WO2011146432A2

WO2011146432A2 - Controlled vaporization system and method for surface priming in semiconductor manufacturing

Info

Publication number: WO2011146432A2
Application number: PCT/US2011/036746
Authority: WO
Inventors: Yanan Annie Xia; Isamu Funahashi; Seiji Haraguchi; Raul Ramirez
Original assignee: Entegris, Inc.
Priority date: 2010-05-18
Filing date: 2011-05-17
Publication date: 2011-11-24
Also published as: WO2011146432A3; TW201203317A

Abstract

A method and corresponding system for a contactor used to introduce a chemical solvent to a gas stream are described. The chemical solvent is directed onto a first side of the contactor and the gas stream is directed onto a second side of the contactor. The first side of the contactor is chemical solvent permeable. The chemical solvent diffuses through the first side of the contactor onto the second side and creates a mixture with the gas stream. The mixture may be used to prime substrate surfaces in photolithography applications to enhance transfer of patterns to substrate surfaces. The flow, concentration, and temperature of the gas stream and adhesion parameter may be controlled.

Description

CONTROLLED VAPORIZATION SYSTEM AND METHOD FOR SURFACE PRIMING IN

SEMICONDUCTOR MANUFACTURING

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/345,897 filed May 18, 2010. The entire teachings of the above application are incorporated herein by reference.

BACKGROUND

Photolithography (optical lithography) relates to use of optical exposure to transfer a pattern (e.g., geometric pattern) from a photo mask onto a silicon wafer coated with light- sensitive chemical photoresist. The adhesion of photoresist to the wafer surface has a direct impact on the success of pattern transfer and its performance in subsequent fabrication processes. To enhance photoresist adhesion, a chemical solvent (e.g., hexamethyldisilazane (HMDS)) may be utilized to prime the wafer surface before photoresist is applied.

HMDS priming may be done by spinning liquid HMDS directly onto the silicon wafer. Although this method is effective and relatively simple, since wafers are typically exposed to the atmosphere, they may entrain additional moisture during liquid HMDS priming. This entrained moisture can react with the liquid HMDS and inhibit its adhesion to the wafer surface.

HMDS vapor priming may be used to minimize the presence of moisture in liquid HMDS priming. The HMDS vapor is often applied to the wafer surface in an enclosed chamber.

The HMDS vapor may be generated by bubbling (using a bubbler) a tank of liquid HMDS using a carrier gas (e.g. , typically nitrogen (i. e. , N₂)) and obtaining a mixture of N₂ and HMDS vapor. This mixture of N₂ and HMDS vapor is typically transferred through a long pipe to the point of use. However, using a using a bubbler to generate HMDS vapor is inefficient and poses various drawbacks. For example, a bubbler setup commands a larger footprint and does not provide for efficient control of HMDS vapor concentration. Further, a bubbler setup typically is positioned far away from the point of use, requiring a long piping of N₂ and HMDS vapor mixture to the point of use. During this long transport, the mixture of N₂ and HMDS vapor is more likely exposed to pressure drops and temperature fluctuations that can increase the chance of condensing of the HMDS vapor that causes defects on the wafer. SUMMARY

Certain example embodiments of the present invention relate to a system and a corresponding method for a point-of-use membrane contactor that is used for providing a mixture for priming a surface of a substrate with a chemical solvent prior to applying an optical exposure that transfers a pattern to a substrate surface. The example embodiment employs a synthetic membrane contactor that is chemical solvent permeable. The system includes a chemical solvent source for supplying a chemical solvent to a first side of the membrane contactor. The chemical solvent diffuses through the first side of the membrane contactor to a second side of the membrane contactor. The system further includes a gas supply source for supplying a gas stream to the second side of the membrane contactor and to the diffused chemical solvent. The gas stream and the diffused chemical solvent form a vapor mixture that is used to cover the substrate surface. The system employs a photolithography optical source for applying an optical exposure that transfers a pattern to the substrate surface. The mixture covering the substrate surface enhances transfer of the pattern to the substrate surface.

Another example embodiment of the present invention relates to a photolithography system that includes a vaporizing contactor and a photolithography optical source. The vaporizing contactor includes an inlet for inputting a chemical solvent into a first side of the contactor. The chemical solvent diffuses through the first side to a second side of the contactor. The vaporizing contactor also includes an inlet for inputting a gas stream into the second side of the contactor. The gas stream creates a mixture with the diffused gas. The vaporizing contactor further includes an outlet for outputting the mixture from the second side of the contactor onto a substrate surface. The photolithography optical source applies an optical exposure that transfers a pattern to the substrate surface, the mixture enhancing the transfer of the pattern to the substrate surface.

Yet another example embodiment of the present invention relates to a photolithography system for enhancing transfer of a pattern to a substrate surface. The system includes a vaporizing contactor including an inlet for inputting a chemical solvent into a first side of the contactor and an inlet for inputting a gas stream into the second side of the contactor. The chemical solvent diffuses through the first side to a second side of the contactor and forms a mixture with the gas on the second side. On the second side of the contactor, an outlet outputs the mixture onto the substrate surface. The system also includes a photolithography optical source that applies an optical exposure that transfers the pattern to the substrate surface. The mixture enhances transfer of the pattern to the substrate surface.

Certain embodiments of the present invention relate to a chemical vaporizing system that may be used to change surface energy of a substrate. The system includes a chemical solvent permeable synthetic membrane, a chemical solvent source, a gas supply source, and a

photolithography optical source. The chemical solvent source supplies a chemical solvent to an inlet on a first side of the membrane. The chemical solvent diffuses through the first side of the membrane to a second side of the membrane. The gas supply source supplies a gas stream to an inlet on the second side of the membrane and to the diffused chemical solvent. The gas stream and the diffused chemical solvent form a mixture that is transferred through an outlet on the second side of the membrane onto the substrate surface. The photolithography optical source applies an optical exposure that transfers the pattern to the substrate surface. The mixture on the substrate surface enhances transfer of the pattern to the substrate surface.

The membrane contactor may be a microporous hollow fiber. The chemical solvent may be liquid or vapor hexamethyldisilazane or isopropyl alcohol (IP A). The gas stream may be a stream of nitrogen gas.

A chemical solvent controller may be used to control flow and pressure of the chemical solvent supply to the first side of the membrane. A chemical solvent temperature controller may be used to control a temperature of the chemical solvent supply. A chemical solvent

concentration controller may be used to control concentration of the chemical solvent.

A gas purifier system may be coupled with the gas supply source to purify the supplied gas stream. A gas flow control may be used to control flow and pressure of the gas supply to the second side of the membrane. A gas stream temperature controller may be used to control a temperature of the gas stream.

