Accession Number : ADA183151

Title :   Radiolysis of Poly(chloroacetaldehyde), A Positive E-Beam Resist.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS UNIV AMHERST DEPT OF POLYMER SCIENCE AND ENGINEERING

Personal Author(s) : Chien,James C ; Lu,Ping-Hung

PDF Url : ADA183151

Report Date : Jun 1987

Pagination or Media Count : 36

Abstract : The gamma radiolysis and deep ultraviolet photolysis of poly(chloroacetaldehyde), PCA, caused efficient depolymerizations at ambient temperature. The processes are promoted by oxygen; the G(m) value (number of monomer produced per 100 eV absorbed) is 11,000 in the presence of air. The chain scission yield is also high (G(s)=5.5) without crosslinking (G(x)=0). These processes are much less efficient in vacuo; G(m)=1,100, G(s) = 1,100, G(s) = 2.1, G(x) = 0. Depolymerizations stop short of completion due to repolymerization of monomer formed. Bu4NBr has no effect on the gamma-induced depolymerization but 2,6-di-t-butyl-p-cresol retards it suggesting the participation of free radicals rather than ionic species in the processes. This interpretation is supported by electron spin resonance evidences. PCA is highly susceptible to degradation by plasma. However, this susceptibility can be suppressed by DUV crosslinking of PCA with bis(azidoformates) prior to plasma exposure. Halogen containing polymers possessing low ceiling temperature may find usages as self-developing plasma etchable positive resists.

Descriptors :   *POLYMERS, *ACETALDEHYDE, TEMPERATURE, DEGRADATION, FREE RADICALS, DEPOLYMERIZATION, GAMMA RAYS, CEILING, LOW TEMPERATURE, OXYGEN, PHOTOLYSIS, ULTRAVIOLET RADIATION, ELECTRON SPIN RESONANCE, RADIOLYSIS, IONS, MONOMERS, EXPOSURE(GENERAL), PLASMAS(PHYSICS), ELECTRON BEAMS

Subject Categories : Radiation and Nuclear Chemistry
      Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE