WO2005047422A1

WO2005047422A1 - Selective etch and cleaning chemistries, methods of production and uses thereof

Info

Publication number: WO2005047422A1
Application number: PCT/US2004/035516
Authority: WO
Inventors: John Starzynski
Original assignee: Honeywell International Inc.
Priority date: 2003-11-11
Filing date: 2004-11-10
Publication date: 2005-05-26
Also published as: TW200606237A

Abstract

An etching and/or cleaning solution includes: a) at least one fluorine-based salt constituent, b) a non-polar solvent constituent in an aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated etching solution comprises a) at least one fluorine-based salt constituent, b) a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. A method of forming an etching and/or cleaning solution includes: a) providing at least one fluorine-based salt constituent; b) providing a non-polar solvent constituent; c) blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated method of forming an etching solution comprises a) providing at least one fluorine-based salt constituent; b) providing a compatible solvent constituent; c) blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

Description

SELECTIVE ETCH AND CLEANING CHEMISTRIES, METHODS OF PRODUCTION AND USES THEREOF

FIELD OF THE SUBJECT MATTER The field of the subject matter is selective etch chemistries and cleaning chemistries for semiconductor, electronic and related applications.

BACKGROUND The technique of bulk residue removal by means of a selective chemical etching and in some cases selective chemical cleaning is a key step in the manufacture of many types of

MEMS (microelectromechanical systems) devices. Each continuous or patterned layer comprises deleterious residues that, if left even partially intact, will contribute to the breakdown and ultimately the failure of any component that comprises that layer. One example of a layer that comprises unwanted residues is a layer that is formed at least in part by using a fluorine-based etching step. In some instances, these fluorine-based etching processes are used to remove at least part of the silicon-based compounds, such as silicon dioxide, from part or all of a metal surface. In a specific example, a Reactive Ion Etching (RIE) etch system can be used to form silicon dioxide pillars on a wafer surface that is coated with aluminum. Since most RTJE etching systems and techniques utilize at least in part fluorocarbon-containing constituents, the etch can leave behind a CF-based polymer on the surface that if left intact will contribute to component failure. The goal in successful selective etching and selective cleaning steps is to remove the residue without removing or compromising the desirable components, which in this case are the silicon-based pillars and the metal-coated wafer surface. Several of the goals that have yet to be addressed in a selective etching solution and a selective cleaning solution are the following: a) the solution constituents should be able to be tailored to be both a selective etching solution and a selective cleaning solution; b) the solution should be effective in both aqueous and non-aqueous environments; c) should be able to selectively etch polymeric compositions from a surface without etching silicon-based compounds or metal-based layers and compounds; and d) can both etch and clean effectively at the center of the wafer and at the edge of the wafer. European Patent No. 887,323 teaches an etching and cleaning solution that comprises hydrofluoric acid and ammonium fluoride in propylene carbonate. This etching solution is specifically designed to etch silicate glass and silicon dioxide. Based on the chemistry disclosed, it appears that this combination of constituents is selective to silicate glass and silicon dioxide. JP 9235619 and US Issued Patent 5,476,816 uses a similar solution replacing propylene carbonate with ethylene glycol in order to remove insulating coatings. JP 10189722 uses a similar solution as JP 9235619 except water is also added and the solution is used to clean oxides from a surface. JP 8222628 and US Issued Patent 3,979,241 use an etching solution of ammonium fluoride and ethylene glycol to remove insulating coatings, and JP 1125831 uses this same blend at a different concentration to remove silicon-based compounds. US Issued Patents 6,090,721 and 5,939,336 blends ammonium fluoride, propylene glycol and water to etch metal-containing etch residues from silicon containing substrates. US Issued Patent 5,478,436 uses ammonium fluoride and ethylene glycol to remove metal-based contaminants from a silicon surface. Although many of these solutions can be tailored to be both a selective etching solution and a selective cleaning solution; can be effective in both aqueous and non-aqueous environments; and can both etch and clean effectively at the center of the wafer and at the edge of the wafer, none of these compounds can selectively etch polymeric compositions from a surface without etching silicon-based compounds and/or metal-based layers and compounds. Therefore, it would be desirable to form a selective etching solution and a selective cleaning solution that can do at least one of the following: a) the solution constituents should be able to be tailored to be both a selective etching solution and a selective cleaning solution; b) the solution should be effective in both aqueous and non-aqueous environments; c) can both etch and clean effectively at the center of the wafer and at the edge of the wafer and at the same time can selectively etch polymeric compositions from a surface without etching silicon-based compounds or metal-based layers and compounds. SUMMARY OF THE SUBJECT MATTER An etching solution contemplated herein comprises a) at least one fluorine-based salt constituent, b) a non-polar solvent constituent in an aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated etching solution comprises a) at least one fluorine-based salt constituent, b) a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. A cleaning solution contemplated herein comprises a) at least one fluorine-based salt constituent, b) a non-polar solvent constituent in an aqueous environment, wherein the solution constituents are at a suitable concentration to clean polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated cleaning solution comprises a) at least one fluorine- based salt constituent, b) a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to clean polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon- based compositions. A method of forming an etching solution contemplated herein comprises a) providing at least one fluorine-based salt constituent; b) providing a non-polar solvent constituent; c) blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated method of forming an etching solution comprises a) providing at least one fluorine-based salt constituent; b) providing a compatible solvent constituent; c) blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer- based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. A method of forming a cleaning solution contemplated herein comprises a) providing at least one fluorine-based salt constituent; b) providing a non-polar solvent constituent; c) blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated method of forming a cleaning solution comprises a) providing at least one fluorine-based salt constituent; b) providing a compatible solvent constituent; c) blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer- based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a 45 degree angle artist's rendition of the center of a wafer, wherein the cylindrical pillars are encrusted with a polymer.

