Patent Application
20050161060
Periodically, chemical vapor deposition (“CVD”) chambers need cleaning to prevent particle contamination. They are typically cleaned using a plasma etch process (e.g., C2F6/O2) that volatizes the CVD residue (e.g., tetraethylorthosilcate, TEOS). Current chamber clean processes are ineffective at removing residue following CVD of porous dielectric materials, however.
While the CVD deposition process desirably forms thin films on a substrate (typically a silicon wafer), the reactions that form these films also occurs non-productively on exposed surfaces inside of the process chamber leaving a large amount of residues on the chamber walls, the showerhead, and the foreline downstream of the process chamber. These residues typically contain carbon, i.e., carbon-containing residues. Additional species that may also be present in the carbon-containing residues include, for example, silicon from the precursor mixture and/or fluorine from exposure to fluorinated gas-based plasmas used for cleaning and/or fluorine-containing precursors. Accumulation of the carbon-containing residues inside the chamber may result in particle shedding, degradation of deposition uniformity, and processing drifts that can affect subsequent depositions. These effects can lead to defects in the deposited structures and device failure. Therefore, periodic cleaning of the process chamber, also referred to as chamber cleaning, is necessary. These residues have to be removed in order to ensure the integrity (uniformity, composition purity, reproducibility) of the composite organosilicate films subsequently deposited. In some cases this carbon-containing residue may be present in the form of oligomers and polymers thus making residue removal more challenging.
In the article “Reducing PFC Emissions from CVD Chamber Cleaning,” Solid State Technology, p. 103 (December 2000), CVD chambers are typically cleaned using fluorocarbon plasmas (e.g., C2F6). A C2F6/O2 plasma is a generally practiced method throughout the semiconductor industry for cleaning CVD chambers. Oxygen (O2 or N2O) additions are necessary to prevent polymer formation in a fluorine deficient discharge. The role of oxygen in these processes is to convert the carbon atoms of the fluorocarbon (e.g., C2F6) into CO2.
In U.S. Pat. No. 5,413,670 and U.S. Pat. No. 6,067,999, residues of SiNx and SiO2 are removed from the walls of a CVD chamber using a plasma generated from NF3 and other diluents (e.g., He, Ar, N2). Fluorine atoms generated in the NF3 plasma react with the CVD residue forming volatile byproducts. Processes having high etch rates are disclosed (NF3 concentration, pressure, radio frequency (“RF”) power, flow rates).
U.S. Pat. No. 6,569,257 B1 teaches a method of cleaning a process chamber following CVD of silicon carbide (SiC) and organosilica glass (OSG). The SiC and OSG material is removed through a combination of hydrogen and fluorine plasmas (e.g., H2 and NF3). U.S. Pat. No. 6,569,257 is specifically directed to removing SiC and OSG residues. The role of the hydrogen plasma in U.S. Pat. No. 6,569,257 is to break silicon-carbon bonds, that are an inherent component of the SiC and OSG structure. SiC and OSG materials can successfully be cleaned using an NF3/O2 plasma. Inclusion of a hydrogen plasma simply increases the etch rate.
U.S. Pat. No. 5,326,723A discloses a method of cleaning a process chamber following tungsten CVD. The CVD chamber is cleaned with an NF3 plasma followed by a H2 plasma. U.S. Pat. No. 5,326,723A is specifically directed to removing tungsten residues. The tungsten is volatized as WF6 by the NF3 plasma. The purpose of the subsequent H2 plasma is to scavenge fluorine byproducts of the NF3-based chamber clean.
U.S. Pat. No. 5,129,958 describes a H2 plasma used to remove fluorine byproducts produced during a preceding chamber clean. Following a generally practiced method of cleaning CVD chambers (e.g., NF3 plasma), residual amounts of fluorine remain in the CVD chamber. U.S. Pat. No. 5,326,958 provides a method of removing these fluorine residues through reaction with a reducing gas (e.g., H2). The purpose of the subsequent H2 plasma is to scavenge fluorine byproducts of the NF3-based chamber clean.
U.S. Pat. No. 6,534,423 teaches that a H2 plasma is used to remove fluorine byproducts produced during a preceding chamber clean. Following a generally practiced method of cleaning CVD chambers (e.g., NF3 plasma), residual fluorine is impregnated in the walls of the CVD chamber, limiting adhesion of the CVD film. U.S. Pat. No. 6,534,423 provides a method of removing these fluorine residues through reaction with a reducing gas (e.g., H2). The purpose of the subsequent H2 plasma is to scavenge fluorine byproducts of the NF3-based chamber clean.
U.S. Pat. No. 6,626,188 B2 discloses that a hydrogen plasma is used to condition the dome of a CVD chamber. The purpose of this invention is to passivate the surfaces of the CVD chamber. Materials of construction for a CVD chamber include Al2O3. During any fluorine-based (e.g., NF3) chamber clean, the chamber walls may be fluorinated. U.S. Pat. No. 6,534,188 shows how the resulting AlF3 may be removed using a hydrogen plasma.
US 2003/0183244 A1 describes an invention that is a replacement to the traditional wet clean, that is performed after a CVD chamber has processed many (e.g., 5000 wafers). No CVD residue is removed from the chamber. After deposition, the CVD chamber must still be cleaned periodically (e.g., after 1 to 5 wafers) using a generally accepted method (e.g., NF3 plasma). After a large number of deposition and clean cycles (e.g., 5000), however, the CVD chamber must be disassembled and its components cleaned using aqueous acids and solvents (e.g., HF and isopropyl alcohol (“IPA”)). US 2003/0183244 proposes a dry etch process to replace this wet cleaning.
U.S. Pat. No. 5,135,775 discloses a H2 plasma used to clean a substrate prior to depositing a thin film by physical vapor deposition (“PVD”) or plasma enhanced CVD (“PECVD”). U.S. Pat. No. 5,135,775 is directed towards preparing a substrate (e.g., silicon wafer) rather than cleaning the process chamber of CVD residues.
WO 2002/007203 teaches that during plasma etching, i.e. reactive ion etching (“RIE”), polymer residue is deposited on the silicon substrate. WO 2002/007203 uses H2/N2 or NH3/N2 mixtures to facilitate removal of this etch residue. This invention is directed towards wafer cleaning following plasma etch, rather than cleaning process chambers following CVD.
JP 2001/102311 describes a plasma comprising of hydrogen (e.g., H2) and halogen (e.g., F2) gases is used to clean polysilicon wafers before forming a gate insulator. Presumably, the H2 and F2 components generate HF that removes any native oxide. JP 2001/102311 relates to wafer cleaning rather than cleaning CVD chambers with a plasma etch process.
The prior art has not addressed removal of porogen from CVD chamber walls after porous dielectric depositions. The typically large unsaturated hydrocarbons which are used as porogens present unique problems of chamber cleaning not considered or addressed by the prior art, yet constituting a significant problem for inclusion of porous dielectric into integrated circuit manufacturing. The present invention overcomes this problem in the industry as will be illustrated below, in contrast to the deficiencies of the prior art.
The present invention is a process for cleaning equipment surfaces in a semiconductor material processing chamber after deposition of a porous film containing a porogen, comprising;
contacting the equipment surfaces with a proton donor containing atmosphere to react with the porogen deposited on the equipment surfaces;
contacting the equipment surfaces with a fluorine donor containing atmosphere to react with the film deposited on the equipment surfaces.
Preferably, the process includes contacting the equipment surfaces with an oxygen donor containing atmosphere to react with the film deposited on the equipment surfaces when contacting with a fluorine donor, particularly when the fluorine donor does not contain oxygen.
More preferably, the present invention is a process for cleaning equipment surfaces in a semiconductor material CVD processing chamber after deposition of a porous dielectric film containing a porogen, comprising;
evacuating a zone contacting the equipment surface;
maintaining the zone under plasma conditions;
contacting the equipment surfaces with a proton donor containing atmosphere to react with the porogen deposited on the equipment surfaces;
evacuating the zone contacting the equipment surface;
contacting the equipment surfaces with a fluorine donor and oxygen source containing atmosphere to react with the dielectric film deposited on the equipment surfaces to clean the equipment surfaces.
Semiconductor devices are fabricated by the sequential deposition, and patterning, of thin film materials (e.g., silicon dioxide) on a silicon wafer. During chemical vapor deposition (CVD) of thin films, material is deposited on the surfaces of the process chamber, as well as the silicon wafer. Periodically, CVD chambers need to be cleaned to prevent particle contamination. The process chamber is cleaned using a plasma etch process that volatilizes the CVD residues on the chamber walls.
The interlayer dielectric (ILD) film of semiconductor devices has historically been a silicon oxide material (e.g., TEOS). These silicon-based materials (e.g., SiO2) can be volatized through reaction with fluorine. Fluorine atoms, generated in a glow discharge, react with silicon to for SiF4 gas that is evacuated from the CVD chamber.
Perfluorocompounds (PFCs, e.g. CF4, C2F6, NF3) as well as fluorine gas (F2) are a convenient source of fluorine atoms or radicals (F) in CVD chamber clean processes. PFCs are easy to handle, since they are non-corrosive and are unreactive with materials of construction or atmospheric gases under ambient conditions, prior to their decomposition. CVD chambers are typically cleaned using a C2F6/O2 or NF3-based plasma etch process.
The interlayer dielectric film is typically a silicon oxide containing film prepared using a precursor such as; tetraethylorthosilcate, triethylmethylorthosilcate, diethoxymethylsilane, methylsilane, trimethylsilane dimethylethylsilane or their corresponding siloxanes, or silane, and their respective homologs and analogs, tetramethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, tetraacetoxysilane, and tetraphenoxysilane, hexamethoxydisiloxane, hexaethoxydisiloxane, hexaphenoxydisiloxane, 1,1,1,3,3-pentamethoxy-3-methyldisiloxane, 1,1,1,3,3-pentaethoxy-3-methyldisiloxane, 1,1,1,3,3-pentamethoxy-3-phenyldisiloxane, 1,1,1,3,3-pentaethoxy-3-phenyldisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,1,3,3-tetraethoxy-1,3-diphenyldisiloxane, 1,1,3-trimethoxy-1,3,3-trimethyldisiloxane, 1,1,3-triethoxy-1,3,3-trimethyldisiloxane, 1,1,3-trimethoxy-1,3,3-triphenyldisiloxane, 1,1,3-triethoxy-1,3,3-triphenyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane and 1,3-diethoxy-1,1,3,3-tetraphenyldisiloxane. Of those, preferred compounds are hexamethoxydisiloxane, hexaethoxydisiloxane, hexaphenoxydisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane; 1,3-diethoxy-1,1,3,3-tetraphenyldisiloxane. Specific examples of these compounds wherein R7 is a group represented by —(CH2)n— include: bis(trimethoxysilyl)methane, bis(triethoxysilyl)methane, bis(triphenoxysilyl)methane, bis(dimethoxymethylsilyl) methane, bis(diethoxymethylsilyl)methane, bis(dimethoxyphenylsilyl)methane, bis(diethoxyphenylsilyl)methane, bis(methoxydimethylsilyl)methane, bis(ethoxydimethylsilyl)methane, bis(methoxydiphenylsilyl)methane, bis(ethoxydiphenylsilyl)methane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane, 1,2-bis(triphenoxysilyl)ethane, 1,2-bis(dimethoxymethylsilyl)ethane, 1,2-bis(diethoxymethylsilyl)ethane, 1,2-bis(dimethoxyphenylsilyl)ethane, 1,2-bis(diethoxyphenylsilyl)ethane, 1,2-bis(methoxydimethylsilyl)ethane, 1,2-bis(ethoxydimethylsilyl)ethane, 1,2-bis(methoxydiphenylsilyl)ethane, 1,2-bis(ethoxydiphenylsilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,3-bis(triethoxysilyl)propane, 1,3-bis(triphenoxysilyl)propane, 1,3-bis(dimethoxymethylsilyl)propane, 1,3-bis(diethoxymethylsilyl)propane, 1,3-bis(dimethoxyphenylsilyl)propane, 1,3-bis(diethoxyphenylsilyl)propane, 1,3-bis(methoxydimethylsilyl)propane, 1,3-bis(ethoxydimethylsilyl)propane, 1,3-bis(methoxydiphenylsilyl)propane; 1,3-bis(ethoxydiphenylsilyl) propane; Of those, preferred compounds are bis(trimethoxysilyl)methane, bis(triethoxysilyl)methane, bis(dimethoxymethylsilyl) methane, bis(diethoxymethylsilyl)methane, bis(dimethoxyphenylsilyl)methane, bis(diethoxyphenylsilyl)methane, bis(methoxydimethylsilyl)methane, bis(ethoxydimethylsilyl)methane, bis(methoxydiphenylsilyl)methane and bis(ethoxydiphenylsilyl)methane, tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, n-propyltriacetoxysilane, isopropyltriacetoxysilane, n-butyltriacetoxysilane, sec-butyltriacetoxysilane, tert-butyltriacetoxysilane, isobutyltriacetoxysilane, n-pentyltriacetoxysilane, sec-pentyltriacetoxysilane, tert-pentyltriacetoxysilane, isopentyltriacetoxysilane, neopentyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane, diethyldiacetoxysilane, di-n-propyldiacetoxysilane, diisopropyldiacetoxysilane, di-n-butyldiacetoxysilane, di-sec-butyldiacetoxysilane, di-tert-butyldiacetoxysilane, diphenyldiacetoxysilane, triacetoxysilane, hydrogen silsesquioxanes (HSQ, HSiO1.5) and methyl silsesquioxanes (MSQ, RSiO1.5 where R is a methyl group) and tetramethylcyclotetrasiloxane.
