The present invention relates generally to semiconductor substrate processing, and more particularly, to systems and methods for a contained chemical surface treatment to remove particles from a surface of a semiconductor substrate during fabrication operations.
During a substrate manufacturing process, a surface of a substrate is continuously exposed to various chemicals. The chemicals used in the various manufacturing process operations may be a source for one or more contaminants that form on the surface of the substrate. These contaminants deposit on the surface of the substrate as particulates and may likely cause damage to the devices and features within the vicinity of the contaminant particles. It is, therefore, necessary to eliminate the contaminants from the surface of the substrate in a timely and efficient manner without damaging features and devices.
Conventional substrate cleaning methods have relied on either mechanical force or chemicals to remove particulate contamination from the substrate surface. As devices and feature sizes continue to decrease in size and they become more fragile, the mechanical force applied in the cleaning methods increase the likelihood of causing damage to these features and devices. Using chemicals to remove contamination has proven another challenge The application and removal of the chemicals cause uncontrolled de-wetting (among other problems) that leads to creation of watermarks and other defects on the surface. In addition, the conventional cleaning methods have been unable to provide a substantially oxygen-free or low oxygen environment in a treatment region during the cleaning operation. The presence of oxygen in the treatment region during cleaning may cause oxidation of copper and other metals used in forming the features at the treatment region, such as interconnects, rendering the features and devices connected by these interconnects inoperable. Thus, efficient and non-damaging removal of contaminants during fabrication represents a continuing challenge.
In view of the foregoing, a more effective and less abrasive cleaning technology is needed in removing the contaminants from the surface of the substrate.
The present invention fills the need by providing improved apparatuses for preparing a surface of a substrate using a proximity head. It should be appreciated that the present invention can be implemented in numerous ways, including apparatuses. Several inventive embodiments of the present invention are described below.
In one embodiment, an apparatus for preparing a surface of a substrate using a proximity head is disclosed. The apparatus includes a carrier to hold and move the substrate along an axis. The apparatus also includes a proximity head having a head surface with a plurality of outlet ports defined thereon. The proximity head is defined to be positioned proximate and over the carrier and the surface of the substrate. A length of the head surface of the proximity head is defined to be greater than a diameter of the substrate and at least partially overlapping over the carrier when the substrate is present. The proximity head includes a first set of outlet ports in a first region. The first set of outlet ports defines a first applicator that is configured to apply a non-Newtonian fluid between a surface of the carrier and the head surface of the proximity head. A second set of outlet ports is defined in a second region of the proximity head. The second set of outlet ports defines a second applicator that is configured to apply a first chemistry to the surface of the substrate when present. The second region is adjacent to the first region. A third set of outlet ports is defined in a third region of the proximity head. The third set of outlet ports defines a third applicator that is configured to apply the non-Newtonian fluid between the head surface of the proximity head and the surface of the substrate when present. The third region is defined adjacent to the second region. A fourth set of outlet ports is defined in the second region of the proximity head to substantially remove the first chemistry from the surface of the substrate when present.
In another embodiment, an apparatus for preparing a surface of a substrate using a proximity head is disclosed. The apparatus includes a carrier to hold and move the substrate along an axis. The apparatus also includes a proximity head having a head surface with a plurality of outlet ports defined thereon. The proximity head is defined to be positioned proximate and over the carrier and the surface of the substrate. A length of the head surface of the proximity head is defined to be greater than a diameter of the substrate and at least partially overlapping over the carrier when the substrate is present. The proximity head includes a first set of outlet ports in a first region. The first set of outlet ports defines a first applicator that is configured to apply a non-Newtonian fluid between a surface of the carrier and the head surface of the proximity head. A second set of outlet ports is defined in a second region of the proximity head. The second set of outlet ports defines a second applicator that is configured to apply a first chemistry to the surface of the substrate when present. The second region is adjacent to the first region. A third set of outlet ports is defined in a third region of the proximity head. The third set of outlet ports defines a third applicator that is configured to apply a second chemistry to the surface of the substrate when present. The third region is defined apart from the second region. A fourth set of outlet ports is defined in a fourth region of the proximity head. The fourth set of outlet ports defines a fourth applicator that is configured to apply the non-Newtonian fluid between the head surface of the proximity head and the surface of the substrate when present. The fourth region is defined in between the second and the third regions of the proximity head. A fifth set of outlet ports is defined in a fifth region of the proximity head defining a fifth applicator configured to apply the non-Newtonian fluid between the head surface of the proximity head and the surface of the substrate when present. The fifth region is defined adjacent to the third region. A sixth set of outlet ports is defined in the second region of the proximity head to substantially remove the first chemistry applied to the surface of the substrate when present. A seventh set of outlet ports is defined in the third region of the proximity head to substantially remove the second chemistry applied to the surface of the substrate when present.
