JP7291691B2 - Systems and methods for treating substrates with cryogenic fluid mixtures - Google Patents

Description

PRIORITY CLAIM This application claims the benefit of US Provisional Patent Application No. 15/721,396, filed September 29, 2017, the disclosure of which is hereby incorporated by reference in its entirety.

Related Application U.S. Nonprovisional Application No. 15/721,396, filed September 29, 2017, is a continuation-in-part of U.S. Nonprovisional Application No. 15/197,450, filed June 29, 2016. , claiming priority thereto, U.S. Provisional Application No. 62/060,130, filed October 6, 2014, U.S. Provisional Application No. 62/141,026, filed March 31, 2015; No. 14/876,199, filed Oct. 6, 2002, and claims priority thereto.

TECHNICAL FIELD This disclosure relates to apparatus and methods for treating the surface of microelectronic substrates and, more particularly, to apparatus and methods for removing objects from microelectronic substrates using cryogenic fluids.

Advances in microelectronics technology have resulted in integrated circuits (ICs) to be formed on microelectronic substrates (eg, semiconductor substrates) with ever-increasing active component densities. IC fabrication can be performed by the application and selective removal of various materials on microelectronic substrates. One aspect of a manufacturing process can include exposing a surface of a microelectronic substrate to a microelectronic substrate cleaning treatment to remove process residues and/or debris (eg, particles) from the microelectronic substrate. Various dry and wet cleaning techniques have been developed to clean microelectronic substrates.

However, advances in microelectronic IC manufacturing have resulted in smaller device features on substrates. Smaller device features have made devices more susceptible to damage from smaller particles than in the past. Therefore, any technique that allows removal of smaller particles and/or relatively larger particles without damaging the substrate would be desirable.

Described herein are several devices and methods that can remove objects (eg, particles) from microelectronic substrates using a variety of different fluids or fluid mixtures. In particular, the fluid or fluid mixture can be exposed to the microelectronic substrate in a manner that can dislodge particles from the surface of the microelectronic substrate. The fluid mixture is a cryogenic aerosol and/or gas cluster formed by expansion of the fluid mixture from a high pressure environment (e.g., above atmospheric pressure) to a lower pressure environment (e.g., below atmospheric pressure) that may contain the microelectronic substrate. Can include but is not limited to jet (GCJ) spray.

Embodiments described herein provide for the removal of larger (e.g., >100 nm) particles below 100 nm without reducing removal efficiency and/or without damaging features of microelectronic substrates during particle removal. It demonstrates unexpected results by improving the particle removal efficiency of particles. Reduced damage may be enabled by avoiding liquefaction of the fluid mixture or limiting liquefaction prior to expansion (eg <1 wt%).

Additional unexpected results include showing a larger cleaning area (~100mm) from a single nozzle. It has been shown that one aspect of enabling a larger cleaning area is based, at least in part, on minimizing the gap distance between the nozzle and the microelectronic substrate. Larger cleaning area sizes reduce cycle time and chemical costs. Additionally, one or more unique nozzles can be used to control the expansion of fluid mixtures that can be used to remove particles from microelectronic substrates.

According to one embodiment, an apparatus is described for treating a surface of a microelectronic substrate via impingement of the surface with at least one fluid. The apparatus includes a processing chamber defining an interior space for processing a microelectronic substrate with at least one fluid within the processing chamber, a movable chuck supporting the substrate within the processing chamber, and a microelectronic substrate for processing with at least one fluid. A substrate having an exposed upper surface at a position and a movable chuck operably coupled to the movable chuck and between a substrate loading position and at least one processing position where the substrate is processed with at least one fluid. a substrate translation drive system operatively coupled to the processing chamber and configured to rotate the substrate; and at least one fluid source connected to the substrate translation drive system configured to translate the one fluid expansion component (e.g., nozzle) effective to direct the fluid mixture toward the upper surface of the substrate when the movable chuck is positioned in at least one of the above-described processing positions to support the substrate; at least one fluid expansion component disposed within the processing chamber;
can include

According to another embodiment, a method for treating a surface of a substrate via impingement of the surface with a cryogenic fluid mixture is described herein. Fluid mixtures include, but are not limited to, nitrogen, argon, xenon, helium, neon, krypton, carbon dioxide, or any combination thereof. The incoming fluid mixture is maintained at a pressure below 273 K and to prevent liquid formation within the fluid mixture. The fluid mixture expands into the process chamber to form an aerosol or gas cluster spray. Expansion can be performed by passing the fluid mixture through a nozzle into a process chamber that can be maintained at 35 Torr or less. Fluid mixture sprays can be used to remove matter from substrates via kinetic and/or chemical means.

The processes described herein have been found to remove large particles (eg, >100 nm) and small particles (eg, <100 nm) in a highly efficient manner. However, particle removal efficiency can be further improved by incorporating a multi-stage treatment method to address different types of particles on microelectronic substrates. A multi-step process can include multiple passes of the microelectronic substrate at different process conditions. For example, a first treatment may include a first set of process conditions used to remove a particular type of particle, followed by a second set of process conditions passed across the microelectronic substrate.

In one embodiment, the GCJ spray treatment method comprises:
processing the microelectronic substrate at a first group of process conditions, the first group of process conditions comprising: chamber pressure, gas pressure, gas temperature, gas chemistry, substrate velocity or residence time, gap distance, including but not limited to. After the first treatment, the same microelectronic substrate can be treated using a second treatment in which at least one of the plurality of process conditions is different or have different sizes. In this way, various types of particles can be targeted for removal by optimizing process conditions that are likely to remove particles while minimizing damage caused by displaced particles or GCJ spray. For example, small particles may require a higher flow rate or residence time to remove, while the process conditions impart excess energy to larger particles, resulting in additional damage to patterned features. can cause However, if the larger particles can be removed at a lower flow rate without damaging the patterned features, the first treatment can include relatively low flow process conditions to remove the larger particles. However, the second treatment may include a relatively high flow rate to remove smaller particles after the larger particles have been removed. Therefore, higher flow rate processing may cause less damage to patterned features because larger particles were removed prior to the second processing.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description below, illustrate the invention. play a role in explaining
Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
1 shows a schematic diagram of a cleaning system and a cross-sectional view of a process chamber of the cleaning system in accordance with at least one embodiment of the present disclosure; FIG. FIG. 3 illustrates a cross-sectional view of a two-stage gas nozzle according to at least two embodiments of the present disclosure; FIG. 3 illustrates a cross-sectional view of a two-stage gas nozzle according to at least two embodiments of the present disclosure; 1 illustrates a cross-sectional view of a single stage gas nozzle in accordance with at least one embodiment of the present disclosure; FIG. 1 illustrates a cross-sectional view of a flush gas nozzle in accordance with at least one embodiment of the present disclosure; FIG. FIG. 5 includes a diagram of the gap distance between a gas nozzle and a microelectronic substrate, according to at least one embodiment of the present disclosure; FIG. FIG. 4 illustrates a diagram of a phase diagram that provides an indication of process conditions that may maintain a cryofluid in a liquid state or a gaseous state, in accordance with at least one embodiment of the present disclosure; FIG. 4 illustrates a diagram of a phase diagram that provides an indication of process conditions that may maintain a cryofluid in a liquid state or a gaseous state, in accordance with at least one embodiment of the present disclosure; 4 shows a flow chart presenting a method of processing a microelectronic substrate with a fluid, according to various embodiments. 4 shows a flow chart presenting another method of treating a microelectronic substrate with a fluid, according to various embodiments. 4 shows a flow chart presenting another method of treating a microelectronic substrate with a fluid, according to various embodiments. 4 shows a flow chart presenting another method of treating a microelectronic substrate with a fluid, according to various embodiments. 4 shows a flow chart representing another method of treating a microelectronic substrate with a fluid, according to various embodiments. 4 shows a flow chart presenting another method of treating a microelectronic substrate with a fluid, according to various embodiments. 4 shows a bar graph of particle removal efficiency improvement between non-liquid containing fluid mixtures and liquid containing fluid mixtures according to various embodiments. FIG. 12 shows a particle map of a microelectronic substrate showing a larger cleaning area based at least in part on a smaller gap distance between the nozzle and the microelectronic substrate; FIG. 4 shows photographs of microelectronic substrate features showing different feature damage differences between the prior art and the technology disclosed herein. 4 shows a flow chart presenting another method of fluidly treating a microelectronic substrate in accordance with various embodiments. 4 shows a flow chart presenting another method of fluidly treating a microelectronic substrate in accordance with various embodiments. 4 shows a flow chart presenting another method of fluidly treating a microelectronic substrate in accordance with various embodiments.

Methods for selectively removing objects from microelectronic substrates are described in various embodiments. One skilled in the relevant art will recognize that the various embodiments can be practiced without one or more of the specific details, or with other substitutions and/or additional methods, materials, or components. Will.
In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of various embodiments of the disclosure. Likewise, for purposes of explanation, specific numbers, materials and configurations are set forth to provide a thorough understanding of the invention. However, systems and methods may be practiced without specific details. Furthermore, with the exception of FIGS. 6A and 6B, it is understood that the various embodiments shown in the figures are exemplary representations and are not necessarily drawn to scale.

Throughout this specification, references to "an embodiment" or "embodiment" indicate that the particular feature, structure, material or property described in connection with the embodiment is included in at least one embodiment of the invention. implied, but not intended to be present in every embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment of the invention. Moreover, any of the specified features, structures, materials or properties may be combined in any suitable manner in one or more embodiments. Various additional layers and/or structures may be included and/or described features may be omitted in other embodiments.

As used herein, "microelectronic substrate" generally means an object to be treated according to the present invention. A microelectronic substrate can comprise any material portion or structure of a device, in particular of a semiconductor device or other electronic device, for example a base substrate structure, such as a semiconductor substrate, or on a base substrate structure. or a thin film-like layer overlying the base substrate structure. Substrate, therefore, is not intended to be limited to any particular base structure, underlayer or overlay layer, patterned or unpatterned, and any such layer or base structure, and , layers and/or base structures in any combination. Although the following description may refer to particular types of substrates, this is for illustrative purposes only and is not limiting. In addition to microelectronic substrates, the techniques described herein can also be used to clean reticle substrates that can be used for patterning microelectronic substrates using photolithographic techniques.

Cryogenic fluid cleaning removes contaminants by imparting sufficient energy from aerosol particles or gas jet particles (e.g., gas clusters) to overcome adhesion forces between contaminants and microelectronic substrates. It is a technique used for Therefore, it may be desirable to generate or expand cryogenic fluid mixtures (eg, aerosol sprays and/or gas cluster jet sprays) of appropriate size and velocity. Aerosol or cluster momentum is a function of mass and velocity. Momentum can be increased by increasing the velocity or mass, which is particularly when the particles are very small (e.g. <100 nm), to overcome the strong adhesion forces between the particles and the substrate surface. can be important. Larger particles will have more surface area than smaller particles for clusters to collide with. Therefore, the higher the amount of clusters, the more likely they are to affect larger particles than smaller ones. Therefore, momentum transfer to larger particles may occur at a higher rate than smaller particles, and thus larger particles may be removed from the microelectronic substrate before smaller particles. highly sexual. Accordingly, processing to remove small particles can impart excessive energy to large particles and damage the microelectronic substrate or patterned features on the microelectronic substrate as they are removed. Therefore, in order to maximize particle removal efficiency, it is necessary to use multi-stage cleaning processes to remove various types of particles.

FIG. 1 includes a schematic diagram of a cleaning system 100 that can be used to clean microelectronic substrates using an aerosol spray or gas cluster jet (GCJ) spray, and a cross-sectional view 102 of a process chamber 104 in which cleaning occurs. . Aerosol sprays or GCJ sprays can be formed by expanding a cryogenically cooled fluid mixture within the process chamber 104 to a sub-atmospheric environment. As shown in FIG. 1, one or more fluid sources 106 can supply pressurized fluid(s) to cryogenic cooling system 108 before being expanded through nozzles 110 within process chamber 104 . . A vacuum system 134 can be used to maintain a sub-atmospheric environment within the process chamber 104 and remove fluid mixtures as needed.

In this application, one or more of the following variables are important for removing objects from microelectronic substrates: the pressure and temperature of the fluid mixture flowing into the nozzle 110 before expansion, the flow rate of the fluid mixture; The composition and ratio of the fluid mixture and the pressure within the process chamber 104; Thus, controller 112 is used to store process recipes in memory 114 and computer processor 116 is used to control the various components of cleaning system 100 that implement the cleaning techniques disclosed herein via network 138 . can issue commands.

Those skilled in the art of semiconductor processing will understand the fluid source(s), cryogenic cooling system, vacuum system 134 and their respective subcomponents (not shown, e.g., sensors, controllers, etc.) to implement the embodiments disclosed herein. etc.) can be configured. For example, in one embodiment, the components of cleaning system 100 can be configured to provide a pressurized fluid mixture between 50 psig and 800 psig. The temperature of the fluid mixture can be maintained in the range of 70K-270K, preferably 70K-150K, by passing the fluid mixture through the liquid nitrogen dewar of cryogenic cooling system 108 . Vacuum system 134 can be configured to maintain process chamber 104 at a pressure of less than 35 Torr, or more preferably less than 10 Torr, to facilitate aerosol and/or gas cluster formation.

