 100 provides adequate sealing to the process tank 101.

The heat transfer member 134 included in the housing 120 is acoustically and mechanically coupled to the probe 104. A piezoelectric transducer 140 included in the housing 120 is also acoustically coupled to the heat transfer member 134. Stand off 141 and electrical connectors 142, 154, and 126 are connected between transducer 140 and an acoustic energy source (not shown). Housing 120 supports inlet conduit 124 and outlet conduit 122 for coolant and has openings 152 for electrical connectors 154 and 126. The housing 120 is closed by an annular plate 118 having an opening 132 for the probe 104. Plate 118 is alternately attached to tank 101. Within the process tank 101, a support or susceptor 108 is disposed in parallel with and close to the probe 104. The susceptor 108 can have a variety of shapes and is formed by a plurality of spokes 108b connected to the hub 108c supported on the shaft 110 extending through the bottom wall of the process tank 101. A method of placement is shown including a supported outer rim 108a. Outside of the tank 101, the shaft 110 is connected to the motor 112.

The extended probe 104 is preferably made of a relatively inert, non-polluting material, such as quartz, which effectively transfers acoustic energy. While using quartz probes is satisfactory for most cleaning solutions, solutions containing hydrofluoric acid can etch quartz. Thus, probes made of sapphire silicon carbide, boron nitride, vitreous carbon, glassy carbon coated graphite, or other suitable materials may be used instead of quartz. Can be. Quartz can also be coated with a material that can withstand HF, such as silicon carbide or glassy carbon.

The probe 104 is a solid, elongated, spindle-shaped or probe-shaped cleaner 104a, and a base or rear 104b. The cross section of the probe 104 may be circular, and the diameter of the cleaning portion 104a is preferably smaller than the diameter of the rear portion 104b. In a preferred embodiment, the rear surface area of the rear portion 104b is 25 times the end surface of the cleaning portion 104a. Of course, non-circular cross-sectional shapes can also be used. In order to concentrate the megasonic energy along the length of the probe 104a, a cylindrical rod or cleaning part 104a having a small diameter is preferred. However, the diameter of the rod 104a must be sufficient to withstand the mechanical vibrations generated by the megasonic energy delivered by the probe. The radius of the rod 104a is preferably equal to or smaller than the wavelength of the frequency of energy applied to it. This structure produces a desirable stationary surface wave motion that induces energy radially into the liquid in contact with the probe. In practice, the rod diameter expands and contracts a small amount at discrete locations along the length of the rod. In a preferred embodiment, the radius of rod 104a is about 0.2 inches and operates at a wavelength of about 0.28 inches. This configuration produces 3-4 wavelengths per inch along the probe length.

The probe cleaner 104a is preferably long enough so that the entire surface area of the wafer 106 is exposed to the probe 104 during wafer cleaning. In the preferred embodiment, since the wafer 106 rotates under the probe 104, the length of the cleaning portion 104b is preferably long enough to reach at least the center of the wafer 106. Thus, as the wafer 106 rotates under the probe 104, the entire surface area of the wafer 106 passes under the probe 104. Megasonic vibrations from the probe tip provide constant agitation towards the wafer center, so that the probe 104 may work satisfactorily even if it does not reach the center of the wafer 106. The length of the probe 104 is also determined by the preferred number of wavelengths. Typically, the probe length changes with increasing half the wavelength of the energy applied to the probe 104. The probe cleaner 104a preferably includes 3-4 wavelengths per inch of applied energy. In this embodiment, the length of the probe cleaner 104a in inches is equal to the preferred number of wavelengths divided by the number between 3 and 4. Because of the change in the transducer, it is necessary to adjust the transducer 140 to obtain the desired wavelength and then operate at a very efficient point.

The rear probe portion 104b located outside of the tank 101 is spread to a diameter larger than the diameter of the cleaning portion 104a. In the embodiment shown in Figures 2-3, the diameter of the rear portion of the probe gradually increases to the cylinder portion 104d. The large surface area at the distal end of the rear 104d is advantageous for transferring large amounts of megasonic energy, which is concentrated in the smaller diameter portion 104a.