Example embodiments provide for smaller footprint and low cost of ownership by minimizing chemical waste and eliminating unnecessary components. Additionally, the point-of- use application minimizes process defects and contamination and improves process control for better process stability.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.

FIG. 1 A illustrates a membrane contactor that may be used as a vaporizer.

FIG. IB illustrates an example embodiment of the present invention.

FIG. 2 is an example embodiment of the present invention for a point-of-use vaporizer.

FIG. 3A is an illustration of an embodiment of the present invention.

FIG. 3B is an illustration of a point-of-use membrane contactor according to example embodiments of the present invention.

FIG. 3C includes plots that illustrate the relationship between the chemical solvent flow rate (HMDS) and the flow rate of the gas stream (N₂).

FIG. 3D includes plots that illustrate the correlation between the chemical solvent (HMDS) vaporization efficiency and gas stream flow (N₂).

FIG. 4 is an illustration of an example embodiment of the present invention.

FIG. 5 schematically depicts a lithographic projection apparatus.

FIG. 6 illustrates a projection system and a radiation system that may be used in the lithographic projection apparatus of FIG. 1.

FIG. 7 illustrates an embodiment of a gas supply system.

DETAILED DESCRIPTION

The present invention is not limited to the particular molecules, compositions, methodologies or protocols described, as these may vary. The terminology used in the description is for the purpose of describing particular versions or embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.

Example embodiments of the present invention provide both a system and a method for adding chemical solvent to a gas stream and using the mixture of the gas and chemical solvent to aid in depositing a photolithographic pattern on a substrate coated with photoresist. Although the present embodiments are directed to the use of the mixture in semiconductor manufacturing such as photolithography, their use is not limited to such systems. Certain example embodiments of the present invention relate to a chemical vaporizing system for use, for example, in priming a substrate prior to photolithographic treatment of the surface. In certain embodiments, a chemical vaporizing system may be used to change surface energy of a substrate. Vaporizing systems are used for adding a vapor (e.g. , chemical vapor solvent) to a gas stream to form a gas mixture. The vapor forms a non-contaminating vapor in the gas stream and the mixture is used to reduce or eliminate contamination optical components in lithographic projection systems, maintain the chemical activity of a coating on a substrate, promote adhesion of the photoresist during processing (e.g. , an adhesion promoter) and enhance photolithographic transfer of a pattern to a substrate surface. Light exposure in photolithography is used to remove parts of a substrate and transfer a pattern from a photo mask to a light sensitive chemical (i. e. , photoresist) to the substrate. Certain chemical treatment is then used to engrave the pattern into the substrate under the photoresist.

Example embodiments of the present invention relate to a chemical vaporizing system for enhancing transfer of a pattern to a substrate surface. The system includes a chemical solvent permeable synthetic membrane, a chemical solvent source that supplies a chemical solvent to an inlet on a first side of the membrane, and a gas supply source that supplies a gas stream to an inlet on a second side of the membrane. The chemical solvent diffuses through the first side of the membrane to the second side of the membrane and forms a vapor mixture with the gas stream. The gas stream is transferred through an outlet on the second side of the membrane onto the substrate surface. The system also includes a photolithography optical source that applies an optical exposure that transfers the pattern to the substrate surface. The mixture on the substrate surface enhances the transfer of the pattern to the substrate surface.

The term "chemical solvent," as used herein, may refer to a chemical solvent in liquid or vapor (gas) forms. The chemical solvent travels through the membrane in the vapor form, such that on the lumen side of the membrane, the chemical solvent can only be in the vapor (gas) form.

The membrane is a chemical solvent permeable synthetic membrane (e.g. , a membrane contactor) that includes a first side (i.e. , shell side) and a second side (i.e. , lumen side). Due to its chemical solvent permeability, the membrane allows for chemical solvents to diffuse through the first side and enter the second side of the membrane. In certain embodiments, the first side of the membrane includes an inlet that is connected to a chemical solvent source to receive a chemical solvent supply, which is diffused to the second side of the membrane. The second side of the membrane includes an inlet and an outlet. The inlet may be connected to a gas supply source to receive a gas stream. The gas stream and the diffused chemical solvent form a mixture that is transferred out of the second side of the membrane through the outlet.

In certain embodiments, the membrane contactor may include a housing and one or more microporous hollow fiber membranes. In such embodiments, the housing has an inlet and a corresponding outlet on a first side of the hollow fibers for inputting and outputting a vapor or liquid (e.g., chemical solvent vapor). The housing further includes an inlet and a corresponding outlet on a second side of the hollow fibers for inputting a gas stream and outputting the gas stream or a gas mixture. The microporous hollow fiber membranes should contribute less that one part per billion of contaminants that degrade the optical properties of optical components in a lithographic projection system. The membrane may be cleaned or treated to reduce or remove such contaminants.

Any chemical solvent suitable for use in semiconductor manufacturing such as for photolithographic applications may be used with the present invention. In a preferred

embodiment the chemical solvent can be a lower surface tension liquid, such as a surfactant for producing lower surface tension on a surface to which it is applied. In a particularly preferred embodiment, the chemical solvent may is liquid or gas hexamethyldisilazane (HMDS). The HMDS is used as a preferred chemical solvent since it is often used in photolithography as an adhesion promoter for priming a substrate to enhance bonding of photoresist to the substrate surface. Other examples of chemical solvents include N-methyl-2-pyrrolidone (NMP), Isopropyl alcohol (IP A), Ethyl lactate, Cyclohexanol, Propylene glycol monomethyl ether acetate

(PGMEA), Propylene glycol monomethyl ether (PGME), or Acetone.

Any gas stream suitable to serve as a carrier gas stream for a chemical solvent vapor in photolithographic applications may be used with the present invention. In a particularly preferred embodiment, the gas stream may be nitrogen (N₂) gas. The gas may be pretreated or pre-processed prior to use such as by purifying and/or humidifying to specifications suitable for its intended use (e.g., purifying the gas stream may be suitable for certain photolithography applications).

The gas source may include an inlet in fluid communication with one or more regenerable purifiers and a purge gas outlet from the purifiers in fluid communication with a purge gas inlet of a vaporizer. The purifiers can be independently regenerable and remove contaminants from the source gas inlet to the purifiers to form a purge gas. The present invention employs a point-of-use contactor (i.e., used at the location of a substrate being used in a photolithography process) to apply the gas-chemical solvent vapor mixture to the wafer, thereby eliminating the need for long transfer line for transferring the gas- chemical solvent mixture to the surface. Additionally, since the membrane contactor uses permeation of the chemical solvent to supply the gas with the chemical solvent, it provides for smaller footprint and low cost of ownership by minimizing chemical waste and eliminating unnecessary components. Moreover, the point-of-use application minimizes process defects and contamination and improves process control for better process stability.

