Compositions comprising 1,1,1,4,4,4-hexafluoro-2-butyne

Abstract

The present disclosure relates to compositions comprising 1,1,1,4,4,4-hexafluoro-2-butyne that may be useful as reaction intermediates, cleaning agents, and etching gases.

Description

COMPOSITIONS COMPRISING 1 ,1,1,4,4,4-HEXAFLUORO-2-BUTYNEFIELD OF THE INVENTION

[0001] The present invention relates to compositions comprising fluorobutyne, in particular hexafluoro-2-butyne. The compositions provide improved results, for example in an etching composition and as a reaction intermediate.BACKGROUND OF THE INVENTION

[0002] A growing public awareness of the environmental impacts from the extraction, transportation and use of fossil fuels are motivating a new environmental sustainability driver in the form of regulations and reduction in output of CO2 equivalence in the atmosphere. In particular, new environmental regulations on refrigerants have forced the refrigeration and air-conditioning industry to look for new refrigerants with low global warming potential (GWP). Replacement compounds and compositions with low global warming potentials (GWP) and ozone depletion potential (ODP) for both existing and new applications in thermal management segments such as refrigerants and cleaning / etching applications will need to adhere to these new regulations.

[0003] Hexafluoro-2-butyne has also been disclosed as an intermediate in producing Z-1,1 ,1 ,4,4,4-hexafluoro-2-butene (HFO-Z-1336mzz or more simply, 1336mzzZ). Z-1,1,1,4,4,4-hexafluoro-2-butene can be used as a refrigerant, heat transfer fluid, foam expansion agent, power cycle working fluid, among other uses. It has also, advantageously, been found that 1336mzzZ has a low global warming potential (GWP), GWP=32.

[0004] Processes to prepare 1336mzzZ are disclosed, for example, in WO 2015 / 120250 A1 , WO2014 / 052695 A1, US2013 / 0158304 A1, CN 103193586, CN 106008147, and CN106966856 (Seabiscuit cases in red). For example, WO 2015 / 120250 A1 discloses 1336mzzZ can be prepared starting from CFC-113a (1,1 ,1-trichloro-2,2,2-trifluoroethane). For example, US2013 / 0158304 A 1 discloses 1336mzzZ can be prepared starting from hexachlorobutadiene (CCl2=CCI-CI=CCl2. Both of these processes produce hexafluoro-2-butyne as intermediates.

[0005] Hexafluoro-2-butyne has been disclosed for use in compositions as etching and cleaning applications, such as in US2002 / 0197761. Advantageously, it has been found that hexafluoro-2-butyne has a low global warming potential (GWP), GWP = 2.

[0006] Hexafluoro-2-butyne produced in the processes disclosed hereinabove has been found to contain compounds that negatively impact downstream processes and equipment in the manufacture of 1336mzzZ as well as performance in etching and cleaning applications. In particular, chlorine-containing compounds may generate HCI when hexafluoro-2-butyne is used as an intermediate in the manufacture of 1336mzzZ. In addition, chlorine-containing compounds may cause undesirable degeneration of substrates in cleaning and etching applications as the chlorine- containing compounds may be more corrosive than the hexafluoro-2-butyne.

[0007] The present invention addresses these issues.SUMMARY

[0008] It has been found that compositions comprising hexafluoro-2-butyne disclosed herein provide improved results with respect to use of such compositions in the manufacture of 1336mzzZ and well as improved performance in etching and cleaning applications.

[0009] In one embodiment of the present invention there is provided a composition comprising 1 ,1 ,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122. The composition comprising hexafluoro-2-butyne may comprise no more than 0.2% or no more than 0.1% or no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122. The composition may comprise PFBY and 113. The composition may comprise PFBY and 122. The composition may comprise PFBY and 123. The composition may comprise PFBY and 1122.

[0010] In one embodiment, the composition further comprises one or more additional compounds chosen from HFC-23, HFC-41, HCFC-132b, HCFC-142b, HFC-143a, HFC-152a, trifluoropropyne, HFC-263fb, HFC-356mff, HCFO-1122, HCFO-Z-1326mxz, HCFO-E-1326mxz, HFO-1327mz, HFO-E-1336mzz, trifluoroacetone. The one or more additional compound may be present in anamount of no more than 0.5% or no more than 0.1% or no more than 0.01%.

[0011] The composition comprising hexafluoro-2-butyne (PFBY) contains at least 95% PFBY or at least 98% PFBY or at least 99% PFBY or at least 99.5% PFBY and preferably greater than 99.8% PFBY.

[0012] In one embodiment, the compositions provided herein are useful as intermediates in chemical processes, such as to produce Z-HFO-1336mzz (Z-1.1.1.4.4.4-hexafluoro-2-butene-Z, 1336mzzZ, or Z-CFsCF CHCFs). This process comprises contacting a composition comprising 1 ,1 ,1 ,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 with hydrogen in the presence of a hydrogenation catalyst to produce Z- CF3CH=CHCF3. Due to the low concentration of the components 113, 122, 123 and 1122 in the PFBY, the process to produce Z-CF3CH=CHCF3 is more efficient, with higher yield, less corrosion and improved catalyst life.

[0013] In one embodiment, the compositions provided herein may be useful in cleaning and etching applications.

[0014] In one embodiment, there is provided a gas mixture suitable for etching comprising oxygen and a composition comprising 1,1,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5%, preferably no more than 0.2%, more preferably no more than 0.1%, still more preferably no more than 0.05%, and still more preferably no more than 0.01% total of one or more of 113, 122, 123 and 1122. The composition comprising 1 ,1 ,1,4,4,4-hexafluoro-2-butyne and no more than 0.5%, preferably contains at least 99% 1,1,1,4,4,4-hexafluoro-2-butyne, more preferably at least 99.5% 1,1,1,4,4,4-hexafluoro-2-butyne, still more preferably at least 99.8%1.1.1.4.4.4-hexafluoro-2-butyne and most preferably at least 99.9% 1, 1,1, 4,4,4- hexafluoro-2-butyne.

[0015] In one embodiment, there is provided a gas mixture suitable for etching comprising oxygen and a composition comprising at least 99.8% 1 , 1 ,1, 4,4,4- hexafluoro-2-butyne and no more than 0.2% total of one or more of 113, 122, 123 and 1122. In one embodiment, there is provided a gas mixture suitable for etching comprising oxygen and a composition comprising at least 99.9% 1 , 1 ,1, 4,4,4- hexafluoro-2-butyne and no more than 0.1% total of one or more of 113, 122, 123 and 1122. In one embodiment, there is provided a gas mixture suitable for etchingcomprising oxygen and a composition comprising at least 99.9% 1 ,1 , 1 ,4, 4, 4- hexafluoro-2-butyne and no more than 0.1% total of one or more of 113, 122, 123 and 1122.

[0016] In one embodiment, the etch gas mixture further comprises a carrier gas. The carrier gas may be chosen from He, Ar, or N2. In one embodiment, the molar ratio of oxygen to the composition comprising PFBY is at least about 1 :1.