When used, the cleaning solution produced as described above in connection with FIG. 1 is sprayed from the nozzle 214 to the wafer top surface while the probe 104 is acoustically excited. Instead of spraying the cleaning solution onto the wafer 106 from the nozzle, the tank 101 may be filled with the cleaning solution. In the spraying method, the liquid creates a meniscus 216 between the bottom of the probe 104 and the adjacent top surface of the rotating wafer 106. Meniscus 216 wets the bottom of the probe cross section. The size of the arc defined by the wetted portion of the cross section is characterized by the nature of the liquid used in the cleaning solution, the material used to make the probe 104, and the gap between the wafer 106 and the lower edge of the probe 104. Varies with vertical distance

The cleaning solution provides a medium in which megasonic energy in the probe 104 is delivered to the wafer surface to loosen the particles. These loose particles are removed by the continuously flowing spray and the rotating wafer 106. When the fluid flow is stopped, a certain amount of drying operation is obtained by centrifugal force, and the cleaning solution is removed from the wafer 106. Alternatively, the cleaning solution or other cleaning medium of the present invention may be supplied to the opposite side of the wafer where the megasonic energy source is located. In this embodiment, it is also desirable that megasonic energy is supplied to the wafer with sufficient power to clean the opposite side of the wafer.

As discussed above, wafer processing / cleaning through the application of megasonic energy is completed before sufficiently CO ₂ and / or N ₂ gas flows out of the cleaning solution and returns the amount of gas in the cleaning solution to the saturated concentration. CO ₂ (and / or N ₂ ) dissolved in the cleaning solution at a supersaturation concentration protects the wafer from being cleaned from damage by megasonic energy delivered to the wafer surface. All functions are performed by a properly programmed processor / controller.

While the invention has been described and illustrated in sufficient detail to enable those skilled in the art to readily make and use it, various alternatives, modifications, and improvements may be made without departing from the scope of the invention. In particular, the present invention is not limited to applying two gases to the cleaning liquid, and includes an embodiment of only one gas dissolved in the cleaning liquid at a supersaturation concentration for the environment in the process chamber. In addition, the addition gas may be present in the cleaning liquid, and / or the cleaning liquid may be a mixture of liquids.

Claims (33)

