Patent ID: 11953832
Assignee: SHIN-ETSU CHEMICAL CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 1:
2. The positive resist composition of claim 1 wherein the repeat units (a) have the formula (a):, wherein RA is hydrogen or methyl,
X1 is a single bond, ester bond, ether bond, phenylene group or naphthylene group,
X2 is a single bond, a phenylene group, or a C1-C12 saturated hydrocarbylene group which may contain an ether bond, ester bond, amide bond, lactone ring or sultone ring,
X3 is a single bond, ester bond or ether bond,
R1 is halogen, hydroxy or a C1-C4 alkyl group,
R2 to R4 are each independently a halogen or a C1-C20 hydrocarbyl group which may contain a heteroatom, R2 and R3 may bond together to form a ring with the sulfur atom to which they are attached, and
m is an integer of 0 to 3.