Positive photoresist compositions having deep UV response, photosensitive elements and thermally stable photochemically imaged systems containing same
申请人:HOECHST CELANESE CORPORATION
公开号:EP0140273A2
公开(公告)日:1985-05-08
Actinic (deep ultraviolet, ultraviolet and visible light sensitive positive photoresist compositions containing a mixture of an alkali-insoluble photoactive compound capable of being transformed into an alkali-soluble species upon exposure to actinic radiation, in an amount sufficient to render the mixture relatively alkali insoluble and a polymer comprising an amount of tCO-NH-COt groups, such as maleimide and especially maleimide - substituted styrene copolymers, sufficient to render the mixture readily alkali soluble upon exposure to actinic radiation are disclosed. The preferred copolymers include maleimide/styrene or a-methylstyrene in a 1:1 molar ratio. The preferred photoactive compound suitable for a positive photoresist composition responsive to deep UV actinic radiation has the formula 18-8 in Table I. The present invention also contemplates photosensitive elements and thermally stable photochemically imaged systems based on the actinic light sensitive positive photoresist compositions. The positive photoresist compositions are coated onto a substrate to produce a photosensitive element, which upon exposure to a pattern of actinic radiation of wavelength in the range of about 200-700 nm produces a photochemically imaged system that can be treated with an alkaline developer to form highly resolved patterns, by highly selective removal of exposed areas. After development, preferred embodiments of the photochemically images systems exhibit insignificant changes in the highly resolved features (one micron) in the patterned image upon postbaking at temperatures of about 230°C and is, thereafter readily stripped. The high thermal stability exhibited by the photochemically imaged systems formed from the positive photoresist compositions of the present invention allows faster processing at higher temperatures, on equipment like plasma etchers and ion implanters; the developed photochemically imaged systems of the present invention retain high resolution, i.e., retain sharp, steep patterned image profiles.
本发明公开了阳极(深紫外线、紫外线和可见光敏感的正极光刻胶组合物,该组合物含有一种碱不溶性光活性化合物的混合物,该化合物在暴露于阳极辐射时能够转变成碱溶性物质,其含量足以使该混合物相对碱不溶,还含有一种包含一定量 tCO-NH-COt 基团的聚合物,例如马来酰亚胺,特别是马来酰亚胺-取代苯乙烯共聚物,其含量足以使该混合物在暴露于阳极辐射时容易碱溶解。优选的共聚物包括马来酰亚胺/苯乙烯或 a-甲基苯乙烯,摩尔比为 1:1。适用于对深紫外线辐射有反应的正性光刻胶组合物的优选光活性化合物具有表 I 中的式 18-8。本发明还考虑了基于光敏正性光刻胶组合物的光敏元件和热稳定光化学成像系统。将正性光致抗蚀剂组合物涂在基底上可产生光敏元件,该光敏元件暴露于波长范围约为 200-700 纳米的光辐射图案后,可产生光化学成像系统,该系统可用碱性显影剂处理,通过高度选择性地去除暴露区域,形成高分辨率图案。经过显影后,光化学成像系统的优选实施例在约 230°C 的温度下进行后烘烤时,图案图像中的高分辨率特征(一微米)会出现微小的变化,随后很容易剥离。由本发明的正性光刻胶组合物形成的光化学成像系统具有很高的热稳定性,可以在等离子刻蚀机和离子注入机等设备上以更高的温度进行更快的加工;本发明的光化学成像系统可以保持高分辨率,即保持清晰、陡峭的图案图像轮廓。