微纳电子技术

以薄膜体声波谐振器(FBAR)的背腔刻蚀为研究背景,研究了光刻工艺参数设置与光刻图形转移效果的关系。分析了紫外曝光剂量大小对光刻图形面积和边角曲率的影响,优化得到最佳工艺流程,以AZ4620光刻胶为掩膜实现了氮化硅的湿法刻蚀。实验结果表明,曝光剂量为60 mJ、显影时间60 s时,曝光图形化质量最佳;随着氮化硅刻蚀液温度的升高,湿法刻蚀速率不断增大,温度过高导致光刻胶被破坏而不能起到掩膜作用,60℃时刻蚀速率为109.5 nm/min,得到了边线规整、底部平整的微结构。刻蚀后表面分子喇曼位移为单晶硅的波峰(519.354 cm^-1),证实氮化硅被完全去除,为氮化硅作掩膜的单晶硅湿法刻蚀提供了一种有效途径。

With the back cavity etching of a film bulk acoustic resonator(FBAR)as the research background,the relationship between the parameter setting of lithographic process and the transfer effect of lithography pattern was studied.The effects of the UV exposure dose on the area and corner curvature of the lithography pattern were analyzed.The optimal technological process was obtained.The wet etching of silicon nitride was realized by using AZ4620 photoresist as the mask.The experiment shows that the quality of the exposure pattern is the best with the condition of the exposure dose of 60 mJ and the developing time of 60 s.With the increase of the temperature of the silicon nitride etching liquid,the wet etching rate increases continuously.When the temperature is too high,the photoresist is destroyed and can't play the role of the mask.The microstructure with good quality in both the edge and bottom is obtained when the etch rate is109.5 nm/min at 60 ℃.The Raman shift of the surface molecule is the wave peak of monocrystalline silicon(519.354 cm^-1)after etching,which confirms that the silicon nitride is completely removed and provides an effective way for monocrystalline silicon wet etching with silicon nitride as the mask.