Certain other embodiments of the present invention relate to a chemical vaporizing method for enhancing transfer of a pattern to a substrate surface. The example embodiments relate to methods for supplying a chemical solvent to an inlet on a first side of a synthetic membrane and supplying a gas stream to an inlet on the second side of the membrane. The chemical solvent diffuses through the first side of the membrane to a second side of the membrane, forming a mixture with the gas stream on the second side. The gas mixture is transferred through an outlet on the second side of the membrane onto the substrate surface. The example embodiment applies an optical exposure that transfers the pattern to the substrate surface. The mixture on the substrate surface enhances transfer of the pattern to the substrate surface.

The optical exposure transfers the pattern to the substrate surface. The gas mixture covering the substrate is used to reduce or eliminate contamination optical components in lithographic projection systems, maintain the chemical activity of a coating on a substrate, and enhance photolithographic transfer of a pattern to a substrate surface.

Certain example embodiments of the present invention relate to a photolithography system for enhancing transfer of a pattern to a substrate surface. The example embodiments include a vaporizing contactor and a photolithography optical source. The vaporizing contactor includes an inlet for inputting a chemical solvent into a first side of the contactor and an inlet for inputting a gas stream into the second side of the contactor. The chemical solvent diffuses through the first side to a second side of the contactor and forms a mixture with the gas stream.

An outlet on the second side of the contactor outputs the mixture from the second side of the contactor onto the substrate surface. The photolithography optical source applies an optical exposure that transfers the pattern to the substrate surface. The mixture enhances transfer of the pattern to the substrate surface. The term "membrane contactor" is used herein to generally refer to devices having hollow fiber membranes that are suitable for use as vaporizers of a chemical solvent. In the present invention, membrane contactors are used as vaporizers that add a vapor from a chemical solvent to a purge gas flow with reduced or less than about 1 part per trillion added contaminants. Membrane contactors that have been used for humidification have been described in U. S. Patent Nos. 6,149, 817, 6,235,641, 6,309, 550, 6,402,818, 6,474,628, 6,616,841, 6,669,177, 6,702,941, 6,842,998, and PCT applications PCT/US2004/023490 and PCT/US2007/007901, the contents of which are incorporated herein by reference. Similar configurations can be used in the present application.

The term "transferring a pattern," as used herein, refers to endowing an incoming radiation beam with a patterned cross-section corresponding to a pattern that is to be created in a target portion of a substrate. The term "light valve" may also be used in this context. Generally, the pattern will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit or other device (see below). An example of such a patterning device is a mask. The concept of a mask is well known in lithography, and it includes mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. Placement of such a mask in the radiation beam causes selective transmission (in the case of a transmissive mask) or reflection (in the case of a reflective mask) of the radiation impinging on the mask, according to the pattern on the mask. In the case of a mask, the support structure will generally be a mask table, which ensures that the mask can be held at a desired position in the incoming radiation beam, and that it can be moved relative to the beam if so desired.

Another example of a patterning device is a programmable mirror array. One example of such an array is a matrix-addressable surface having a viscoelastic control layer and a reflective surface. The basic principle behind such an apparatus is that, for example, addressed areas of the reflective surface reflect incident light as diffracted light, whereas unaddressed areas reflect incident light as undiffracted light. Using an appropriate filter, the undiffracted light can be filtered out of the reflected beam, leaving only the diffracted light behind. In this manner, the beam becomes patterned according to the addressing pattern of the matrix-addressable surface. An alternative embodiment of a programmable mirror array employs a matrix arrangement of tiny mirrors, each of which can be individually tilted about an axis by applying a suitable localized electric field, or by employing piezoelectric actuators. Once again, the mirrors are matrix-addressable, such that addressed mirrors will reflect an incoming radiation beam in a different direction to unaddressed mirrors. In this manner, the reflected beam is patterned according to the addressing pattern of the matrix-addressable mirrors. The required matrix addressing can be performed using suitable electronics. In both of the situations described hereabove, the patterning device can comprise one or more programmable mirror arrays. More information on mirror arrays as here referred to can be seen, for example, from United States Patents 5,296,891 and 5,523,193, and PCT publications WO 98/38597 and WO 98/33096. In the case of a programmable mirror array, the support structure may be embodied as a frame or table, for example, which may be fixed or movable as required.

Another example of a patterning device is a programmable LCD array. An example of such a construction is given in U. S. Patent 5,229,872. As above, the support structure in this case may be embodied as a frame or table, for example, which may be fixed or movable as required.

The terms "radiation" and "beam" are intended to encompass all types of electromagnetic radiation used to pattern a resist on a substrate. These can include X-rays, ultraviolet (UV) radiation (e.g., with a wavelength of 365 nm, 248 nm, 193 nm, 157 ran, or 126 nm) and extreme ultra-violet (EUV) radiation (e.g., having a wavelength in the range 5-20 nm), as well as particle beams, such as ion beams or electron beams.

Certain embodiments of the invention may include an additional step for measuring a concentration ratio of the gas-chemical solvent vapor. For example, in certain embodiments, a sensor may be used to determine the mass flow rate of the gas through the gas supply source.

Alternatively or additionally, certain embodiments of the invention may measure the pressure of the chemical solvent in the membrane contactor.

Certain embodiments of the present invention include an additional step for controlling and/or adjusting a concentration ratio of gas to chemical solvent in the gas-chemical solvent mixture to a predetermined ratio. For example, some embodiments of the invention may adjust and/or control the concentration ratio of gas to chemical solvent in the gas-chemical solvent mixture by adjusting/controlling the mass flow rate of the gas through the gas supply source. Alternatively or additionally, certain embodiments of the invention may adjust/control the pressure and/or the flow of the chemical solvent prior to or at the point where the solvent enters the membrane contactor. In some embodiments, the pressure and/or the flow of the chemical solvent when the chemical solvent is in the membrane contactor may be adjusted and/or controlled. These features will be further describes below with regard to the Figures. FIG. 1 A illustrates a membrane contactor that may be used as a vaporizer. A gas stream 1 enters the vaporizer 2 through the fiber lumens 3 at connection 10, traverses the interior of the vaporizer 2 while in the lumens 3, where it is separated from a chemical solvent vapor 4 by the membrane contactor 2, and exits the membrane contactor 2 through the fiber lumens at connection 40. Chemical solvent vapors 4 enters the housing through connection 30 and substantially fills the space between the inner wall of the housing and the outer diameters of the fibers (i.e., membrane contactor shell), and exits through the connector 20.

