采用红外快速热退火的晶体管TED效应与沟道尺寸的关系研究  

Channel size-dependent TED effect in MOSFETs with infrared rapid thermal anneal

作　　者：任梦远 陈霏 Ren Mengyuan;Chen Fei(School of Microelectronics,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学微电子学院,天津300072

出　　处：《红外与激光工程》2021年第5期104-111,共8页Infrared and Laser Engineering

摘　　要：硼的瞬间增强扩散(transient enhanced diffusion,TED)导致MOS晶体管出现反短沟道效应,阈值电压异常升高,严重影响器件性能和良品率,不同的器件尺寸,阈值电压增量不同,为探究沟道内杂质离子分布情况和器件尺寸对TED效应的影响,在40 nm CMOS工艺平台下,对调阈值注入、低掺杂漏极(LDD)离子注入和碳离子协同注入工艺进行参数调整实验,测量不同工艺参数、不同尺寸的晶体管阈值电压,采用TCAD工具仿真沟道内硼离子和间隙原子的浓度分布。实验结果表明:沟道长度逐渐缩小,阈值电压先上升,在0.55μm处达到最高后迅速下降,上升速率随着沟道宽度的减小而降低。当沟道长度不变时,阈值电压随沟道宽度一直下降,且下降得越来越快。间隙硅原子由LDD离子注入引入并向沟道扩散,而硼离子聚集在LDD-沟道边界位置,但是在LDD和沟道形成的角落会向浅沟槽隔离(STI)区域泄漏,聚集和泄漏作用共同控制沟道内硼离子的浓度分布。TED效应导致的阈值电压漂移是受器件尺寸调控的,另外,高能量的碳协同注入结合红外快速热退火技术可以有效地抑制TED效应。Boron transient enhanced diffusion(TED)causes reverse short channel effect,and threshold voltage(Vt)increases abnormally,which seriously affects the device performance and yield.The Vt increment is different with different channel size.To investigate channel impurity distribution and the influence of channel size on TED,Vt adjustment ion-implantation,LDD ion-implantation and carbon co-implantation experiments were performed on 40 nm CMOS process,measuring Vt with different channel size and process,and using TCAD tools for process simulation.Experiments results show that Vt rises first with channel length decreasing and then drops sharply after reaching the maximum at 0.55μm.The Vt-L curve slope decreases when channel width decreases.Vt decreases with channel width and it is decreasing faster and faster when channel length is constant.The interstitial Si atoms are injected by LDD ion-implantation and diffuse into channel,while boron pile up at the LDD-channel boundary.However,boron leak into the shallow trench isolation(STI)area at the corner formed by LDD and channel.Both pile-up and leakage control boron concentration distribution in channel.The Vt shift induced by boron TED is channel size-dependent,and high energy carbon co-implantation and infrared rapid thermal anneal can suppress TED effect effectively.

关 键 词：瞬间增强扩散 阈值电压 离子注入 沟道尺寸 间隙硅原子 红外快速热退火 

分 类 号：TN386.1[电子电信—物理电子学]