In yet another embodiment, an apparatus for preparing a surface of a substrate using a proximity head is disclosed. The apparatus includes a substrate supporting device to receive and hold the substrate along a plane and a proximity head having a plurality of outlet ports to supply a non-Newtonian fluid and a Newtonian fluid. The proximity head includes a first set of outlet ports defining a non-Newtonian fluid applicator to apply a non-Newtonian fluid between the surface of the substrate and a head surface of the proximity head. The applied non-Newtonian fluid defines a containment wall along one or more sides between the head surface and the surface of the substrate. The one or more sides provided with the non-Newtonian fluid defines a treatment region on the substrate between the head surface and the surface of the substrate. The proximity head further includes a second set of outlet ports defining a Newtonian fluid applicator to apply a Newtonian fluid to the surface of the substrate, such that the applied Newtonian fluid is substantially contained in the treatment region due to the defined containment wall. The Newtonian fluid aids in the removal of one or more contaminants from the surface of the substrate. The Newtonian fluid is immiscible in the non-Newtonian fluid.
Other aspects and advantages of the invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the present invention.
The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings. These drawings should not be taken to limit the invention to the preferred embodiments, but are for explanation and understanding only.
Several embodiments for effectively removing the contaminants from a surface of a substrate will now be described. It will be obvious, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.
Effective removal of contaminants from the surface of a substrate is important to preserve the quality and functionality of the features formed on the substrate and the resulting semiconductor products, e.g., microchips. In one embodiment of the invention, the contaminants are removed by applying a Newtonian fluid, typically a cleaning chemistry, DI water, or mixtures of fluids to the surface of the substrate using a proximity head. As described herein, a Newtonian fluid is a fluid in which the viscosity depends on temperature and pressure (and chemical composition) and not on the shear stress acting upon it. A Newtonian fluid adheres to the definition of Newton's Law of viscosity.
For additional information about Non-Newtonian and Newtonian fluids, reference can be made to U.S. application Ser. No. 11/174,080, filed on Jun. 30, 2005 and entitled “METHOD FOR REMOVING MATERIAL FROM SEMICONDUCTOR WAFER AND APPARATUS FOR PERFORMING THE SAME.” This patent application, which is assigned to Lam Research Corporation, the assignee of the subject application, is incorporated herein by reference.
As described herein, a proximity head is a substrate treatment apparatus that can deliver precise volumes of a fluid to a surface of a substrate to be treated, and remove the fluid from the surface, when the proximity head is placed in close relation to the surface of the substrate. In one example, the proximity head has a head surface and the head surface is placed substantially parallel to the surface of the substrate. A meniscus is formed between the head surface and the surface of the substrate. The proximity head may also be configured to deliver a plurality of fluids and are configured with vacuum ports for removing the plurality of fluids that were delivered.