Example embodiments of the present invention employ a membrane contactor 2 that is permeable to chemical solvent vapors. The chemical solvent vapors enter the housing through the shell side and diffuse through the membrane into membrane lumen. The resulting mixture exits the membrane contactor 2 through the fiber lumens at connection 40.

Preferred vaporizers for use in the invention include a first region containing a purge gas flow and a second region containing a chemical solvent, where the first and second regions are separated by a gas-permeable membrane that is substantially resistant to liquid intrusion.

The membranes can be a sheet, which can be folded or pleated, or can be joined at opposite sides to form a hollow fiber. It is only essential that the membrane, in combination with any sealants or adhesives used to join the membrane to a housing, prevents liquid from intruding into the gas under normal operating conditions (e.g., pressures of 30 psig or less). The membrane is preferably configured to maximize the surface area of the membrane contacting the gas and the chemical solvent and minimize the volume of the membrane. A vaporizer can contain more than one membrane per device, as described below.

Vaporizers having hollow fiber membranes typically include:

a) a bundle of a plurality of gas-permeable hollow fiber membranes having a first end and a second end, where the membranes have an outer surface and an inner surface, with the inner surface encompassing one of the first and second regions; b) each end of the bundle potted with a liquid tight seal forming an end structure with a surrounding housing where the fiber ends are open to fluid flow;

c) the housing having an inner wall and an outer wall, where the inner wall defines the other of the first and second regions between the inner wall and the hollow fiber membranes;

d) the housing having a purge gas inlet connected to the gas source and a purge gas mixture outlet; and e) the housing having a chemical solvent inlet connected to the chemical solvent source and a chemical solvent outlet, wherein either the gas inlet is connected to the first end of the bundle and the gas mixture outlet is connected to the second end of the bundle or the chemical solvent inlet is connected to the first end of the bundle and the chemical solvent outlet is connected to the second end of the bundle.

The hollow fiber membranes used in the versions of the vaporizer of the invention are typically one of the following: a) hollow fiber membranes having a porous skinned inner surface, a porous outer surface and a porous support structure between; b) hollow fiber membranes having a non-porous skinned inner surface, a porous outer surface and a porous support structure between; c) hollow fiber membranes having a porous skinned outer surface, a porous inner surface and a porous support structure between; or d) hollow fiber membranes having a non- porous skinned outer surface, a porous inner surface and a porous support structure between. These hollow fiber membranes can have an outer diameter of about 350 microns to about 1450 microns.

When these hollow fiber membranes are hollow fiber membranes having a porous skinned inner surface, a porous outer surface and a porous support structure between or hollow fiber membranes having a porous skinned outer surface, a porous inner surface and a porous support structure between, the porous skinned surface pores are preferably from about 0.001 microns to about 0.005 microns in diameter or their largest aspect. The pores in the skinned surface preferably face the liquid flow.

Suitable materials for the membranes include polyether ether ketone (PEEK),

polyethylene, polytetrafluoroethylene (PTFE), polypropylene, polysulfone, perfluoroalkoxy (PFA), and other thermoplastic polymers, or perfluorinated polymers. PEEK is particularly preferred for use with HMDS and having a polyethylene (PE) housing. Non-wettable polymers, such as the perfluorinated polymers, are particularly preferred, especially polymers that are suitable for use with high pressure fluids and are substantially free of inorganic oxides (e.g., SO_x and NO_x, where x is an integer from 1-3). Suitable materials for hollow fiber membranes need to be thermally compatible with the materials used for the housing. Factors such as porosity, surface energy, wettability and hydrophobicity may also be considered in selecting the materials for the hollow fibers. Certain embodiments may apply surface treatments to the hollow membranes to allow compatibility with the chemical solvent being used. Such materials include perfluorinated thermoplastic polymers such as poly (tetrafluoroethylene-co- perfluoro

(alkylvinylether)) (poly (PTFE-CO-PFVAE) ), poly (tetrafluoroethylene-co- hexafluoropropylene) (FEP) or a blend thereof, because these polymers are not adversely affected by severe conditions of use. PFA Teflon® is an example of a poly (PTFE-CO-PFVAE) in which the alkyl is primarily or completely the propyl group. FEP Teflon® is an example of poly (FEP). Both are manufactured by DuPont. Neoflon™ PFA (Daikin Industries) is a polymer similar to DuPont's PFA Teflon®. A poly (PTFE-CO-PFVAE) in which the alkyl group is primarily methyl is described in U. S. Patent No. 5,463, 006, the contents of which are incorporated herein by reference. A preferred polymer is Hyflon® poly (PTFE-CO-PFVAE) 620, obtainable from Ausimont USA, Inc., Thorofare, N. J. Methods of forming these polymers into hollow fiber membranes are disclosed in U. S. Patent Nos. 6,582,496 and 4,902,456, the contents of which are incorporated herein by reference.

Potting is a process of forming a tube sheet having liquid tight seals around each fiber. The tube sheet or pot separates the interior of the vaporizer from the environment. The pot is thermally bonded to the housing vessel to produce a unitary end structure. A unitary end structure is obtained when the fibers and the pot are bonded to the housing to form a single entity consisting solely of thermoplastic materials (e.g., perfluorinated thermoplastic materials). The unitary end structure comprises the portion of the fiber bundle which is encompassed in a potted end, the pot and the end portion of the thermoplastic housing, the inner surface of which is congruent with the pot and bonded to it. By forming a unitary structure, a more robust vaporizer is produced, less likely to leak or otherwise fail at the interface of the pot and the housing.

Moreover, forming a unitary end structure avoids the need to use adhesives such as epoxy to bond the fibers in place. Such adhesives typically include volatile hydrocarbons, which contaminate the purge gas flowing through the vaporizer. For example, purge gas humidified using a Liqui-cel moisturizer marketed by Perma Pure noticeably smelled of epoxy, which clearly indicates an unacceptable hydrocarbon content in the purge gas, likely in the hundreds of ppm. The potting and bonding process is an adaptation of the method described in U. S. Application No. 60/1 17,853 filed Jan. 29, 1999 and is disclosed in U. S. Patent No. 6, 582,496, and

PCT/US2000/002378, the teachings of which are incorporated by reference. The bundles of hollow fiber membranes are preferably prepared such that the first and second ends of the bundle are potted with a liquid tight thermoplastic seal (e.g., perfiuoronated sealing) forming a single unitary end structure comprising both the first and second ends with a surrounding thermoplastic housing (e.g., perfluoronated housing) where the fibers of the ends are separately open to fluid flow. In some embodiments, unsaturated polyester (UPE) potting may be used for potting UPE fibers.

