Development of new electron-beam resist

以偶氮二异丁腈为引发剂，在苯中通过溶液聚合制备了甲基丙烯酸2，3-环硫丙酯（ETMA）-苯乙烯衍生物共聚物，并研究了该共聚物的电子束曝光特性。使用对氯苯乙烯（pCS）、间氯苯乙烯（mCS）和氯甲基苯乙烯（CMS）作为苯乙烯衍生物。采用溶解-沉淀法对本体共聚物进行分级，得到了分子量分布较低的共聚物。结果表明：共聚物的电子束敏感性随分子量和ETMA含量的增加而增加;具有较低分子量和较低分子量分布的共聚物显示出较高的对比度。ETMA-PCS共聚物的灵敏度略低于ETMA-MCS共聚物，对比度顺序与ETMA-MCS共聚物相反。的敏感性。虽然ETMA-CMS共聚物具有比ETMA-pCS和ETMA-MCS更高的灵敏度，但ETMA-CMS作为电子束抗蚀剂是不稳定的。ETMA-pCS共聚物比ETMA均聚物具有更高的耐干蚀刻性。ETMA-PCS和ETMA-MCS共聚物分别显示出0.6 μ m和0.45 μ m的分辨率。

Copolymers of 2, 3-epithiopropyl methacrylate (ETMA)-styrene derivatives were prepared by solution polymerization in benzene using azbisisobutyronitrile as an initiator and the electron-beam exposure characteristics of these copolymers were investigated. p-Chlorostyrene (pCS), m-chlorostyrene (mCS), and chloromethylstyrene (CMS) were used as styrene derivatives. The copolymers with lower molecular weight distribution were obtained by fractionation of bulk copolymers using dissolution-precipitation method. The following results on. electron-beam exposure charactreristics were obtained : Electron-beam sensitivity of these copolymers increased with increasing molecular weight and ETMA content. The copolymers with lower molecular weight and lower molecular weight distribution showed higher contrast. The sensitivity of ETMA-PCS copolymers was slightly lower than that of ETMA-MCS copolymers, and the order of contrast was reverse to that. of sensitivity. Although ETMA-CMS copolymers had higher sensitivity than ETMA-pCS and ETMA-MCS, the ETMA-CMS was unstable as electron beam resist. ETMA-pCS copolymers had higher dry etching resistance than ETMA homopolymers. ETMA-PCS and ETMA-MCS copolymers showed resolution capacity of 0.6 mum and 0.45 mum, respectively.