A “meniscus”, as used herein, refers to a volume of chemistry bounded and contained in part by surface tension of the chemistry between the head surface of a proximity head and a surface of the substrate. The meniscus thus formed, may be moved over the surface in the contained shape and is used to remove the contaminants, particulates or unwanted materials from the surface of the substrate. Furthermore, the meniscus shape can be controlled by precision fluid delivery and removal systems that may further include a computing system. For more information on the formation of a meniscus and the application to the surface of a substrate, reference may be made to: (1) U.S. Pat. No. 6,616,772, issued on Sep. 9, 2003 and entitled “METHODS FOR WAFER PROXIMITY CLEANING AND DRYING,”; (2) U.S. patent application Ser. No. 10/330,843, filed on Dec. 24, 2002 and entitled “MENISCUS, VACUUM, IPA VAPOR, DRYING MANIFOLD,” (3) U.S. Pat. No. 6,988,327, issued on Jan. 24, 2005 and entitled “METHODS AND SYSTEMS FOR PROCESSING A SUBSTRATE USING A DYNAMIC LIQUID MENISCUS,” (4) U.S. Pat. No. 6,988,326, issued on Jan. 24, 2005 and entitled “PHOBIC BARRIER MENISCUS SEPARATION AND CONTAINMENT, ” and (5) U.S. Pat. No. 6,488,040, issued on Dec. 3, 2002 and entitled “CAPILLARY PROXIMITY HEADS FOR SINGLE WAFER CLEANING AND DRYING,” each is assigned to Lam Research Corporation, the assignee of the subject application, and each is incorporated herein by reference.
By controlling the delivery and removal of the fluids to the meniscus, the meniscus can be controlled and moved over the surface of the substrate. In some embodiments, the substrate can be moved, while the proximity head is still, and in other embodiments, the proximity head moves and the substrate remains still, during the processing period. Further, for completeness, it should be understood that the processing can occur in any orientation, and as such, the meniscus can be applied to surfaces that are not horizontal (e.g., vertical substrates or substrates that are held at an angle).
For additional information with respect to the proximity head, reference can be made to an exemplary proximity head, as described in the U.S. Pat. No. 6,616,772, issued on Sep. 9, 2003 and entitled “METHODS FOR WAFER PROXIMITY CLEANING AND DRYING.” This U.S. patent application, which is assigned to Lam Research Corporation, the assignee of the subject application, is incorporated herein by reference.
For additional information about top and bottom menisci, reference can be made to the exemplary meniscus, as disclosed in U.S. patent application Ser. No. 10/330,843, filed on Dec. 24, 2002 and entitled “MENISCUS, VACUUM, IPA VAPOR, DRYING MANIFOLD.” This U.S. patent application, which is assigned to Lam Research Corporation, the assignee of the subject application, is incorporated herein by reference.
In one embodiment, a proximity head is first used to apply a non-Newtonian fluid between the surface of the substrate and a head surface of the proximity head.
As described herein, a non-Newtonian fluid is a fluid in which the viscosity changes with an applied shear stress. A non-Newtonian fluid does not obey Newton's Law of viscosity. The shear stress is a non-linear function of the shear rate. Depending on how the apparent viscosity changes with shear rate, the flow behavior of the non-Newtonian fluid will also change. An example of a non-Newtonian fluid is a soft condensed matter which occupies a middle ground between the extremes of a solid and a liquid. The soft condensed matter is easily deformable by external stresses. Examples of the soft condensed matter include emulsions, gels, colloids, foam, etc. As used herein, an emulsion is a mixture of immiscible liquids such as, for example, toothpaste, mayonnaise, oil in water, etc.
For more information about non-Newtonian fluid, reference can be made to U.S. patent application Ser. No. 11/153,957, filed on Jun. 15, 2005, and entitled “METHOD AND APPARATUS FOR CLEANING A SUBSTRATE USING NON-NEWTONIAN FLUIDS”; and U.S. patent application Ser. No. 11/154,129, filed on Jun. 15, 2005, and entitled “METHOD AND APPARATUS FOR TRANSPORTING A SUBSTRATE USING NON-NEWTONIAN FLUID.” These patent applications, which are assigned to Lam Research Corporation, the assignee of the subject application, are incorporated herein by reference.