Fig. 2 shows a 45 degree angle artist's renditione of a wafer from the center of the wafer after a 10 minute static bath dip at about 22°C using a contemplated solution.

Fig. 3 shows a 45 degree angle artist's rendition of a wafer from the edge of the wafer after a 10 minute static bath dip at about 22°C using a contemplated solution.

Fig. 4 shows a 45 degree angle artist's rendition of a wafer from the center of the wafer after a 15 minute static bath dip at about 22°C using a contemplated solution. Fig. 5 shows a 45 degree angle artist's rendition of a wafer from the edge of the wafer after a 15 minute static bath dip at about 22°C using a contemplated solution.

DETAILED DESCRIPTION A selective etching solution and a selective cleaning solution has been developed and will be disclosed herein that can do at least one of the following: a) the solution constituents can be tailored to be both a selective etching solution and a selective cleaning solution; b) the solution can be effective in both aqueous and non-aqueous environments; c) the solution can both etch and clean effectively at the center of the wafer and at the edge of the wafer and at the same time the solution can selectively etch polymeric compositions from a surface without etching silicon-based compounds or metal-based layers and compounds. Methods of forming and uses of these selective etch and cleaning chemistries are also contemplated herein. Such methods include providing the constituents of the selective etch chemistry formulation, blending the constituents to form the formulation and applying the formulation to a surface or substrate. In some embodiments, the formulation may be produced in situ (directly on the surface) or may be formed before application to the surface. An etching solution contemplated herein comprises a) at least one fluorine-based salt constituent, b) a non-polar solvent constituent in an aqueous environment, wherein. the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated etching solution comprises a) at least one fluorine-based salt constituent, b) a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. A cleaning solution contemplated herein comprises a) at least one fluorine-based salt constituent, b) a non-polar solvent constituent in an aqueous environment, wherein the solution constituents are at a suitable concentration to clean polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated cleaning solution comprises a) at least one fluorine- based salt constituent, b) a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to clean polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon- based compositions. As used herein, the term "metal" means those elements that are in the d-block and f- block of the Periodic Chart of the Elements, along with those elements that have metal-like properties, such as silicon and germanium. As used herein, the phrase "d-block" means those elements that have electrons filling the 3d, 4d, 5d, and 6d orbitals surrounding the nucleus of the element. As used herein, the phrase "f-block" means those elements that have electrons filling the 4f and 5f orbitals surrounding the nucleus of the element, including the lanthanides and the actinides. Preferred metals include such as titanium, silver, copper, aluminum, tin and alloys thereof. The term "metal" also includes alloys, metal/metal composites, metal ceramic composites, metal polymer composites, as well as other metal composites. As used herein, the term "compound" means a substance with constant composition that can be broken down into elements by chemical processes. The silicon-based compositions and/or the metal-based compositions may be laid down or formed as a continuous layer of material, in a pattern, in a non-continuous form or as a combination thereof. For example, a metal-based layer may be laid down or formed in a continuous layer and a silicon-based composition may be laid down or formed in a pattern. As used herein, the phrase "non-continuous form" means that the composition or material is not laid down in a contmuous layer and is also not laid down in a pattern. The composition or material in a non-continuous form is laid down or formed having a more random or non- pattern-like appearance. Both the etching and the cleaning solutions contemplated herein utilize at least one fluorine-based salt as one of the constituents of the solutions. As used herein, the phrase "fluorine-based salts" mean those salts that comprise fluorine, such as quartenary ammonium compounds like tetraalkylammonium fluoride compounds, such as tetramethylammonium fluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride and tetraethylammonium fluoride, and other fluorine-based salts, such as ammonium fluoride. Ammonium salts are also contemplated, such as those having the formula (Pvl)(R2)(R3)(R4)NF, where Rl, R2, R3 and R4 may be the same or different and may comprise hydrogen or alkyl groups, including straight-chain and branched alkyl groups. The fluorine-based salts contemplated herein are present in solution at less than about 3 weight percent relative to the solvent constituent. In some embodiments, the fluorine-based salts contemplated herein are present in solution at less than about 2 weight percent relative to the solvent constituent. In other embodiments, the fluorine-based salts contemplated herein are present in solution at less than about 1 weight percent relative to the solvent constituent. At this point it should be understood that, unless otherwise indicated, all numbers expressing quantities of ingredients, constituents, interaction conditions and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the subject matter presented herein. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the subject matter presented herein are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. The etching and cleaning solutions contemplated herein can be custom blended for specific applications; however, it is contemplated that the process of custom blending does not require undue experimentation once the disclosure herein, including the stated goals, is understood by one of ordinary skill in the art of etching and cleaning solutions for electronic and semiconductor applications. Both the etching and the cleaning solutions contemplated herein also utilize a non- polar solvent (aqueous applications) or a compatible solvent (non-aqueous applications). It has been found that in aqueous applications, the solvent should be either non-polar or as non- polar as possible, in order to get sufficient etching and/or cleaning of a surface without etching and/or cleaning off silicon-based compositions and metal-based layers and compositions. In environments where the application is non-aqueous and there's no interference from a polar compound, such as water, the solvent may be polar or non-polar depending on what is compatible with the fluorine-based salt and the environmental concerns. As used herein, the term "environment" means that environment in the solution containing the fluorine-based salt and/or the non-polar or compatible solvent. The term "environment" does not mean the environment surrounding the solution, such as the environment present in the lab or in the building. For example, a non-aqueous environment means that the solution is non- aqueous and does not refer to the overall humidity level of the air in the lab or building. Contemplated solvents include any suitable pure or mixture of organic molecules that are volatilized at a desired temperature, such as the critical temperature, or that can facilitate any of the above-mentioned design goals or needs. The solvent may also comprise any suitable pure or mixture of polar and non-polar compounds, as long as the environment is non-aqueous. As used herein, the term "pure" means that component that has a constant composition. For example, pure water is composed solely of H₂O. As used herein, the term "mixture" means that component that is not pure, including salt water. As used herein, the term "polar" means that characteristic of a molecule or compound that creates a substantial unequal charge, partial charge or spontaneous charge distribution at one point of or along the molecule or compound. As used herein, the term "non-polar" means that characteristic of a molecule or compound that creates a substantially equal charge, partial charge or spontaneous charge distribution at one point of or along the molecule or compound. It should be understood that those compounds included under the definition of "non-polar" are those compounds that are both clearly non-polar or slightly polar. One of ordinary skill in the art of chemistry and etching solutions will know which solvents are non-polar/slightly polar and which solvents are clearly polar in nature. It is also contemplated that the solvents used herein may comprise any suitable impurity level, such as less than about 1 ppm, less than about 100 ppb, less than about 10 ppb and in some cases, less than about 1 ppb. These solvents may be purchased having impurity levels that are appropriate for use in these contemplated applications or may need to be further purified to remove additional impurities and to reach the less than about 10 ppb and less than about 1 ppb levels that are becoming more desirable in the art of etching and cleaning. In some contemplated embodiments, the solvent or solvent mixture (comprising at least two solvents) comprises those solvents that are considered part of the hydrocarbon family of solvents. Hydrocarbon solvents are those solvents that comprise carbon and hydrogen. It should be understood that a majority of hydrocarbon solvents are non-polar; however, there are a few hydrocarbon solvents that could be considered polar. Hydrocarbon solvents are generally broken down into three classes: aliphatic, cyclic and aromatic. Aliphatic hydrocarbon solvents may comprise both straight-chain compounds and compounds that are branched and possibly crosslinked, however, aliphatic hydrocarbon solvents are not considered cyclic. Cyclic hydrocarbon solvents are those solvents that comprise at least three carbon atoms oriented in a ring structure with properties similar to aliphatic hydrocarbon solvents. Aromatic hydrocarbon solvents are those solvents that comprise generally three or more unsaturated bonds with a single ring or multiple rings attached by a common bond and/or multiple rings fused together. Contemplated hydrocarbon solvents include toluene, xylene, p-xylene, m-xylene, mesitylene, solvent naphtha H, solvent naphtha A, alkanes, such as pentane, hexane, isohexane, heptane, nonane, octane, dodecane, 2-methylbutane, hexadecane, tridecane, pentadecane, cyclopentane, 2,2,4-trimethylpentane, petroleum ethers, halogenated hydrocarbons, such as chlorinated hydrocarbons, nitrated hydrocarbons, benzene, 1,2-dimethylbenzene, 1,2,4-trimethylbenzene, mineral spirits, kerosine, isobutylbenzene, methyhiaphthalene, ethyltoluene, ligroine. Particularly contemplated solvents include, but are not limited to, pentane, hexane, heptane, cyclohexane, benzene, toluene, xylene and mixtures or combinations thereof. In other contemplated embodiments, the solvent or solvent mixture may comprise those solvents that are not considered part of the hydrocarbon solvent family of compounds, such as ketones, such as acetone, diethyl ketone, methyl ethyl ketone and the like, alcohols, esters, carbonate-based compounds, such as propylene carbonate and the like, ethers and amines. In yet other contemplated embodiments, the solvent or solvent mixture may comprise a combination of any of the solvents mentioned herein. As mentioned, in some embodiments a solvent mixture may be present in the solution as opposed to one solvent component. The constituents of a solvent mixture may not only be present to solvate the other constituents in solution but may also serve another purpose. For example, solid tetramethylammonium fluoride has 4 waters of hydration associated with each TMAF: (CH₃)₄NF(H₂O) . Apparently, it is difficult to remove the water without decomposing the TMAF. The water can be removed by adding acetic anhydride to one of the contemplated solutions that comprises TMAF and propylene carbonate. The acetic anhydride will react with the water to form acetic acid:

