晶圆级封装中硅基盖帽的湿法腐蚀工艺  

Wet Etching Process for Silicon-Based Cap in Wafer Level Packaging

作　　者：吴鹏 郭杰[1] 袁俊 李志华[2] 黎秉哲 孙丽存 Wu Peng;Guo Jie;Yuan Jun;Li Zhihua;Li Bingzhe;Sun Licun(Yunnan Key Laboratory of Photoelectric Information Technology,Yunnan Normal University,Kunming 6S0S00,China;Kunming Institute of Physics,Kunming 650223,China)

机构地区：[1]云南师范大学,云南省光电信息技术重点实验室,昆明650500 [2]昆明物理研究所,昆明650223

出　　处：《微纳电子技术》2020年第6期498-502,共5页Micronanoelectronic Technology

基　　金：国家自然科学基金资助项目(61774130,61705192)。

摘　　要：对于晶圆级封装中硅基盖帽的制备工艺,采用NaOH腐蚀体系对Si〈100〉衬底进行湿法深腐蚀,研究了腐蚀液质量分数、添加剂添加量及腐蚀温度对腐蚀速率和形貌的影响。针对深腐蚀中掩膜易脱落的缺点,提出了一种先用等离子体增强化学气相沉积(PECVD)法沉积SiO2介质层,再用磁控溅射生长CrAu金属层的方法,SiO2介质层和CrAu金属层作为双层掩膜。研究结果表明:硅的腐蚀速率随温度的增加呈指数增加,在饱和NaOH溶液中腐蚀速率最快,腐蚀速率可达15μm/min。最终腐蚀出表面平整、界面清晰的硅基盖帽,盖帽空间面积为2 cm×2 cm,深度超过100μm,复合掩膜层没有开裂、脱落现象,具有优异的抗腐蚀性。该腐蚀工艺对红外焦平面阵列(IRFPA)探测器晶圆级封装具有重要的应用价值。For the preparation process of a silicon-based cap in wafer level packaging,the wet deep etching of the Si〈100〉substrate was carried out by using the NaOH etching system.The effects of the etching solution mass fraction,additives addition amount and etching temperature on the etching rate and morphology were studied.In order to resolve the shortcomings of the mask easily falling off in deep etching,a method was proposed,i.e.firstly depositing a SiO2 dielectric layer by plasma enhanced vapor deposition(PECVD)method and then growing a CrAu metal layer by magnetron sputtering.The SiO2 dielectric layer and CrAu metal layer were used as a double-layer mask.The research result shows that the etching rate of the silicon exponentially increases with the increase of the temperature.The fastest etching rate of 15μm/min can be obtained in the saturated NaOH solution.Finally,a silicon-based cap with flat surface and clear interface was finally obtained by etching.The space area of the cap is 2 cm×2 cm,and the depth is more than 100μm.The composite mask layer has no cracking or peeling,and has excellent etching resistance.The etching process has important application value for wafer-level packaging of infrared focal plane array(IRFPA)detectors.

关 键 词：红外焦平面阵列(IRFPA) 晶圆级封装 湿法腐蚀 腐蚀速率 掩膜 

分 类 号：TN305.2[电子电信—物理电子学]