A pressurized cooled fluid mixture can be expanded into the process chamber 104 through the nozzle 110 and an aerosol or GCJ spray can be directed at the microelectronic substrate 118 . At least one nozzle 110 can be supported within the process chamber 104 , the nozzle 110 having at least one nozzle orifice that directs the fluid mixture onto the microelectronic substrate 118 . For example, in one embodiment nozzle 110 may be a nozzle spray bar having multiple openings along the length of the nozzle spray. Nozzle 110 may be adjustable so that the angle of fluid spray impinging on microelectronic substrate 118 may be optimized for a particular process. A microelectronic substrate 118 may be secured to a moveable chuck 122 providing at least one translational degree of freedom 124, preferably along the longitudinal axis of the vacuum chamber 120, via a fluid spray emitted from nozzle 110. A movable chuck that facilitates linear scanning of at least a portion of the microelectronic substrate 118 may include one or more slide and guide mechanisms for defining a path of movement of the movable chuck 122. Substrate translation drive system 128 and a drive mechanism may be utilized to impart the movement to movable chuck 122 along its guide path. A drive mechanism can include any electrical, mechanical, electromechanical, hydraulic, or pneumatic device. The drive mechanism is at least partially through the area of the fluid spray emanating from the at least one nozzle 110 to provide a range of length sufficient to permit movement of the exposed surface of the microelectronic substrate 118 . may be designed to The substrate translation drive system 128 can have a support arm (not shown) arranged to extend through a sliding vacuum seal (not shown) in the wall of the vacuum chamber 120 and a first distal end. is attached to movable chuck 122 and the second distal end engages an actuator mechanism located outside vacuum chamber 120 .

Additionally, the movable chuck 122 can also include a substrate rotation drive system 130 that provides at least one rotational degree of freedom 126, preferably about an axis perpendicular to the exposed surface of the microelectronic substrate 118, from the first predetermined index position. , facilitates rotational indexing of the microelectronics substrate 118 to a second predetermined indexing position exposing another portion of the microelectronics substrate 118 to the fluid spray. In other embodiments, movable chuck 122 can rotate at a continuous speed without stopping at the index position. Further, the movable chuck 122 can change the angle of incidence of the fluid spray by changing the position of the microelectronic substrate 118 in conjunction with changing the angle of the nozzle 110 or by itself.

In another embodiment, movable chuck 122 includes a mechanism for securing microelectronic substrate 118 to the upper surface of movable chuck 122 during impingement of at least one fluid spray on the exposed surface of microelectronic substrate 118. can be done. The microelectronic substrate 118 may be secured to the moveable chuck 122 using mechanical fasteners or clamps, vacuum clamps, or electrostatic clamps, as may be practiced by those skilled in the art of semiconductor processing, for example.

Furthermore, the movable chuck 122 can include a temperature control mechanism to control the temperature of the microelectronic substrate 118 to an elevated temperature above ambient temperature or a temperature reduced to below ambient temperature. The temperature control mechanism may include a heating system (not shown) or a cooling system (not shown) configured to regulate and/or control the temperature of movable chuck 122 and microelectronic substrate 118 . The heating or cooling system receives heat from the movable chuck 122 and transfers heat to a heat exchange system (not shown) when cooling, or transfers heat from the heat exchange system to the movable chuck when heating. It can have a recirculation flow of fluid. In other embodiments, the movable chuck 122 can have heating/cooling elements such as resistive heating elements or thermoelectric heaters/coolers.

As shown in FIG. 1, the process chamber 104 has a dual nozzle configuration (e.g., a second Nozzle 132) may be included. However, a dual nozzle configuration is not required. Some examples of nozzle 110 designs are described in the discussion of FIGS. 2A-4. Although nozzles 110, 132 are shown arranged in parallel, they need not be parallel to each other to perform the cleaning process. In other embodiments, the nozzles 110 , 132 are at opposite ends of the vacuum chamber 120 and the movable chuck 122 moves the substrate into positions where one or more of the nozzles 110 , 132 can spray the fluid mixture onto the microelectronic substrate 118 . 118 can be moved.

In another embodiment, the exposed surface area of the microelectronic substrate 118 (e.g., the area that contains the electronic devices) can be ejected from the first nozzle 110 and/or the second nozzle 132 at the same time or similar times (parallel processing) or at different times (parallel processing). The microelectronic substrate 118 can move such that it can be bombarded by fluid mixtures (eg, aerosols or GCJs), eg, in continuous processes. For example, a cleaning process may include an aerosol cleaning process followed by a GCJ cleaning process, or vice versa. Further, first nozzle 110 and second nozzle 132 may be positioned such that their respective fluid mixtures impinge microelectronic substrate 118 simultaneously at different locations. In one example, the substrate 118 can be rotated to expose the entire microelectronic substrate 118 to different fluid mixtures.

Nozzle 110 receives a cryogenic (eg, <273K) fluid mixture having inlet pressures (eg, 50 psig to 800 psig) that are substantially higher than outlet pressures (eg, <35Toor). It may be configured as The internal design of nozzle 110 may allow expansion of the fluid mixture to produce solid and/or liquid particles that may be directed toward microelectronic substrate 118 . The dimensions of the nozzle 110 impact the properties of the expanded fluid mixture and can range in configurations from simple orifices located along the spray bar, to multi-expansion volume configurations, to single expansion volume configurations. be. Figures 2A-4 illustrate some nozzle 110 embodiments that may be used. However, the scope of the present disclosure is not limited to the illustrated embodiments, and the methods disclosed herein can be applied to any nozzle 110 design. As noted above, the illustration of nozzle 110 may not be drawn to scale.

FIG. 2A includes a cross-sectional view of a two-stage gas nozzle 200, which may include two gas expansion regions that may be in fluid communication with each other, with a fluid mixture traveling through the two-stage gas (TSG) nozzle 200. As the pressure increases, the fluid mixture may undergo pressure changes. A first stage of TSG nozzle 200 may be a reservoir component 202 capable of receiving a fluid mixture via an inlet 204 that may be in fluid communication with cryogenic cooling system 108 and fluid source 106 . The fluid mixture may expand into reservoir component 202 to a pressure that may be less than the inlet pressure. The fluid mixture can flow through transition orifice 206 to outlet component 208 . In some embodiments, the fluid mixture may be compressed to a higher pressure as it flows through transition orifice 206 .
As the fluid mixture is exposed to the low pressure environment of vacuum chamber 120 through outlet orifice 210, the fluid mixture expands again into outlet component 208 and may contribute to the formation of an aerosol spray or gas cluster jet. . Broadly, TSG nozzle 200 can incorporate any dimensional design that can allow for a dual expansion of the fluid mixture between inlet orifice 204 and outlet orifice 210 . The scope of TSG nozzle 200 cannot be limited to the examples described herein.

In the embodiment of FIG. 2A, reservoir component 202 may include a cylindrical design extending from inlet orifice 204 to transition orifice 206 . The cylinder can have a diameter 212 that can vary from the size of the transition orifice 206 to three times the size of the transition orifice 206 or more.

In one embodiment, the TSG nozzle 200 may have an inlet orifice 204 diameter that may range from 0.5 mm to 3 mm, preferably from 0.5 mm to 1.5 mm. The reservoir component 202 can comprise a cylinder with a diameter 212 of 2mm to 6mm, preferably 4mm to 6mm. The reservoir component 208 can have a length 214 of 20mm to 50mm, preferably 20mm to 25mm. The non-inlet end of reservoir component 208 can transition to a smaller diameter that can compress the fluid mixture through transition orifice 206 into outlet component 208 .

A transition orifice 206 can be present in several different embodiments and can be used to condition the fluid mixture during transition between the reservoir component 202 and the outlet component 208 . In one embodiment, transition orifice 206 may be a simple orifice or opening at one end of reservoir component 202 . The diameter of this transition orifice 206 may range from 2 mm to 5 mm, but is preferably from 2 mm to 2.5 mm. In another embodiment, as shown in FIG. 2A, transition orifice 206 may have a more substantial volume than the simple opening in the previous embodiment. For example, transition orifice 206 may have a cylindrical shape that may be constant along a distance that may be less than 5 mm. In this embodiment, the diameter of transition orifice 206 may be larger than the initial diameter of outlet component 208 . In this example, there may be a step height between transition orifice 206 and outlet component 208 . The step height can be less than 1 mm. In one particular embodiment, the step height can be about 0.04mm. Outlet component 208 may have a conical shape that increases in diameter between transition orifice 206 and outlet orifice 210 . The conical portion of the outlet component 208 can have a half angle of 3° to 10°, preferably 3° to 6°.

FIG. 2B shows another embodiment 220 of TSG nozzle 200 that includes reservoir component 202 having diameter 218 that is approximately the same size as transition orifice 206 . In this embodiment, diameter 218 can be between 2 mm and 5 mm and can have length 214 similar to the embodiment of FIG. 2A. The embodiment of FIG. 2B may reduce the pressure differential between the reservoir component 202 and the outlet component 208 and improve the stability of the fluid mixture during the first stage of the TSG nozzle 200. However, in other embodiments, a single stage nozzle 300 can be used to reduce pressure fluctuations in embodiments of the TSG nozzle 200 and can reduce turbulence in the fluid mixture.

FIG. 3 shows a cross-sectional view of one embodiment of a single stage gas (SSG) nozzle 300 that may incorporate a single expansion chamber between inlet orifice 302 and outlet orifice 304 . The expansion chamber of the SSG nozzle 300 can vary, but in the embodiment of FIG. ) are shown. The conical design may include half angles of 3° to 10°, preferably 3° to 6°. A half angle may be the angle between an imaginary centerline through the expansion chamber of the SSG nozzle 300 (from inlet orifice 302 and outlet orifice 304) and a sidewall (eg, conical wall) of the expansion chamber. Finally, the SSG nozzle 300 can have a length 308 between 18mm and 40mm, preferably between 18mm and 25mm. Another variation of SSG nozzle 300 may have a continuous taper of expansion volume from inlet orifice 302 to outlet orifice 304, as shown in FIG.

FIG. 4 includes a cross-sectional view of a flush gas (FG) nozzle 400, which may have a continuous expansion chamber with no offsets or constrictions between inlet orifices 402 and outlet orifices 404. FIG. As its name suggests, the initial diameter of the expanded volume may be flush with the inlet diameter 402 and may have an inlet diameter which may be between 0.5 mm and 3 mm, preferably between 1 mm and 1.5 mm. In one embodiment, the outlet diameter 404 can be 2-4 times the size of the inlet diameter 402, preferably 2mm-12mm. Furthermore, the half angle can be between 3° and 10°, preferably between 3° and 6°. The expansion volume length 406 should vary between 10 mm and 50 mm between inlet orifice 402 and outlet orifice 404 . Furthermore, the following embodiments can be applied to both the embodiments of FIGS. 3 and 4. FIG. In one particular embodiment, the nozzle can have a cone length of 20 mm, a half angle of 3°, and an exit orifice diameter of about 4 mm. In another particular embodiment, the cone length can be 15mm to 25mm and the outlet orifice diameter can be 3mm to 6mm. In other specific examples, the outlet orifice diameter can be about 4 mm, the inlet diameter can be about 1.2 mm, and the cone length can be about 35 mm.

Another feature that can affect the cleaning efficiency of cleaning system 100 can be the distance between nozzle outlet 404 and microelectronic substrate 118 . In some process embodiments, the gap distance is determined not only by the amount of particles removed, but also by the amount of surface area that particles can be removed during a single pass across substrate 118. can also affect cleaning efficiency. In some examples, if the exit orifice of the nozzle 110 is closer (eg, <50 mm) to the microelectronic substrate 118, the aerosol spray or GCJ spray can clean a larger surface area of the substrate 118.

FIG. 5 includes a diagram 500 illustrating gap distance 502 between outlet orifice 404 of nozzle 110 and microelectronic substrate 118, in accordance with at least one embodiment of the present disclosure. In one example, gap distance 502 may be measured from the end of nozzle 110 assembly that forms the structure or support for nozzle 110 . In another example, gap distance 502 may be measured from a plane extending across the maximum diameter of the conical extension area exposed to microelectronic substrate 118 .

Gap distance 502 may vary depending on chamber pressure, gas composition, fluid mixture temperature, inlet pressure, nozzle 110 design, or some combination thereof. Typically, the gap distance 502 can be between 2 mm and 50 mm. Typically, the vacuum chamber 120 pressure can be less than 35 Torr and can operate within gap distances 502 of 2 mm and 50 mm. However, if the chamber pressure can be less than 10 Torr and the gas nozzle 110 has an exit orifice of less than 6 mm, the gap distance 502 can be optimized to be less than 10 mm. In some particular embodiments, the desired gap distance 502 may be about 5 mm for a nozzle 110 with a vacuum chamber 120 pressure of less than 10 Torr and an outlet diameter of less than 5 mm.

In other embodiments, gap distance 502 may be based, at least in part, on an inverse relationship with the pressure of vacuum chamber 120 . For example, gap distance 502 may be less than or equal to a value derived by dividing a constant value by the pressure in chamber 120 . In one embodiment, the constant may be a dimensionless parameter, or may be in units of mm×Torr, and the pressure in vacuum chamber 120 may be measured in Torr. See Equation 1:
Gap distance ≤ constant/chamber pressure (1)

Thus, the value obtained by dividing the constant by the chamber pressure provides the gap distance 502 that can be used in the cleaning process. For example, in one particular embodiment, the constant may be 50 and the chamber pressure may be approximately 7 Torr. In this case the gap distance is less than or equal to 7 mm under equation (1). In other embodiments, the constant may range from 40-60 and the pressure may range from 1 Torr to 10 Torr. In another embodiment, the constant can range from 0.05 to 0.3 and the pressure can range from 0.05 Torr to 1 Torr. Although gap distance 502 can positively impact cleaning efficiency, there are several other process variables that can contribute to cleaning efficiency using aerosol spray and gas cluster jet spray.

The hardware described in the legends of FIGS. 1-5 can be used to enable aerosol spray and gas cluster jet (GCJ) spray with minor changes in hardware and substantial changes to process conditions. can be done. Process conditions may vary between different fluid mixture compositions and ratios, inlet pressures, inlet temperatures, or vacuum chamber 120 pressures. One substantial difference between the aerosol spray and the GCJ spray process can be the phase composition of the fluid mixture entering nozzle 110 . For example, the aerosol spray fluid mixture may have a higher fluid concentration than the GCJ fluid mixture, which may exist in a gaseous state with very little or no fluid in the GCJ fluid mixture entering the nozzle 110.