CH₃COOOCCH₃ + H₂O => 2CH₃COOH

Acetic anhydride would be added in an amount suitable to react with all the water thus creating non-aqueous TMAF and acetic acid in propylene carbonate. Surfaces contemplated herein may comprise any desirable substantially solid material, such as a substrate, wafer or other suitable surface that comprises at least in part a metal-based layer, a metal-based pattern, a silicon-based layer and/or a silicon-based pattern. In contemplated embodiments, the surface, wafer or other suitable surface comprises a metal- based layer or pattern and a silicon-based layer or pattern. It should be understood that the metal-based layer, the metal-based pattern, the silicon-based layer and/or the silicon-based pattern may be coupled to the surface or substrate and/or may actually be the surface and/or substrate. As used herein, the term "coupled" means that the surface and layer or two layers are physically attached to one another or there's a physical attraction between two parts of matter or components, including bond forces such as covalent and ionic bonding, and non- bond forces such as Van der Waals, electrostatic, coulombic, hydrogen bonding and/or magnetic attraction. Also, as used herein, the term coupled is meant to encompass a situation where the surface and layer or two layers are directly attached to one another, but the term is also meant to encompass the situation where the surface and the layer or plurality of layers are coupled to one another indirectly - such as the case where there's an adhesion promoter layer between the surface and layer or where there's another layer altogether between the surface and layer or plurality of layers. Surface and/or substrate layers comprise at least one layer and in some instances comprise a plurality of layers. In preferred embodiments, the substrate comprises a silicon, gallium arsenide or germanium-silicon die or wafer surface, a packaging surface such as found in a copper, silver, nickel or gold plated leadframe, a copper surface such as found in a circuit board or package interconnect trace, a via-wall or stiffener interface ("copper" includes considerations of bare copper and it's oxides), a polymer-based packaging or board interface such as found in a polyimide-based flex package, lead or other metal alloy solder ball surface, glass and polymers such as polyimide. In more preferred embodiments, the substrate comprises a material common in the integrated circuit industries as well as the packaging and circuit board industries such as silicon, copper, glass, and another polymer. Suitable surfaces contemplated herein may also include another previously formed layered stack, other layered component, or other component altogether. An example of this may be where a dielectric material and CVD barrier layer are first laid down as a layered stack - which is considered the "surface" for the subsequently spun-on layered component.