The non-Newtonian fluid defines a containment wall (wall) along one or more sides between the head surface and the surface of the substrate. The one or more sides of the containment wall define a treatment region on the substrate. A meniscus of Newtonian fluid is then applied to the surface of the substrate through the proximity head, such that the applied Newtonian fluid is substantially contained in the treatment region defined by the containment wall. The Newtonian fluid includes chemistry that aids in substantial removal of contaminants from the surface of the substrate when the Newtonian fluid flows within the containment wall of the non-Newtonian fluid in the treatment region.
The purpose of the containment wall formed by the non-Newtonian fluid is two-fold. First, the containment wall acts as a barrier or interface that substantially prevents the Newtonian fluid in the treatment region from flowing out, thereby conserving use of the Newtonian fluid. Additionally, some of these Newtonian fluids may have certain hazardous properties and so the Newtonian fluids have to be handled and disposed carefully. Utilizing the containment wall to control the Newtonian fluid, less amount of Newtonian fluid is expended while facilitating safe and efficient removal of contaminants from the surface of the substrate. Second, the containment wall acts as a barrier preventing any other external chemicals and contaminants from the ambient environment such as air, oxygen, nitrogen, etc. from flowing into the treatment region, so that highly concentrated and uncontaminated Newtonian fluids can be applied directly to the surface of the substrate. Controlled application of the Newtonian fluid provides for efficient and effective removal of contaminants from the surface of the substrate. The Newtonian fluid may be a chemistry that is substantially oxygen-free or a low oxygen chemistry that is applied to the surface of the substrate for removal of the contaminants. Utilizing non-Newtonian fluids to provide containment walls, a substantially oxygen-free or a low oxygen chemical treatment region can be achieved.
In one embodiment, the presence of oxygen in the treatment region may result in the oxygen reacting with layers of the semiconductor substrate, resulting in increased dielectric constants, poor adhesion characteristics of subsequent layers, and other material changes to the properties of semiconductor materials used in the fabrication process. The oxygen-free or a low oxygen chemical treatment region prevents oxidation of metal features within the treatment region, thereby, enhancing the functionality of the features.
The enclosed channel, between the containment walls 140, defines a treatment region. This treatment region may occupy either a portion of a surface 115 of a substrate 110 or the entire surface 115 of the substrate 110 when applied to the surface 115 of the substrate 110. A Newtonian fluid 102 is then applied through the proximity head 130 such that the Newtonian fluid 102 is contained in the channel defining the treatment region formed by the non-Newtonian fluid 101. The Newtonian fluid 102 contained within the treatment region may scan the surface 115 of the substrate 110 providing treatment of the entire surface 115 of the substrate 110 when applied to the surface 115 of the substrate 110. The Newtonian fluid 102 aids in the removal of the contaminants from the surface 115 of the substrate 110 when the contaminants are exposed to the Newtonian fluid 102 contained in the treatment region.
The Newtonian fluid 102 is applied such that the Newtonian fluid 102 is contained within the treatment region 205 defined by the containment wall 140. The channel enables the Newtonian fluid 102 to flow between the containment wall 140 formed by the non-Newtonian fluid 101. The Newtonian fluid 102 flowing between the containment wall 140 aids in the removal of one or more contaminants while preserving the functionality of the features formed on the substrate 110. The containment of the Newtonian fluid 102 within the containment wall 140 helps in expending less Newtonian fluid 102 while effectively removing contaminants from the surface 115 of the substrate 110.
The thickness of the containment wall 140 formed by the non-Newtonian fluid 101 can be varied based on one or more characteristics of the Newtonian fluid 102 applied to the surface of the substrate. Some of the characteristics of the Newtonian fluid 102 that may affect the thickness of the non-Newtonian fluid 101 may include viscosity, temperature, pressure exerted by the Newtonian fluid 102, chemistry of the Newtonian fluid, etc.
