非制冷红外焦平面阵列读出电路的BCB牺牲层接触平坦化(英文)  

Planarization on ROIC surface topography with BCB for uncooled infrared focal plane arrays

作　　者：刘欢[1] 刘卫国[1] 周顺[1] 蔡长龙[1] 

机构地区：[1]西安工业大学陕西省薄膜技术与光学检测重点实验室,陕西西安710032

出　　处：《红外与激光工程》2012年第5期1163-1167,共5页Infrared and Laser Engineering

基　　金：西安市科技局计划项目(CXY1015-1);陕西省教育厅科研计划项目(12JK0686);西安工业大学校长基金(XAGDXJJ1002)

摘　　要：研究了一种基于BCB材料的牺牲层接触平坦化技术,用于红外焦平面阵列Post CMOS工艺之前对读出电路表面的平坦化,以利于微测辐射热计微桥阵列与读出电路的集成。利用该方法成功将2μm的电路表面突起,平坦化为表面起伏56 nm的平面,可替代会给器件带来颗粒和损伤的化学机械抛光(CMP)技术。并在该平坦层上方成功进行了非晶硅敏感薄膜的沉积、微桥结构的图形化以及同时作为牺牲层的BCB的释放。通过实验研究了BCB膜层的厚度与转速、固化温度的关系,实验发现BCB的收缩率随温度小范围变化,约为30%。研究了BCB的等离子刻蚀特性,表明该材料适合用等离子刻蚀的方法进行接触孔的刻蚀和牺牲层释放。最后,利用BCB牺牲层接触平坦化技术成功地在读出电路(ROIC)芯片上制作了160×120面阵的非制冷红外焦平面阵列。A planarization procedure was developed to achieve a flat surface of readout integrated circuit （ROIC） for the integration between microbolometer arrays and ROIC. The planarization material benzocyclobutene （BCB） was used as sacrificial layer. Amorphous Silicon （a-Si） film was deposited on the planarization layer and in the contact holes using plasma enhanced chemical vapor deposition （PECVD）, and then patterned by lithography and plasma etching. The BCB was removed to form the a- Si self-supporting micro-bridge structure. The shrinkage rate of BCB films thickness after curing was about 30%, which slightly changed with temperature, Under the optimal condition, BCB film successfully reduces the 2 t^m height of the bumps on ROIC down to less than 56 nm, which satisfies the surface topology requirement for the subsequent fabrication of flat microbolometer structure. 160x120 bolometer arrays are fabricated over the planarized BCB polymer mesas and then the BCB sacrificial layers are removed successfully.

关 键 词：BCB 测辐射热计阵列 ROIC 平坦化 等离子刻蚀 

分 类 号：TN405[电子电信—微电子学与固体电子学]