Contemplated dielectric and low dielectric materials comprise inorganic-based compounds, such as silicon-based disclosed in commonly assigned US Patent 6,143,855 and pending US Serial No. 10/078919 filed February 19, 2002; (for example Honeywell NANOGLASS® and HOSP® products), gallium-based, germanium-based, arsenic-based, boron-based compounds or combinations thereof, and organic-based compounds, such as polyethers, polyarylene ethers disclosed in commonly assigned US Patent 6,124,421 (such as Honeywell FLARE™ product), polyimides, polyesters and adamantane-based or cage-based compounds disclosed in commonly assigned WO 01/78110 and WO 01/08308 (such as Honeywell GX-3™ product). The dielectric and low dielectric materials may be applied by spin coating the material on to the surface, dip coating, spray coating, rolling the material on to the surface, dripping the material on to the surface, and/or spreading the material on to the surface. Other contemplated layers may include solder materials, coating compositions and other related materials, including solder pastes, polymer solders and other solder-based formulations and materials, such as those found in the following Honeywell International Inc.'s issued patents and pending patent applications, which are incorporated herein in their entirety: US Patent Application Serial Nos. 09/851103, 60/357754, 60/372525, 60/396294, and 09/543628; and PCT Pending Application Serial No.: PCT/US02/14613, and all related continuations, divisionals, continuation-in-parts and foreign applications. A method of forming an etching solution contemplated herein comprises a) providing at least one fluorine-based salt constituent; b) providing a non-polar solvent constituent; c) blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated method of forming an etching solution comprises a) providing at least one fluorine-based salt constituent; b) providing a compatible solvent constituent; c) blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer- based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. A method of forming a cleaning solution contemplated herein comprises a) providing at least one fluorine-based salt constituent; b) providing a non-polar solvent constituent; c) blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. Another contemplated method of forming a cleaning solution comprises a) providing at least one fluorine-based salt constituent; b) providing a compatible solvent constituent; c) blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer- based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. The fluorine-based salt constituent, the non-polar solvent constituent and/or the compatible solvent constituent may be provided by any suitable method, including a) buying at least some of the fluorine-based salt constituent, the non-polar solvent constituent and/or the compatible solvent constituent from a supplier; b) preparing or producing at least some of the fluorine-based salt constituent, the non-polar solvent constituent and/or the compatible solvent constituent in house using chemicals provided by another source and/or c) preparing or producing at least some of the fluorine-based salt constituent, the non-polar solvent constituent and/or the compatible solvent constituent in house using chemicals also produced or provided in house or at the location. Once the at least one fluorine-based salt component, the non-polar solvent constituent and/or the compatible solvent constituent are provided, they are blended to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon- based compositions. Blending the constituents may be achieved by utilizing any suitable method or methods known in the art, such as mixing and then stirring the constituents. Another method of blending the constituents may be to synthesize one of the components or constituents directly into the solution. For example, at least one of the fluorine-based salts could be synthesized directly in the solvent. More specifically, TMAF can be made or purchased initially or can be made in situ by reacting tetramethylammonium hydroxide (TMAH) with HF. Once the etching and/or cleaning solutions are formed, a contaminated wafer or surface may be placed in the path of the solution for etching and/or cleaning. It should be understood that the etching or cleaning solutions will at least etch or clean in part the residue or layer from the surface, substrate or wafer. In some contemplated embodiments, the etching or cleaning solutions will etch or clean the entire residue or layer from the surface, substrate or wafer. The wafer may be dipped into solution once and held for a particular time period or dipped multiple times, may be rinsed by the solution, may have the solution applied in a methodical patterned form, may be masked and then rinsed by the solution, etc. In contemplated embodiments where the wafer or substrate is dipped into solution and held for a particular time period, the time period is greater than about 5 minutes. In some contemplated embodiments where the wafer or substrate is dipped into solution and held for a particular time period, the time period is greater than about 10 minutes. In other contemplated embodiments where the wafer or substrate is dipped into solution and held for a particular time period, the time period is greater than about 15 minutes. In yet other contemplated embodiments where the wafer or substrate is dipped into solution and held for a particular time period, the time period is greater than about 20 minutes. The etching and/or cleaning solution may also be held at a particular temperature which optimizes the etching and/or cleaning abilities of the solution or may be varied with respect to temperature depending on the wafer or surface to be cleaned. The term "varied" is used herein with respect to temperature to mean that the solution temperature may be varied while the wafer is being processed or may be varied from wafer to wafer depending on the extent of residue that needs to be etched or removed. In some contemplated embodiments, the temperature of the etching and/or cleaning solution is held at less than about 30°C. In other contemplated embodiments, the temperature of the etching and/or cleaning solution is held at less than about 25°C. In yet other contemplated embodiments, the temperature of the etching and/or cleaning solution is held at about 22°C. The substrates, wafers and surfaces described herein, once etched or cleaned by the solutions disclosed herein, may be used alone or in combination with other layers to form a substrate, a layered component, a semiconductor component or an electronic component. Electronic-based products can be "finished" in the sense that they are ready to be used in industry or by other consumers. Examples of finished consumer products are a television, a computer, a cell phone, a pager, a palm-type organizer, a portable radio, a car stereo, and a remote control. Also contemplated are "intermediate" products such as circuit boards, chip packaging, and keyboards that are potentially utilized in finished products. Electronic products may also comprise a prototype component, at any stage of development from conceptual model to final scale-up/mock-up. A prototype may or may not contain all of the actual components intended in a finished product, and a prototype may have some components that are constructed out of composite material in order to negate their initial effects on other components while being initially tested.