As noted above, the non-Newtonian fluid 101 is a fluid in which the viscosity changes with an applied shear force. An example of a non-Newtonian fluid 101 is a soft condensed matter which occupies a middle ground between the extremes of a solid and a liquid. The soft condensed matter is easily deformable by external stresses and examples of the soft condensed matter include emulsions, gels, colloids, foam, etc. It should be appreciated that an emulsion is a mixture of immiscible liquids such as, for example, toothpaste, mayonnaise, oil in water, etc. A colloid is polymers dispersed in water, and gelatin is an example of a colloid. Foam is gas bubbles defined in a liquid matrix, and shaving cream is an example of a foam.
The non-Newtonian fluid 101 applied to the surface of the substrate is selected such that it is substantially immiscible with the Newtonian fluid 102. The non-Newtonian fluid 101 may be a non-aqueous tri-state compound which includes a solid component, a liquid component and a gas component. The solid component is, in one embodiment, a fatty acid. The fatty acid is defined by one of lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, gadoleic acid, eurcic acid, butyric acid, caproic acid, caprylic acid, myristic acid, margaric acid, behenic acid, lignoseric acid, myristoleic acid, palmitoleic acid, nervanic acid, parinaric acid, timnodonic acid, brassic acid, clupanodonic acid, lignoceric acid, or cerotic acid.
The gas component is defined to occupy 5% to 99.9% of the tri-state compound by volume. In another embodiment, the gas portion can occupy between about 15% and about 40% of the tri-state body, and still another embodiment, the gas portion can occupy between about 20% and about 30% of the tri-state body. The gas or gases defining a gas portion can be either inert, e.g., nitrogen (N2), argon (Ar), etc., or reactive, e.g., oxygen (O2), ozone (O3), hydrogen peroxide (H2O2), air, hydrogen (H2), ammonia (NH3), hydrogen fluoride (HF), hydrochloric acid (HCl), etc. In one embodiment, the gas portion includes only a single type of gas, for example, nitrogen (N2). In another embodiment, the gas portion is a gas mixture that includes mixtures of various types of gases, such as: ozone (O3), oxygen (O2), carbon dioxide (CO2), hydrochloric acid (HCl), hydrofluoric acid (HF), nitrogen (N2), and argon (Ar); ozone (O3) and nitrogen (N2); ozone (O3) and argon (Ar); ozone (O3), oxygen (O2) and nitrogen (N2); ozone (O3), oxygen (O2) and argon (Ar); ozone (O3), oxygen (O2), nitrogen (N2), and argon (Ar); and oxygen (O2), argon (Ar), and nitrogen (N2). It should be appreciated that the gas portion can include essentially any combination of gas types as long as the resulting gas mixture can be combined with a liquid portion and a solid portion to form a tri-state compound that can be utilized in substrate cleaning or preparation operations.
The liquid component, being a continuous medium, is one is one of de-ionized (DI) water, a hydrocarbon, a base fluid, a hydrofluoric acid (HF) solution, an ammonia based solution, or mixtures of DI water and chemicals.
A bi-state compound is one that includes the solid component and a liquid component. For more information on tri-state compounds and the like, reference may be made to Provisional Application No. 60/755,377, filed Dec. 30, 2005, assigned to the assignee, and incorporated herein by reference.
In one embodiment, the Newtonian fluid 102 can be applied at one extreme point of the channel such that the Newtonian fluid 102 flows in the channel towards the other extreme end. In another embodiment, the Newtonian fluid 102 is applied at the center of the channel such that the Newtonian fluid 102 flows from the center to the outer extremes of the treatment region. The Newtonian fluid 102 reacts with the contaminants on the surface of the substrate exposed to the treatment region and substantially removes the contaminants.
In an alternate embodiment illustrated in
In addition to a lateral movement, the carrier 120 is configured to rotate the substrate along the axis of rotation. The substrate is rotated at a velocity so as to enable substantial exposure of the surface of the substrate to the Newtonian fluid 102 for effective removal of the contaminants from the surface 115 of the substrate 110. The embodiment illustrated in
Continuing reference to
The non-Newtonian fluid 101 forms a containment wall 140 defining a treatment region 205 on the respective surfaces 115 of the substrate 110. In the embodiment illustrated in
A Newtonian fluid applicator in or connected to the proximity heads 130 and 135 is used to apply a Newtonian fluid 102 between the respective surfaces 115 of the substrate 110 and the respective head surface of the proximity heads 130 and 135 such that the Newtonian fluid 102 is substantially contained within the treatment region 105 formed on the top and bottom surfaces 115 of the substrate 110, as illustrated in operation 615. The Newtonian fluid applicator (not shown) includes a reservoir for the Newtonian fluid 102 with an inlet and a pair of outlets. The inlet is used for receiving cleaner and fresher Newtonian fluid 102 into the Newtonian fluid applicator.
