28nm高K金属栅技术平台光阻回刻工艺中提高刻蚀工艺稳定性的方法研究  

Study on methods to Improve Process Stability in the Photoresist Etching Back Process of the 28nm High-K Metal Gate Technology

作　　者：吕煜坤 王宇威 唐在峰 LYU Yukun;WANG Yuwei;TANG Zaifeng(Shanghai Huali Integrated Circuit Manufacturing Co.,Ltd.,Shanghai 201317,China)

机构地区：[1]上海华力集成电路制造有限公司,上海201317

出　　处：《集成电路应用》2024年第6期66-69,共4页Application of IC

摘　　要：阐述在28nm高K金属栅(28HKMG)技术平台中解决NMOS/PMOS区域栅极阻挡层高度差的主要方案,是在金属栅极制造工艺前插入光阻回刻系列工艺流程,使NMOS区域与PMOS区域的栅极高度获得一致。但该方案在实际量产中的主要难点是第二道回刻工艺(Etch Back2,即EB2)不稳定,腔体的刻蚀速率与面内分布随着作业时间的增加会出现明显的趋势变化,导致产品端用于表征刻蚀结果的量测参数“牛角高度”(Spacer1二氧化硅保护层高度与栅极高度之间的高度差)在片内具有较高波动性,易造成缺陷,无法安全生产。为此,详细探讨28HKMG平台EB2刻蚀工艺不稳定的原因,并针对实际量产过程中发生的异常,给出切实可行的解决方案,有利于维护腔体微环境稳定,提高产品质量。This paper expounds that In the 28nm high-K metal gate technology,to address the issue of the stephigh between NMOS and PMOS regions,the main solution is to insert a photoresist etchback(PREB)loop before the metal gate manufacturing process.Through this process,it is possible to ensure consistent gate heights between NMOS and PMOS regions.However,the main difficulty of this scheme in production is that the second etch back(EB2)process is unstable.The etching rate and within wafer inline distribution will change significantly with the increase of process time,resulting in high variation of the measurement parameter"horn height"(the gap between the spacer1 silicon dioxide and the gate height),which is easy to cause defects and cannot be safely produced.In this paper,the reasons of the EB2 etching process instability in 28nm high-K metal gate technology are discussed in detail,and the feasible solutions are given for the anomalies in the actual production process,which is conductive to maintaining the stability of the chamber’s microenvironment and improving the product quality.

关 键 词：集成电路制造 28nm 高K金属栅 光阻回刻 工艺稳定性 

分 类 号：TN405[电子电信—微电子学与固体电子学]