The housing or the membrane contactor shell can be made of any material that is compatible with the chemical solvent, the intended use, and the hollow fiber membranes. For example, the housing can be stainless steel, polyethylene, polypropylene, PFA, PTFE, or same materials as fibers described above.

FIG. IB illustrates an example embodiment of the present invention. The example embodiment relates to a point-of-use membrane contactor 2 that utilizes fluoropolymer-based hollow fiber membranes to introduce a chemical solvent vapor (e.g., HMDS vapor) into a gas stream (e.g., N₂ gas stream). The chemical solvent vapor 430 is supplied by a chemical solvent source 435. The flow, temperature, concentration, and/or pressure of the chemical solvent 430 may be controlled by a controller 450. A gas supply source 100 also supplies a gas stream to the membrane contactor 2. The flow, temperature, concentration, and/or pressure of the gas stream may be controlled by a controller 460. The chemical solvent vapor 430 flows in the shell side 2A of the membrane through an inlet 101 and the gas stream flows on the lumen side 2B of the membrane contactor 2 through an inlet 102. The chemical solvent vapor diffuses through the membranes into the carrier gas. The carrier gas carries the chemical solvent vapor, resulting in a carrier gas-vapor mixture that may be deposited on a substrate to enhance transfer of a photolithographic pattern on a substrate coated with photoresist. The gas-chemical solvent mixture 505 may be transferred to the substrate via an inlet 103 through a gas-chemical solvent mixture line. By providing gas-chemical solvent mixture at the point-of-use, embodiments of the present invention minimize process defect and contamination and improve process control for better process stability.

FIG. 2 is an example embodiment of the present invention for a point-of-use contactor 2

(shown in FIGs. 1 A- IB) that is coupled with the gas supply system 100 (described below with relation to FIG. 7) and serves as a vaporizer system for the supplied gas 128. Embodiments of the present invention may use point-of-use contactor 2 to introduce a chemical solvent vapor into the gas supplied by the gas supply system. The point-of-use contactor 2 may be coupled one or more of the gas outlets 130, 131 , 132. The contactor 2 may utilize fluoropolymer-based hollow fiber membranes to introduce the chemical solvent vapor into the gas stream 420. The vapor may be a chemical solvent 430 (supplied by supply source 435) such as liquid or gas hexamethyldisilazane (HMDS). Other possible chemical solvents 430 include N-methyl- 2-pyrrolidone (NMP), Isopropyl alcohol (IP A), Ethyl lactate, Cyclohexanol, Propylene glycol monomethyl ether acetate (PGMEA), Propylene glycol monomethyl ether (PGME), or Acetone.

The membrane contactor 2 is in fluid communication with the gas supply source 100 and the chemical solvent supply source 435. The gas supply source 100 supplies a predetermined amount of gas (such as N₂) to the lumen side 2B of the membrane contactor 2 and the housing 512. Similarly, the chemical solvent source 435 provides the chemical solvent to the shell side 2A of the membrane contactor 2 and the housing 512. As explained with reference to FIG. 1 A, since the shell side of the contactor 2A is chemical solvent permeable, the chemical solvent diffuses through the contactor 2 onto the gas stream resulting in creating a chemical solvent vapor-gas mixture.

The membrane contactor 2 is also in fluid communication with the chemical solvent-gas mixture line 505 on the other end of membrane contactor 2. Chemical solvent-gas mixture line 505 is used to transport the chemical solvent-gas mixture which is formed in membrane contactor 2 for use in priming a substrate surface in photolithographic applications.

Thermal sensing and control devices (generally shown as chemical solvent controller 450 and gas controller 460) may further be used to maintain a stable temperature of the chemical solvent-gas mixture. Specifically, since the chemical solvent is added to a gas stream, properties of the chemical solvent-gas mixture, such as the concentration or purity of the chemical solvent, may be accurately controlled. For example, accuracy of the concentration of chemical solvent in the gas stream may be achieved by controlling the temperature of the gas stream (generally shown as heated or unheated gas stream 470), chemical solvent, or combination of these to about ± 1°C or less. The concentration of the chemical solvent in the gas stream may be controlled by maintaining the pressure between the gas and chemical solvent such that the gas does not intrude into the chemical solvent and the chemical solvent concentration in the gas is constant to within about 5% or less. The concentration of chemical solvent in the gas stream may be maintained by controlling the temperature, pressure, gas flow rate or any combination of these so that the concentration of the chemical solvent in the gas is essentially constant, for example the chemical solvent concentration in the gas mixture varies by about 5% or less, in some versions it varies by 1% or less, and in still other versions the concentration of the vapor in the purge gas mixture less than about 0.5% during the time over which the chemical solvent-gas mixture is made. The concentration of chemical solvent 430 in the mixture can be controlled by controlling the flow rate of the gas into the vaporizer (gas flow controller 460), the flow rate of a diluent gas mixed with the gas mixture, or any combination of these to achieve a chemical solvent concentration that varies by 5% or less.

The output from a chemical solvent concentration sensor may be used with a controller

450 in a control loop to adjust the gas or chemical solvent pressure, to adjust the temperature of the chemical solvent or gas, to adjust the amount of a dilution gas added to the gas mixture, or any combination of these to achieve an amount of chemical solvent in the gas to form a gas mixture that provides a chemical solvent concentration that varies by less than 5% in some versions of the invention, by less than 1% in some versions, and in still other versions by less than 0.5%.

It can be advantageous to maintain the temperature of the gas or gas mixture to a temperature range within the photolithographic process tolerances to minimize thermal expansion or contraction of optical elements in the projection apparatus and to reduce changes in refractive index. It can be advantageous to maintain the concentration of chemical solvent in a gas mixture within these ranges to minimize changes in refractive index and the outcome of interferometric measurements.

The relative amount of chemical solvent in the gas mixture can be controlled in different ways. For example, the amount of gas without chemical solvent 430 brought into the contactor 2 relative to the amount of gas with chemical solvent 430 may be controlled. The controlled parameters may be one or more of the inside temperature, flow, pressure, residence time of the gas in the chemical solvent.

Temperature is known to have an effect on the saturation amount of a chemical solvent. To control the temperature, the contactor 2 may be provided with a heating element (not shown) which is controlled by a control device, or controller, in response to a temperature signal representing a temperature inside the contactor provided by a temperature measuring device.

