28nm HKMG技术中镍硅化物异常生长引发的失效  

Failure Induced by Abnormal Nickel Silicide Formation in 28 nm HKMG Technology

作　　者：方精训 姜兰 Fang Jingxun;Jiang Lan(Shanghai Huali Integrated Circuit Corporation,Shanghai 201203,China)

机构地区：[1]上海华力集成电路制造有限公司,上海201203

出　　处：《半导体技术》2024年第9期838-843,共6页Semiconductor Technology

摘　　要：针对28nm高介电常数金属栅(HKMG)技术研发初期出现的镍硅化物异常导致的失效进行了深入探究。发现第二道镍硅化物激光退火工艺对产品良率有重要影响。对裸晶内失效位置进行透射电子显微镜(TEM)检测,结果表明失效区域均为PMOS器件的SiGe区域。这意味着在相同的热预算条件下,PMOS的工艺窗口相较于NMOS会更狭窄。结合激光退火工艺特性,在首次扫描过程中,受降温阶段的影响,晶圆特定区域会累积额外热量,使得该区域热预算异常升高,镍硅化物产生异常,导致产品良率损失;当激光退火温度降低40℃,镍硅化物缺陷问题得以成功解决,产品良率也得到明显提升。The failure caused by abnormal nickel silicide during the early stages of 28 nm high-k metal gate(HKMG)technology development was explored in depth.It is found that the second nickel silicide laser annealing process has a significant impact on product yield.The transmission electron microscope(TEM)test results of the failure locations within the die show that the failure areas are all SiGe regions of the PMOS device.It means that the process window for PMOS is narrower than that for NMOS at the same thermal budget.Combined with the characteristics of laser annealing process,additional heat may accumulate in specific areas of the wafer during cooling stage in the first scan,resulting in an abnormally high thermal budget in these areas and abnormal nickel silicide formation,leading to product yield loss.When the laser annealing temperature is reduced by 40℃,the problem of nickel silicide defects is successfully solved and the product yield is significantly improved.

关 键 词：镍硅化物 良率 激光退火 热预算 高介电常数金属栅(HKMG) 

分 类 号：TN3055[电子电信—物理电子学]