[0017] In one embodiment, the etch gas mixture further comprises a second etch gas, wherein the second etch gas is a fluorinated compound, SFe, or NF3. In one embodiment, the second etch gas is selected from the group consisting of tetrafluoromethane, hexafluoroethane, octafluoropropane, perfluorotetrahydrofuran, hexaflurobutadiene, and octafluorocyclobutane.

[0018] In one embodiment, there is provided a method of operation of a semiconductor manufacturing process chamber, comprising etching a film on a semiconductor using an etch gas mixture comprising oxygen and a composition comprising 1 ,1 , 1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122.

[0019] In one embodiment, the method of operation of a semiconductor manufacturing process chamber, the step of etching a film further comprises, transferring a photomask to the semiconductor to create a masked surface and an exposed surface, forming a plasma of said etch gas mixture, and exposing the exposed surface of the semiconductor to the plasma to remove portions of the exposed surface of the semiconductor to form an etched surface of the semiconductor.

[0020] In one embodiment, the method of operation of a semiconductor manufacturing process chamber further comprises the steps of forming a second etch gas, activating the second etch gas to form a second plasma, depositing the second plasma on the etched surface to form a polymer layer on the etched surface of the semiconductor, wherein the second etch gas is a fluorinated compound, SFe, or NF3.

[0021] The surface deposit may be selected from the group consisting of silicon oxide, gallium nitride, silicon nitride, silicon oxynitride, silicon carbonitride, tungsten nitride, titanium nitride, and tantalum nitride.

[0022] In one embodiment, the step of forming a plasma from the etch gas is performed in a remote chamber or in the process chamber.

[0023] In one embodiment, the molar ratio of oxygen to the composition comprising PFBY is at least about 1:1.

[0024] In one embodiment of any of the methods of operation of a semiconductor manufacturing process chamber, the pressure in the process chamber is no more than 30 torr.

[0025] In one embodiment of any of the methods of operation of a semiconductor manufacturing process chamber, the pressure in the remote chamber is from 0.5 torr to 50 torr.

[0026] In one embodiment, there is provided a method for removing surface deposits from a surface in a process chamber, comprising activating a gas mixture comprising oxygen and a composition comprising 1,1,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, wherein the molar percentage of PFBY in the said gas mixture is from about 5% to about 99%, and contacting said activated gas mixture with the surface deposits and thereby removing at least some of said deposits. In one embodiment, the process chamber is the interior of a deposition chamber that is used in fabricating electronic devices.DETAILED DESCRIPTION

[0027] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or notpresent), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0028] The transitional phrase "consisting of' excludes any element, step, or ingredient not specified. If in the claim, such would close the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith. When the phrase "consists of" appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

[0029] The transitional phrase "consisting essentially of" is used to define a composition, method that includes materials, steps, features, components, or elements, in addition to those literally disclosed provided that these additional included materials, steps, features, components, or elements do not materially affect the basic and novel characteristic(s) of the claimed invention, especially the mode of action to achieve the desired result of any of the processes of the present invention. The term “consisting essentially of’ occupies a middle ground between “comprising” and “consisting of’.

[0030] Where applicants have defined an invention or a portion thereof with an open-ended term such as “comprising,” it should be readily understood that (unless otherwise stated) the description should be interpreted to also include such an invention using the terms “consisting essentially of’ or “consisting of.”

[0031] Also, use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

[0032] As used herein, the term “about” is meant to account for variations due to experimental error (e.g., plus or minus approximately 10% of the indicated value). All measurements reported herein are understood to be modified by the term “about”, whether or not the term is explicitly used, unless explicitly stated otherwise.

[0033] When an amount, concentration, or other value or parameter is given as either a range, preferred range or a list of upper preferable values and / or lowerpreferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

[0034] The term “compound” as used herein is meant to include all stereoisomers, geometric isomers, tautomers, and isotopes of the structures or chemical described. Compounds herein identified by name or structure as one particular tautomeric form are intended to include other tautomeric forms unless otherwise specified.

[0035] As used herein, the term “catalyst”, refers to a substance that speeds up the chemical reaction, but is not consumed by the reaction; thus it can be recovered chemically unchanged at the end of the reaction.COMPOSITIONS

[0036] The compositions disclosed herein comprising 1 ,1 ,1 ,4,4,4-hexafluoro-2- butyne are useful as starting materials and / or intermediates in the manufacture of useful molecules. While not intending to be limited, the compositions are illustrated herein as useful in the manufacture of 1336mzzZ.

[0037] The compositions disclosed herein comprising 1 ,1 ,1 ,4,4,4-hexafluoro-2- butyne are also suitable for cleaning and / or etching applications as a component of a gas mixture containing oxygen. The gas mixture is suitable for use in methods for cleaning substrates and process chambers used in manufacture of electronic components, including semiconductor materials.

[0038] Table 1 provides a list of compounds which may be present in the compositions disclosed herein.TABLE 1. COMPOUND NAMES AND FORMULAE

[0039] The present invention provides a composition comprising 1 ,1,1 ,4,4,4- hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122. It is recognized that “0.5%” is the same as 5000 ppm and “0.1%” is the same as 1000 ppm and so on. For purposes herein, all amounts written as percent, “%” reflect mole percent.

[0040] In one embodiment, the composition comprises no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122. In another embodiment, the composition comprises no more than 0.2% (mole percent) total of one or more of 113, 122, 123 and 1122. In another embodiment, the composition comprises no more than 0.1% (mole percent) total of one or more of 113, 122, 123 and 1122. In another embodiment, the composition comprises no more than 0.05% (mole percent) total of one or more of 113, 122, 123 and 1122. In another embodiment, the composition comprises no more than 0.01% (mole percent) total of one or more of 113, 122, 123 and 1122.

[0041] In one embodiment the composition comprises PFBY and 113, wherein 113 is present in an amount of less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprises PFBY and 122, wherein 122 is present in an amount of less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprises PFBY and 123, wherein 123 is present in an amount of less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprises PFBY and 1122 wherein 1122 is present in an amount of less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%.

[0042] In one embodiment the composition comprising PFBY comprises 113 and 122, wherein the total amount of 113 and 122 is than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01 %. In one embodiment the composition comprising PFBY comprises 113 and 123, wherein the total amount of 113 and 123 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprising PFBY comprises 113 and 1122, wherein the total amount of 113 and 1122 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprising PFBY comprises 122 and 123, wherein the total amount of 122 and 123 is less than 0.5% or less than 0.2% or less than 0.1 % or less than 0.05% or less than 0.01 %. In one embodiment the composition comprising PFBY comprises 122 and 1122, wherein the total amount of 122 and 1122 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprising PFBY comprises123 and 1122 wherein the total amount of 123 and 1122 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%.

[0043] In one embodiment the composition comprising PFBY comprises 113, 122 and 123, wherein the total amount of 113, 122 and 123 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprises PFBY, 122 and 1122, wherein the total amount of 113, 122 and 1122 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%. In one embodiment the composition comprises PFBY, 122, 123 and 1122, wherein the total amount of 122, 123 and 1122 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%.