As used herein, the term "electronic component" means any device or part that can be used in a circuit to obtain some desired electrical action. Electronic components contemplated herein may be classified in many different ways, including classification into active components and passive components. Active components are electronic components capable of some dynamic function, such as amplification, oscillation, or signal control-, which usually requires a power source for its operation. Examples are bipolar transistors, field-effect transistors, and integrated circuits. Passive components are electronic components that are static in operation, i.e., are ordinarily incapable of amplification or oscillation, and usually require no power for their characteristic operation. Examples are conventional resistors, capacitors, inductors, diodes, rectifiers and fuses.

Electronic components contemplated herein may also be classified as conductors, semiconductors, or insulators. Here, conductors are components that allow charge carriers (such as electrons) to move with ease among atoms as in an electric current. Examples of conductor components are circuit traces and vias comprising metals. Insulators are components where the function is substantially related to the ability of a material to be extremely resistant to conduction of current, such as a material employed to electrically separate other components, while semiconductors are components having a function that is substantially related to the ability of a material to conduct current with a natural resistivity between conductors and insulators. Examples of semiconductor components are transistors, diodes, some lasers, rectifiers, thyristors and photosensors.

Electronic components contemplated herein may also be classified as power sources or power consumers. Power source components are typically used to power other components, and include batteries, capacitors, coils, and fuel cells. As used herein, the term "battery" means a device that produces usable amounts of electrical power through chemical reactions. Similarly, rechargeable or secondary batteries are devices that store usable amounts of electrical energy through chemical reactions. Power consuming components include resistors, transistors, ICs, sensors, and the like. Still further, electronic components contemplated herein may also be classified as discreet or integrated. Discreet components are devices that offer one particular electrical property concentrated at one place in a circuit. Examples are resistors, capacitors, diodes, and transistors. Integrated components are combinations of components that that can provide multiple electrical properties at one place in a circuit. Examples are ICs, i.e., integrated circuits in which multiple components and connecting traces are combined to perform multiple or complex functions such as logic.

EXAMPLES An 8-inch wafers that had silicon dioxide pillars covered with polymer from the RIE etch used to create them was used in this Example to show how a contemplated solution can remove deleterious polymer residues. The pillars were oriented pe endicularly to the wafer surface. The wafer surface was covered with alurninum in this Example, but as described earlier, any metal-based composition will work, except for pure titanium. In this case, it was desirable to remove the polymer without any silicon dioxide or aluminum loss. The polymer on the edge of the wafer was more difficult to remove than the center of the wafer. Figure 1 is a 45° angle artist's rendition of the center of the wafer (100) as received. The cylindrical pillars (110) are encrusted with polymer forming spherical structures (120). Trenches (130) are also shown in Figure 1. Wafer pieces were dipped in contemplated solutions comprising TMAF and propylene carbonate in an aqueous and non-aqueous environment and it was shown that these solutions removed the polymer but did not etch the silicon dioxide post or aluminum. Figure 2 is a 45° angle artist's rendition of a wafer piece from the center of the wafer

(200) after a 10 minute static bath dip at about 22 °C. No polymer is present on the cylindrical pillars (210). Trenches (230) are also shown in Figure 2. Figure 3 is a 45° angle artist's rendition of a wafer piece from the edge of the wafer (300) after a 10 minute static bath dip at about 22 °C. Residual polymer (320) is still present on the pillars (310). Trenches (330) are also shown in Figure 3. Figure 4 is a 45° angle artist's rendition of a wafer piece from the center of the wafer (400) after a 15 minute static bath dip at about 22 °C. No polymer is present on the cylindrical pillars (410). Trenches (430) are also shown in Figure 4. Figure 5 is a 45° angle artist's rendition of a wafer piece from the edge of the wafer (500) after a 15 minute static bath at about 22 °C. No polymer is present on the pillars (510). Trenches (530) are also shown in Figure 5. Based on these results, a 15 to 20 minute dip in a static or flowing bath of the contemplated chemistry at about 22°C will remove substantially all of polymer from the entire wafer. Thus, specific embodiments and applications of etching and/or cleaning solutions have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. Moreover, in interpreting the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present,. or utilized, or combined with other elements, components, or steps that are not expressly referenced.