A first outlet is used for supplying the Newtonian fluid 102 to the surface of the substrate through the proximity heads 130 and 135. A second outlet at the Newtonian fluid applicator is used to remove the Newtonian fluid mixed with the contaminants so that cleaner Newtonian fluid 102 can be introduced for more effective cleaning. The Newtonian fluid applicator supplies the Newtonian fluid 102 in the form of a fluid meniscus to the surface 115 of the substrate 110 within the treatment region 205. A channel defined by the containment wall 140 and formed within the treatment region 205 enables the Newtonian fluid 102 to flow between the walls 140 of the non-Newtonian fluid 101. The Newtonian fluid 102 flowing in the channel acts on one or more contaminants and removes the contaminants from the top and bottom surfaces 115 of the substrate 110 at the treatment region 205, as illustrated in operation 620.
The speed of the carrier 120 carrying the substrate 110 may be adjusted so that the pressure of the Newtonian fluid 102 exerted on the non-Newtonian fluid 101 when applied by the proximity heads 130 and 135 are counter-balanced by a shift of non-Newtonian fluid 101 caused by the movement of the carrier 120. Similarly, the thickness of the non-Newtonian fluid 101 can be adjusted based on one or more characteristics of the Newtonian fluid 102 in order to enable the non-Newtonian fluid 101 to substantially contain the Newtonian fluid 102.
In another embodiment, the non-Newtonian fluid 101 is applied between the surface of a carrier 120 and the head surface of the proximity head at an area on the carrier 120 just outside the edge exclusion region 113 of the substrate 110 received on the carrier 120 so that the non-Newtonian fluid 101 forms a treatment region 205 that covers the entire top and bottom surface 115 of the substrate 110. In this embodiment, the containment wall 140 of non-Newtonian fluid meniscus forms a circular barrier between the head surface of the proximity head 130 and the top surface of the carrier 120 just outside the edge exclusion region of the substrate 113. In the embodiments discussed above with reference to
However, it is not necessary that the entire top and bottom surface 115 of the substrate 110 be enclosed by the treatment region. In another embodiment, the proximity heads 130 and 135 can be used to apply the non-Newtonian fluid 101 to the surface 115 of the substrate 110 such that a treatment region 205 is formed at the top and bottom surface 115 of the substrate 110 covering only a portion of the surface 115 of the substrate 110. In this embodiment, the substrate 110, in addition to being moved along a lateral axis, is rotated along an axis of rotation when the substrate 110 is under the proximity heads 130 and 135 so that different portions of the surface 115 of the substrate 110 are substantially exposed to the Newtonian fluid 102 contained within the treatment region 205.
In this embodiment, the proximity heads may not necessarily be a “head” in configuration, but may be any suitable configuration, shape, and/or size such as, for example, a manifold, a circular puck, a bar, a square, an oval puck, a tube, plate, etc., as long as the non-Newtonian fluid applicator and the Newtonian fluid applicator may be configured in a manner that would enable the generation of a controlled, stable, manageable fluid meniscus of non-Newtonian 101 and Newtonian fluids 102.
The embodiments of the current invention are not restricted to applying a non-Newtonian fluid 101 and a Newtonian fluid 102 to the surface of the substrate. The embodiments of the current invention illustrated in
The embodiments of the current invention is not restricted to applying a single type of Newtonian fluid 102 to the surface of the substrate. The embodiments of the current invention can also be used to apply more than one type of Newtonian fluid 102 to the surface of the substrate.