[0044] In one embodiment the composition comprises PFBY, 113, 122, 123 and 1122, wherein the total amount of 113, 122, 123 and 1122 is less than 0.5% or less than 0.2% or less than 0.1% or less than 0.05% or less than 0.01%.

[0045] In one embodiment, the composition further comprises one or more additional compounds chosen from HFC-23, HFC-41, HCFC-132b, HCFC-142b, HFC-143a, HFC-152a, trifluoropropyne, HFC-263fb, HFC-356mff, HCFO-1122, HCFO-Z-1326mxz, HCFO-E-1326mxz, HFO-1327mz, HFO-E-1336mzz, trifluoroacetone. The additional compound may be present in an amount of no more than 0.5% or no more than 0.1% or no more than 0.01%.

[0046] In one embodiment, the composition comprising 1 ,1,1,4,4,4,-hexafluoro-2- butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFC-23. In one embodiment, the composition comprising 1 ,1 ,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFC-41. In one embodiment, the composition comprising 1,1,1 ,4,4,4, -hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFC-132b. In one embodiment, the composition comprising 1 ,1 ,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises CFC- 142b. In one embodiment, the composition comprising 1 ,1,1,4,4,4,-hexafluoro-2- butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFC-143a. In one embodiment, thecomposition comprising 1,1,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFC-152a. In one embodiment, the composition comprising 1, 1,1, 4,4,4, - hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises trifluoropropyne. In one embodiment, the composition comprising 1,1,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFC-263fb. In one embodiment, the composition comprising 1 ,1 ,1 ,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFC-356mff. In one embodiment, the composition comprising 1,1,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-1122. In one embodiment, the composition comprising 1 ,1 ,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-Z- 1326mxz. In one embodiment, the composition comprising 1 , 1 ,1, 4,4,4, -hexafluoro- 2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-E-1326mxz. In one embodiment, the composition comprising 1,1,1,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFO-1327mz. In one embodiment, the composition comprising 1 ,1 ,1 ,4,4,4,-hexafluoro-2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HFO-E-1336mzz. In one embodiment, the composition comprising 1,1 , 1,4, 4, 4, -hexafluoro- 2-butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises trifluoroacetone.

[0047] In one embodiment, the composition comprising 1 ,1,1,4,4,4,-hexafluoro-2- butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-Z-1326mxz and HCFO-E-1326mxz.

[0048] In one embodiment, the composition comprising 1 ,1,1,4,4,4,-hexafluoro-2- butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-Z-1326mxz, HCFO-E-1326mxz, and HFO-1327mz.

[0049] In one embodiment, the composition comprising 1 ,1,1,4,4,4,-hexafluoro-2- butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-1122, HCFO-Z-1326mxz and HCFO-E- 1326 mxz.

[0050] In one embodiment, the composition comprising 1 ,1,1,4,4,4,-hexafluoro-2- butyne (PFBY) and no more than 0.5% (mole percent) total of one or more of 113, 122, 123 and 1122 further comprises HCFO-1122, HCFO-Z-1326mxz, HCFO-E- 1326mxz, and HFO-1327mz.PROCESSES

[0051] The present invention provides compositions of materials useful as intermediates for producing fluoroolefins, particularly 1336mzzZ.Preparation of 1,1,1,4,4,4-hexafluoro-2-butyne

[0052] The compositions provided herein may be produced by the following process.

[0053] One step (a) comprises providing a composition comprising 113a and no more than 0.5% total of one or more of 113, 122, 123 and 1122, or no more than 0.2% total of one or more of 113, 122, 123 and 1122, 0.1% total of one or more of 113, 122, 123 and 1122, or 0.05% total of one or more of 113, 122, 123 and 1122, or 0.01% total of one or more of 113, 122, 123 and 1122.

[0054] The process further comprises a step (b) of contacting a composition comprising 113a with hydrogen in the presence of a step (b) catalyst to produce a first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, wherein the composition comprising 113a comprises less than 0.5% total of one or more of 113, 122, 123 and 1122.

[0055] The step (b) catalyst comprises a transition metal. The transition metal may be chosen from ruthenium, rhodium, palladium, and platinum. The step (b) catalyst may comprise a support. The support may be chosen from silicon carbide (SiC), tungsten carbide (WC), alumina.

[0056] Typical reaction conditions for step (b) are as follows. The reaction may be conducted at a temperature in the range of 90°C to 200°C. The pressure for the reaction in step (b) is typcially in the rant of 80 to 200 psig (0.55 to 1.38 MPa). Step (b) may be conducted with a contact time in the range of 30 to 100 seconds (30-100 s), such as a contact time of 70 seconds (70 s).

[0057] In some embodiments, the composition comprising 113a in step (b) comprises 113. In some embodiments, the composition comprising 113a in step (b) comprises 122. In some embodiments, the composition comprising 113a in step (b) comprises 123. In some embodiments, the composition comprising 113a in step (b) comprises 1122.

[0058] In some embodiments, the composition comprising 113a in step (b) comprises 113 and 122. In some embodiments, the composition comprising 113a in step (b) comprises 113 and 123. In some embodiments, the composition comprising 113a in step (b) comprises 113 and 1122. In some embodiments, the composition comprising 113a in step (b) comprises 122 and 123. In some embodiments, the composition comprising 113a in step (b) comprises 122 and 1122. In some embodiments, the composition comprising 113a in step (b) comprises 123 and 1122. In some embodiments, the composition comprising 113a in step (b) comprises 113, 122, 123 and 1122.

[0059] In some embodiments, the composition comprising 113a and no more than 0.5% or no more than 0.2% or no more than 0.1% or no more than 0.05% or no more than 0.01 % total of one or more of 113, 122, 123 and 1122 in step (a) and step (b), further comprises no more than 0.5% total of one or more of one or more of 112, 112a, 114, 114a, 115, 215ba, 216, 316, 318, and PCE. In some embodiments, the composition comprising 113a and no more than 0.5% total of one or more of 113, 122, 123 and 1122 in step (a) or step (b), comprises no more than 0.5% total of one or more of 111 , 214cb, CHCI2CCI3 and CCI3CCI3. In some embodiments, the composition comprising 113a and no more than 0.5% total of one or more of 113, 122, 123 and 1122 in step (a) or step (b), comprises no more than 0.5% total of one or more of 112, 112a, 113, 114a, and 318.

[0060] The process further comprises a step (c) of purifying the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, byfractional distillation using a no less than 1 :1 or 2: 1 or 3: 1 to provide a composition comprising 1316mxx and no more than 0.5% total of one or more of 113, 122, 123 and 1122.

[0061] This step (c) is generally performed at a pressure of 200 psig or less, or 150 psig (1.03 MPa) or less or 80 psig (0.55 MPa) or less, that is a range of ambient pressure up to 200 psig (1.38 MPa).