A method of cleaning at least one substrate, (a) placing the substrate in a process chamber in a gas environment having a first temperature and a first partial pressure with respect to the first gas; (b) supplying a solution comprising a cleaning liquid and the first gas to the process chamber to form a layer of the solution on at least one surface of the substrate; And (c) applying acoustic energy through the solution to the substrate to clean the substrate while the substrate is in contact with the solution Including; And said first gas cleans at least one substrate dissolved in said cleaning liquid at a supersaturated concentration relative to said first temperature and first partial pressure. The method of claim 1, At least one step (c) is completed before the first gas is sufficiently discharged from the solution and the concentration of the first gas dissolved in the cleaning liquid is lowered to a saturation concentration with respect to the first temperature and the first partial pressure. A method of cleaning a substrate. The method of claim 1, And the first gas is carbon dioxide. The method of claim 3, wherein The supersaturation concentration of carbon dioxide in the cleaning liquid is a method for cleaning at least one substrate in the range of 50 to 2000 ppm. The method of claim 4, wherein And at least one substrate having a supersaturation concentration of carbon dioxide in said cleaning liquid is 1000 ppm. The method of claim 1, Wherein said first gas is at least one substrate selected from the group consisting of nitrogen, oxygen, helium, and argon. The method of claim 1, The solution provides a cleaning liquid in a gas environment having a second temperature and a second partial pressure of the first gas, such that the first gas is at or below a saturation concentration relative to the second temperature and the second partial pressure. Cleaning at least one substrate produced by dissolving the first gas in the cleaning liquid in an amount such that The method of claim 7, wherein And wherein the first gas is dissolved in the cleaning liquid through a membrane contactor. The method of claim 1, The substrate is a semiconductor wafer, and steps (b)-(c) are performed after the etching of a line or trench of material comprising polysilicon, metal or dielectric on the wafer is performed. The method of claim 1, And the solution further comprises a second gas dissolved in the cleaning liquid. 11. The method of claim 10, Wherein the first gas protects the substrate from damage by the acoustic energy, and the second gas cleans at least one substrate to promote removal of particles from the substrate. 11. The method of claim 10, And the second gas is dissolved in the cleaning liquid at a supersaturation concentration relative to the first temperature and the first partial pressure of the gaseous environment of the process chamber relative to the second gas. The method of claim 1, And the acoustic energy is megasonic energy. The method of claim 1, Said process chamber cleaning at least one substrate at atmospheric pressure. The method of claim 1, And wherein the gaseous environment of the process chamber comprises at least one substrate. The method of claim 1, And the substrate cleans at least one substrate supported in the process chamber in a horizontal direction. delete delete delete delete The method of claim 1, The step (c) is completed before the first gas is sufficiently discharged from the solution and the concentration of the first gas dissolved in the cleaning liquid is lowered to the saturation concentration with respect to the first temperature and the first partial pressure; The solution provides the cleaning liquid in a gas environment having a second temperature and a second partial pressure of the first gas, wherein the first gas has a saturation concentration or less relative to the second temperature and the second partial pressure. Generated by dissolving the first gas in the cleaning liquid in an amount such that it is suitable; The first gas is carbon dioxide; The solution further comprises a second gas dissolved in the cleaning liquid and removing particles from the substrate; The steps (b)-(c) are performed after the metal line etching step is performed on the wafer; The gaseous environment of the process chamber comprises air; And the pressure of the gaseous environment in the process chamber is at least one substrate at atmospheric pressure. The method of claim 1, Wherein said cleaning solution is at least one substrate selected from the group consisting of deionized water, RCA solution, diluted acid, diluted base or semi-aqueous solvent. A method of cleaning at least one semiconductor wafer, (a) placing a semiconductor wafer in a process chamber; (b) supplying a solution comprising a cleaning liquid and first and second gases dissolved in the cleaning liquid into the process chamber to contact the wafer; And (c) applying acoustic energy to the wafer through the solution to clean the wafer Including; Wherein the first gas promotes particle removal from the wafer and the second gas protects the wafer from damage by acoustic energy. The method of claim 23, wherein And wherein the first gas is selected from the group consisting of nitrogen, oxygen, helium, and argon. 25. The method of claim 24, And the second gas is carbon dioxide. The method of claim 25, The process chamber includes a gaseous environment of a first temperature and a first partial pressure of carbon dioxide, wherein the carbon dioxide dissolved in the cleaning liquid cleans at least one semiconductor wafer at a supersaturated concentration with respect to the first temperature and the first partial pressure. Way. The method of claim 26, The carbon dioxide is dissolved in the cleaning liquid in an environment having a second temperature and a second partial pressure of carbon dioxide, And the carbon dioxide is dissolved in the cleaning liquid in an amount such that the carbon dioxide is at a saturation concentration or less with respect to the second temperature and the second partial pressure. 28. The method of claim 27, At least one semiconductor wafer where step (c) is completed before the carbon dioxide is sufficiently discharged from the solution and the concentration of the carbon dioxide dissolved in the cleaning liquid is lowered to a saturation concentration with respect to the first temperature and the first partial pressure. How to clean. A system for cleaning at least one substrate, A process chamber having a gaseous environment of a first temperature and a first partial pressure of the first gas; A support for supporting at least one substrate in the process chamber; Dissolving means for dissolving the first gas in a cleaning liquid to form a solution; Supply means for supplying a layer of the solution to at least one surface of the substrate supported by the support; An acoustic energy source for delivering acoustic energy through the layer of solution to a substrate supported by the support; And (1) controlling the dissolution means such that the first gas is dissolved in the cleaning liquid at a supersaturated concentration with respect to the first temperature and the first partial pressure, and (2) a substrate is placed on the support and the layer of solution is on the substrate. A controller that activates an acoustic energy source when supplied to The acoustic energy is applied to the layer of the solution before the first gas is sufficiently discharged from the solution and the concentration of the first gas dissolved in the cleaning liquid is lowered to a saturation concentration with respect to the first temperature and the first partial pressure. Cleaning at least one substrate that passes through and reaches the substrate. 30. The method of claim 29, And the first gas is carbon dioxide. 30. The method of claim 29, The dissolving means has a gas environment having a second temperature and a second partial pressure of the first gas, wherein the first gas is in an amount such that it is at or below a saturation concentration relative to the second temperature and the second partial pressure. A system for cleaning at least one substrate dissolved in the cleaning liquid. 30. The method of claim 29, Said dissolving means cleaning at least one substrate that is a film contactor. 30. The method of claim 29, And the first gas cleans at least one substrate that protects the substrate from damage by acoustic energy.

Images