The rate at which the chemical solvent permeates through the contactor increases when the chemical solvent may be increased as a function of pressure. This permeation rate may also increase as a result of the chemical solvent having the chemical property of a lower surface tension. As gas is flowed through the lumen side 2B of the contactor 2, this permeated chemical solvent vapor is mixed in the gas stream, forming a gas-chemical solvent mixture. Permeation may occur as long as there is a concentration differential between the chemical solvent and the gas and the gas is not saturated. The gas-chemical solvent mixture only carries chemical solvent vapors in the gas stream. There are no liquid molecules in the gas- chemical solvent mixture.

FIG. 3 A is an example embodiment of a system that supplies a chemical solvent-gas mixture to a substrate 650 according to example embodiments of the present invention. The system includes a membrane contactor 2, a substrate (e.g., wafer) 650, concentration sensor 670, temperature controller (heater) 680, gas mass flow controller 690, liquid pressure regulator 695, and liquid flow meter 699.

As explained above, a gas stream is supplied to the membrane contactor 2 by gas supply source 100 that may have variable pressures. The gas supply may be directed through a temperature controller 680 and the mass flow controller 690. The temperature controller 680 may heat or cool the gas to control its temperature. Since the gas reservoir supplies the gas at variable pressure, the gas mass flow controller 690 may be used to provide a steady flow of the gas to the membrane contactor 2. The gas mass flow controller 690 may be coupled to a properly programmed processor (not shown), which in turn may be coupled to a concentration sensor 670, to control the concentration ratio of the gas.

The chemical solvent supply source 435 supplies a chemical solvent (e.g. , liquid or gas HMDS) to the membrane contactor 2. The chemical solvent liquid supply 435 may be coupled with a liquid pressure regulator 695 and a liquid flow meter 699. The liquid pressure regulator 695 and liquid flow meter 699 control the liquid mass flow rate into membrane contactor 2. The regulator 695 and meter 699 may be coupled to a properly programmed processor (not shown) coupled to the concentration sensor 670. The concentration sensor 670 facilitates control of the chemical solvent mass flow rate into membrane contactor 2 and controls the liquid pressure within the membrane contactor 2.

The chemical solvent diffuses into the lumen side 2B of the contactor 2 while the gas is passing through the lumen side. The chemical solvent is carried by the gas, forming a gas- chemical solvent mixture. This mixture vapor is applied to the substrate or wafer 650 to enhance transfer of a pattern to the substrate surface.

A concentration sensor 670 may be used to measure the concentration levels of the gas and the chemical solvent in the mixture. The concentration sensor 670 may be electrically coupled to a properly programmed processor (not shown), which in turn may be coupled to either a gas mass flow controller 690 or a pressure regulator 695 and a flow meter 699. The programmed processor analyzes this data to determine if it matches variables entered by an operator that determine a desired concentration ratio of the gas and chemical solvent in the mixture. If the concentration sensor data does not match the predetermined concentration ratio data, the processor communicates with and adjusts either the gas mass flow controller 690 or the liquid pressure regulator 695 accordingly.

FIG. 3 B is an illustration of a point-of-use membrane contactor 2 according to example embodiments of the present invention. As explained above, a gas stream 420 and a chemical solvent 430 are introduced to respective inlets of a membrane contactor 2 and a chemical solvent- gas mixture 505 is transferred from an outlet on the lumen side of the membrane connector onto a substrate 650 (e.g. , wafer) surface. A hotplate 660 may be used to heat the substrate 650 for transferring a pattern to the substrate 650. The point-of-use nature of the membrane contactor 2 reduces process contamination and removes need for large transfer pipes for transferring the mixture to the substrate surface.

FIG. 3C includes plots that illustrate the relationship between the chemical solvent evaporation rate (1/min/m ) and the flow rate of the gas stream (1/min/m ), normalized over membrane area. The chemical solvent used in the example shown in FIG. 3C is HMDS, the gas stream is nitrogen, and a PEEK hollow fiber membrane is used that is compatible with liquid HMDS and allows good permeation of the HMDS vapor.

Data points labeled with hollow circles represent HMDS flowing through a membrane area of 0.14 square feet. Data points labeled with solid circles represent HMDS flowing through a membrane area of 0.035 square feet, and data points labeled with plus signs represent HMDS flowing through a membrane area of 0.14 square feet. As shown in FIG. 3C, at a fixed membrane area, the chemical solvent level increases as the gas stream flow rate decreases (see data points labeled P-2 and CF-3). At a given stream gas flow, the chemical solvent saturation level increases as membrane area increases.

The numbers appearing adjacent to each data point (i.e., hollow circles, solid circles, and plus signs) represent the measured HMDS vapor concentration percentage corresponding to specific gas (horizontal axis) and chemical solvent (vertical axis) flow rates. For example, for a specific device, having approximately 0.14 square feet membrane area, when the gas flow is 400 liter per minute per square meter (1/min/m²) and the chemical solvent flow is 4 liter per minute per square meter, the measured concentration of the chemical solvent vapor in the outlet is about 40 percent. The data point labeled with a plus sign and the term "P-2" is an outlier due to experimental error. FIG. 3D includes plots that illustrate the correlation between the chemical solvent vaporization efficiency (as % HMDS saturation) and gas stream flow (1/min/m²). The chemical solvent used in the example shown in FIG. 3D is HMDS, the gas stream is nitrogen, and a particular surface treated PEEK hollow fiber membrane is used. The plots shown in FIG. 3D illustrate the level of HMDS vapor saturation as a function of nitrogen flow normalized per membrane area.

As noted with respect to FIG. 3C, the chemical solvent vapor saturation level is shown to increase as membrane area increases. Since the rate limiting step is the vaporization of HMDS through the membrane, the plot shown in FIG. 3D may be used in determining the appropriate size of the membrane area for applications in which target chemical solvent saturation level and gas stream flow rates are known. To obtain the plots shown in FIG. 3D, vaporizers with various membrane surface areas were made. The vaporizers were used in various testing conditions to measure percentage of HMDS vapor (denoted by "Y") at various nitrogen flow rates (denoted by "X). The following relationship, relating the percentage of HMDS vapor (Y) to nitrogen flow rate (X), may be obtained:

ln(Y) = -0.445 * ln(X) + 6.41

For example, using the above formulation, to reach 90 percent HMDS vapor

concentration, the nitrogen flow, normalized over the surface area, is about 72 1/min/m².