Claims

We claim:

1. An etching solution, comprising: at least one fluorine-based salt constituent, and a non-polar solvent constituent in an aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

2. The etching solution of claim 1, wherein the at least one fluorine-based salt constituent comprises a quarternary ammonium compound.

3. The etching solution of claim 2, wherein the quarternary ammonium compound comprises a tetraalkylammomum fluoride compound.

4. The etching solution of claim 3, wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

5. The etching solution of claim 1, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

6. The etching solution of claim 5, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

7. The etching solution of claim 6, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

8. The etching solution of one of claims 1, 2 or 4, wherein the non-polar solvent constituent comprises propylene carbonate.

9. An etching solution, comprising: at least one fluorine-based salt constituent, and a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

10. The etching solution of claim 9, wherein the at least one fluorine-based salt constituent comprises a quarternary ammonium compound.

11. The etching solution of claim 10, wherein the quarternary ammonium compound comprises a tetraalkylammonium fluoride compound.

12. The etching solution of claim 11 , wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

13. The etching solution of claim 9, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

14. The etching solution of claim 13, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

15. The etching solution of claim 14, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

16. The etching solution of one of claims 9, 10 or 12, wherein the compatible solvent constituent comprises propylene carbonate.

17. A cleaning solution, comprising: at least one fluorine-based salt constituent, and a non-polar solvent constituent in an aqueous environment, wherein the solution constituents are at a suitable concentration to clean polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. 18. The cleaning solution of claim 17, wherein the at least one fluorine-based salt constituent comprises a quarternary ammonium compound.

19. The cleaning solution of claim 18, wherein the quartemary ammonium compound comprises a tetraalkylammonium fluoride compound.

20. The cleaning solution of claim 19, wherein the tetraalkylammonium fluoride compound comprises teframethylammonium fluoride.

21. The cleaning solution of claim 17, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

22. The cleaning solution of claim 21, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

23. The cleaning solution of claim 22, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

24. The cleaning solution of one of claims 17, 18 or 20, wherein the non-polar solvent constituent comprises propylene carbonate.

25. A cleaning solution, comprising: at least one fluorine-based salt constituent, and a compatible solvent constituent in an non-aqueous environment, wherein the solution constituents are at a suitable concentration to clean polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

26. The cleaning solution of claim 25, wherein the at least one fluorine-based salt constituent comprises a quarternary ammonium compound.

27. The cleaning solution of claim 26, wherein the quartemary ammonium compound comprises a tetraalkylammonium fluoride compound.

28. The cleaning solution of claim 27, wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

29. The cleaning solution of claim 25, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

30. The cleaning solution of claim 29, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

32. The cleaning solution of claim 30, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

33. The cleaning solution of claim 25, wherein the compatible solvent constituent comprises propylene carbonate.

34. A method of forming an etching solution, comprising: providing at least one fluorine-based salt constituent; providing a non-polar solvent constituent; and blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions. 35. The method of claim 34, wherein the at least one fluorine-based salt constituent comprises a quartemary ammonium compound.

36. The method of claim 35, wherein the quartemary ammonium compound comprises a tetraalkylammonium fluoride compound.

37. The method of claim 36, wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

38. The method of claim 34, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

39. The method of claim 38, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

40. The method of claim 39, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

41. The method of one of claims 34, 35 or 37, wherein the non-polar solvent constituent comprises propylene carbonate.

42. The method of claim 34, wherein blending comprises mixing the at least one fluorine based salt component and the solvent component. 43. The method of claim 34, wherein blending comprises synthesizing the at least one fluorine-based salt in the solvent component.

44. The method of claim 34, wherein blending comprises synthesizing at least one of the at least one fluorine-based salt in the solvent component.

45. A method of forming an etching solution, comprising: providing at least one fluorine-based salt constituent; providing a compatible solvent constituent; and blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

46. The method of claim 45, wherein the at least one fluorine-based salt constituent comprises a quartemary ammonium compound.

47. The method of claim 46, wherein the quartemary ammonium compound comprises a tetraalkylammonium fluoride compound.

48. The method of claim 47, wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

49. The method of claim 45, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

50. The method of claim 49, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

51. The method of claim 50, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

52. The method of one of claims 45, 46 or 48, wherein the solvent constituent comprises propylene carbonate. 53. The method of claim 44, wherein blending comprises mixing the at least one fluorine based salt component and the solvent component.

54. The method of claim 44, wherein blending comprises synthesizing the at least one fluorine-based salt in the solvent component.

55. The method of claim 44, wherein blending comprises synthesizing at least one of the at least one fluorine-based salt in the solvent component.