In an aerosol spray embodiment, the temperature of cryogenic cooling system 108 may be set to a point where at least a portion of the fluid mixture entering nozzle 110 may be in the liquid phase. In this embodiment, the nozzle mixture can be at least 10% by weight in the liquid state. The liquid/gas mixture is then expanded at high pressure into the process chamber 104 where a cryogenic aerosol can be formed and can include a substantial portion of solid and/or liquid particles. However, as discussed below, the state of the fluid mixture may not be the only difference between the aerosol process and the GCJ process.

In contrast, the GCJ spray fluid mixture entering the nozzle 110 contains very little liquid phase (eg, <1 vol.%) or may be completely gaseous with no liquid phase. For example, the temperature of the cryogenic cooling system 108 may be set to a point that prevents the fluid mixture from existing in the liquid phase for the GCJ cleaning process. A phase diagram can thus be one way to identify process temperatures and pressures that can be used to enable the formation of an aerosol or GCJ spray within the process chamber 104 .

6A-6B, state diagrams 600, 608 indicate in which phases the components of the incoming fluid mixture may exist, or more likely include liquid phase, gas phase, or a combination thereof. can be shown. To explain and illustrate the exemplary phase diagrams, an argon phase diagram 602, a nitrogen phase diagram 604, an oxygen phase diagram 610, and a xenon phase diagram 612 are shown. Those skilled in the art may be able to find state diagram information in the literature, or through the National Institute of Standards and Technology, Gaithersburg, Maryland, or other sources. Other chemicals described herein may also have representative phase diagrams, but are not shown here for ease of illustration.

The state diagrams 600, 608 may be represented by graphical representations highlighting the relationship between pressure (e.g., y-axis) and temperature (e.g., x-axis) and the possibility that an element may exist in gaseous or liquid form. . A phase diagram may be represented by a gas-liquid phase transition line 606 (or a vapor-liquid transition line )). In these embodiments, if the pressure and temperature of the element are to the left of the gas-liquid transition line 606, then there is a high probability that a liquid phase is present, and if the pressure and temperature of the element are to the right of the gas-liquid transition line 606, the liquid phase is likely to be present. In some cases, the gas phase can predominate. Furthermore, if the pressure and temperature of the element are very close to the gas-liquid phase transition line 606, the probability that the element is in the gas-liquid phase is greater than if the pressure and temperature are further away from the gas-liquid phase transition line 606. is also expensive. For example, considering the phase diagram 602 for argon, when argon is maintained at a temperature of 100 K and a pressure of 300 psi, argon is in the liquid phase more than when argon is maintained at a temperature of 130 K and a pressure of 300 psi. It is more likely that it contains a portion or has a higher liquid concentration (by weight). The liquid concentration of argon can be increased as the temperature is lowered from 130 K while maintaining a pressure of 300 psi. Similarly, the liquid concentration of argon may increase as the pressure increases from 300 psi while maintaining a temperature of 130K. Generally, according to phase diagram 600, the temperature should be above 83 K to keep argon in the gaseous state, and the temperature should be above 63 K to keep nitrogen in the gaseous state. . However, the phase of any nitrogen-argon mixture, argon or nitrogen may depend on the relative concentrations of the elements and may also depend on the pressure and temperature of the fluid mixture. However, the state diagram 600 can be used as a guideline that can provide an indication of the phase of an argon-nitrogen mixture, an argon or nitrogen environment, or at least an indication of the likelihood that a liquid may be present. For example, for an aerosol cleaning process, the incoming fluid mixture may have a temperature or pressure above or to the left of the gas-liquid transition line 606 for one or more elements of the incoming fluid mixture. In contrast, the GCJ cleaning process is more likely to use an inlet fluid mixture that may have pressures and temperatures that may be to the right of the gas-liquid phase transition line 606 for one or more elements in the GCJ inlet fluid mixture. expensive. In some cases, the system 100 can alternate between aerosol and GCJ processes by varying the inlet temperature and/or pressure of the fluid mixture.

It should be noted that the gas-liquid phase transition line 606 is similar to each state diagram 600, 608; however, their values may be specific to the chemical assigned to each state diagram 600, 608, but , state diagrams 600 , 608 can be used by those skilled in the art as described in the description of the argon state diagram 602 . A person skilled in the art can use the state diagrams 600, 608 to optimize the amount of liquid and/or gas in the fluid mixture of the aerosol or GCJ spray.

A cryogenic aerosol spray can be formed with a fluid or fluid mixture that has been subjected to a cryogenic temperature at or near the liquefaction temperature of at least one fluid, and then expand the fluid mixture through a nozzle 110 into the low pressure environment of the process chamber 104. The expansion conditions and composition of the fluid mixture can play a role in forming small droplets and/or solid particles with an aerosol spray that can impinge on the substrate 118 . The aerosol spray reduces contamination of the microelectronic substrate 118 by imparting sufficient energy from the aerosol spray (e.g., small droplets, solid particles) to overcome adhesion forces between the contaminants and the microphone and electronic substrate 118. It can be used to dislodge matter (eg particles). The momentum of an aerosol spray can play an important role in removing particles based, at least in part, on the amount of energy that may be required for the aforementioned adhesion forces. Particle removal efficiency can be optimized by generating a cryogenic aerosol that can have different mass and/or velocity components (eg, droplets, crystals, etc.). The momentum required to remove contaminants is a function of mass and velocity. Mass and velocity can be very important to overcome strong adhesion forces between the particles and the surface of the substrate, especially if the particles are very small (<100 nm).

FIG. 7 shows a flow chart 700 of a method of treating a microelectronic substrate 118 with a cryogenic aerosol to remove particles. As mentioned above, one approach to improving particle removal efficiency can be to increase the momentum of the aerosol spray. Momentum can be the product of the mass and velocity of the contents of the aerosol spray, thus increasing the mass and/or velocity of the components of the aerosol spray can increase the kinetic energy. The mass and/or velocity are dependent on a variety of factors, which may include, but are not limited to, the fluid mixture composition, the pressure and/or temperature of the incoming fluid mixture, and/or the temperature and/or pressure of the process chamber 104. obtain. Flowchart 700 illustrates one embodiment of optimizing momentum by using various combinations of nitrogen and/or argon and at least one other carrier gas and/or pure argon or pure nitrogen.

Referring to FIG. 7, at block 702 the system 100 may receive the microelectronic substrate 118 within the process chamber 104 . Microelectronic substrate 118 can include semiconductor materials (such as silicon) that can be used to fabricate electronic devices that can include, but are not limited to, memory devices, microprocessor devices, light emitting displays, solar cells, and the like. Microelectronic substrate 118 may include a patterned or blanket film, which may contain contamination that may be removed by an aerosol cleaning process performed on system 100 . System 100 may include a process chamber 104 in fluid communication with a cryogenic cooling system 108 and one or more fluid sources 106 . The process chamber may also include a fluid expansion component (eg, TSG nozzle 200, etc.) that may be used to expand the fluid mixture to form an aerosol spray for cleaning the microelectronic substrate 118.

At block 704, the system 100 may supply the fluid mixture to the fluid expansion component via the cryogenic cooling system 108, which may cool the fluid mixture below 273K. In one embodiment, the temperature of the fluid mixture may be greater than or equal to 70K and less than or equal to 200K, more particularly the temperature may be less than 130K. Also, the system 100 can maintain the fluid mixture at a pressure higher than atmospheric pressure. In one embodiment, the pressure of the fluid mixture can be maintained between 50 psig and 800 psig.

In one embodiment, the fluid mixture may comprise a first fluid component comprising molecules with an atomic weight of less than 28 and at least one additional fluid component comprising molecules with an atomic weight of at least 28. One skilled in the art can optimize the fluid mixture of two or more fluids to achieve the desired momentum of the aerosol spray components to maximize particle removal efficiency or target different types or sizes of particles. could be In this case, the first fluid component may include, but is not limited to, helium, neon, or combinations thereof. The at least one additional fluid component may include, but is not limited to, nitrogen ( _N2 ), argon, krypton, xenon, carbon dioxide, or combinations thereof. In one particular embodiment, the additional fluid component may include a mixture of _N2 and argon and the first fluid component may include helium. However, the temperature, pressure and concentration of the fluid mixture can be varied to provide different types of aerosol sprays. In other embodiments, the phases or states of the fluid mixture may include various concentrations of gas, liquid, gas-liquid, as described below.

The ratio between the first fluid component and the additional fluid component may vary depending on the type of spray desired for cleaning the microelectronic substrate 118 . A fluid mixture may vary by chemical composition and concentration and/or by phase or state of matter (eg, gas, liquid, etc.). In one aerosol embodiment, the first fluid component comprises at least 50% to 100% by weight of the fluid mixture, and the fluid mixture may include a first portion in a gaseous state and a second portion in a liquid state. In most cases, the fluid mixture will have at least 10% by weight in the liquid phase. The fluid mixture may be optimized to accommodate different types and/or sizes of particles that may be present on patterned or non-patterned microelectronic substrate 118 . One approach to changing particle removal performance is to adjust the composition and/or concentration of the fluid mixture to improve particle removal performance. In another fluid mixture embodiment, the first fluid component comprises 10% to 50% by weight of the fluid mixture. In another embodiment, the first fluid component may comprise 20% to 40% by weight of the fluid mixture. In another fluid mixture embodiment, the first fluid component may comprise 30% to 40% by weight of the fluid mixture. The phases of the aforementioned aerosol-fluid mixtures can also be varied widely to adjust for different types of particles and films on substrate 118 . For example, a fluid mixture can include a first portion that can be in a gaseous state and a second portion that can be in a liquid state.

In one embodiment, the second portion can be at least 10% by weight of the fluid mixture. However, in certain cases, a lower concentration liquid may be desirable to remove particles. In lower liquid concentration embodiments, the second portion may be 1% or less by weight of the fluid mixture. A fluid mixture can include a liquid phase or a gas phase of one or more components. In these fluid mixture embodiments, the system 100 can perform an aerosol spray by flowing between 120 slm and 140 slm for the additional fluid component and between 30 slm and 45 slm for the first fluid component.

In addition to the inlet pressure, concentration, and composition of the fluid mixture, the momentum and composition of the aerosol spray can also be affected by the pressure within the process chamber 104 . More specifically, chamber pressure can affect the mass and/or velocity of the liquid droplets and/or solid particles in the aerosol spray. Expansion of the fluid mixture may depend on the pressure differential across nozzle 110 .

At block 706 , system 100 may provide the fluid mixture into process chamber 104 such that at least a portion of the fluid mixture contacts microelectronic substrate 118 . Expansion of the fluid mixture through a fluid expansion component (eg, nozzle 110) may form small droplets and/or solid particles of the aerosol spray. System 100 may maintain process chamber 104 at a chamber pressure of 35 Torr or less. In certain cases, it may be desirable to maintain the process chamber 104 at a much lower pressure to optimize the mass and/or velocity of the small droplets and/or solid particles in the aerosol spray. In one particular embodiment, the particle removal properties of an aerosol spray may be more desirable for certain particles if the process chamber is maintained below 10 Torr. It was also noted that the particle removal efficiency covers a larger surface area if the process chamber 104 is maintained below 5 Torr during expansion of the fluid mixture.

When the fluid mixture flows through the fluid expansion component, the fluid mixture undergoes a phase transition associated with expansion of the fluid mixture from a relatively high pressure (eg, >atmospheric pressure) to a relatively low pressure (eg, <35 Torr). Can receive. In one embodiment, the incoming fluid mixture can be in a gas or liquid-gas phase and is under a relatively higher pressure than the process chamber 104 . However, as the fluid mixture flows or expands through the low pressure of the process chamber 104, the fluid mixture may begin to transition and form droplets and/or solid states as described above. For example, the expanded fluid mixture may include a combination of gas phase, liquid phase, and/or solid phase portions. This may include cryogenic aerosols as described above. In yet another embodiment, the fluid mixture may also include gas clusters. In one embodiment, a GCJ or aerosol spray of an expanded fluid mixture can be the aggregation of atoms or molecules due to weak attractive forces (eg van der Waals forces). In one example, a gas cluster is considered a phase of matter between a gas and a solid, and the size of a gas cluster can range from a few molecules or atoms to over 105 atoms.

In another embodiment, the fluid mixture may be transferred between aerosols and gas clusters (eg, GCJ) within the same nozzle while processing the same microelectronic substrate 118 . In this way, the fluid mixture can transition between the aerosol and the GCJ by proceeding from higher liquid concentrations to lower liquid concentrations in the fluid mixture. Alternatively, the fluid mixture may transition between the GCJ and the aerosol by proceeding from a lower liquid concentration to a higher liquid concentration in the fluid mixture. As described above in the description of Figures 6A-6B, the liquid phase concentration can be controlled by temperature, pressure, or a combination thereof. For example, in transitioning from aerosol to GCJ, in one particular embodiment, the concentration of the fluid mixture may transition from 10% by weight to less than 1% by weight. In another particular embodiment, the transition from GCJ to aerosol can occur when the liquid concentration of the fluid mixture transitions from 1 wt% to less than 10 wt%. However, the transition between the aerosol and the GCJ and vice versa is not limited to the percentages in the specific embodiments described above and is merely illustrative and non-limiting. .

At block 708, the expanded fluid can be directed toward the microelectronic substrate 118 and can dislodge particles from the microelectronic substrate 118 as the fluid expansion component moves across the surface of the microelectronic substrate 118. In some embodiments, system 100 may include multiple fluid expansion components that may be arranged around microelectronic substrate 118 . Multiple fluid expansion components can be used concurrently or serially to remove particles. Alternatively, some of the plurality of fluid expansion components may be dedicated to aerosol processing and the remaining fluid expansion components may be used for GCJ processing.

