US 10,915,021 B2  169  170  -continued  0  j  0  ___r-{O_z_~F3  o~  ,  Lso$_{3}$ - o  Q_>-o-<:-t:~  -continued  0  ,-q-o  I  0  0  0  F3C~S03- I  ,-q  0  I  When the resist composition contains the acid generator  of addition type, an appropriate amount of the generator  added is 0.1 to 50 parts, more preferably 1 to 40 parts by  weight per 100 parts by weight of the base resin.  The resist composition may further comprise any addi› tives such as a quencher, dissolution regulator, surfactant,  and acetylene alcohol.  The addition of the quencher to the resist composition is  effective, for example, for reducing the rate of acid diffusion  in the resist film, thus contributing to a further improvement  in resolution. Suitable quenchers are basic compounds  including those described in JP-A 2008-111103, paragraphs  [0146]-[0164] (U.S. Pat. No. 7,537,880). Preferred are pri› mary, secondary and tertiary amine compounds, specifically  amine compounds having a hydroxyl group, ether bond,  ester bond, lactone ring, cyano group or sulfonic ester bond.  An appropriate amount of the basic compound added as the  quencher is Oto 100 parts, more preferably 0.001 to 50 parts  by weight per 100 parts by weight of the base resin.  Also useful are quenchers of polymer type as described in  JP-A2008-239918 (U.S. Pat. No. 7,598,016). The polymeric  quencher segregates at the resist surface after coating and  thus enhances the rectangularity of resist pattern. When a  protective film is applied on the resist film, the polymeric  Other Components 