超薄膜腐蚀自停止技术的缺陷分析  

Defects analysis of ultrathin film fabricated by self-stopped etching technique

作　　者：李晓波[1] 徐晨[1] 戴天明[1] 邓琛[1] 沈光地[1] 

机构地区：[1]北京工业大学电子信息与控制工程学院北京市光电子技术实验室,北京100124

出　　处：《红外与激光工程》2009年第3期410-413,432,共5页Infrared and Laser Engineering

基　　金：国家863计划资助项目(SQ2007AA03Z431230);北京市人才强教计划资助项目(05002015200504)

摘　　要：作为气动红外探测器密封微电容检测腔的核心部件,要求敏感薄膜必须无孔,平整。浓硼硅腐蚀自停止技术制备超薄膜时,扩散前待扩硼区经常会存在各种表面微缺陷,导致扩硼后,再进行反向腐蚀形成的超薄膜会出现微腐蚀孔。利用小孔扩散模型和流体力学中小孔的热壅塞理论详细计算了缺陷的结构尺寸对缺陷底端局部硼浓度的影响。当缺陷半径r0垲姨Dt,其底端的局部硼浓度会远远低于浓硼硅腐蚀自停止的临界浓度5×1019/cm3,从而在下一步的反向腐蚀出膜过程中,表面有缺陷的扩硼区出现微腐蚀孔的几率大大增加。最后,针对膜区域出现的微腐蚀孔,提出了几种解决方案。As a key part of sealed micro capacitance detection cavity of pneumatic infrared detector, leveling,imporous film is necessary. In the process of fabricating boron-doped p^＋-silicon freehanding diaphragm using self-stopped etching technique,there were many kinds of defects in the region of diffusing B before diffusing, which led to micro -etching holes in the film while reverse etching after diffusing. The relation of the defects＇ structure size and B concentration was calculated using the diffusion model in the small hole and the theory of Thermal Jam.When radius of defects was less than √Dt , B concentration at the bottom would be far lower than 5×l0^19/cm^3,which is critical concentration of self-stopped etching. During the next process of reverse etching, the emerging probability of micro-etching holes in the region of diffusing B with defects would increase greatly. At last, some solution schemes were proposed aiming at the micro-etching holes in the film region.

关 键 词：浓硼重掺杂硅薄膜 气动红外探测器 钻蚀缺陷 小孔扩散模型 微腐蚀孔 

分 类 号：TN21[电子电信—物理电子学]