In addition to aerosol processing, microelectronic substrate 118 may be cleaned using GCJ processing. A cryogenic gas cluster includes a heat exchanger vessel (e.g., cryogenic cooling system 108) such as a Dewar that exposes the gas to cryogenic temperatures where gaseous species such as argon or nitrogen or mixtures thereof may exceed the liquefaction temperature of any gaseous component. It can be formed as it passes through. The high pressure cryogenic gas may then be expanded through a nozzle 110 or nozzle array that is angled or perpendicular to the surface of the microelectronic substrate 118 . The GCJ spray is used to remove particles from the surface of the semiconductor wafer without causing damage or limiting the amount of damage to the surface of the microelectronic substrate 118. can be used.

A gas cluster can be a collection or agglomeration of atoms/molecules held together by forces (e.g. van der Waals forces), but as a separate phase of matter between the atoms or molecules in the gas and the solid phase. classified and sizes can range from a few atoms to 105 atoms. Hagena's empirical cluster scaling parameter (Γ*) given in equation (2) provides a critical parameter that can influence the cluster size. k is the condensation parameter (gas species property) related to bond formation, d is the nozzle orifice diameter, α is the expansion half angle, Po and To are pre-expansion pressure and temperature. A nozzle geometry with a conical shape helps to constrain the expanding gas and increase the number of collisions between atoms or molecules for more efficient cluster formation. In this manner, nozzle 110 can facilitate the formation of clusters large enough to dislodge contaminants from the surface of substrate 118 . The GCJ spray emitted from nozzle 110 is not ionized before striking substrate 118, but remains as a neutral set of atoms.

Atoms or molecular aggregates that make up the cluster can have a size distribution that can provide better processability due to the proximity of the low temperature cluster size to the contaminant size on the microelectronic substrate 118; Cleaning contaminants of size less than 100 nm can be targeted. Also, the small size of the cold clusters striking the microelectronic substrate 118 can prevent or minimize damage to the microelectronic substrate 118, which may have sensitive structures that need to be protected during processing.

Similar to the aerosol process, the GCJ process can use the same or similar hardware as described in the description of system 100 of FIG. 1 and components described in the description of FIGS. 2A-5. However, implementation of the GCJ method is not limited to the hardware embodiments described herein. In certain embodiments, the GCJ process may use the same or similar process conditions as the aerosol process, but the GCJ process may have a lower liquid phase concentration for the fluid mixture. However, the GCJ process need not have a lower liquid concentration than all embodiments of the aerosol process described herein. One of ordinary skill in the art can implement a GCJ method that increases the amount or density of gas clusters relative to any small droplets and/or solid particles (e.g., frozen liquid) that may be present in the GCJ method described herein. can. These GCJ methods may have several different techniques for optimizing the cleaning process, and those skilled in the art will be able to use any combination of these techniques to clean any microelectronic substrate 118. can do. For example, one of ordinary skill in the art can determine the design and/or orientation of the nozzle 110, the composition or concentration of the fluid mixture, the inlet pressure and/or temperature of the fluid mixture, and the pressure and/or temperature of the process chamber 104 to clean the microelectronic substrate 118. /or the temperature can be changed.

FIG. 8 provides a flow chart 800 for a cryogenic method for producing a GCJ process for removing particles from microelectronic substrates 118 . In this embodiment, the method is representative of a GCJ process in which a multi-stage nozzle 110 can be used, similar to the two-stage gas (TSG) nozzle 200 described herein in the description of FIGS. 2A-2B. can be done. The embodiment of FIG. 8 may reflect pressure differentials or changes in the fluid mixture as it transitions from a high pressure environment to a low pressure environment through the multi-stage nozzle 110 .

Referring to FIG. 8, at block 802, system 100 can receive microelectronic substrate 118 into vacuum process chamber 120, which can include a fluid expansion component (eg, TSG nozzle 200). The system may bring the process chamber 104 to sub-atmospheric pressure prior to exposing the microelectronic substrate 118 to any fluid mixture provided by the cryogenic cooling system 108 .

At block 804, the system 100 may supply or condition a fluid mixture that is at a temperature below 273K and a pressure above atmospheric pressure. For example, the temperature of the fluid mixture may be between 70K and 200K, or more specifically between 70K and 120K. The mixed fluid pressure may be between 50 psig and 800 psig. Generally, at least the majority (by weight) of the fluid mixture may be in the gas phase. However, in other embodiments, the fluid mixture may be less than 10% by weight in the gas phase, more particularly less than 1% by weight in the gas phase.

The fluid mixture can be, but is not limited to, a single fluid composition or combination of fluids that can include _N2 , argon, xenon, helium, neon, krypton, carbon dioxide, or any combination thereof. not. One skilled in the art can select combinations of one or more of the aforementioned fluids to process substrates using one fluid mixture at a time, or to process the same microelectronic substrate 118 using combinations of fluid mixtures. Substrates can be processed.

In one embodiment, the fluid mixture may include a combination of _N2 and argon in a ratio between 1:1 and 11:1. Those skilled in the art can optimize the ratio in relation to the liquid concentration of N ₂ and/or argon to remove particles from the microelectronic substrate 118 . However, in other embodiments, one skilled in the art can also optimize the energy or momentum of the GCJ fluid mixture to optimize particle removal efficiency. For example, the fluid mixture may contain another carrier gas that can change the mass and/or velocity of the GCJ process. Carrier gases can include, but are not limited to, xenon, helium, neon, krypton, carbon dioxide, or any combination thereof. In one embodiment, the fluid mixture can be a 1:1 to 1:4 mixture of argon to _N2 and one or more of xenon, krypton, carbon dioxide, or any combination thereof. It can include mixtures in which the carrier gas can be mixed. In another example, the carrier gas composition and concentration can be optimized with different ratios of _N2 and argon with different ratios of carrier gas. In other embodiments, a carrier gas may be included based on the Hagena value, k, as shown in Table 1.

Generally, in some embodiments, the low k fluid should be of equal or greater concentration when mixed with N ₂ , argon, or a combination thereof. For example, if the carrier gas is mixed with N ₂ , argon, or a combination thereof (eg, 1:1 to 4:1), the ratio between N ₂ , argon, or a combination thereof and the carrier gas is It should be done using a ratio mixture of at least 4:1, where xenon, krypton, carbon dioxide or any combination thereof is used in a mixture ratio up to 11:1. In contrast, when combining helium, neon, or combinations thereof with N ₂ , argon, or combinations thereof (eg, 1:1 to 4:1), the mixing ratio is N ₂ , argon, or combinations thereof ( for example 1:1 to 4:1) and helium, neon or combinations thereof, at least 1:4. The above _N2 , argon and/or carrier gas combinations can also be applied to other aerosol and GCJ methods described herein.

In other embodiments, the fluid mixture may include a combination of argon and _N2 in a ratio between 1:1 and 11:1. The fluid mixture can also include a carrier gas (eg, Table 1). However, the fluid mixture can also contain pure argon or pure nitrogen compositions that can be used with the aerosol or GCJ methods described herein.

At block 806, the system 100 may provide a fluid mixture from the fluid source 106 and/or from the cryogenic cooling system 108 to the fluid expansion component. System 100 may also maintain process chamber 104 at a pressure of less than 35 Torr. For example, the system 100 may use the vacuum system 134 to control the pressure of the process chamber 104 to control the process chamber 104 before or when the fluid mixture is introduced into the process chamber 104 . In some embodiments, the pressure in process chamber 104 may be between 5 Torr and 10 Torr, and in some embodiments the pressure may be less than 5 Torr.

A GCJ spray may form when the fluid mixture transitions between a relatively high pressure environment (eg, upstream of nozzle 110) and a low pressure environment (eg, a process chamber). In the embodiment of FIG. 8, the fluid expansion component may be a TSG nozzle 200 capable of subjecting the fluid mixture to at least two pressure changes or expansions before impinging on the microelectronic substrate 118 .

At block 808, the fluid mixture may expand through the inlet orifice 204 into the reservoir component 202 to achieve or maintain a reservoir pressure above the process chamber 104 pressure and below the inlet pressure of the fluid mixture. Generally, the reservoir pressure can be less than 800 psig and greater than or equal to 35 Torr. However, variations in gas flow within the confined space illustrated in FIGS. 2A-2B can cause variations in reservoir pressure.

The fluid mixture may pass to transition orifice 206 which may or may not be smaller than the diameter of reservoir component 202 .
If the transition orifice 206 is smaller than the diameter of the reservoir component 202 , the fluid mixture will experience a higher pressure as it flows through or through the transition orifice 206 and into the outlet component 208 of the TSG nozzle 200 . can be compressed.

At block 810, the fluid mixture may be maintained at an outlet pressure within the outlet component 208 of the fluid expansion component.
The outlet pressure can be above the chamber pressure and below the reservoir component 202 pressure. During the transition between transition orifice 206 and exit orifice 210, the fluid mixture may expand and form gas clusters as described above. The pressure difference between the outlet component 208 and the process chamber 104 may be due to the smaller closed volume of the outlet component 210 compared to the larger volume of the process chamber 104 .

The gas cluster can be directed toward the outlet orifice 210 and the fluid mixture can continue to expand after the fluid mixture exits the TSG nozzle 200. Momentum, however, can direct at least a majority of the gas cluster spray toward the microelectronic substrate 118 . As mentioned above, the size of gas clusters can vary between a few atoms up to 105. The process can be optimized to control the number and size of gas clusters by varying the process conditions described above. For example, one skilled in the art can vary the incoming fluid mixture pressure, the composition/concentration of the fluid mixture, the process chamber 104 pressure, or any combination thereof to remove particles from the microelectronic substrate 118.

At block 812 , GCJ spray components may be used to kinetically or chemically remove matter or contaminants from the microelectronic substrate 118 . Objects can be removed by the kinematic effects of the GCJ spray and/or by chemical interactions with objects that the fluid mixture may have. However, removal of objects is not limited to theories of kinetic and/or chemical removal, and removal of objects after application of the GCJ spray is any arbitrary method used to describe removal of objects. Any theory to explain the removal of the object is applicable in that it can be sufficient evidence for an applicable theory of .

Also, the relative positions of the TSG nozzle 200 and the microelectronic substrate 118 can be used to optimize object removal. For example, the incident angle of the GCJ spray can be adjusted by moving the TSG nozzle 200 between the surface of the microelectronic substrate 118 and the plane of the exit orifice 210 between 0° and 90°. In one particular embodiment, the angle of incidence may be 30° to 60° to ablate objects based on composition or pattern on microelectronic substrate 118 . Alternatively, the angle of incidence can be between 60° and 90°, more specifically about 90°. In other embodiments, more than one nozzle 110 may be used to process the microelectronic substrate 118 at similar or varying angles of incidence.

In the removal embodiments described above, the microelectronic substrate 118 can be translated and/or rotated during the removal process. The removal rate can be optimized for the desired residence time of the GCJ spray on a particular portion of the microelectronic substrate 118. One skilled in the art can optimize the residence time and GCJ spray impingement position to achieve the desired particle removal efficiency. For example, a desired particle removal efficiency may be greater than 80% removal between before and after particle measurement.

Similarly, the gap distance between the exit orifice 210 and the surface of the microelectronic substrate 118 can be optimized to enhance particle removal efficiency. The gap distance is explained in more detail in the discussion of Figure 5, but generally the gap distance may be less than 50mm.

The GCJ process may also be performed using single stage nozzles 300, 400 similar to those described in the descriptions of FIGS. that the single stage nozzle 300, 400 includes a single expansion chamber that can be continuous in that the expansion region diameter 306 is the same or increases between the inlet orifice 302 and the outlet orifice 304; can be done. For example, single stage nozzles 300 , 400 may not have a transition orifice 206 like TSG nozzle 200 . However, the single stage GCJ method can also be used with the TSG nozzle 200 system 100 and is not limited to the single stage nozzle system 100 . Similarly, the methods described in the descriptions of FIGS. 9-12 can also be used with single stage nozzles 300,400.

FIG. 9 shows a flowchart 900 for another method of treating a microelectronic substrate 118 with GCJ spray. The positioning of nozzle 110 relative to microelectronic substrate 118 can have a strong impact on particle removal efficiency. In particular, the gap distance between the exit orifice 304 and the surface of the microelectronic substrate 118 can affect particle removal efficiency. The gap distance affects the fluid flow and distribution of the GCJ spray and can affect the size of the surface area cleaned by the nozzle 110 . In this manner, cycle time for the GCJ process can be reduced due to fewer passes or shorter dwell times for nozzles 110 .

Referring to FIG. 9, at block 902, the microelectronic substrate 118 can be received within the process chamber 104, which can have a gas expansion component (GEC) (eg, nozzles 300, 400). The GEC can be any of the nozzles 110 described herein, but can be of the same or similar configuration as the TSG nozzle 200, SSG nozzle 300, or flush nozzle 400, among others. Generally, the nozzle may include an inlet orifice 402 that receives the fluid mixture and an outlet orifice 404 that allows the fluid mixture to enter the process chamber 104 .

At block 904 , the system 100 may position the microelectronic substrate 118 on the opposite side of the GEC such that the exit orifice 404 is positioned on or adjacent to the microelectronic substrate 118 . Also, the GEC can be placed at an angle to the surface of the microelectronic substrate 118 . The surface is the part on which microelectronic devices are manufactured. The angle can range from 0° to 90°. GEC positioning can also be optimized based on gap distance 502, as described in FIG. Gap distance 502 may affect the flow distribution to and/or across microelectronic substrate 118 . As the gap distance 502 increases, the cleaning surface area decreases and may require additional nozzle paths to maintain or improve particle removal efficiency. The velocity of the expanding fluid mixture may also vary depending on gap distance 502 . For example, lateral flow of fluid across microelectronic substrate 118 may increase as gap distance 502 decreases. In some embodiments, higher velocities can provide higher particle removal efficiencies.