[0062] The composition provided by purifying the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122 in step (c) by fractional distillation using a reflux ratio of no less than 1 :1 or 2:1 or 3:1 , comprises 1316mxx and no more than 0.5% total of one or more of 113, 122, 123 and 1122. The composition provided in step (c) may comprise Z-1316mxx or E-1316mxx or a mixture of Z-1316mxx and E-1316mxx. When the composition provided in step (c) comprises a mixture of Z-1316mxx and E-1316mxx, the ratio of Z-1316mxx to E- 1316mxx (Z / E) is in the range of 1 to 99 or 5 to 95 or 10 to 90 or 15 to 85 or 20 to 80 or 25 to 75 or 30 to 70 or 35 to 65 or 40 to 60 or 45 to 55 or 50 to 50 or 55 to 45 or 60 to 40 or 65 to 35 or 70 to 30 or 75 to 25 or 80 to 20 or 85 to 15 or 90 to 10 or 95 to 5 or 99 to 1. The ratio of Z-1316mxx to E-1316mxx (Z / E) is preferably in the range 10 to 90 or 15 to 85 or 20 to 80 or 25 to 75 or 30 to 70 or 35 to 65 or 40 to 60 or 45 to 55 or 50 to 50 or 55 to 45 or 60 to 40 or 65 to 35 or 70 to 30 or 75 to 25 or 80 to 20 or 85 to 15 or 90 to 10. More preferably, the ratio of Z-1316mxx to E-1316mxx (Z / E) is in the range of 65 or 40 to 60 or 45 to 55 or 50 to 50 or 55 to 45 or 60 to 40 or 65 to 35.

[0063] In purifying the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122 in step (c), by fractional distillation using a reflux ratio of no less than 1 :1 or 2:1 or 3:1 , the first product mixture fed to the step may comprise more than 0.5% or more than 0.2% or more than 0.1 % or more than 0.05% or more than 0.01% total of one or more of 113, 122, 123 and 1122. The purifying step (c) provides a composition comprising 1316mxx and no more than 0.5% or no more than 0.2% or no more than 0.1 % or no more than 0.05% or no more than 0.01 % total of one or more of 113, 122, 123 and 1122.

[0064] In one embodiment, the reflux ratio is at least 1 :1. In one embodiment, the reflux ratio is at least 2:1. In one embodiment, the reflux ratio is at least 3:1.

[0065] In one embodiment for step (c) of purifying the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 1:1 or 2:1 or 3:1 , the first product mixture comprises more than 0.1% total of one or more of 113, 122, 123 and 1122 to provide a composition comprising 1316mxx and no more than 0.1% or no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122.

[0066] In one embodiment for purifying in step (c) the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 1:1, the first product mixture comprises more than 0.1% total of one or more of 113, 122, 123 and 1122. In one embodiment for purifying in step (c) the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 2:1 , the first product mixture comprises more than 0.1% total of one or more of 113, 122, 123 and 1122. In one embodiment for purifying the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 3:1, the first product mixture comprises more than 0.05% total of one or more of 113, 122, 123 and 1122.

[0067] In one embodiment for purifying the first product mixture comprising 1316mxx and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 1 :1 or 2:1 or 3:1 , the first product mixture comprises more than 0.05% total of one or more of 113, 122, 123 and 1122 to provide a composition comprising 1316mxx and no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122.

[0068] The process further comprises a step (d) of contacting a composition comprising 1316mxx with hydrogen, in the presence of a catalyst selected from the group consisting of copper on carbon, nickel on carbon, copper and nickel on carbon and copper and palladium on carbon, to produce a second product mixture, comprising 1326mxz and at least one of 113, 122, 123 and 1122, wherein the composition comprising 1316mxx comprises less than 0.5% total of one or more of 113, 122, 123 and 1122. The composition comprising 1316mxx used in step (d) may comprise less than 0.2% total of one or more of 113, 122, 123 and 1122. The composition comprising 1316mxx used in step (d) may comprise less than 0.1% totalof one or more of 113, 122, 123 and 1122. The composition comprising 1316mxx used in step (d) may comprise less than 0.05% total of one or more of 113, 122, 123 and 1122. The composition comprising 1316mxx used in step (d) may comprise less than 0.01% total of one or more of 113, 122, 123 and 1122. Additional compounds may be present in the composition comprising 1316mxx used in step (d) as recited hereinabove.

[0069] In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113, 122, 123 and 1122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113, 122, and 123. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113, 122, and 1122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 122, 123 and 1122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113 and 122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113 and 123. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113 and 1122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 122 and 123. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 122 and 1122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 123 and 1122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 113. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 122. In one embodiment, the composition comprising 1316mxx used in step (d) comprises 123, In one embodiment, the composition comprising 1316mxx used in step (d) comprises 1122.

[0070] Step (d) is generally performed at a temperature in the range of 150°C to 250°C and a pressure of 80 to 300 psig (0.55 to 2.07 MPa). The contact time is typically in the range of 50 to 200 seconds.

[0071] The second product mixture comprising 1326mxz produced in step (d) may comprise more than 0.5% total of one or more of one or more of 113, 122, 123 and 1122 or more than 0.2% total of one or more of one or more of 113, 122, 123 and 1122 or more than 0.1% total of one or more of one or more of 113, 122, 123 and 1122.

[0072] The process further comprises a step (e) of purifying the second product mixture comprising 1326mxz by fractional distillation using a reflux ratio of no less than 1 :1 or 2:1 or 3:1 to provide a composition comprising 1326mxz and no more than 0.5% total of one or more of 113, 122, 123 and 1122.

[0073] The second product mixture may comprise more than 0.5% or more than 0.2% or more than 0.1% or more than 0.05% or more than 0.01% total of one or more of 113, 122, 123 and 1122. By purifying the second product mixture, there is provided a composition comprising 1326mxz and no more than 0.5% or no more than 0.2% or no more than 0.1 % or no more than 0.05% or no more than 0.01 % total of one or more of 113, 122, 123 and 1122.

[0074] In one embodiment, the reflux ratio of step (e) is at least 1 :1. In one embodiment, the reflux ratio of step (e) is at least 2: 1. In one embodiment, the reflux ratio of step (e) is at least 3:1 .

[0075] In one embodiment of step (e) for purifying the second product mixture comprising 1326mxz and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 1 :1 , the second product mixture comprises more than 0.1% total of one or more of 113, 122, 123 and 1122. In one embodiment of step (e) for purifying the second product mixture comprising 1326mxz and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 2:1 , the second product mixture comprises more than 0.1% total of one or more of 113, 122, 123 and 1122. In one embodiment of step (e) for purifying the second product mixture comprising 1326mxz and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 3:1 , the second product mixture comprises more than 0.1% total of one or more of 113, 122, 123 and 1122.

[0076] The conditions for step (e) are the same as those for step (c). That is, step (e) is generally performed at a pressure of 200 psig or less, or 150 psig (1.03 MPa) or less or 80 psig (0.55 MPa) or less, that is a range of ambient pressure up to 200 psig (1.38 MPa).

[0077] The process further comprises a step (f) of contacting a composition comprising 1326mxz and no more than 0.5% total of one or more of 113, 122, 123 and 1122 with an alkali metal hydroxide in an aqueous basic solution in the presenceof a phase transfer catalyst to produce a third product mixture comprising hexafluoro-2-butyne. The composition comprising 1326mxz used in step (f) may comprise less than 0.2% total of one or more of 113, 122, 123 and 1122. The composition comprising 1326mxz used in step (f) may comprise less than 0.1% total of one or more of 113, 122, 123 and 1122. The composition comprising 1326mxz used in step (f) may comprise less than 0.05% total of one or more of 113, 122, 123 and 1122. The composition comprising 1326mxz used in step (f) may comprise less than 0.01% total of one or more of 113, 122, 123 and 1122. Additional compounds may be present in the composition comprising 1326mxz used in step (d) as recited hereinabove.

