利用光刻胶作刻蚀掩模对半导体样品进行感应耦合等离子体干法刻蚀时发现光刻胶掩模在刻蚀后表面出现凸起和孔洞等异常现象, 等离子体会透过部分孔洞对样品表面产生刻蚀损伤。利用探针式表面轮廓仪和激光共聚焦显微镜对这些异常现象进行了分析, 认为是刻蚀时等离子体气氛中的紫外线对作为掩模的光刻胶进行了曝光作用而释放出一定量的氮气, 从而在光刻胶内外形成了压强差而使光刻胶局部表面产生微凸起; 当光刻胶的强度无法阻止内部氮气的膨胀时, 则会发生类似爆炸的效果, 在光刻胶表面形成孔洞状缺陷, 导致掩模保护作用的失效。

Inductively Coupled Plasma (ICP) dry etching of semiconductor samples was carried out using photoresist as the etching mask. It was found that the abnormal structures such as lumps and holes appeared on the surface of the mask after ICP etching, and the plasma could etch through some holes and cause damage to the sample which led to a procedure failure. The abnormal surface of the mask was analyzed with stylus profiling and laser confocal measurement, and it was thought that the abnormality of the mask was due to the exposure reaction between the photoresist and the ultraviolet light produced by ICP plasma which would release nitrogen gas. Pressure difference formed by the released nitrogen swelled the mask at dispersive tiny spots. When the pressure was too big to be sustained by the mask, an explosive effect would happen and holes were formed on the surface thereafter, which led to the failure of the protection effect of the mask.