Typically, the GEC can be within 50 mm of the surface of microelectronic substrate 118 . However, in most embodiments the gap distance 502 may be less than 10 mm for the aerosol or GCJ processes described herein. In one particular embodiment, the gap distance 502 may be approximately 5 mm prior to dispensing the fluid mixture into the process chamber 104 through the GEC.

At block 906, the system 100 may supply the fluid mixture to the GEC at a temperature that may be less than 273K and at a pressure that prevents liquid formation in the fluid mixture at the temperature at which the fluid mixture is provided. In this way, the liquid concentration within the fluid mixture can be absent or at least less than 1% by weight of the fluid mixture. A person skilled in the art of chemical processing can use any known technique to measure the liquid concentration of a fluid mixture. Further, one skilled in the art can use phase diagrams 600, 608 or other known phase diagram literature available for single species or mixtures of species to select appropriate combinations of temperature and pressure. can do.

In one embodiment, the temperature can be above 70 K and below 273 K for fluid mixtures that can include nitrogen, argon, xenon, helium, carbon dioxide, krypton, or any combination thereof. Similarly, the pressure may be selected using state diagrams 600, 608, or by other known measurement techniques that minimize the liquid concentration in the liquid mixture to less than 1% by weight. In most embodiments, the pressure may be 10 Torr or less, but in other embodiments the pressure may exceed 10 Torr for maximum particle removal efficiency.

At block 908 , the system can provide the fluid mixture into the process chamber 104 via the GEC such that at least a portion of the fluid mixture contacts the microelectronic substrate 118 . As noted above, the fluid mixture may expand within the process chamber 104 from a relatively high pressure to a low pressure. In one embodiment, process chamber 104 may be maintained at a chamber pressure of 35 Torr or less.

In one embodiment, the fluid mixture may comprise a combination of _N2 and argon in a ratio between 1:1 and 11:1, especially less than 4:1. In other embodiments, the fluid mixture may contain another carrier gas that can change the mass and/or velocity of the GCJ spray. Carrier gases can include, but are not limited to, xenon, helium, neon, krypton, carbon dioxide, or any combination thereof. In one embodiment, the fluid mixture can be a 1:1 to 1:4 mixture of argon to _N2 and one or more of senone, krypton, carbon dioxide, or any combination thereof. It can include mixtures in which the carrier gas can be mixed.

In other embodiments, the fluid mixture can include a combination of argon and _N2 in an argon ratio of between 1:1 and 11:1. The fluid mixture can also include a carrier gas (eg, Table 1). However, the fluid mixture can also contain pure argon or pure nitrogen compositions that can be used with the aerosol or GCJ methods described herein.

For example, if the carrier gas is mixed with N ₂ , argon, or a combination thereof (eg, 1:1 to 4:1), the ratio between N ₂ , argon, or a combination thereof and the carrier gas is It should be done using a mix ratio of at least 4:1, where xenon, krypton, carbon dioxide or any combination thereof is used in a mix ratio of up to 11:1. In contrast, when combining helium, neon, or combinations thereof with N ₂ , argon, or combinations thereof (eg, 1:1 to 4:1), the mixing ratio is N ₂ , argon, or combinations thereof ( for example 1:1 to 4:1) and helium, neon or combinations thereof, at least 1:4. The above _N2 , argon and/or carrier gas combinations can also be applied to other aerosol and GCJ methods described herein.

In another embodiment, the fluid mixture may include _N2 , combined with helium or neon, and may include at least one of argon, krypton, xenon, carbon dioxide. In one particular embodiment, the mixing ratio of said combination may be 2:1.8:1.

At block 910, the expanded fluid mixture (eg, GCJ spray) can be directed toward the microelectronic substrate 118, contacting objects on the surface (eg, kinematic and/or chemical interaction), Such objects can be removed from the microelectronic substrate 118 . The kinematic and/or chemical interaction of the GCJ spray can overcome adhesion forces between the object and the microelectronic substrate 118. Objects may be removed from the process chamber 104 via the vacuum system 134 or may be deposited elsewhere within the process chamber 104 .

FIG. 10 shows another flowchart 1000 of another method of treating a microelectronic substrate 118 with a cryogenic fluid. In this embodiment, the fluid mixture can produce a GCJ spray that can have a relatively low liquid concentration. As noted above, the temperature and pressure of the fluid mixture can affect the amount (weight) of liquid in the fluid mixture. In this case, the liquid concentration of the fluid mixture can be optimized by changing the temperature.

Referring to FIG. 10, at block 1002, a microelectronic substrate 118 may be received within the process chamber 104, which may include gas expansion components (GECs) (eg, nozzles 300, 400). The GEC can be any of the nozzles 110 described herein, but can be of the same or similar configuration as the TSG nozzle 200, SSG nozzle 300, or flush nozzle 400, among others. Generally, the nozzle may include an inlet orifice 402 that receives the fluid mixture and an outlet orifice 404 that allows the fluid mixture to enter the process chamber 104 .

At block 1004 , the system 100 may be positioned opposite the microelectronic substrate 118 with the outlet orifice 404 positioned above or adjacent to the microelectronic substrate 118 . Also, the GEC can be placed at an angle to the surface of the microelectronic substrate 118 . The surface is the part on which microelectronic devices are manufactured. The angle can range from 0° to 90°. GEC positioning can also be optimized based on gap distance 502, as described in FIG. Generally, the GEC can be within 50 mm of the surface of the microelectronic substrate 118 . However, in most implementations the gap distance 502 may be less than 20 mm for the GCJ or aerosol described herein. In one particular embodiment, the gap distance 502 may be about 5 mm prior to dispensing the fluid mixture into the process chamber 104 through the GEC.

At block 1006, the system 100 supplies the fluid mixture to the GEC at a pressure above atmospheric pressure and at a temperature below 273 K and above the condensation temperature of the fluid mixture at the given pressure. can be done. The condensation temperature can vary between different gases and can vary between different gas mixtures with different compositions and concentrations. One skilled in the art can determine the gas condensation temperature of a fluid mixture using known literature (e.g., phase diagrams) or empirical techniques based at least in part on observations and/or measurements of the fluid mixture. .

In one example, the condensation temperature at a given pressure is the temperature at which a fluid may exist transitioning to the liquid phase. For example, if the fluid mixture is held above the condensation temperature, the fluid mixture may exist in a gaseous state without any liquid phase, or with very small amounts of liquid (e.g., <1% by weight). Show what you can do. In most embodiments, the temperature of the fluid mixture may vary between 50K and 200K, but more specifically between 70K and 150K, depending on the composition of the fluid mixture comprising gases with different condensation temperatures. varies between

For example, in an N ₂ fluid mixture embodiment, the amount by weight of the liquid can be estimated by using the N ₂ phase diagram 604 . For inlet pressures of about 100 psi, the temperature of the fluid mixture can exceed 100 K to minimize the amount of liquid. In this embodiment, the fluid mixture may have no liquid, or at least less than 1% by weight, when the inlet temperature is about 120 K and the pressure is 100 psi.

At block 1008 , the system 100 can provide the fluid mixture into the process chamber 104 via the GEC such that at least a portion of the fluid mixture contacts the microelectronic substrate 118 .
In this embodiment, the pressure in the process chamber 104 may be at least sub-atmospheric, but particularly less than 10 Torr.

In one embodiment, the fluid mixture may comprise a combination of _N2 and argon in a ratio between 1:1 and 11:1, especially less than 4:1. In other embodiments, the fluid mixture may contain another carrier gas that can change the mass and/or velocity of the GCJ spray. Carrier gases can include, but are not limited to, xenon, helium, neon, krypton, carbon dioxide, or any combination thereof. In one embodiment, the fluid mixture can be a 1:1 to 1:4 mixture of argon to _N2 and one or more of senone, krypton, carbon dioxide, or any combination thereof. It can include mixtures in which the carrier gas can be mixed.

For example, if the carrier gas is mixed with N ₂ , argon, or a combination thereof (eg, 1:1 to 4:1), the ratio between N ₂ , argon, or a combination thereof and the carrier gas is It should be done using a mix ratio of at least 4:1 level, where xenon, krypton, carbon dioxide or any combination thereof is used in mix ratios up to 11:1. In contrast, when combining helium, neon, or combinations thereof with N ₂ , argon, or combinations thereof (eg, 1:1 to 4:1), the mixing ratio is N ₂ , argon, or combinations thereof ( for example 1:1 to 4:1) and helium, neon or combinations thereof, at least 1:4. The above _N2 , argon and/or carrier gas combinations can also be applied to other aerosol and GCJ methods described herein.

In other embodiments, the fluid mixture can include a combination of argon and _N2 in an argon ratio of between 1:1 and 11:1. The fluid mixture can also include a carrier gas (eg, Table 1). However, the fluid mixture can also contain pure argon or pure nitrogen compositions that can be used with the aerosol or GCJ methods described herein.

At block 1010, the expanded fluid mixture (eg, GCJ spray) is projected toward the microelectronic substrate 118, contacting objects (eg, kinematic and/or chemical interactions) on the surface, and can be removed from the microelectronics substrate 118 . The kinematic and/or chemical interaction of the GCJ spray can overcome adhesion forces between the object and the microelectronic substrate 118. Objects may be removed from the process chamber 104 via the vacuum system 134 or may be deposited elsewhere within the process chamber 104 .

FIG. 11 shows a flowchart 1100 of another method of treating a microelectronic substrate 118 with a cryogenic fluid. In this embodiment, the fluid mixture can produce a GCJ spray that can have a relatively low liquid concentration. As noted above, the temperature and pressure of the fluid mixture can affect the amount (weight) of liquid in the fluid mixture. In this case, the liquid concentration of the fluid mixture can be optimized by varying the pressure. Additionally, the gap distance 502 may be specified using the controller 112 for calculation using the recipe pressure and constant values described below.

Referring to FIG. 11, at block 1102, the microelectronic substrate 118 may be received within the process chamber 104, which may include a gas expansion component (GEC) (eg, nozzle 300). The GEC can be any of the nozzles 110 described herein, but can be of the same or similar configuration as the TSG nozzle 200, SSG nozzle 300, or flush nozzle 400, among others. Generally, the nozzle may include an inlet orifice 402 that receives the fluid mixture and an outlet orifice 404 that allows the fluid mixture to enter the process chamber 104 .

At block 1104, the gas mixture is supplied to the GEC at a temperature below 273K and at an inlet pressure that prevents liquid formation in the gas mixture at inlet temperatures. For example, in the _N2 embodiment, the _N2 phase diagram 604 indicates that a fluid mixture at approximately 100K would likely have a pressure of less than 100 psi to maintain the _N2 in the gas phase. If the pressure is about 150 psi or higher, the presence of a liquid phase in the _N2 process gas is more likely.

At block 1106 , the system 100 may provide the fluid mixture into the process chamber 104 via the GEC such that at least a portion of the fluid mixture contacts the microelectronic substrate 118 . In this embodiment, the pressure in the process chamber 104 may be at least sub-atmospheric, but particularly less than 10 Torr.

In one embodiment, the fluid mixture may comprise a combination of _N2 and argon in a ratio between 1:1 and 11:1, especially less than 4:1. In other embodiments, the fluid mixture may contain another carrier gas that can change the mass and/or velocity of the GCJ spray. Carrier gases can include, but are not limited to, xenon, helium, neon, krypton, carbon dioxide, or any combination thereof. In one embodiment, the fluid mixture can be a 1:1 to 1:4 mixture of argon to _N2 and one or more of senone, krypton, carbon dioxide, or any combination thereof. It can include mixtures in which the carrier gas can be mixed.

For example, if the carrier gas is mixed with N ₂ , argon, or a combination thereof (eg, 1:1 to 4:1), the ratio between N ₂ , argon, or a combination thereof and the carrier gas is , should be performed using a mix ratio of at least a 4:1 level, where xenon, krypton, carbon dioxide or any combination thereof is used in a mix ratio of up to 11:1. The contrast is when helium, neon, or combinations thereof are combined with N ₂ , argon, or combinations thereof (eg, 1:1 to 4:1). The mixing ratio can be at least 1:4 between N ₂ , argon or combinations thereof (eg 1:1 to 4:1) and helium, neon or combinations thereof. The above _N2 , argon and/or carrier gas combinations can also be applied to other aerosol and GCJ methods described herein.

In other embodiments, the fluid mixture can include a combination of argon and _N2 in an argon ratio of between 1:1 and 11:1. The fluid mixture can also include a carrier gas (eg, Table 1). However, the fluid mixture can also contain pure argon or pure nitrogen compositions that can be used with the aerosol or GCJ methods described herein.

At block 1108 , system 100 may position microelectronic substrate 118 at gap distance 502 between an outlet (eg, outlet orifice 404 ) and microelectronic substrate 118 . Gap distance 502 is based, at least in part, on the ratio of chamber pressure and a constant parameter having a value between 40 and 60, as shown in Equation 1 in the description of FIG. In one embodiment, the units of the constant parameter may have units of length/pressure (eg, mm/Torr).

At block 1110 , the expanded fluid mixture is injected toward the microelectronic substrate 118 and contacts objects (eg, kinematic and/or chemical interactions) on the surface, such objects interacting with the microelectronic substrate 118 . can be removed from The kinematic and/or chemical interaction of the GCJ spray can overcome adhesion forces between the object and the microelectronic substrate 118. Objects may be removed from the process chamber 104 via the vacuum system 134 or may be deposited elsewhere within the process chamber 104 .