[0078] In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113, 122, 123 and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113, 122, and 123. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113, 122, and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 122, 123 and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113 and 122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113 and 123. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113 and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 122 and 123. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 122 and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 123 and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 113. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 123, In one embodiment, the composition comprising 1326mxz used in step (f) comprises 1122.

[0079] Typical reaction conditions for step (f) are as follows. Temperature is from 150°C to 250°C, pressure is in the range fo 80 to 300 psig (0.55 to 2.07 MPa). The contact time is in the range of 50 to 200 seconds.

[0080] The process further comprises a step (g) of purifying the third product mixture comprising hexafluoro-2-butyne (PFBY) by fractional distillation using a reflux ratio of no less than 1 :1 or 2:1 or 3:1 to provide a composition comprising PFBY and no more than 0.5% or no more than 0.2% or no more than 0.1% or no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122.

[0081] The third product mixture may comprise more than 0.5% or more than 0.2% or more than 0.1% or more than 0.05% or more than 0.01% total of one or more of 113, 122, 123 and 1122. By purifying the third product mixture, there is provided a composition comprising PFBY and no more than 0.5% or no more than 0.2% or no more than 0.1% or no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122.

[0082] In one embodiment, the reflux ratio of step (g) is at least 1 :1. In one embodiment, the reflux ratio of step (g) is at least 2:1. In one embodiment, the reflux ratio of step (g) is at least 3:1.

[0083] In one embodiment of step (g) for purifying the third product mixture comprising PFBY and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 1:1, the third product mixture comprises more than 0.5% or more than 0.2% or more than 0.1% or more than 0.05% or more than 0.01% total of one or more of 113, 122, 123 and 1122. In one embodiment of step (g) for purifying the third product mixture comprising PFBY and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 2:1 , the third product mixture comprises more than 0.5% or more than 0.2% or more than 0.1% or more than 0.05% or more than 0.01% total of one or more of 113, 122, 123 and 1122. In one embodiment for purifying the third product mixture comprising PFBY and at least one of 113, 122, 123 and 1122, by fractional distillation using a reflux ratio of no less than 3:1 , the third product mixture comprises more than 0.5% or more than 0.2% or more than 0.1% or more than 0.05% or more than 0.01% total of one or more of 113, 122, 123 and 1122.

[0084] The conditions for step (g) are the same as those for step (c). That is, step(g) is generally performed at a pressure of 200 psig or less, or 150 psig (1.03 MPa) or less or 80 psig (0.55 MPa) or less, that is a range of ambient pressure up to 200 psig (1.38 MPa).

[0085] The product from purifying the third product mixture in step (g) can provide the compositions disclosed herein.Preparation of HFO-Z-1,1,1,4,4,4-hexafluoro-2-butene (1336mzzZ)

[0086] The compositions disclosed herein may be used further to produce a product mixture comprising 1336mzzZ.

[0087] In a process to produce 1336mzzZ, there is a step (h) of contacting a composition comprising hexafluoro-2-butyne as set forth herein which comprises no more than 0.5% or no more than 0.2% or no more than 0.1% or no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122 with Lindlar’s catalyst, or a palladium catalyst further comprising a lanthanide element or silver in the presence of hydrogen to produce a fourth product mixture comprising 1336mzzZ.

[0088] The composition comprising PFBY used in step (h) may comprise less than 0.2% total of one or more of 113, 122, 123 and 1122. The composition comprising PFBY used in step (h) may comprise less than 0.1% total of one or more of 113, 122, 123 and 1122. The composition comprising used in step (h) may comprise less than 0.05% total of one or more of 113, 122, 123 and 1122. The composition comprising PFBY used in step (h) may comprise less than 0.01% total of one or more of 113, 122, 123 and 1122.

[0089] In one embodiment, the composition comprising PFBY used in step (h) comprises 113, 122, 123 and 1122. In one embodiment, the composition comprising PFBY used in step (h) comprises 113, 122, and 123. In one embodiment, the composition comprising PFBY used in step (h) comprises 113, 122, and 1122. In one embodiment, the composition comprising PFBY used in step (h) comprises 122, 123 and 1122. In one embodiment, the composition comprising PFBY used in step(h) comprises 113 and 122. In one embodiment, the composition comprising PFBY used in step (h) comprises 113 and 123. In one embodiment, the composition comprising PFBY used in step (h) comprises 113 and 1122. In one embodiment, thecomposition comprising PFBY used in step (h) comprises 122 and 123. In one embodiment, the composition comprising PFBY used in step (h) comprises 122 and 1122. In one embodiment, the composition comprising 1326mxz used in step (f) comprises 123 and 1122. In one embodiment, the composition comprising PFBY used in step (h) comprises 113. In one embodiment, the composition comprising PFBY used in step (h) comprises 122. In one embodiment, the composition comprising PFBY used in step (h) comprises 123, In one embodiment, the composition comprising PFBY used in step (h) comprises 1122.

[0090] Typical reaction conditions for step (h) are as follows. Temperature is in the range of 30°C to 60°C and pressure is in the range of atmospheric to 50 psig (atmospheric to 0.34 MPa). The residence time is in the range of 0.5 hour to 5 hours.

[0091] By using the process steps (a) through (h) as disclosed herein, the fourth product comprising 1336mzzZ produced in step (h) can be produced in high purity, with fewer byproducts and less product yield loss. Thus, purification of the fourth product comprising 1336mzzZ is simplified.APPLICATIONS

[0092] The compositions comprising PFBY disclosed herein are useful in semiconductor manufacturing applications, such as etching semiconductors and as cleaning gases for removing surface deposits in CVD and PECVD chambers. In one embodiment, PFBY can be used to replace hexachlorobutadiene in etching applications.

[0093] In one embodiment of this invention there is provided a methods for removing surface deposits from the interior of a chemical vapor deposition chamber. This method comprises using an activated gas mixture created by activating a gas mixture in a chemical vapor deposition chamber or in a remote chamber, where the gas mixture comprises oxygen and a composition comprising PFBY and no more than no more than 0.5% or no more than 0.2% or no more than 0.1% or no more than 0.05% or no more than 0.01% total of one or more of 113, 122, 123 and 1122.

[0094] In one embodiment, the present invention provides a gas mixture suitable for cleaning and etching applications that have low GWP and low EHS (Environmental, Health, and Safety) issues, so that even if unreacted gases are released, they have reduced environmental impact. In one embodiment, there is provided a gas mixture comprises oxygen and a composition comprising 1, 1,1 , 4,4,4- hexafluoro-2-butyne and no more than 0.5% or no more than 0.1% total of one or more of 113, 122, 123 and 1122.

