熔性/亚熔性激光退火工艺过程数值分析  

Numerical Analysis on Processes of the Melt/Sub-Melt Laser Annealling

作　　者：王浩[1,2] 严利人[1,2] 周伟[3] 孙德明[3] 王全[3] 张伟[1,2] 

机构地区：[1]清华大学微电子学研究所,北京100084 [2]清华大学信息科学与技术国家重点实验室(筹),北京100084 [3]上海集成电路研发中心,上海201210

出　　处：《微电子学》2015年第1期125-129,135,共6页Microelectronics

基　　金：国家科技重大专项课题资助项目(2011ZX02503-004)

摘　　要：熔性/亚熔性激光退火在IGBT类电力电子器件制造中有着重要的作用。该工艺涉及瞬间、局部、高强度的能量馈入冲击,材料在升温段涉及固态至亚熔或局部熔化状态的相变,在随后降温段的退火,还有离子注入杂质在此短暂过程中的激活和扩散再分布等复杂的物理过程。为了从机理上比较好地处理和揭示这样的工艺步骤,在大量激光退火实验的基础上,进行了工艺过程的全数值分析。首先,利用瞬态热场分析技术计算出激光作用下的硅材料浅表层中,不同时刻和不同位置处沿硅晶圆深度方向各点的温度-时间变化曲线,之后将菲克第二定律推广到方程式中相关量为时变的情况,利用数值积分计算出最终的杂质再扩散量,并与实验结果相比较验证。该工作初步建立起了熔性/亚熔性激光退火工艺步骤的可量化的物理模型。Melt and/or sub-melt laser annealing acted as an important role in fabricating power devices such as IGBTs.The process involved the pulsed high intensity laser irradiation onto small area of a wafer surface,the phase transient from solid to surface melted or sub-melted state as the temperature increasing and the reversed process as the temperature decreasing,and finally the impurity activation and redistribution in the silicon.To deal with the complicated process schematically,a full numerical analysis was carried out based on a lot of experiments.Transient thermal field analysis was performed to obtain temperature profile on the wafer surface at different times.Then the impurity re-distribution was calculated by numerical integration,regarding parameters in the Fick’s law as time varying.The calculated and the experimental results were compared so that a physical illustration of the melt/submelt laser annealing process was constructed reliably.

关 键 词：激光退火 热场分析 杂质再扩散 

分 类 号：TN305.99[电子电信—物理电子学]