The production of 1,1,2-trifluoro-2-(trifluoromethyl)cyclobutane (TFMCB). More specifically, the present invention relates to a process for making 1,1,2-trifluoro-2-(trifluoromethyl)cyclobutane via a continuous catalytic reaction from commercially available raw materials ethylene and hexafluoropropene.

The production of 1,1,2-trifluoro-2-(trifluoromethyl)cyclobutane (TFMCB). More specifically, the present invention relates to a process for making 1,1,2-trifluoro-2-(trifluoromethyl)cyclobutane via a continuous catalytic reaction from commercially available raw materials ethylene and hexafluoropropene.

A halogenated cycloalkane compound is obtained at a high conversion rate by reacting a halogenated cycloalkene compound and a hydrogen-containing gas in the presence of a hydrogenated catalyst or a catalyst having a hydrogen content of 0.1 to 1.5 mass %.

A halogenated cycloalkane compound is obtained at a high conversion rate by reacting a halogenated cycloalkene compound and a hydrogen-containing gas in the presence of a hydrogenated catalyst or a catalyst having a hydrogen content of 0.1 to 1.5 mass %.

A halogenated cycloalkane compound is obtained at a high conversion rate by reacting a halogenated cycloalkene compound and a hydrogen-containing gas in the presence of a hydrogenated catalyst or a catalyst having a hydrogen content of 0.1 to 1.5 mass %.

Provided is an octafluorocyclobutane purification method capable of removing contained fluorocarbons to yield a highly pure octafluorocyclobutane. The octafluorocyclobutane purification method includes a decomposition step of mixing a crude octafluorocyclobutane containing octafluorocyclobutane and fluorocarbons as impurities with oxygen gas or air to give a mixed gas containing the oxygen gas or air at a concentration of 1% by volume or more and 90% by volume or less and bringing the mixed gas into contact with an impurity decomposing agent containing alumina and an alkaline earth metal compound and to decompose fluorocarbons, at a temperature of 100° C. or more and 500° C. or less to decompose the fluorocarbons and a concentration step of removing, from the mixed gas in which the fluorocarbons have been decomposed in the decomposition step, the gas containing oxygen gas or air (except octafluorocyclobutane) to increase the concentration of the octafluorocyclobutane.

Provided is an octafluorocyclobutane purification method capable of removing contained fluorocarbons to yield a highly pure octafluorocyclobutane. The octafluorocyclobutane purification method includes a decomposition step of mixing a crude octafluorocyclobutane containing octafluorocyclobutane and fluorocarbons as impurities with oxygen gas or air to give a mixed gas containing the oxygen gas or air at a concentration of 1% by volume or more and 90% by volume or less and bringing the mixed gas into contact with an impurity decomposing agent containing alumina and an alkaline earth metal compound and to decompose fluorocarbons, at a temperature of 100° C. or more and 500° C. or less to decompose the fluorocarbons and a concentration step of removing, from the mixed gas in which the fluorocarbons have been decomposed in the decomposition step, the gas containing oxygen gas or air (except octafluorocyclobutane) to increase the concentration of the octafluorocyclobutane.

A plasma etching method according to an embodiment is a method for etching a silicon-containing film by using plasma of a fluorocarbon gas. The fluorocarbon gas includes at least one selected from a first fluorocarbon which has a main chain of six or more carbons bonded in a linear manner, the main chain having a structure of single bond and double bond alternately joined, a second fluorocarbon which has a main chain of six or more carbons bonded in a linear manner, the main chain having a structure of single bond and triple bond alternately joined, and a third fluorocarbon which has a main chain of five or more carbons bonded in a linear manner, the main chain having a structure which includes double bond and triple bond.

A plasma etching method according to an embodiment is a method for etching a silicon-containing film by using plasma of a fluorocarbon gas. The fluorocarbon gas includes at least one selected from a first fluorocarbon which has a main chain of six or more carbons bonded in a linear manner, the main chain having a structure of single bond and double bond alternately joined, a second fluorocarbon which has a main chain of six or more carbons bonded in a linear manner, the main chain having a structure of single bond and triple bond alternately joined, and a third fluorocarbon which has a main chain of five or more carbons bonded in a linear manner, the main chain having a structure which includes double bond and triple bond.

Etching gases are disclosed for plasma etching channel holes, gate trenches, staircase contacts, capacitor holes, contact holes, etc., in Si-containing layers on a substrate and plasma etching methods of using the same. The etching gases are trans-1,1,1,4,4,4-hexafluoro-2-butene; cis-1,1,1,4,4,4-hexafluoro-2-butene; hexafluoroisobutene; hexafluorocyclobutane (trans-1,1,2,2,3,4); pentafluorocyclobutane (1,1,2,2,3-); tetrafluorocyclobutane (1,1,2,2-); or hexafluorocyclobutane (cis-1,1,2,2,3,4). The etching gases may provide improved selectivity between the Si-containing layers and mask material, less damage to channel region, a straight vertical profile, and reduced bowing in pattern high aspect ratio structures.