[0095] In one embodiment, the composition comprising 1 ,1, 1,4,4, 4-hexafluoro-2- butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122 in the gas mixture contains at least 99.5% 1,1,1,4,4,4-hexafluoro-2-butyne.

[0096] In one embodiment, the composition comprising 1 ,1, 1,4,4, 4-hexafluoro-2- butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122 in the gas mixture contains at least 99.8% 1,1,1,4,4,4-hexafluoro-2-butyne and no more than 0.2% total of one or more of 113, 122, 123 and 1122.

[0097] In one embodiment, the composition comprising 1 ,1, 1,4,4, 4-hexafluoro-2- butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122 in the gas mixture contains contains at least 99.9% 1 ,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.1% total of one or more of 113, 122, 123 and 1122.

[0098] In another embodiment, there is provided methods of using the gas mixture as an etching gas, wherein the etching gas is used to etch a film on an electronic material, such as a semiconductor. In an alternative embodiment, the invention provides a method of using an etching gas comprising oxygen and a composition comprising 1 ,1 ,1,4,4,4-hexafluoro-2-butyne and no more than 0.5% or no more than 0.1% total of one or more of 113, 122, 123 and 1122 to remove deposits from a manufacturing process chamber for electronic materials.

[0099] The invention also comprises methods for cleaning the process chamber of deposits of material, comprising activating the gas, either in a remote chamber or in situ in the process chamber, wherein the gas mixture comprises an oxygen source and a composition comprising 1,1,1 ,4,4,4-hexafluoro-2-butyne and no more than no more than 0.5% total of one or more of 113, 122, 123 and 1122, and contacting the activated gas with the surface deposits for a time sufficient to remove said deposits. The gas mixture can be activated by an RF source using sufficient power for asufficient time such that said gas mixture reaches a neutral temperature of about 800-3, 000°K to form an activated gas mixture or alternatively using a glow discharge to activate the gas, and thereafter contacting said activated gas mixture with the surface deposits and thereby removing at least some of said surface deposits.

[0100] The etch gas mixture of claim 14, wherein composition comprising1 ,1 ,1,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, contains at least 99.5% 1 ,1 ,1 ,4,4,4-hexafluoro-2-butyne.

[0101] The etch gas mixture of claim 14, wherein composition comprising1 ,1 ,1,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, contains at least 99.8% 1 ,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.2% total of one or more of 113, 122, 123 and 1122.

[0102] The etch gas mixture of claim 14, wherein composition comprising1 ,1 ,1,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, contains at least 99.9% 1 ,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.1% total of one or more of 113, 122, 123 and 1122

[0103] Surface deposits removed with this invention include those materials commonly deposited by chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD) or similar processes. Such materials include nitrogen-containing deposits such as, without limitation, silicon nitride, silicon oxynitride, silicon carbonitride (SiCN), silicon boronitride (SiBN), and metal nitrides, such as tungsten nitride, titanium nitride or tantalum nitride. In one embodiment of the invention, a preferred surface deposit is silicon nitride.

[0104] In one embodiment of the invention surface deposits are removed from surfaces used in the manufacture of electronic materials. For example, in one embodiment, there is provided a method to remove surface deposits from the interior walls of a process chamber that is used in fabricating electronic devices. Such a process chamber could be a CVD chamber or a PECVD chamber. Other embodiments of the invention include, but are not limited to, removing surface deposits from metals, the cleaning of plasma etching chambers and removal of N- containing thin films from a wafer.

[0105] In one embodiment, the process of the present invention involves an activating step wherein a cleaning gas mixture is activated in a remote chamber. Activation may be accomplished by any means allowing for the achievement of dissociation of a large fraction of the feed gas, such as: radio frequency (RF) energy, direct current (DC) energy, laser illumination, and microwave energy. One embodiment of this invention is using transformer coupled inductively coupled lower frequency RF power sources in which the plasma has a torroidal configuration and acts as the secondary of the transformer. The use of lower frequency RF power allows the use of magnetic cores that enhance the inductive coupling with respect to capacitive coupling; thereby allowing the more efficient transfer of energy to the plasma without excessive ion bombardment which limits the lifetime of the remote plasma source chamber interior. Typical RF power used in this invention has a frequency lower than 1000 kHz. In another embodiment of this invention the power source is a remote microwave, inductively, or capacitively coupled plasma source. In yet another embodiment of the invention, the gas is activated using a glow discharge.

[0106] Activation of the cleaning gas mixture uses sufficient power for a sufficient time to form an activated gas mixture. In one embodiment of the invention the activated gas mixture has a neutral temperature on the order of at least about 1000- 3,000 K. The neutral temperature of the resulting plasma depends on the power and the residence time of the gas mixture in the remote chamber. Under certain power input and conditions, neutral temperature will be higher with longer residence times. In one embodiment of the invention, a preferred neutral temperature of the activated gas mixture is over about 3,000 K. Under appropriate conditions (considering power, gas composition, gas pressure and gas residence time), neutral temperatures of at least about 1000-5,000 K may be achieved.

[0107] Preferably, the PFBY may be blended with oxygen is a HFO / O2 ratio of 0.1- 3 : 1.0 - 0.1 or existing etch / cleaning gases, or both. Preferably, the blend is further mixed with a carrier gas, such as argon, helium or nitrogen.

[0108] The activated gas may be formed in a separate, remote chamber that is outside of the process chamber, but in close proximity to the process chamber. In this invention, remote chamber refers to the chamber other than the cleaning orprocess chamber, wherein the activated gas plasma may be generated, and process chamber refers to the chamber wherein the surface deposits are located. The remote chamber is connected to the process chamber by a conduit or other means allowing for transfer of the activated gas from the remote chamber to the process chamber. For example, the transport passage may comprise a short connecting tube and a showerhead of the CVD / PECVD process chamber. The remote chamber and means for connecting the remote chamber with the process chamber are constructed of materials known in this field to be capable of containing activated gas mixtures. For instance, ceramics, aluminum and anodized aluminum are commonly used for the chamber components. Sometimes AI2O3 is coated on the interior surface to reduce the surface recombination. In other embodiments of the invention, the activated gas mixture may be formed directly in the process chamber.

[0109] The etch gas or etch gas mixture that is activated to form the activated gas comprises 1 ,1,1 ,4,4,4-hexafluoro-2-butyne (PFBY) and no more than 0.5% total of one or more of 113, 122, 123 and 1122. As used herein, an etch gas or etch gas mixture is defined as a gas or mixture of gases that are used in semiconductor manufacture that are activated to form a plasma, where the plasma may be used for etching a surface of the semiconductor, depositing a polymer layer on the surface of the semiconductor, or cleaning the process chamber of the device used in semiconductor manufacture. When used to etch a surface or clean the chamber, the etch gas may further comprise an oxygen source, a nitrogen source or an inorganic fluorine source. Typical inorganic fluorine sources include NF3 and SFe. In one embodiment of the invention, the gas mixture further comprises a fluorinated compound.

