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(In general formula (a), Ra is an unsubstituted alkyl group, R 6 to Rd are each a fluorine atom or a fluorine atom› substituted alkyl group, and at least one of Ra to Rd includes a fluorine atom.) Note that the compound represented by general formula (a) is a fluorine-containing compound, and a solvent that comprises this fluorine-containing compound is a fluorine-containing solvent. 

[0106] Examples of unsubstituted alkyl groups that can constitute Ra in general formula (a) include unsubstituted alkyl groups having a carbon number of not less than 1 and not more than 5, of which, a methyl group or an ethyl group is preferable. 

[0107] Moreover, the fluorine atom-substituted alkyl group that can constitute any ofR $^{6 }$to Rd in general formula (a) is preferably a fluorine atom-substituted alkyl group having a carbon number of not less than 1 and not more than 5, and more preferably a 1,1,2,2,3,3,3-heptafluoropropyl group or a 1,1,2,2,2-pentafluoroethyl group. 

[0108] Although the rinsing liquid can contain one com› pound represented by general formula (a) or can contain a plurality of compounds represented by general formula ( a), it is preferable that the rinsing liquid contains only one compound represented by general formula (a) from a view› point of ease of collection and re-use of the rinsing liquid. Note that it is preferable that the rinsing liquid does not substantially contain, in addition to a compound represented by general formula (a), any of the compounds previously described as the "developer" or any other solvent that can typically be used in a pattern formation method using a main chain scission-type positive resist composition. The phrase "does not substantially contain" refers to an extremely low ratio relative to the overall rinsing liquid, such as less than 0.1 volume %. 

[0109] In particular, preferable examples of compounds that can be represented by general formula (a) and can be contained in the rinsing liquid include methyl nonafluo› robutyl ether (surface tension: 13.6 mN/m; SP value: 6.5 (cal/cm 3 ) 112 ; freezing point: -135° C.; boiling point: 61 ° C.) represented by general formula (a-1), shown below, ethyl nonafluorobutyl ether (surface tension: 13.6 mN/m; SP value: 6.3 (cal/cm 3 ) 112 ; freezing point: -138° C.; boiling point: 76° C.) represented by general formula (a-2), shown below, and 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(tri› fluoromethyl)pentane (surface tension: 15.0 mN/m; SP value: 6.2 ( cal/cm 3 ) 112 ; freezing point (pour point): -38° C.; boiling point: 98° C.) represented by general formula (a-3), shown below, with methyl nonafluorobutyl ether represented by general formula (a-1) and ethyl nonafluorobutyl ether represented by general formula (a-2) being more preferable from a viewpoint of even more effectively inhibiting the presence of residues in an obtained resist pattern. 

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[0110] The solubility parameter (SP value) of the rinsing liquid is preferably 11.0 ( cal/cm 3 ) $^{112 }$or less, more preferably less than 6.8 (cal/cm 3 ) 112 , and even more preferably 6.5 ( cal/cm 3 ) 112 or less from a viewpoint of even more effec› tively inhibiting the presence of residues in an obtained resist pattern. Note that the SP value of the rinsing liquid can, for example, be 2.0 (cal/cm 3 ) $^{112 }$or more. The freezing point of the rinsing liquid is preferably -30° C. or lower, and may be -100° C. or lower. The boiling point of the rinsing liquid is preferably 100° C. or lower, and more preferably 80° C. or lower. Note that the "freezing point" and the "boiling point" of the rinsing liquid are values at 1 atm (absolute pressure). 

[0111] The temperature of the rinsing liquid is not spe› cifically limited and can be set as not lower than 21 ° C. and not higher than 25° C., for example. Moreover, the rinsing time can be set as not less than 5 seconds and not more than 3 minutes, for example. 

[0112] The following provides a more specific description of the present disclosure based on examples. However, the present disclosure is not limited to the following examples. In the following description, "%" and "parts" used in expressing quantities are by mass, unless otherwise speci› fied. 

[0113] In the examples and comparative examples, the following methods were used to measure and evaluate the weight-average molecular weight, number-average molecu› lar weight, and molecular weight distribution of a copoly› mer, and the density and sensitivity to extreme ultraviolet light of a resist film. Note that the SP value of a developer and the SP value of a rinsing liquid were calculated by the group contribution method of Hoy. Moreover, the surface tension of a developer and the surface tension of a rinsing liquid were measured by the ring method at 25° C. 

[0114] <Weight-Average Molecular Weight, Number-Av› erage Molecular Weight, and Molecular Weight Distribu› tion> 

[0115] The weight-average molecular weight (Mw) and the number-average molecular weight (Mn) of a copolymer obtained in each example or comparative example were measured by gel permeation chromatography, and then the molecular weight distribution (Mw/Mn) of the copolymer was calculated. Specifically, the weight-average molecular weight (Mw) and the number-average molecular weight (Mn) of the copolymer were determined as values in terms of standard polystyrene using a gel permeation chromato› graph (HLC-8220 produced by Tosoh Corporation) with 

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## EXAMPLES 