FIG. 12 shows a flowchart 1200 for another method of treating a microelectronic substrate 118 with a cryogenic fluid. In this embodiment, the fluid mixture can produce a GCJ spray that can have a relatively low liquid concentration. As noted above, the temperature and pressure of the fluid mixture can affect the amount (weight) of liquid in the fluid mixture. In this case, the system 100 can maintain a ratio between the pressure of the incoming fluid mixture and the chamber 104 pressure to optimize momentum or composition (eg, gas clusters, etc.). Additionally, the system 100 can also optimize the pressure of the incoming fluid mixture and control the liquid concentration of the incoming fluid mixture within the pressure ratio relationship between the inlet pressure and the process chamber 104 pressure.

Referring to FIG. 12, at block 1202, the microelectronic substrate 118 may be received within the process chamber 104, which may include gas expansion components (GECs) (eg, nozzles 300, 400). The GEC can be any of the nozzles 110 described herein, but can be of the same or similar configuration as the TSG nozzle 200, SSG nozzle 300, or flush nozzle 400, among others. Generally, the nozzle may include an inlet orifice 402 that receives the fluid mixture and an outlet orifice 404 that allows the fluid mixture to enter the process chamber 104 .

At block 1204, the system 100 can supply the fluid mixture to the vacuum process chamber 104, and the system 100 can maintain the fluid mixture at a temperature and/or pressure that maintains the fluid mixture in the gas phase. The fluid mixture may include, but is not limited to, at least one of nitrogen, argon, xenon, krypton, carbon oxides or helium.

In another embodiment, the fluid mixture can include _N2 , combined with at least helium or neon, and combined with at least one of argon, krypton, xenon, carbon dioxide. In one particular embodiment, the ratio of the aforementioned fluid mixture combinations can be about 1:2:2. In another more specific embodiment, the ratio of said fluid mixture may be 1:2:1.8.

At block 1206, the system 100 uses the pressure ratio to maintain the pressure of the process chamber 104 and the pressure of the incoming fluid mixture. In this manner, system 100 can ensure that there is a balance or relationship between inlet pressure and process pressure (eg, ratio = (inlet pressure/process pressure)). The pressure ratio may be a threshold that may or may not be exceeded, or the pressure ratio may include a range that may be maintained despite changes in inlet pressure or chamber pressure. The pressure ratio value may range from 200 to 500,000. However, the pressure ratio may act on a threshold that may be exceeded, not exceeded, or may specify a range within which a given recipe condition stored in controller 112 may be maintained. In this way, the pressure differential across the nozzle can be controlled to maintain the momentum or composition (eg, gas cluster size, gas cluster density, solid particle size, etc.) of the GCJ/aerosol spray.

In pressure ratio embodiments, the values consider similar units so that the controller 112 can convert the pressures to the same or similar units to control the inlet pressure and the chamber pressure.

An upper threshold embodiment may include a pressure ratio that should not be exceeded such that the inlet pressure to chamber pressure may be less than the upper threshold ratio. For example, the upper threshold may be any value of 300000, 5000, 3000, 2000, 1000 or 500.

In another embodiment, the controller 112 can maintain the inlet pressure and process pressure within pressure ratio values. Exemplary ranges may include, but are not limited to, 100,000 to 300,000, 200,000 to 300,000, 50,000 to 100,000, 5,000 to 25,000, 200 to 3,000, 800 to 2,000, 500 to 1,000, or 700 to 800.

At block 1208 , the system 100 may position the microelectronic substrate 118 at the gap distance 502 between the outlet (eg, exit orifice 404 ) and the microelectronic substrate 118 . Gap distance 502 is based, at least in part, on the ratio of chamber pressure and a constant parameter having a value between 40 and 60, as shown in Equation 1 in the description of FIG. In one embodiment, the units of the constant parameter may have units of length/pressure (eg, mm/Torr).

At block 1210 , the expanded fluid mixture is injected toward the microelectronic substrate 118 and contacts objects (eg, kinematic and/or chemical interactions) on the surface, such objects interacting with the microelectronic substrate 118 . can be removed from The kinematic and/or chemical interaction of the GCJ spray can overcome adhesion forces between the object and the microelectronic substrate 118. Objects may be removed from the process chamber 104 via the vacuum system 134 or may be deposited elsewhere within the process chamber 104 .

FIG. 13 includes a bar graph 1300 of particle removal efficiency enhancement between non-liquid containing fluid mixtures (eg, GCJ) and liquid containing fluid mixtures (eg, aerosol). One of the unexpected results disclosed herein relates to improved particle removal efficiency for sub-100 nm particles, and maintaining or improving particle removal efficiency for particles greater than 100 nm. about doing Previous techniques may involve processing microelectronic substrates with cryogenic fluid mixtures having liquid concentrations greater than 10%. New techniques that produce unexpected results may include treating microelectronic substrates 118 with cryogenic fluid mixtures that do not have liquefying concentrations.

In the embodiment of Figure 13, the microelectronic substrate 118 was deposited with silicon nitride particles using a commercially available deposition system. Silicon nitride particles had similar density and size in both tests. A baseline low temperature process (e.g., >1 wt% liquid concentration) is applied to at least one microelectronic substrate 118, and GCJ is also applied to a different group of microelectronic substrates 118 covered with silicon nitride particles. bottom. In this case, the GCJ process includes a 2:1 nitrogen to argon flow ratio with an inlet pressure of 83 psig prior to the nozzle 110 separating the high pressure fluid source from the vacuum chamber maintained at about 9 Torr. The nozzle 110 inlet diameter was ~0.06". The gap distance 502 was between 2.5-4 mm. , was passed under the nozzle twice, and the particles were measured before and after treatment using a KLA-SURF SCAN SP2-XP from KLA-Tencor™, Milpitas, CA.

Under previous technology, the sub-100 nm particle removal efficiency (PRE) is greater than 80% for particles greater than 90 nm, but less than 30% for particles less than 42 nm, as shown in FIG. decreased to Specifically, PRE decreased from ˜87% (@>90 nm particles) to ˜78% for particles between 65 nm and 90 nm. The decrease in PRE between 55 nm-65 nm particles and 40 nm-55 nm particles was more pronounced. PRE decreased to ~61% and ~55%, respectively. Finally, the largest drop in PRE was seen for ≤40 nm particles, ~24% PRE.

Given this data, it was expected that the sub-100 nm particle efficiency improvement would show a similarly decreasing return with decreasing particle size. However, the GCJ technique disclosed herein not only improved sub-100 nm PRE, but also maintained a higher degree of PRE than expected. For example, as shown in Figure 13, GCJ PRE did not fall below ~80% for any particle bin size.

As shown in Figure 13, the GCJ PRE for particles greater than 90 nm improved to over 95%, an improvement of over 5% over the results using conventional techniques. Furthermore, the GCJ process showed greater ability to remove particles below 100 nm as the particle size decreased compared to previous techniques. For example, the 65nm-90nm, 55nm-65nm and 40nm-55nm bins had a PRE of at least 90%. Improvements between ˜15% and ˜35% for each bin size. However, the greatest improvement was for bin sizes below 40 nm, where PRE improved from 25% to ~82%.

The unexpected result of GCJ PRE was two-fold. First, the increase in PRE for particles above 90 nm was coupled with the increase in PRE for particles below 90 nm. Second, between the bins sizes for the GCJ process showed a much tighter distribution than the PRE results for the aerosol process using a similar range of process conditions.

FIG. 14 includes a microelectronic substrate particle map 1400 showing a larger cleaning area due, at least in part, to a smaller gap distance 502 between nozzle 110 and microelectronic substrate 118 . Generally, as a gas expands from a high pressure environment to a low pressure environment, it becomes more likely to cover a larger surface area or coverage area, further away from its initial expansion point. It was believed that positioning the gas nozzles away from the microelectronic substrate 118 in this manner would increase the effective cleaning area. However, this is not the case and in practice having a smaller gap distance 502 achieved the completely counter-intuitive result of obtaining a larger cleaning area on the microelectronic substrate 118 .

As shown in the post-clean particle map, the 5 mm gap distance has a wider cleaning area than the 10 mm gap distance. The 5 mm gap particle map 1406 shows that the PRE is ˜70% for the right half of the microelectronic substrate 118 . In contrast, the 10 mm gap particle map 1408 had a PRE of ˜50% for the right half of the 200 mm microelectronic substrate 118 . In this case, the 5 mm gap particle map shows a cleaning area 1410 about 80 mm wide from a nozzle 110 with an exit orifice of 6 mm or less. It was unexpected that a nozzle 110 with such a small exit orifice could have an effective cleaning distance of more than 12 times its own size.

FIG. 15 includes an image 1500 of microelectronic substrate features showing different feature damage differences between previous techniques (eg, aerosol) and techniques disclosed herein (eg, GCJ). Differences in damage are visible to the naked eye and confirmed by closer examination by scanning electron microscopy (SEM). In this embodiment, polysilicon features were formed on a microelectronic substrate using known patterning techniques. The features had a width of approximately 20 nm and a height of approximately 125 nm. Separate feature samples (eg, line structures) were exposed to processes similar to the GCJ and aerosol processes disclosed herein.

In previous techniques, damage to line structures was revealed by discoloration of images 1502, 1504 of microelectronic substrate 118 exposed to the aerosol cleaning process. Visible line damage is confirmed by aerosol SEM image 1506 . In contrast, GCJ images 1508, 1510 show no discoloration and GCJ SEM image 1512 shows no damage. Thus, the lack of discoloration in the GCJ images 1508, 1510 and the lack of damage in the GCJ SEM image 1512 demonstrate that the GCJ techniques described herein are less destructive to the microelectronic substrate 118 than the aerosol process. Suggest.

Another example of patterned feature damage (not shown) may include damage caused by larger particles as they migrate from the surface of the microelectronic substrate. Larger particles may have relatively higher momentum than smaller particles, in part because of their higher mass, when they are removed or if After they are removed from the microelectronic substrate, they are more likely to cause damage to the patterned features if they are carried along the surface.

The processes described herein have been found to remove large particles (eg, >100 nm) and small particles (eg, <100 nm) in a highly efficient manner. However, the ratio of adhesion to removal force for relatively large particles (eg, >100 nm) can in some cases be less than the ratio of adhesion to removal force for small particles. Thus, processing operations that remove small particles can impart excessive energy to larger particles and damage the microelectronic substrate or patterned features on the microelectronic substrate as they are removed. However, if larger particles are removed during the first treatment under the first group of process conditions, then the second treatment uses the second group of process conditions, the second group of process conditions being the first group of process conditions. It includes at least one process condition that differs from the process conditions of the group. In one specific embodiment, a two-stage process can include a first process having a relatively low flow rate to remove larger particles, followed by a higher flow rate to remove smaller particles. A second process with a flow rate can be included. Thus, the lower flow rate imparts less energy to the larger particles to minimize their momentum as they are removed from the microelectronic substrate. Ideally, the lower momentum minimizes the amount or degree of damage to patterned features as larger particles are removed.

Particle removal efficiency can therefore be improved by incorporating a multi-step processing method to address different types of particles on the microelectronic substrate 118 . A multi-step process may involve performing multiple passes across the microelectronic substrate 118 at different process conditions. For example, a first treatment includes a first set of process conditions used to remove a particular type of particle, and then passes microelectronic substrate 118 with a second set of process conditions. Figures 16A/16B and 17 illustrate exemplary embodiments of these multi-step processes.

16A and 16B show a flowchart 1600 of another method of treating microelectronic substrates 118 with GCJ spray using the multi-step treatment process associated with the processes disclosed herein. In these multi-step embodiments, the process conditions of the GCJ spray and the positioning of the nozzle 110 relative to the microelectronic substrate 118 can impact particle removal efficiency. Varying the GCJ spray process conditions and/or the gap distance between the exit orifice 304 and the surface of the microelectronic substrate 118 removes particles and minimizes damage to the microelectronic substrate 118 during the treatment process. can be optimized by those skilled in the art. In some embodiments, process gas process conditions may include, but are not limited to, fluid flow rate, chemical composition, temperature, inlet pressure to GEC (eg, nozzle 400), vacuum process chamber 104 pressure. Additionally, the gap distance 502 can also be varied between processing stages to improve cleaning efficiency or minimize damage to pattern features on the microelectronic substrate 118 . Referring to FIG. 16A, flowchart 1600 outlines one embodiment of a multi-stage treatment process that may be implemented by system 100 shown in FIG.

At block 1602, the microelectronic substrate 118 may be received within the process chamber 104, which may include fluid or gas expansion components (GECs) (eg, nozzles 300, 400). The GEC can be any of the nozzles 110 described herein, but can be of the same or similar configuration as the TSG nozzle 200, SSG nozzle 300, or flush nozzle 400, among others. In general, a GEC may include an inlet orifice 402 or inlet that receives the fluid mixture and an outlet orifice 404 or outlet that allows the fluid mixture to flow into the process chamber 104 . As shown in FIG. 1, the GEC may be in fluid communication with a cryogenic cooling gas source capable of maintaining the gas mixture at a temperature of 70K-200K and a pressure of less than 800 psig.

The microelectronic substrate 118 can be fixed to a movable chuck 122 that can rotate and/or translate beneath or beneath the GEC, as further disclosed in the description of FIG. Movable chuck 112 may be configured to mechanically and/or electronically secure microelectronic substrate 118 during movement. This ability prevents the microelectronic substrate 118 from moving or falling off the movable chuck 122 during processing. Once the microelectronic substrate 118 is secured in place, initial processing can continue.

At block 1604, the vacuum process chamber may be maintained at a process pressure of 35 Torr or less using controller 112 to control vacuum system 134 to maintain a stable process pressure throughout the multi-step process. Those skilled in the art of semiconductor processing will be able to design and configure a closed loop control system to maintain pressure at a desired set point during the multi-step processing disclosed herein. For example, the pressure setpoint can be maintained even if the gas flow conditions to the vacuum process chamber 104 change during the multi-step treatment process disclosed herein.

Typically, the process pressure can be maintained at a much lower pressure than the incoming gas mixture, inhibiting gas cluster formation as the gas mixture transitions from relatively high pressure to relatively low pressure as it passes through the GEC. can be made possible. Furthermore, in other embodiments, the process pressure of the vacuum chamber can be varied during the multi-step processing process to alter the flow characteristics of the fluid across the microelectronic substrate 118 or to the particles transferred from the gas flow to the particles. The amount of energy can be varied to overcome surface adhesion of particles to microelectronic substrate 118 . In addition to pressure control, particle removal efficiency can also be affected by incoming gas pressure, composition, and/or flow rate.

At block 1606, a fluid mixture may be supplied to the GEC from the fluid source 106, and the temperature of the incoming fluid mixture may be controlled between 70K and 200K using the cryogenic system 108. The pressure of the incoming fluid mixture can be greater than 5 psig and less than 800 psig and can be optimized to achieve optimum particle removal efficiency, which depends on vacuum chamber pressure, fluid mixture composition, and the present It can be done in conjunction with other process conditions described herein.

In one embodiment, the fluid mixture may include nitrogen, argon, or any combination thereof ranging from 100% nitrogen to 100% argon by weight. For example, the fluid mixture may include a 1:1 weight mixture of nitrogen to argon and may range up to a 1:4 weight mixture of nitrogen to argon. Fluid compositions of nitrogen and argon can be varied to optimize particle removal efficiency based, at least in part, on various factors, which factors include the type of patterned features and/or It may include, but is not limited to, composition and particle size.

In another embodiment, the fluid mixture described in the previous embodiment may contain additional chemicals to modify the size, weight and density of clusters in the gas cluster spray. Gas cluster properties can be optimized to remove specific types of particles. For example, the fluid mixture may include nitrogen and/or argon mixed with one or more chemicals of xenon, krypton, helium, hydrogen, _{C2H6 ,} or carbon dioxide. In one particular embodiment, the fluid mixture is a 4:1 mixture by _weight of at least one chemical of nitrogen or argon pair, xenon, krypton, helium, hydrogen, _C2H6 or carbon dioxide. obtain.

In other embodiments, the fluid mixture may include nitrogen and/or argon mixed with one or more chemicals of helium or neon. In one particular embodiment, the fluid mixture may be a 4:1 mixture by weight of at least one of the following chemicals: nitrogen or argon paired with helium or neon.

The multi-step process can be initiated by setting and maintaining process conditions related to fluid mixture composition, fluid mixture pressure and temperature, and vacuum chamber pressure via the controller 112 of the system 100 .

At block 1608, the system 100 operates under a first group of process conditions (eg, fluid composition, fluid pressure and/or temperature, vacuum chamber pressure, gap distance 502) to maintain the fluid mixture to the fluid expansion component. can be used for Microelectronic substrate 118 undergoes a first treatment using this first set of process conditions used to remove particles from microelectronic substrate 118 .

In one particular embodiment, a first group of process conditions can be used to target larger sizes (e.g., >100 nm) by flowing the fluid mixture at a first flow rate. can be high enough to remove larger particles and low enough to minimize particle momentum to minimize damage when the larger particles are removed from the microelectronic substrate 118. In this example, the flow rate of the fluid mixture can be about 100 slm with a 100 wt% argon composition and can have a temperature of the fluid mixture of less than 200K. Gap distance 502 can be about 10 mm between outlet orifice 404 and the surface of microelectronic substrate 118 .

At block 1610 , the fluid mixture is then passed into the vacuum process chamber through an outlet (eg, outlet orifice 404 ) such that the expanded fluid mixture (eg, GCJ spray) flows across the surface of microelectronic substrate 118 . can be inflated.

At block 1612, the movable chuck 122 can rotate and/or translate the microelectronic substrate 118 under the outlet orifice 404, thereby exposing the particles to the expanded fluid mixture (eg, GCJ spray). , a plurality of first objects (eg, particles) can be removed from the microelectronic substrate 118 . In this case, larger particles can be removed at a higher rate. This is because it has a lower adhesion to removal force ratio than smaller particles that have a higher adhesion to removal force ratio. A larger surface area can allow a higher momentum transfer rate from the fluid mixture to the larger particles. This is because there are more clusters that are more likely to collide with larger particles than with smaller particles.

One skilled in the art can determine residence time (eg, rotation speed and/or travel speed) to optimize particle removal efficiency as needed. Residence time is the amount of time a GEC is positioned across from any location on the microelectronic substrate 118 . In one embodiment, the GEC is fixed in one position and the movable chuck 122 rotates and translates the microelectronic substrate 118 through an expanded fluid mixture flowing from the GEC. Therefore, the translation and rotation speeds control the amount of time any portion of the microelectronic substrate 118 is under or across from the GEC. For example, the translational and/or rotational speed may be adjusted such that any one portion of the microelectronic substrate 118 spends a longer amount of time across from or opposite the outlet orifice 404 . By decreasing, the residence time can be increased. Similarly, by increasing the translational and/or rotational speed, the residence time can be decreased so that any one portion of the microelectronic substrate 118 is opposite or facing the outlet orifice 404 . can reduce the amount of time to In one particular embodiment, the translational speed can range from 2 mm/s to 120 mm/s and the rotational speed can range from 30 rpm to 300 rpm, varying between stages of the multi-stage process. can be done. In one particular embodiment, system 100 can be configured to rotate the substrate at 30-60 rpm and translate between 2 mm/s and 100 mm/s. After completing the first part of the multi-step process, the process conditions can transition to different values to continue the multi-step process.

At block 1614, the system 100 stops the incoming flow of the fluid mixture and sets a second group of process conditions prior to subsequent processing, or when all process conditions have reached their new set points. The second part of the multi-step treatment process may be transitioned by transitioning the process conditions on-the-fly to .

In one embodiment, migration can occur when the microelectronic substrate 118 is not positioned directly below the outlet office 404 . However, in other embodiments, the GEC may remain positioned above the microelectronic substrate 118 .

In another embodiment, the system 100 can maintain the fluid mixture to the fluid expansion component under a second group of process conditions, where at least one process condition is the first group of process conditions. and the second group of process conditions. For example, the system 100 may transition one or more of the following process conditions to setpoint values that were not used during the first portion of the multi-stage process. Therefore, not all of these values need change to be considered a second group of process conditions. Only one change in process conditions is sufficient for the second group of process conditions to exist even though some of the first group of process conditions are unchanged for subsequent processing. . The process conditions may be the flow rate of the fluid mixture, the chemical composition of the fluid mixture, the temperature of the fluid mixture, the fluid pressure of the fluid mixture, the distance between the microelectronic substrate 118 and the fluid expansion component (e.g. gap distance 502), or chamber pressure of the vacuum process chamber, but is not limited to these. In one embodiment, one or more of the process conditions can be varied by at least 10% of the set point used during the initial portion of the multi-step process.

For example, in one embodiment, the temperature of the fluid mixture entering the GEC may be changed from an initial setting of 150K to a subsequent setting of 135K or less for subsequent portions of the multi-stage process. Similarly, the inlet fluid temperature can be varied from 150K to 165K to 200K.

In other embodiments, the vacuum chamber pressure can be varied between a first group of process conditions and a second group of process conditions by reducing the pressure by at least 10%. For example, the initial chamber pressure can be approximately 20 Torr and the second chamber pressure can be 3 Torr or less. In one particular embodiment, the process pressure can be about 14 Torr as the initial pressure and 8 Torr as the second chamber pressure.

In one specific embodiment, a first fluid flow rate of about 100 slm for the initial portion of the multi-stage process can be changed to a second fluid flow rate of about 160 slm for the subsequent part of the multi-stage process.

In other embodiments, transitioning between the first group of process conditions and the second group of process conditions may comprise changing the chemical composition of the fluid mixture. Modifications can include transitions between any of the chemical compositions disclosed herein. Compositions disclosed herein are defined by weight unless otherwise specified. For example, a first group of process conditions can include 100 wt. can be migrated.

In another embodiment, the gap distance 502 can be varied between the first group of process conditions and the second group of process conditions to alter the lateral flow profile of the fluid mixture across the surface of the microelectronic substrate 118. can be changed. For example, the gap distance 502 can be varied from 50 mm to 3 mm to increase the amount of force transferred to the surface of the microelectronic substrate, resulting in smaller particles having a higher ratio of adhesion force to removal force. can be removed. However, in other embodiments the gap distance may vary between 2 mm and 100 mm.

In other embodiments, more than one variable can change between initial and subsequent processing of the same microelectronic substrate 118 . For example, in one example, both the flow rate and the vacuum chamber pressure may change when transitioning between a first group of process conditions and a second group of process conditions. System 100 can be used in any of the multi-step processes within the process range disclosed herein or within any other value used by those skilled in the art of semiconductor processing to improve particle removal efficiency. It can be programmed to transition one or more process conditions that change during any transition. For example, changes can include flow rate and vacuum chamber pressure, while remaining process conditions can be maintained the same or similar between the first group of process conditions and the second group of process conditions. In another example, the flow rate of the fluid mixture and the temperature of the fluid mixture can be varied between a first group of process conditions and a second group of process conditions. Further, the three-variation embodiment comprises varying the flow rate of the fluid mixture, the pressure of the vacuum chamber, and the temperature of the fluid mixture between a first group of process conditions and a second group of process conditions. can contain.

In one embodiment, the system 100 and system 100 for supplying the fluid mixture to the vacuum process chamber 104 maintains the fluid mixture at a temperature and/or pressure that maintains the fluid mixture in the gas phase (eg, <1% liquid phase). be able to. However, the fluid mixture need not be less than 1% liquid phase for all multi-stage processing embodiments.

The system 100 can be programmed to transition the process conditions of the fluid mixture, as described above, and can perform the transition in stages by shutting down the flow of the fluid mixture during the transition. Alternatively, the transition can be performed on-the-fly while the microelectronic substrate 118 is translating and/or rotating under the exit orifice 404 . However, regardless of when and how the transition occurs, the fluid mixture is exposed to the microelectronic substrate 118 in the next iteration of the multi-step process. However, for purposes of flowchart 1600, the transition occurs in stages.

At block 1616, the system 100 allows the mixed fluid flow to flow when the setpoint of the second group of process conditions is reached. The fluid mixture is expanded into the vacuum process chamber through an outlet (eg, outlet orifice 404) such that the expanded fluid mixture flows laterally across the microelectronic substrate. The expanded fluid mixture can form gas clusters (eg, GCJ spray) that enable particle removal by colliding and repelling particles.

At block 1618 , the expanding fluid mixture can apply sufficient energy to the particles on the microelectronic substrate 118 to cause the fluid mixture flowing across the microelectronic substrate 118 to move the plurality of second objects from the microelectronic substrate 118 . (eg, particles) can be removed. This subsequent treatment can target particles with a higher adhesion to removal force ratio than particles removed during the initial treatment. In some instances, smaller particles (<100 nm) have been found to have a higher adhesion to removal force ratio than larger particles. However, subsequent processing is not limited to removing particles of a particular size, but can be used to target other types of particles, regardless of particle size.

Subsequent processing can follow to remove additional groups (eg, third, fourth, etc.) of objects from the microelectronic substrate 118 . As such, the cleaning process can be optimized by varying the process conditions disclosed herein to maximize particle removal efficiency. Process conditions may be varied to account for different types of particles, materials, and features found on microelectronic substrate 118 . For example, the particles can vary in size, composition, and orientation or location (e.g., surface stacking, embedding), and one skilled in the art can use GCJ spray to minimize damage to existing features. To eliminate them, process conditions can be optimized without undue experimentation. Additionally, the surface of the microelectronic substrate 118 may have different exposed materials, allowing different surface adhesion properties for particles dispersed across the microelectronic substrate 118 . Subsequent processing can therefore account for different types of materials and maximize particle removal efficiency by adjusting the process conditions disclosed herein. Additionally, patterned features on microelectronic substrate 118 vary in geometry, topography, and density across the die and microelectronic substrate 118 . Topography (e.g., trenches, holes, isolation lines, dense lines, etc.) can vary across the die and/or microelectronic substrate 118, affecting the fluid flow and dynamics of the GCJ spray. can be done. Variations in topography across the die or microelectronic substrate 118 can shield or limit the ability of the GCJ spray to remove objects or particles from the microelectronic substrate 118 . Accordingly, those skilled in the art will be able to remove particles residing in trenches, located on top of dense line features, or located in spaces between line features patterned within the die or across the microelectronic substrate 118. To do so, process conditions can be developed to address these topography differences.

Further, subsequent processing can target specific areas of the microelectronic substrate 118 . Characteristic grain patterns can be found on the microelectronic substrate 118 and can be addressed by changing process conditions and processing locations. For example, the particle pattern may be known to impact edges of the microelectronic substrate 118 . In this case, subsequent processing may include moving chucks 122 or GECs to address particles located in specific areas without processing the entire microelectronic substrate 118 to reduce cycle time or chemical usage. The edge of the microelectronic substrate 118 can be targeted by positioning the .

While the flowchart 1600 embodiment may imply separate starting and stopping of fluid mixture flow during multi-step processing, the claims are not limited to these types of processes, as shown in the embodiment of FIG. not intended to be limiting.

FIG. 17 shows a flowchart 1700 of another method of treating a microelectronic substrate 118 with a cryogenic fluid using multi-step processing. In this case, the multi-stage process can be performed by actively transitioning to different setpoints while the fluid mixture is flowing, or by stopping the fluid mixture and waiting for transitions to different setpoints to complete. can be performed by changing the process conditions on the fly while the Process conditions can include, but are not limited to, any process conditions disclosed herein.