In the embodiment illustrated in
A first Newtonian fluid 102-A is applied using the proximity head 130 to the surface 115 of the substrate 110 such that the first Newtonian fluid 102-A is substantially contained within a first treatment sub-region 207 in the treatment region 205 of the substrate 110 defined by the containment wall 140. A second Newtonian fluid 102-B is applied using the proximity head 130 to the surface of the substrate 115 so that the second Newtonian fluid 102-B is substantially contained within a second treatment sub-region 209 in the treatment region 205 of the substrate 110. The first Newtonian fluid 102-A and the second Newtonian fluid 102-B are different from each and are chosen such that they are substantially immiscible with the non-Newtonian fluid 101. The first treatment sub-region 207 is separated from the second treatment sub-region 209 by the non-Newtonian fluid 101. The two Newtonian fluids 102-A and 102-B independently act on the various contaminants that are present on the surface 115 of the substrate 110 when applied at the treatment region 205 and help in substantially removing the contaminants from the surface 115 of the substrate 110.
In an alternate embodiment of
In an alternate embodiment, the first non-Newtonian fluid 101 is applied to the surface of the substrate between the head surface of the proximity head and the surface 115 of the substrate 110 defining a treatment region 205. In this embodiment, a second non-Newtonian fluid 101-A is applied to the surface of the substrate such that it is contained within a first sub-region 207 of the treatment region 205. A Newtonian fluid 102 is applied to the surface 115 of the substrate 110 such that the Newtonian fluid 102 is substantially contained within the second sub-region 209 of the treatment region 205. The second non-Newtonian fluid 101-A and the Newtonian fluid 102 are chosen such that they are different from the first non-Newtonian fluid 101 and are substantially immiscible with the first non-Newtonian fluid 101. The first treatment sub-region 207 is separated from the second treatment sub-region 209 by the first non-Newtonian fluid 101. The second non-Newtonian fluid 101-A and the Newtonian fluid 102 within the treatment region independently act on the various contaminants that are present on the surface 115 of the substrate 110 exposed in the treatment region 205 and help in substantially removing the contaminants from the surface 115 of the substrate 110.
In another embodiment illustrated in
In an alternate embodiment illustrated in
In yet another embodiment illustrated in
In a typical fabrication process of a substrate, chemistry used in the fabrication or the external uncontrolled environment may cause oxidation of features or layers formed at the substrate. This oxidation may affect later processing. For instance, excessive oxidation may prevent some layers to properly adhere or can cause less than desired conductive interfaces between layers or features. For example, in electroless deposition of metal layers, the electroless plating process is highly dependent on the surface characteristics and composition of the substrate 110. When oxidation occurs on the surface of the substrate, the electroless deposition process is inhibited by the formation of an atomically thin metal oxide layer formed due to the presence of oxygen. An additional step of removing the oxidized (metal oxide) layer has to be performed prior to the electroless deposition process resulting in increased cost, and time for the overall fabrication. Managing surface preparation sequence prior to subsequent fabrication is critical in the overall fabrication process.
In an embodiment, illustrated in
In one embodiment, an inert gas may be applied to the treatment region 205 using the proximity head 130, to the surface 115 of the substrate 110, such that the inert gas occupies the treatment region 205, displacing any chemistries or gases that might be present within the treatment region 205. The application of the inert gas to the treatment region 205 provides a substantially oxygen-free environment in the treatment region 205, that is substantially isolated from an external uncontrolled environment.
By creating a substantially oxygen-free environment in the treatment region and substantially isolating the treatment region 205 with the containment wall 140, it is possible to clean, prepare, or fabricate different layers, features, or structures (such as electroplating or electroless plating, etching, etc) immediately after processing of other features, layers or structures, while preventing the substrate from coming into contact with the external uncontrolled environment (e.g. environment having more oxygen or other undesired elements including moisture than may be desired).