FIG. 4 is a high-level example embodiment of the present invention. The example embodiment includes a membrane contactor 2 that is arranged to be chemical solvent permeable. The example embodiment 600 further includes a adhesive promoter supply source 435 for supplying a chemical solvent 430 to a first side of the membrane 2 A. The chemical solvent 430 diffuses through the first side of the membrane 2 A to a second side of the membrane 2B. The example embodiment 600 further includes a gas supply source 100 that supplies a gas stream 420 to the second side 2B of the membrane and to the diffused chemical solvent. The gas stream 420 and the diffused chemical solvent form a gas-chemical solvent mixture 505 that is used to cover a substrate surface 510. The example embodiment further includes a photolithography optical source 520 that applies an optical exposure 530 that transfers a pattern to the substrate surface 510. The gas-chemical solvent mixture 505 covering the substrate surface 510 enhances transfer of the pattern to the substrate surface 510.

FIG. 5 schematically depicts a lithographic projection apparatus 1 that may be used with example embodiments of the present invention. The apparatus 1 includes a base plate BP and a gas supply system 100. The apparatus 1 may also include a radiation source LA (e.g. , EITV radiation). A first object (mask) table MT is provided with a mask holder configured to hold a mask MA (e.g., a reticle), and is connected to a first positioning device PM that accurately positions the mask with respect to a projection system or lens PL. A second object (substrate) table WT is provided with a substrate holder configured to hold a substrate W (e.g. , a resist- coated silicon wafer), and is connected to a second positioning device PW that accurately positions the substrate with respect to the projection system PL. The projection system or lens PL (e. g. , a mirror group) is configured to image an irradiated portion of the mask MA onto a target portion C of the substrate W. The target portion C may comprise of one or more dies.

The apparatus 1 is of a reflective type and includes a reflective mask (mask MA).

However, in general, the apparatus 1 may also be of a transmissive type and include a transmissive mask. Alternatively, the apparatus may employ another kind of patterning device, such as a programmable mirror array. The radiation source LA (e.g. , a discharge or laser- produced plasma source) produces radiation. This radiation is fed into an illumination system (illuminator) IL, either directly or after having traversed a conditioning device (e.g. , a beam expander EX). The illuminator IL may include an adjusting device AM that sets the outer and/or inner radial extent (commonly referred to as s-outer and s-inner, respectively) of the intensity distribution in the beam. In addition, it may generally comprise various other components, such as an integrator IN and a condenser CO. In this way, the beam PB impinging on the mask MA has a desired uniformity and intensity distribution in its cross-section.

The source LA may be within the housing of the lithographic projection apparatus, as is often the case when the source LA is a mercury lamp, but that it may also be remote from the lithographic projection apparatus. The radiation which it produces is led into the apparatus. This latter scenario is often the case when the source LA is an excimer laser.

The beam PB subsequently intercepts the mask MA, which is held on a mask table MT.

Having traversed the mask MA, the beam PB passes through the lens PL, which focuses the beam PB onto a target portion C of the substrate W. With the aid of the second positioning device PW and interferometer IF, the substrate table WT can be moved accurately (e.g. , so as to position different target portions C in the path of the beam PB). Similarly, the first positioning device PM can be used to accurately position the mask MA with respect to the path of the beam PB (e.g. , after mechanical retrieval of the mask MA from a mask library, or during a scan). In general, movement of the object tables MT, WT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning). However, in the case of a wafer stepper (as opposed to a step and scan apparatus) the mask table MT may just be connected to a short stroke actuator, or may be fixed. The mask MA and the substrate W may be aligned using mask alignment marks Ml and M2 and substrate alignment marks PI and P2.

The depicted apparatus can be used in two different modes: First, in step mode, the mask table MT is kept essentially stationary, and an entire mask image is projected at once (i.e., a single "flash" onto a target portion C). The substrate table WT is then shifted in the X and/or Y directions so that a different target portion C can be irradiated by the beam PB. Second, in scan mode, the same scenario applies, except that a given target portion C is not exposed in a single "flash." Instead, the mask table MT is movable in a given direction (the so-called "scan direction," e.g. , the Y direction) with a speed v, so that the beam of radiation PB is caused to scan over a mask image. Concurrently, the substrate table WT is simultaneously moved in the same or opposite direction at a speed, V = Mv, in which M is the magnification of the lens PL (typically, M = 1/4 or 1/5). In this manner, a relatively large target portion C can be exposed, without having to compromise on resolution.

FIG. 6 illustrates a projection system (PL) and a radiation system 2 that may be used in the lithographic projection apparatus 1 of FIG. 5. The radiation system 2 includes an

illumination optics unit 4. The radiation system 2 may also comprise a source-collector module or radiation unit 3. The radiation unit 3 is provided with a radiation source LA that can be formed by a discharge plasma. The radiation source LA may employ a gas or vapor, such as Xenon (Xe) gas or Lithium (Li) vapor in which a very hot plasma may be created to emit radiation in the EUV range of the electromagnetic spectrum. The very hot plasma is created by causing a partially ionized plasma of an electrical discharge to collapse onto the optical axis 0. Partial pressures of 0.1 mbar of Xe, Li vapor, or any other suitable gas or vapor may be required for efficient generation of the radiation. The radiation emitted by radiation source LA is passed from the source chamber 7 into collector chamber 8 via a gas barrier structure or "foil trap" 9. The gas barrier structure 9 includes a channel structure such as, for instance, described in detail in U.S. Patent No. 6,862,075 and U.S. Patent No. 6,359,969.

The collector chamber 8 comprises a radiation collector 10, which can be a grazing incidence collector. Radiation passed by collector 10 is reflected off a grating spectral filter 11 to be focused in a virtual source point 12 at an aperture in the collector chamber 8. From chamber 8, the projection beam 16 is reflected in illumination optics unit 4 via normal incidence reflectors 13 and 14 onto a reticle or mask positioned on reticle or mask table MT. A patterned beam 17 is formed, which is imaged in projection system PL via reflective elements 18 and 19 onto a wafer stage or substrate table WT. More elements than shown may generally be present in illumination optics unit 4 and projection system PL.

The lithographic projection apparatus 1 includes a gas supply system 100. Gas supply outlets 130-133 of the gas supply system 100 are positioned in the projection system PL and the illumination optics unit 4 near the reflectors 13 and 14 and the reflective elements 18 and 19. However, if so desired, other parts of the apparatus may likewise be provided with a gas supply system. For example, a reticle and one or more sensors of the lithographic projection apparatus may be provided with a purge gas supply system.

The gas supply system 100 may be positioned inside the lithographic projection apparatus 1. The gas supply system 100 may be controlled in any manner suitable for the specific implementation using any device outside the apparatus 1. However, it is likewise possible to position at least some parts of the gas supply system 100 outside the lithographic projection apparatus 1 (the gas mixture generator 120).