As disclosed above, the fluid mixture can be used to control the temperature and pressure of the fluid mixture to affect the amount of liquid (by weight) contained in the liquid mixture, thus allowing the GCJ spray of relatively low liquid concentrations to be reduced. can be generated. The system 100 optimizes the pressure and temperature of the incoming fluid mixture and controls the liquid concentration of the incoming fluid mixture (e.g., less than 1% by weight of liquid) for some, but not all, embodiments. gas mixtures can be achieved.

At block 1702, the microelectronic substrate 118 can be received within the process chamber 104, which can include a fluid or gas expansion component (GEC) (eg, nozzle 400). Typically, the nozzle may include an inlet orifice 402 or inlet for receiving the fluid mixture and an outlet orifice 404 or outlet for allowing the fluid mixture to enter the process chamber 104 . As shown in FIG. 1, the GEC can be in fluid communication with a cryogenic cooling gas source capable of maintaining gas mixtures at temperatures between 70K and 200K and pressures below 800 psig.

The microelectronic substrate 118 can be fixed to the movable chuck 122 or can be placed thereon, under or beneath the nozzle 400, as further disclosed in the description of FIG. or subject) can be rotated and/or translated. Movable chuck 122 can be configured to secure microelectronic substrate 118 during movement. This ability prevents the substrate from moving or falling off the movable chuck 122 during processing. Once the microelectronic substrate 118 is secured on the movable chuck 122, initial processing can continue. In summary, the system 100 can maintain a first set of conditions for initial processing, where the process conditions are the chamber pressure of the vacuum process chamber 104 at values for each of the process condition ranges disclosed herein; the gas flow rate of the gas mixture, the chemical composition of the gas mixture, the temperature of the gas mixture, and/or the distance between the microelectronic substrate 118 and the gas expansion component;
can include, but are not limited to,

At block 1704, the system 100 passes the gas or gas mixture with no liquid in the gas or with very little liquid (e.g., less than 1% by weight) to the gas expansion component prior to initial processing. may be configured to supply The system 100 can maintain the gas mixture at temperatures below 273 K and pressures that prevent or minimize liquid formation in the gas mixture using the techniques described in FIGS. 6A and 6B for nitrogen and argon. , this can be applied using other phase diagrams for any gas or gas mixture disclosed herein.

In many embodiments, the gas temperature is between 70 K and 200 K and the pressure ranges between 5 psi and 800 psig. The gas can consist of, but is not limited to, nitrogen, argon, or combinations thereof. In other embodiments, the gas can consist of nitrogen, argon, xenon _, krypton, helium, hydrogen, _C2H6 or carbon dioxide, or any combination thereof. In another embodiment, the gas mixture, which may include _N2 , may be combined with at least helium or neon, and may be combined with at least one of argon, krypton, xenon, carbon dioxide. In one specific embodiment, the ratio of the above gas mixtures can be about 1:2:2. In another more specific embodiment, the ratio of said gas mixture can be 1:2:1.8.

In many embodiments, the system 100 can maintain the vacuum process chamber 104 at process pressures of 35 Torr or less to enable gas cluster formation during the processing process. In one particular embodiment, the process pressure can be about 10 Torr or less. Additionally, the position of the microelectronic substrate 118 relative to the GEC can be adjusted to improve particle removal efficiency.

In summary, the system 100 can maintain a first set of conditions for initial processing, where the process conditions are the chamber pressure of the vacuum process chamber 104 at values for each of the process condition ranges disclosed herein; can include, but are not limited to, the gas flow rate of the gas mixture, the chemical composition of the gas mixture, the temperature of the gas mixture, the gas pressure of the gas mixture, and/or the distance between the microelectronic substrate 118 and the gas expansion component. not to be

At block 1706, the microelectronic substrate 118 can be placed opposite the gas expansion component, leaving a gap distance between the microelectronic substrate 118 and the outlet (eg, exit orifice) in the range of 2 mm to 50 mm. provided, the gas expansion component can be located on the opposite side of the microelectronic substrate 118 . Gap distance 502 can be adjusted to control the flow characteristics of the GCJ spray across microelectronic substrate 118 . The proximity of the microelectronic substrate 118 to the GEC affects the flow characteristics and the amount of energy transferred to the particles, and the particle removal efficiency, or the degree to which the microelectronic substrate 118 is below the GEC. It can affect the size of the surface area from which the particles are removed as they move.

In other embodiments, the GEC may be placed at an angle that allows for flow changes across the substrate during the treatment process. For example, the positioning of the microelectronic substrate 118 with respect to the nozzle may be maintained at an angle of incidence between 45° and 90°. Initial processing can begin when the system 100 determines that initial process conditions have been achieved or are sufficiently maintained to begin initial processing.

At block 1708, the system 100 enables the gas mixture to flow through the GEC, expand through the gas expansion component outlet, across the gap (eg, gap distance 502), and into the process chamber. A multi-stage process can be initiated by allowing at least a portion of the expanded gas mixture to flow over the microelectronic substrate 118 and multiple gas-filled gas chambers located on and/or embedded in the surface of the microelectronic substrate 118 . transfer energy to the particles of

At block 1710, during initial processing, the moveable chuck 112 may translate and/or rotate the microelectronic substrate 118 below or opposite the GEC, which may be positioned above the moveable chuck, as shown in FIG. The first group of process conditions removes such that the microelectronic substrate 118 moves along a path adjacent to the expanded gas mixture or a GCJ spray can be used to remove the plurality of first particles. can be adjusted to For example, in one embodiment, an initial treatment can be used to remove relatively large particles (eg, >100 nm) using relatively low gas flow rates (eg, >100 slm). It has been found that small particles (eg, <100 nm) are relatively less likely to be removed at flow rates. However, it may be advantageous to remove larger particles at a lower flow rate which gives the larger particles less energy. In such a manner, the larger particles have lower momentum and are therefore less capable of causing damage to features present on the microelectronic substrate 118 due to their lower momentum. After removal of larger particles (e.g., initial processing), subsequent processing can be performed while minimizing damage to existing features (e.g., lines, holes, trenches, fins, film stacks, etc.). , can remove other particles that require different amounts of energy or process conditions to remove from the microelectronic substrate 118 .

At block 1712, a subsequent cleaning process of the microelectronic substrate 118 can be initiated by changing at least one process condition for the gas mixture and/or vacuum process chamber, which process condition was used during the initial process. different from the process conditions used. Subsequent processing can be used to remove a plurality of secondary particles that were not completely removed during the initial processing.

In one embodiment, changing the process conditions may include changing the gas flow rate to a higher magnitude for subsequent processing of the microelectronic substrate. For example, the initial flow rate can be changed by at least 5% between initial and subsequent treatments, and the flow can be varied and/or the amount of energy applied to the microelectronic substrate 118 can be varied. . In one specific embodiment, the initial gas flow rate can be about 100 slm for initial treatment and can be changed to 160 slm for subsequent treatments. Higher flow rates can be used to remove particles with a higher adhesive force to removal force ratio.

In another embodiment, the amount of energy applied from the expanded gas mixture to the microelectronic substrate 118 can be varied by varying the gap distance 502 for subsequent processing. For example, the gap distance can vary between 2 mm and 10 mm during multi-step processing. Additionally, the flow profile across the microelectronic substrate 118 can be affected by the gap distance 502, which can affect the amount of surface area around the GEC as it moves across the microelectronic substrate 118. Additionally, the gap distance 502 can also affect the size and/or density of gas clusters, which can be determined by those skilled in the art to target different types/sizes of particles without undue experimentation. can be optimized.

More broadly, in other embodiments, the system 100 can be configured to vary a combination of two or more of the following process conditions to improve particle removal efficiency: gas flow of the gas mixture; rate, chemical composition of the gas mixture, temperature of the gas mixture, gas pressure of the gas mixture, distance between the microelectronic substrate and the gas expansion component, chamber pressure of the vacuum process chamber.

Although only certain embodiments of the present invention have been described in detail, it will be readily apparent to those skilled in the art that many modifications may be made thereto without departing substantially from the novel teachings and advantages of the present invention. will understand. Accordingly, all such modifications are intended to be included within the scope of this invention. For example, the above-described embodiments may be combined together, and portions of the embodiments may be added or omitted as desired. Accordingly, the number of embodiments is not limited to only the specific embodiments described herein, and one of ordinary skill in the art may create additional embodiments using the teachings described herein. .

Claims (15)

A method of processing a microelectronic substrate, comprising:
receiving a microelectronic substrate in a vacuum process chamber comprising a fluid expansion component having an inlet and an outlet;
maintaining a process pressure of 35 Torr or less in the vacuum process chamber;
receiving a fluid mixture into the fluid expansion component, the fluid mixture comprising nitrogen or argon, the fluid mixture being at a temperature in the range of 70 K to 200 K and a pressure less than 800 psig;
maintaining the fluid mixture into the fluid expansion component and the vacuum process chamber under a first group of process conditions;
expanding the fluid mixture into the vacuum process chamber through the outlet, such that the expanded fluid mixture flows across the microelectronic substrate;
removing a plurality of first objects from the microelectronic substrate with the fluid mixture flowing across the microelectronic substrate;
maintaining the fluid mixture into the fluid expansion component and the vacuum process chamber under a second group of process conditions, between the first group of process conditions and the second group of process conditions, a step in which at least one process condition is different;
expanding the fluid mixture into the vacuum process chamber through the outlet, such that the expanded fluid mixture flows across the microelectronic substrate;
removing a plurality of second objects from the microelectronic substrate with the fluid mixture flowing across the microelectronic substrate ;
said first object is a larger particle and said second object is a smaller particle;
said first group of process conditions comprising a first fluid flow rate;
said second group of process conditions comprising a second fluid flow rate higher than said first fluid flow rate;
The method, wherein removing the plurality of second objects is performed after removing the plurality of first objects . said first group of process conditions comprising a first fluid flow rate of about 100 slm;
said second group of process conditions comprises a second fluid flow rate of about 160 slm;
The method of claim 1. The first group of process conditions or the second group of process conditions comprises: a flow rate of the fluid mixture; a chemical composition of the fluid mixture; a temperature of the fluid mixture; a fluid pressure of the fluid mixture; further comprising a distance between a fluid expansion component or a chamber pressure of said vacuum process chamber;
The method of claim 1. the fluid mixture comprises nitrogen, argon, or a combination thereof;
The method of claim 1. said fluid mixture comprises a mixture of one or more of xenon, krypton, helium, hydrogen, C2H6 or carbon dioxide and at least nitrogen or argon;
The method of claim 1. A method of cleaning a microelectronic substrate, comprising:
receiving a microelectronic substrate in a vacuum process chamber comprising a fluid expansion component having an inlet and an outlet;
supplying a gas mixture to the fluid expansion component, the gas mixture having a temperature that is less than 273 K and a pressure that prevents liquid formation in the gas mixture within the fluid expansion component; ,
maintaining a first set of process conditions for the gas mixture and the vacuum process chamber;
positioning the microelectronic substrate opposite the fluid expansion component to provide a gap distance between the microelectronic substrate and the outlet in a range between 2 mm and 50 mm; a component is positioned opposite the microelectronic substrate;
expanding the gas mixture through the outlet of the fluid expansion component and through the gap into the vacuum process chamber, such that the expanded gas mixture flows across the microelectronic substrate; , step and
moving the microelectronic substrate along a path adjacent to the fluid expansion component for initial processing of the microelectronic substrate;
changing at least one process condition for the gas mixture or vacuum process chamber for subsequent processing after the initial processing of the microelectronic substrate , wherein changing the process condition comprises: increasing the flow rate, thereby removing larger particles before smaller particles;
method including. the temperature is above 70 K and below 150 K;
7. The method of claim 6 . the vacuum process chamber is maintained below 10 Torr;
7. The method of claim 6 . positioning the microelectronic substrate includes maintaining an angle of incidence of 45° to 90° between the microelectronic substrate and the fluid expansion component;
7. The method of claim 6 . said gas mixture being cooled and pressurized comprises nitrogen, argon or combinations thereof;
7. The method of claim 6 . said gas mixture being cooled and pressurized comprises a mixture of one or more of xenon, krypton, helium, hydrogen, _C2H6 or carbon dioxide and at least nitrogen or argon _;
7. The method of claim 6 . varying the process conditions comprises varying at least one process condition from initial processing of the microelectronic substrate to subsequent processing of the microelectronic substrate;
7. The method of claim 6 . varying the process conditions includes varying the gap distance for subsequent processing of the microelectronic substrate;
7. The method of claim 6 . Varying the process conditions comprises: gas flow rate of the gas mixture; chemical composition of the gas mixture; temperature of the gas mixture; gas pressure of the gas mixture; varying at least two process conditions of distance, chamber pressure of the vacuum process chamber, or any combination thereof;
7. The method of claim 6 . A method of processing a microelectronic substrate, comprising:
receiving the microelectronic substrate in a vacuum process chamber, the vacuum process chamber comprising a fluid expansion component having an inlet and an outlet, the vacuum process chamber being at a pressure of 35 Torr or less, the microelectronic substrate wherein the microelectronic substrate is positioned to provide a gap distance in the range of 2 mm to 50 mm between and the outlet of the fluid expansion component;
a first treatment occurring under a first set of process conditions in which a pressurized and cooled fluid is expanded into the vacuum process chamber under conditions effective to remove particles from the microelectronic substrate; the steps to use;
a second treatment occurring under a second set of process conditions in which a pressurized and cooled fluid is expanded into the vacuum process chamber under conditions effective to remove particles from the microelectronic substrate; the steps to use;
including
said first group of process conditions comprising a first fluid flow rate and said second group of process conditions comprising a second fluid flow rate, said first fluid flow rate being greater than said second fluid flow rate;
the particles removed by the first process are larger than the particles removed by the second process;
The method , wherein using the second process occurs after using the first process .

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