锗硅SiGe外延技术中提高西格玛沟槽刻蚀工艺稳定性的方法
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摘要
伴随着CMOS技术集成度的日益增大以及关键尺寸的日渐缩小,传统CMOS工艺中采用的应力拉升方式已经无法满足器件对于PMOS驱动电流的要求。在关键尺寸进入28 nm及以下后,必须采用锗硅(SiGe)外延技术来加大PMOS的压应力,以此提高器件的整体响应速度。而在锗硅(SiGe)外延技术中,西格玛沟槽刻蚀是影响PMOS驱动电流的关键工艺步骤。西格玛沟槽刻蚀的关键尺寸的稳定性决定了器件性能的稳定性。西格玛沟槽刻蚀由一系列的干法刻蚀、湿法清洗、湿法刻蚀组成,其工艺的关键尺寸达到原子量级的卡控标准,但是干法刻蚀后的高分子副产物以及后续硅表面多种溶液的湿法处理,给整个西格玛沟槽刻蚀的关键尺寸的稳定性带来了诸多影响因子。基于干法/湿法刻蚀以及硅表面的清洗处理,提出锗硅(SiGe)外延技术中提高西格玛沟槽刻蚀工艺稳定性的方法。
With the increasing integration of CMOS technology and the shrinking of key sizes,the stress-lifting method adopted in traditional CMOS technology can no longer meet the device requirements for PMOS driving current. When the critical size is below 28 nm, SiGe epitaxy technology must be used to increase the compressive stress of PMOS, so as to improve the overall response speed of the device. In SiGe epitaxy technology, Sigma groove etching is the key process to affect the driving current of PMOS. The stability of the key dimensions of Sigma groove etching determines the stability of device performance. Sigma groove etching consists of a series of dry etching, wet cleaning and wet etching. The key dimensions of Sigma groove etching process are up to the atomic-scale card control standard. However, the polymer by-products after dry etching and the subsequent wet treatment of various solutions on silicon surface bring many factors to the stability of the key dimensions of Sigma groove etching. Based on dry/wet etching and silicon surface cleaning, a method to improve the stability of SiGe groove etching process is proposed.
With the increasing integration of CMOS technology and the shrinking of key sizes,the stress-lifting method adopted in traditional CMOS technology can no longer meet the device requirements for PMOS driving current. When the critical size is below 28 nm, SiGe epitaxy technology must be used to increase the compressive stress of PMOS, so as to improve the overall response speed of the device. In SiGe epitaxy technology, Sigma groove etching is the key process to affect the driving current of PMOS. The stability of the key dimensions of Sigma groove etching determines the stability of device performance. Sigma groove etching consists of a series of dry etching, wet cleaning and wet etching. The key dimensions of Sigma groove etching process are up to the atomic-scale card control standard. However, the polymer by-products after dry etching and the subsequent wet treatment of various solutions on silicon surface bring many factors to the stability of the key dimensions of Sigma groove etching. Based on dry/wet etching and silicon surface cleaning, a method to improve the stability of SiGe groove etching process is proposed.
引文
[1]Ghani T,et al.A 90nm high volume manufacturing logic technology featuring novel 45nm gate length strained silicon CMOS transistors[J].Electron Devices Meeting,2003,11(6):1.
[2]Tamura N,et al.Embedded silicon germanium(eSiGe)technologies for 45nm nodes and beyond.Junction Technology[C].2008.IWJT’08.Extended Abstracts-2008 8th International workshop on,2008:73-77.
[3]Thong J T L,et al.TMAH etching of silicon and the interaction of etching parameters[J].Sensors and Actuators A:Physical,1997,63:243.
[4]Sui Y Q,et al.A Study of Sigma-Shaped Silicon Trench Formation[J].ESC Trans,2013,52(1):331-335.
[2]Tamura N,et al.Embedded silicon germanium(eSiGe)technologies for 45nm nodes and beyond.Junction Technology[C].2008.IWJT’08.Extended Abstracts-2008 8th International workshop on,2008:73-77.
[3]Thong J T L,et al.TMAH etching of silicon and the interaction of etching parameters[J].Sensors and Actuators A:Physical,1997,63:243.
[4]Sui Y Q,et al.A Study of Sigma-Shaped Silicon Trench Formation[J].ESC Trans,2013,52(1):331-335.