56. A method of forming a cleaning solution, comprising: providing at least one fluorine-based salt constituent; providing a non-polar solvent constituent; and blending the fluorine-based salt constituent and the non-polar solvent constituent in an aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

57. The method of claim 56, wherein the at least one fluorine-based salt constituent comprises a quarte ary ammonium compound.

58. The method of claim 57, wherein the quartemary ammonium compound comprises a tetraalkylammonium fluoride compound.

59. The method of claim 58, wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

60. The method of claim 56, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

61. The method of claim 60, wherem the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

62. The method of claim 61 , wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

63. The method of one of claims 56, 57 or 59, wherein the non-polar solvent constituent comprises propylene carbonate.

64. The method of claim 56, wherein blending comprises mixing the at least one fluorine based salt component and the solvent component.

65. The method of claim 56, wherein blending comprises synthesizing the at least one fluorine-based salt in the solvent component.

66. The method of claim 56, wherein blending comprises synthesizing at least one of the at least one fluorine-based salt in the solvent component.

67. A method of forming a cleaning solution, comprising: providing at least one fluorine-based salt constituent; providing a compatible solvent constituent; and blending the fluorine-based salt constituent and the compatible solvent constituent in an non-aqueous environment to form a solution, wherein the solution constituents are at a suitable concentration to etch polymer-based residues from a surface without reacting with metals, metal-based compositions and silicon-based compositions.

68. The method of claim 67, wherein the at least one fluorine-based salt constituent comprises a quartemary ammonium compound.

69. The method of claim 68, wherein the quartemary arnmonium compound comprises a tetraalkylammonium fluoride compound.

70. The method of claim 69, wherein the tetraalkylammonium fluoride compound comprises tetramethylammonium fluoride.

71. The method of claim 67, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 3 percent.

72. The method of claim 71 , wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 2 percent.

73. The method of claim 72, wherein the at least one fluorine-based constituent is present in the solution at a weight percent of less than 1 percent.

74. The method of one of claims 67, 68 or 70, wherein the solvent constituent comprises propylene carbonate.

75. The method of claim 67, wherein blending comprises mixing the at least one fluorine based salt component and the solvent component.

76. The method of claim 67, wherein blending comprises synthesizing the at least one fluorine-based salt in the solvent component.

77. The method of claim 67, wherein blending comprises synthesizing at least one of the at least one fluorine-based salt in the solvent component.

78. A layered component comprising at least one layer etched using the solution in claim 1.

79. A layered component comprising at least one layer etched using the solution in claim 8.

80. A layered component comprising at least one layer cleaned using the solution in claim 17.

81 A layered component comprising at least one layer cleaned using the solution in claim 24.

82. A layer etched using the solution in claim 1.

83. A layer etched using the solution in claim 8.

84. A layer cleaned using the solution in claim 17.

85. A layer cleaned using the solution in claim 24.

86. A method of etching a residue or layer on a substrate, comprising: providing a substrate having a deleterious residue or layer; providing the etching solution of one of claims 1 or 9; applying the etching solution to the substrate for a period of time and at a temperature sufficient to remove at least part of the residue or layer.

87. The method of claim 86, wherein a period of time comprises less than about 20 minutes.

88. The method of claim 87, wherein a period of time comprises less than about 15 minutes.

89. The method of claim 86, wherein a temperature sufficient to remove at least part of the residue or layer comprises a temperature less than about 30°C.

90. The method of claim 89, wherein a temperature sufficient to remove at least part of the residue or layer comprises a temperature less than about 25°C.

91. The method of claim 90, wherein a temperature sufficient to remove at least part of the residue or layer comprises a temperature of about 22°C.

92. A method of cleaning a residue or layer from a substrate, comprising: providing a substrate having a deleterious residue or layer; providing the cleaning solution of one of claims 17 or 25; applying the cleaning solution to the substrate for a period of time and at a temperature sufficient to remove at least part of the residue or layer.

93. The method of claim 92, wherein a period of time comprises less than about 20 minutes.

94. The method of claim 93, wherein a period of time comprises less than about 15 minutes.

95. The method of claim 92, wherein a temperature sufficient to remove at least part of the residue or layer comprises a temperature less than about 30°C.

96. The method of claim 95, wherein a temperature sufficient to remove at least part of the residue or layer comprises a temperature less than about 25°C.

97. The method of claim 96, wherein a temperature sufficient to remove at least part of the residue or layer comprises a temperature of about 22°C.

98. A substrate etched at least in part by the method of claim 86.

99. A substrate cleaned at least in part by the method of claim 92.

100. A layered component comprising the substrate of claim 98.

101. A layered component comprising the substrate of claim 99.