[0110] In certain blends to include nitrogen, typical nitrogen sources include molecular nitrogen (N2) and NF3. When NF3 is the inorganic fluorine source, it can also serve as the nitrogen source. Typical oxygen sources include molecular oxygen (O2). When the fluorocarbon is octafluorotetrahydrofuran or other oxygen containing fluorocarbon, that can also serve as the oxygen source. In one embodiment of the invention, the oxygen:PFBY molar ratio is at least 0.3:1. In another embodiment of the invention, the oxygen:PFBY molar ratio is at least 0.5:1. In another embodiment, the oxygen: PFBY molar ratio is at least 1 :1 or at least 3:1.

[0111] The gas mixture that is activated to form the activated gas mixture of the invention may further comprise a carrier gas. Examples of suitable carrier gasses include noble gasses such as argon and helium.

[0112] In an embodiment of the invention, the temperature in the process chamber during etching the semiconductor surface or deposition of the polymer layer may be from about -50 °C to about 150 °C.

[0113] In an embodiment of the invention, the temperature in the process chamber during removal of the surface deposits may be from about 50 °C to about 150 °C.

[0114] The total pressure in the remote chamber during the activating step may be between about 0.5 torr and about 20 torr using the Astron source. The total pressure in the process chamber may be between about 0.5 torr and about 15 torr. With other types of remote plasma sources or in situ plasmas the pressure ranges.

[0115] The gas mixture that is activated to form the activated gas mixture of the invention may further comprise a carrier gas. Examples of suitable carrier gasses include noble gasses such as argon and helium.

[0116] In an embodiment of the invention, the temperature in the process chamber during etching the semiconductor surface or deposition of the polymer layer may be from about -50 °C to about 150 °C.

[0117] In an embodiment of the invention, the temperature in the process chamber during removal of the surface deposits may be from about 50 °C to about 150 °C.

[0118] The total pressure in the remote chamber during the activating step may be between about 0.5 torr and about 20 torr using the Astron source. The total pressure in the process chamber may be between about 0.5 torr and about 15 torr. With other types of remote plasma sources or in situ plasmas the pressure ranges.

[0119] It is found in this invention that the combination of oxygen and fluorobutyne results in high etching rates of nitride films such as silicon nitride. These increases also provide lower sensitivity of the etch rate to variations in source gas pressure, chamber pressure and temperature.

[0120] Without further elaboration, it is believed that one skilled in the art can, using the description herein, utilize the present invention to its fullest extent. Afterreading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the invention. The following specific embodiments are, therefore, to be construed as merely illustrative, and do not constrain the remainder of the disclosure in any way whatsoever.EXAMPLES

[0121] Materials. The materials used to prepare the Examples are commercially available or may be prepared by known methods.Example 1. Preparation of 1316mxx from 113a

[0122] An inconel tube (1 / 2 inch OD) is filled with 2 cc (1.07 gm) of 1% Ru / SiC 1 / 8” pellets. The temperature of the catalyst bed was raised to 120°C and purged with hydrogen (50 seem) for 60 minutes and then at 250°C for 180 minutes. The temperature was then lowered to 175°C for 120 minutes while maintaining a hydrogen flow of 20 seem. The temperature was lowered to 160°C and the flow of CFC-113a free of 122 is set to 2.31 ml / hour and the hydrogen to 32 seem. The reactor effluent is analyzed every hour for 113a, 1316mxx and 122via online GCMS. Conversion is 80% and selectivity is 80% to 1316mxx which contains 100 ppm of 122.Example 2. Preparation of 1326mxz

[0123] An Inconel tube® (0.5 inch OD, 15 inch length, 0.34 in wall thickness) was filled with 3 cc (1.2 gm) of Pd / Cu on acid washed carbon (12-20 mesh). The temperature of the reactor was raised to 100°C for 30 minutes under N2 flow (30 seem). The temperature was then increased to 200°C under H2 flow for one hour. A mixture of Z- and E-isomers of 1316mxx containing 50 ppm 122 (0.87 g / mL) was fed with 12 seem H2 at 175°C and 145 psig. The contact time is 90 s. The effluent of the reactor is analyzed online periodically for 1316mxx, 1326mxz and 1122 using an Agilent® 6890 GC / 5973 MS and a Restek® PC2618 5% Krytox® CBK-D / 60 / 80 6 meter x 2mm ID 1 / 8” OD packed column purged with helium at 30 seem. The product mixture contains 10-25 ppm 1122 (CHCI=CF2) and 10-15% 1326mxz (mixture of Z- and E-isomers of 1326mxz).Comparative example 2. Preparation of 1326mxz

[0124] An Inconel tube® (0.5 inch OD, 15 inch length, 0.34 in wall thickness) was filled with 3 cc (1 .2 gm) of Pd / Cu on acid washed carbon (12-20 mesh). The temperature of the reactor was raised to 100°C for 30 minutes under N2 flow (30 seem). The temperature was then increased to 200°C under H2 flow for one hour. 1316mxx containing 100 ppm 122 (0.87 g / mL) was fed with 12 seem H2 at 175°C and 145 psig. The contact time is 90 s. The effluent of the reactor is analyzed online periodically for 1316mxx, 1326mxz and 1122 using an Agilent® 6890 GC / 5973 MS and a Restek® PC2618 5% Krytox® CBK-D / 60 / 80 6 meter x 2 mm ID 1 / 8” OD packed column purged with helium at 30 seem. 20- 50 ppm 1122 (CHCI=CF2) formation was observed along with 10-15% formation of 1326mxz (mixture of Z- and E-isomers of 1326mxz).Example 3. Preparation of pfby

[0125] NaOH aqueous solution (12 mL, 0.12 mol) is added to the mixture of Z / E- 1326mxz containing 100 ppm 1122 (20 g, 0.1 mol) and water (18 mL) in the presence of Aliquat® 336 (0.53 g, 0.001325 mol) at 35°C. The reaction temperature was raised to 70°C after the addition, and gas chromatography was used to monitor the reaction for 1326mxz, PFBY and 1122. The reaction is completed after 2.5 hour and 15.0 product (conversion: 100%; yield: 92% PFBY containing 100 ppm 1122) was collected in a dry ice trap.Example 4. Preparation of 1336mzzz

[0126] An Inconel tube® (0.5 inch OD, 15 inch length, 0.34 in wall thickness) was filled with 2.6 cc (3.2 gm) of 200 ppm Pd on AI2O3 (12-20 mesh). The temperature of the reactor was raised to 100°C for 30 minutes under N2 flow (30 seem). The temperature was then increased to 200°C under H2 flow for one hour. PFBY containing 500 ppm 1122 (2 seem) was fed with 25.9 seem H2 in N2 (5% H2 in N2) at 95°C and 50 psig. The contact time was 20 s. The effluent of the reactor was analyzed online for PFBY, 1326mxzZ, 1326mxzE and 1336mzzZ using an Agilent®6890 GC / 5973 MS and a Restek® PC2618 5% Krytox® CBK-D / 60 / 80 6 meter x 2mm ID 1 / 8” OD packed column purged with helium at 30 seem. 10 ppm 1326mxzZ and 1 ppm 1326mxzE formation was observed along with 26% formation of 1336mzzZ.Comparative example 4. Preparation of 1336mxxz

[0127] An Inconel tube® (0.5 inch OD, 15 inch length, 0.34 in wall thickness) was filled with 2.6 cc (3.2 gm) of 200 ppm Pd on AI2O3 (12-20 mesh). The temperature of the reactor was raised to 100°C for 30 minutes under N2 flow (30 seem). The temperature was then increased to 200°C under H2 flow for one hour. PFBY containing 1000 ppm 1122 (2 seem) was fed with 25.9 seem H2 in N2 (5% H2 in N2) at 95°C and 50 psig. The contact time was 20 s. The effluent of the reactor was analyzed online for PFBY, 1326mxzZ, 1326mxzE and 1336mzzZ using an Agilent® 6890 GC / 5973 MS and a Restek® PC2618 5% Krytox® CBK-D / 60 / 80 6 meter x 2mm ID 1 / 8” OD packed column purged with helium at 30 seem. 25 ppm 1326mxzZ and 2 ppm 1326mxzE formation was observed along with 26% formation of 1336mzzZ.

