US 10,921,710 B2  89  90  -continued  ~  0- y  ;\_____;coo- s  ~  Q  O C;C  CC  I~  ,,-::9  0  +  -continued  _  ()  ¢  0  +  ;\_____;coo- ~  When used, the quencher is preferably added in an  amount of0.001 to 12 parts, more preferably 0.01 to 8 parts  by weight per 100 parts by weight of the base resin (A). The  inclusion of the quencher allows for easy control of resist  sensitivity and holds down the diffusion rate of acid in the  resist film, which leads to many advantages including  improved resolution, minimized sensitivity change follow› ing exposure, reduced substrate poisoning and environment  dependency, and improved exposure latitude and pattern  profile. The quencher is also effective for improving adhe› sion to the substrate. The quencher may be used alone or in  admixture.  The resist composition may further comprise a surfactant  which is insoluble or substantially insoluble in water and  soluble in alkaline developer, and/or a surfactant which is  insoluble or substantially insoluble in water and alkaline  Surfactant 