The inert gas, as referred herein, is used to control the treatment region between the head surface of the proximity head and the surface of the substrate, wherein the non-Newtonian fluid creates an enclosed treatment region 205. In one embodiment, an inert gas controlling system (not shown) may be coupled to one or more ports of the proximity head 130 via a manifold (not shown). The manifold uses computer controls or manual controls to control what is introduced through the ports into the treatment region.
In one example, the inert gas controlling system may include pumps, gauges, controls and valves that meter and control the pumping of inert gas into the treatment region and the oxygen or chemicals out of the treatment region. Clean room facilities (not shown) may also couple to the inert gas controlling system, so that inert gas can be applied through the proximity head, and thus allows the replacement of oxygen with an inert gas. (i.e., the space previously occupied by oxygen or chemicals containing oxygen is now filled with inert gas). The pumps that remove the oxygen or other chemicals are monitored, so that proper conditions can be maintained during any stages of fabrication process. Meters, manual controls and/or computer controls can monitor and adjust the pumping and flows of inert gases, such as N2, Ar, He, Ne, Kr, Xe, etc. with out limitation.
Referring to
In addition to providing a substantially oxygen-free environment within the treatment region 205, the defined embodiments prevent uncontrolled de-wetting of the surface of the substrate by controlling the environment within the treatment region, thereby providing for a highly efficient fabrication process.
As illustrated in
Example systems and processes for performing plating operations are described in more detail in: (1) U.S. Pat. No. 6,864,181, issued on Mar. 8, 2005; (2) U.S. patent application Ser. No. 11/014,527 filed on Dec. 15, 2004 and entitled “WAFER SUPPORT APPARATUS FOR ELECTROPLATING PROCESS AND METHOD FOR USING THE SAME”; (3) U.S. patent application Ser. No. 10/879,263, filed on Jun. 28, 2004 and entitled “METHOD AND APPARATUS FOR PLATING SEMICONDUCTOR WAFERS”; (4) U.S. patent application Ser. No. 10/879,396, filed on Jun. 28, 2004 and entitled “ELECTROPLATING HEAD AND METHOD FOR OPERATING THE SAME”; (5) U.S. patent application Ser. No. 10/882,712, filed on Jun. 30, 2004 and entitled “APPARATUS AND METHOD FOR PLATING SEMICONDUCTOR WAFERS”; (6) U.S. patent application Ser. No. 11/205,532, filed on Aug. 16, 2005, and entitled “REDUCING MECHANICAL RESONANCE AND IMPROVED DISTRIBUTION OF FLUIDS IN SMALL VOLUME PROCESSING OF SEMICONDUCTOR MATERIALS”; and (7) U.S. patent application Ser. No. 11/398,254, filed on Apr. 4, 2006, and entitled “METHODS AND APPARATUS FOR FABRICATING CONDUCTIVE FEATURES ON GLASS SUBSTRATES USED IN LIQUID CRYSTAL DISPLAYS”; each of which is herein incorporated by reference. Thus, embodiments of the current invention may be used in providing a substantially oxygen-free environment within a treatment region.
Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications can be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.
This application is a divisional application of U.S. application Ser. No. 11/704,435 entitled “Method for Contained Chemical Surface Treatment” filed on Feb. 8, 2007, and incorporated herein by reference. This application is related to U.S. patent application Ser. No. 10/608,871, filed Jun. 27, 2003, and entitled “Method and Apparatus for Removing a Target Layer from a Substrate Using Reactive Gases”; U.S. patent application Ser. No. 10/746,114, filed on Dec. 23, 2003, and entitled “Method and Apparatus for Cleaning Semiconductor Wafers using Compressed and/or Pressurized Foams, Bubbles, and/or Liquids”; U.S. patent application Ser. No. 11/532,491, filed on Sep. 15, 2006, and entitled “Method and Material for cleaning a substrate”; U.S. patent application Ser. No. 11/532,493, filed on Sep. 15, 2006, and entitled “Apparatus and System for cleaning a substrate”. The disclosure of each of these related applications is incorporated herein by reference for all purposes.
Number | Date | Country | |
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Parent | 11704435 | Feb 2007 | US |
Child | 12949762 | US |