[0128] While not wishing to be bound by theory, it is suggested that during PFBY hydrogenation to 1336mzzZ, 1122 that is present in the PFBY is hydrogenated to form 152a plus HCI. HCI addition to PFBY forms 1326mxzZ and 1326mxzE, which have boiling points of 35°C and 42°C, respectively. Since the boiling point of 1336mzzZ is 33°C, 1326mxz formation may negatively impact the product purity due separation difficulty (close boiling points). In addition, HCI formation in PFBY hydrogenation in combination with inadvertent moisture that may be present may cause equipment corrosion. For these reasons, there is particular benefit to understand the concentration of 1122 and 1122 precursors in starting materials and intermediates that are used in producing 1336mzzZ.

Claims

CLAIMSWhat is claimed is:

1. A composition comprising 1 ,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122.

2. The composition of claim 1 wherien the composition comprises no more than 0.2% total of one or more of 113, 122, 123 and 1122.

3. The composition of claim 1 wherien the composition comprises no more than 0.1 % total of one or more of 113, 122, 123 and 1122.

4. The composition of claim 1 wherien the composition comprises no more than 0.05% total of one or more of 113, 122, 123 and 1122.

5. The composition of claim 1 wherien the composition comprises no more than 0.01% total of one or more of 113, 122, 123 and 1122.

6. The composition any of claims 1-5, wherein the composition comprises 113.

7. The composition any of claims 1-5, wherein the composition comprises 122.

8. The composition any of claims 1-5, wherein the composition comprises 123.

9. The composition any of claims 1-5, wherein the composition comprises 1122.

10. The composition any of claims 1-9, wherein the composition further comprises at least one of HFC-23, HFC-41 , HCFC-132b, HCFC-142b, HFC- 143a, HFC-152a, trifluoropropyne, HFC-263fb, HFC-356mff, HCFO-1122, HCFO-Z-1326mxz, HCFO-E-1326mxz, HFO-1327mz, HFO-E-1336mzz, and trifluoroacetone.11 . The composition of claim 10 wherein the composition comprises no more than 0.5% total of one or more of HFC-23, HFC-41, HCFC-132b, HCFC-142b,H FC- 143a, H FC- 152a, trifluoropropyne, HFC-263fb, HFC-356mff, HCFO- 1122, HCFO-Z-1326mxz, HCFO-E-1326mxz, HFO-1327mz, HFO-E-1336mzz, and trifluoroacetone.

12. The composition of claim 11 comprising HCFO-Z-1326mxz, HCFO-E- 1326mxz, and HFO-1327mz.

13. The composition of claim 11 , wherein the composition comprises HCFO-1122, HCFO-Z-1326mxz, and HCFO-E-1326mxz.

14. An etch gas mixture comprising oxygen and a composition comprising1,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122.

15. The etch gas mixture of claim 14, wherein composition comprising1,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, contains at least 99.5% 1 ,1, 1,4,4, 4-hexafluoro-2- butyne.

16. The etch gas mixture of claim 14, wherein composition comprising1,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, contains at least 99.8% 1 ,1, 1,4,4, 4-hexafluoro-2- butyne and no more than 0.2% total of one or more of 113, 122, 123 and 1122.

17. The etch gas mixture of claim 14, wherein composition comprising1,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, contains at least 99.9% 1 ,1, 1,4,4, 4-hexafluoro-2- butyne and no more than 0.1% total of one or more of 113, 122, 123 and 1122.

18. The etch gas mixture of any of claim 14-17, further comprising a carrier gas.

19. The etch gas mixture of any of claim 14-17, wherein the carrier gas is He, Ar, or N2,20. The etch gas mixture of any of claim 14-17, wherein the etch gas mixture further comprises a second etch gas, wherein the second etch gas is a fluorinated compound, SFe, or NF3.

21. The etch gas mixture of claim 20, wherein the second etch gas is selected from the group consisting of tetrafluoromethane, hexafluoroethane, octafluoropropane, perfluorotetrahydrofuran, hexaflurobutadiene, and octafluorocyclobutane.

22. A method of operation of a semiconductor manufacturing process chamber, comprising etching a film on a semiconductor using the etch gas mixture of any of claims 14-17.

23. The method of claim 22, wherein the step of etching a film further comprises, i. transferring a photomask to the semiconductor to create a masked surface and an exposed surface, ii. forming a plasma of said etch gas mixture, and iii. exposing the exposed surface of the semiconductor to the plasma to remove portions of the exposed surface of the semiconductor to form an etched surface of the semiconductor.

24. The method of claim 23, wherein the method further comprises the steps of forming a second etch gas, activating the second etch gas to form a second plasma, depositing the second plasma on the etched surface to form a polymer layer on the etched surface of the semiconductor, wherein the second etch gas is a fluorinated compound, SFe, or NF3.

25. The method of claim 23 wherein the said surface deposit is selected from the group consisting of silicon oxide, gallium nitride, silicon nitride, silicon oxynitride, silicon carbonitride, tungsten nitride, titanium nitride, and tantalum nitride.

26. The method of claim 22, wherein step of forming a plasma from the etch gas is performed in a remote chamber or in the process chamber.

27. The method of claim 22, wherein the molar ratio of etch gas mixture comprises oxygen in molar ratio of oxygen : PFBY is at least about 1 :1.

28. The method of claim 27, wherein the pressure in the process chamber is no more than 30 torr.

29. The method of claim 27, wherein the pressure in the remote chamber is from 0.5 torr to 50 torr.

30. The method of any of claims 22-27, wherein the etch gas mixture replaces hexachlorobutadiene.31 . A method for removing surface deposits from a surface in a process chamber, comprising activating a gas mixture comprising oxygen and a composition comprising 1 ,1 ,1 ,4,4,4-hexafluoro-2-butyne and no more than 0.5% total of one or more of 113, 122, 123 and 1122, wherein the molar percentage of PFBY in the said gas mixture is from about 5% to about 99%, and contacting said activated gas mixture with the surface deposits and thereby removing at least some of said deposits.

32. The method of claim 30 wherein said process chamber is the interior of a deposition chamber that is used in fabricating electronic devices.

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