FIG. 7 illustrates an embodiment of a gas supply system 100. A gas inlet 1 10 is connected to a gas supply apparatus (not shown) that supplies a dry gas that is substantially without moisture. For example, a pressurized gas supply circuit, a cylinder with compressed dry air (e.g., nitrogen (N₂), helium or other gas) may be used. The dry gas is fed through the gas mixture generator 120. In the gas mixture generator 120 the dry gas may further be purified.

In some embodiment of the gas supply source 120 may be coupled to a purifier apparatus 128, a flow meter 127, a valve 125, a reducer 129, a heat exchanger 126, and a vaporizer according to embodiments of the present invention.

A gas supply may be supplied to the purifier apparatus 128 via a gas inlet 1 10. For example, a compressed dry air (CDA) from a CDA source (not shown) can be supplied to the purifier apparatus 128 via the purge gas inlet 1 10. The CDA is purified by the purifier 128. The purifier 128 includes two parallel flow branches 128 A and 128B each including, in the flow direction: an automatic valve 1281 or 1282 and a regenerable purifier device 1283 or 1284. The regenerable purifier devices 1283 and 1284 are each provided with a heating element to heat and thereby regenerate the respective purifier devices 1283 and 1284 separately and independently. For example, one purifier can be used to make the gas while the other purifier is off-line being regenerated. The flow branches are connected downstream of the purifier devices 1283 and 1284 to a shut-off valve 1285 that can be controlled by a gas purity sensor 1286.

A heat exchanger 126 may provide a purified compressed dry air (CDA) at a substantially constant temperature. The heat exchanger 126 extracts or adds heat to the purified gas such as purified CDA in order to achieve a gas temperature that is suitable for the specific

implementation. In a lithographic projection apparatus, for example, stable processing conditions are used and the heat exchanger may thus stabilize the temperature of the purified CDA to have a gas temperature that is constant or in a predetermined narrow temperature range over time. The heat exchanger 126 may be used to condition the temperature of the gas to modify the uptake of vapor from a vaporizable liquid in a vaporizer.

The purified gas may be passed through restrictions 143-145 and output through a number of gas outlets 130, 131, 132. The restrictions 143, 144, 145 limit the gas flow, such that at each of the purge gas outlets 130, 131, 132 a desired, fixed purge gas flow and pressure is 50 obtained. A suitable value for the purge gas pressure at the purge gas outlets may be, for example, 100 mbar. It may be possible to use adjustable restrictions to provide an adjustable gas flow at each of the purge gas outlets 130, 131, 132.

The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.

While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

Claims

CLAIMS What is claimed is:

1. A chemical vaporizing system for enhancing transfer of a pattern to a substrate surface, the system comprising:

a chemical solvent permeable synthetic membrane;

a chemical solvent source for supplying a chemical solvent to an inlet on a first side of the membrane, the chemical solvent diffusing through the first side of the membrane to a second side of the membrane;

a gas supply source for supplying a gas stream to an inlet on the second side of the membrane and to the diffused chemical solvent, the gas stream and the diffused chemical solvent forming a mixture transferred through an outlet on the second side of the membrane onto the substrate surface; and

a photolithography optical source for applying an optical exposure that transfers the pattern to the substrate surface, the mixture on the substrate surface enhancing transfer of the pattern to the substrate surface.

2. The system of Claim 1 wherein the synthetic membrane is a microporous hollow fiber.

3. The system of Claim 1 wherein the chemical solvent is hexamethyldisilazane.

4. The system of Claim 1 wherein the gas stream is a stream of nitrogen gas.

5. The system of Claim 1 further including a controller configured to control flow pressure of the chemical solvent source to the first side of the membrane.

6. The system of Claim 1 further including a temperature controller configured to control a temperature of the chemical solvent.

7. The system of Claim 1 further including a chemical solvent concentration controller

configured to control concentration of the chemical solvent.

8. The system of Claim 1 further including a gas purifier system coupled with the gas supply source that purifies the supplied gas stream.

9. The system of Claim 1 further including a gas flow control configured to control flow pressure of the gas supply to the second side of the membrane.

10. The system of Claim 1 further including a gas stream temperature controller configured to control a temperature of the gas stream.

11. A chemical vaporizing method for enhancing transfer of a pattern to a substrate surface, the method comprising:

supplying a chemical solvent to an inlet on a first side of a synthetic membrane, the chemical solvent diffusing through the first side of the membrane to a second side of the membrane;

supplying a gas stream to an inlet on the second side of the membrane and to the diffused chemical solvent, the gas stream and the diffused chemical solvent forming a mixture transferred through an outlet on the second side of the membrane onto the substrate surface; and

applying an optical exposure that transfers the pattern to the substrate surface, the mixture on the substrate surface enhancing transfer of the pattern to the substrate surface.

12. The method of Claim 11 wherein the synthetic membrane is a microporous hollow fiber.

13. The method of Claim 1 1 wherein the chemical solvent is hexamethyldisilazane.

14. The method of Claim 11 wherein the gas stream is a stream of nitrogen gas.

15. The method of Claim 11 further including controlling flow pressure of the chemical solvent to the first side of the membrane.

16. The method of Claim 11 further including controlling a temperature of the chemical solvent.

17. The method of Claim 11 further including controlling concentration of the chemical solvent.

18. The method of Claim 11 further including purifying the supplied gas stream.

19. The method of Claim 11 further including controlling flow pressure of the gas supply to the second side of the membrane.

20. The method of Claim 11 further including controlling a temperature of the gas stream.

21. A photolithography system for enhancing transfer of a pattern to a substrate surface, the system comprising:

a vaporizing contactor including an inlet for inputting a chemical solvent into a first side of the contactor, the chemical solvent diffusing through the first side to a second side of the contactor, an inlet for inputting a gas stream into the second side of the contactor, the gas stream forming a mixture with the diffused chemical solvent, and an outlet for outputting the mixture from the second side of the contactor onto the substrate surface; and

a photolithography optical source for applying an optical exposure that transfers the pattern to the substrate surface, the mixture enhancing transfer of the pattern to the substrate surface.

22. A vaporization system for changing surface energy of a substrate, the system comprising:

a chemical solvent permeable synthetic membrane;

a gas supply source for supplying a gas stream to an inlet on the second side of the membrane and to the diffused chemical solvent, the gas stream and the diffused chemical solvent forming a mixture transferred through an outlet on the second side of the membrane onto the substrate surface; and a photolithography optical source for applying an optical exposure that transfers the pattern to the substrate surface, the mixture on the substrate surface enhancing transfer of the pattern to the substrate surface.

The vaporization system of Claim 22 wherein the chemical solvent is isopropyl alcohol.