content_image/914220.jpg content_image/914223.jpg content_image/914224.jpg content_image/914219.jpg content_image/914221.jpg
Exemplary PAGs are described in JP-A 2008-111103, para› graphs [0122]-[0142](U.S. Pat. No. 7,537,880). 

[0098] As the PAG used herein, sulfonium salts having the formula (1-1) and iodonium salts having the formula (1-2) are also preferred. 

101 102 R103 R104 [0099] In formulae (1-1) and (1-2) R , R , , and R $^{105 }$are each independently a C$_{1 }$-C$_{20 }$hydrocarbyl group which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated and straight, ~ranched or cyclic. Examples thereof include those exemplified above for R $^{21 }$to R $^{28 }$in formulae (fl) to (f3). 

[0100] R 101 and R $^{102 }$may bond together to form a ring with the sulfur atom to which they are attached. Preferred examples of the ring are shown by the following structure 

<img src='content_image/914220.jpg'>

<img src='content_image/914223.jpg'>

<img src='content_image/914224.jpg'>

(1-1) 

(1-2) 

[0101] Herein the broken line designates an attachment to R103_ 

[0102] Examples of the cation in the sulfonium salt having formula (1-1) are shown below, but not limited thereto. 

<img src='content_image/914219.jpg'>

-continued 

<img src='content_image/914221.jpg'>