Preferably, the porous film is selected from the group consisting of diethoxymethylsilane, dimethoxymethylsilane, di-isopropoxymethylsilane, di-t-butoxymethylsilane, methyltriethoxysilane, methyltrimethoxysilane, methyltri-isopropoxysilane, methyltri-t-butoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-isopropoxysilane, dimethyldi-t-butoxysilane, 1,3,5,7-tetramethylcyclotatrasiloxane, octamethyl-cyclotetrasiloxane, tetraethoxysilane, and mixtures thereof.
The ILD film may also be an OSG with the composition represented by the formula SivOwCxHyFz, where v+w+x+y+z=100%, v is from 5 to 35 atomic %, w is from 10 to 65 atomic %, x is from 5 to 70 atomic %, y is from 10 to 70 atomic %, and z is from 0 to 15 atomic %.
Fabrication of advanced semiconductors requires an ILD having a lower dielectric constant than that of silicon oxide (4.0). The dielectric constant of interlayer dielectric (ILD) materials can be reduced by incorporating porosity. ILDs are made porous by introducing a porogen (e.g., terpenes) during chemical vapor deposition (CVD). The porogen is subsequently removed from the deposited ILD film in a post-CVD treatment (e.g., heat or UV exposure) that introduces voids where the porogen had been, reducing the material density, and dielectric constant. Carbon-doped silicon dioxide (CDO) deposited using diethoxymethylsilane (“DEMS”), typically has a dielectric constant of 3.0. By introducing terpenes during CVD, the dielectric constant can be reduced to 2.2 to 2.5. A “porogen”, as used herein, is a reagent that is used to generate void volume within the resultant film. Broadly the porogen can be at least one member selected from the group represented by: (a) at least one cyclic hydrocarbon having a cyclic structure and the formula CnH2n, where n is 4 to 14, a number of carbons in the cyclic structure is between 4 and 10, and the at least one cyclic hydrocarbon optionally contains a plurality of simple or branched hydrocarbons substituted onto the cyclic structure; (b) at least one linear or branched, saturated, partially or fully unsaturated hydrocarbon having the formula CnH(2n+2)−2y where n=2-20 and where y=0-n; (c) at least one singly or multiply unsaturated cyclic hydrocarbon having a cyclic structure and the formula CnH2n−2x, where x is a number of unsaturated sites, n is 4 to 14, a number of carbons in the cyclic structure is between 4 and 10, and the at least one singly or multiply unsaturated cyclic hydrocarbon optionally contains a plurality of simple or branched hydrocarbons substituents substituted onto the cyclic structure, and contains unsaturation inside endocyclic or on one of the hydrocarbon substituents; (d) at least one bicyclic hydrocarbon having a bicyclic structure and the formula CnH2n−2, where n is 4 to 14, a number of carbons in the bicyclic structure is from 4 to 12, and the at least one bicyclic hydrocarbon optionally contains a plurality of simple or branched hydrocarbons substituted onto the bicyclic structure; (e) at least one multiply unsaturated bicyclic hydrocarbon having a bicyclic structure and the formula CnH2n−(2+2x), where x is a number of unsaturated sites, n is 4 to 14, a number of carbons in the bicyclic structure is from 4 to 12, and the at least one multiply unsaturated bicyclic hydrocarbon optionally contains a plurality of simple or branched hydrocarbons substituents substituted onto the bicyclic structure, and contains unsaturation inside endocyclic or on one of the hydrocarbon substituents; (f) at least one tricyclic hydrocarbon having a tricyclic structure and the formula (a) CnH2n−4, where n is 4 to 14, a number of carbons in the tricyclic structure is from 4 to 12, and the at least one tricyclic hydrocarbon optionally contains a plurality of simple or branched hydrocarbons substituted onto the cyclic structure; and mixtures thereof.
More specifically, suitable porogens for use in the dielectric materials of the present invention include labile organic groups, solvents, decomposable polymers, surfactants, dendrimers, hyper-branched polymers, polyoxyalkylene compounds, organic macromolecules, or combinations thereof. Typical porogens include; alpha-terpinene, limonene, cyclohexane, 1,2,4-trimethylcyclohexane, 1,5-dimethyl-1,5-cyclooctadiene, camphene, adamantane, 1,3-butadiene, substituted Cx dienes where x=2-18 and decahydronaphthelene.
In addition, porous dielectric films can be produced using molecules containing porogen functionality bonded to the silica precursors, such as; porogenated 1,3,5,7-tetramethylcyclo-tetrasiloxanes, such as di-neohexyl-diethoxysilane, 1,4-bis(diethoxysilyl)cyclohexane, trimethylsilylethyl-1,3,5,7-tetramethylcyclo-tetrasiloxane, 1-neohexyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1-neopentyl-1,3,5,7-tetramethylcyclotetrasiloxane, neopentyldiethoxysilane, neohexyldiethoxysilane, neohexyltriethoxysilane, neopentyltriethoxysilane and neopentyl-di-t-butoxysilane.
Removal from CVD chamber walls of large molecules and oligomers, typically unsaturated porogen, for example alpha-terpinene (“ATRP”) and ATRP oligomers, used in the CVD process is problematic for the subsequent chamber clean process, however. The processes typically used to clean CVD chambers (e.g., C2F6/O2 or NF3 plasmas) have been found ineffective for DEMS-ATRP-type porous dielectric deposition recipes. Initially, a method to volatize the ATRP residue on the CVD chamber walls using an O2 plasma step (Step 1) followed by oxygen (e.g., O2 or N2O) additions to the NF3/C2F6 etch process (Step 2) was attempted. Examples of these C2F6-based and NF3-based chamber cleans are summarized in Table 1; Ex. 1 & 2. The purpose of the oxygen additions was to oxidize the porogen residue on the CVD chamber walls, as volatile carbon oxides (e.g., CO2 and CO). The silicon oxides are volatized as SiF4 by the fluorine plasma.
A C2F6 clean was run under the conditions recited above after a 2.0 μm DEMS-ATRP deposition. The QMS profile during the C2F6 clean that follows a 2.0 μm DEMS-ATRP deposition (
After three 2.0 μm DEMS-ATRP depositions (i.e., 6.0 μm cumulative deposition), each followed by a C2F6 chamber clean at conditions recited in Table 1, the PECVD chamber was visually inspected. A considerable amount of brown residue remained on the chamber walls and pumping channel per column 4 of Table II. Since a wet clean had been performed on the PECVD chamber before investigating this chamber clean, the condition of the PECVD chamber is striking, considering only three wafers had been processed. While the QMS monitor indicated that the clean was complete, based upon traditional interpretation of the QMS, the conclusion is that the prior art C2F6-clean does not effectively remove all residue from the CVD chamber. A similar result was observed for the NF3-clean (at conditions recited in Table 1).
In the present invention, a reducing chemistry is used for removing the porous dielectric film from the CVD reaction chamber walls, i.e., DEMS-ATRP residue. Although not wanting to be held to any particular theory, it is believed the present inventions use of a reducing or proton donor process step reduces and cracks the residual porogen left on the CVD chamber walls after porous dielectric deposition, generating a saturated hydrocarbon, that does not polymerize in the subsequent fluorine-based clean plasma. The proton donor or hydrogen source of the proton donor containing atmosphere may be H2, CH4, C2H6, CxHy, NH3, or H2O where x is 1-5 and y is 4-12, preferably fully saturating the hydrocarbon proton donor. The fluorine source of the fluorine donor containing atmosphere may be F2, NF3, CF4, C2F6, C3F8, C4F8, C4F8O, CHF3, COF2, bisfluoroxydifluoromethane, Cx hydrofluorocarbons, perfluorocarbons and oxygenated fluorocarbons where x=1-6 or other hydrofluorocarbons. The fluorine donor containing atmosphere may include a source of oxygen selected from the group consisting of oxygen, ozone, water, nitric oxide, nitrous oxide, nitrogen dioxide, silicon dioxide and mixtures thereof. The pressure may be 0.1-100 torr. The evacuation step before, between and after Step 1 and Step 2 can be less than 600 torr. The plasma conditions can be generated by RF of 500 to 10,000 Watts. The plasma can be a remote plasma decomposing the fluorine source upstream and outside the reaction chamber to be cleaned or it can be an in-situ generated plasma within the reaction chamber to be cleaned. Other energy sources, than RF, are contemplated for generating the plasma.
An example of the present invention used to clean a CVD chamber is given in Table 1 (Ex. 3). The porogen clean of this example is a two step process using H2 and NF3 at conditions recited in Table 1. The QMS profile during this Porogen-clean is shown in
After three 2.0 μm DEMS-ATRP depositions (i.e., 6.0 μm cumulative deposition), each followed by the present invention porogen-clean (Table 1), the PECVD chamber was visually inspected. There was no brown residue on the chamber walls, as reported in column 4 of Table II.
Feasibility experiments demonstrate that by including a reducing chemistry or proton donor (e.g., a H2 plasma step), the PECVD chamber is more effectively cleaned following a porous ILD deposition such as the porogen-containing DEMS-ATRP deposition, i.e., carbon-containing residues as described above. The reducing chemistry of the proton donor step, such as H2 plasma, reduces and cracks the porogen, typically large unsaturated molecules otherwise subject to fluorine-generated polymerization, generating saturated hydrocarbons, that are not polymerized in the subsequent fluorine plasma. The silicon oxide source, such as DEMS is etched as SiF4 in the NF3/O2 plasma process (Step 2).
The present invention has determined that traditional fluorine donor cleans are inadequate to remove porogens from dielectric deposition chamber surfaces. Such fluorine donor cleans historically had been adequate to clean dielectric precursors and reaction products when they did not contain porogens. With the recent move to considering porogens in dielectric film depositions to achieve needed low dielectric constants, a solution to porogen and porogen reaction products and by-products has been identified in the present invention as necessary. It is particularly appropriate to reduce or crack large and unsaturated porogens on chamber walls prior to exposure to fluorine containing cleaning gases, which have the potential to polymerize the porogen at the site of unsaturation and to perfluorinate the porogen to make it relatively inert to further reaction with cleaning reagents. Hydrogen treatments have been used in semiconductor and chamber processing, but never in the presence of large molecule and/or unsaturated porogen-type molecules. Therefore, the effects of proton donor treatment of reaction chamber surfaces to clean inadvertent depositions of such molecules has not been experienced, or even recognized as a problem in the prior art, nor has the resolution of the inadvertent deposition of such porogen molecules by proton donor or hydrogen reducing atomospheres been identified by the prior art.
The present invention has been set forth with regard to several exemplary embodiments, but the full scope of the present invention should be ascertained from the claims which follow.
The present application is a continuation-in-part of U.S. Provisional Application Ser. No. 60/538,832 filed 23 Jan. 2004.
| Number | Date | Country | |
|---|---|---|---|
| 60538832 | Jan 2004 | US |
