CAJ | 학술논문

动态随机存储器栅极侧壁硅化钨残留造成的短路成为制约提高产品良率及可靠性的瓶颈.为此,采用X射线荧光光谱(XRF)、扫描电镜(SEM)等检测分析手段优化/鸽原子组成比为2.45.透射电镜(1'EM)及电性参数测试结果表明,经30 s、1000℃快速热处理可获得方块阻值为12Ω/cm2的硅化钨,且可刻蚀性能好.在硅化钨刻蚀前利用电子束扫描发现,15 min的氢氟酸和10 min浓硫酸与过氧化氢混合溶液(SPM)在300 W超声波条件下的新湿法清洗工艺.能去除84.7%的表面微粒及残留聚合物.整合上述优化工艺可以将硅化钨残留造成的65 nm动态随机存储器芯片失效率由31.3%降到1.9%,为研究下一代产品提供有效借鉴.
동태수궤존저기책겁측벽규화오잔류조성적단로성위제약제고산품량솔급가고성적병경.위차,채용X사선형광광보(XRF)、소묘전경(SEM)등검측분석수단우화/합원자조성비위2.45.투사전경(1'EM)급전성삼수측시결과표명,경30 s、1000℃쾌속열처리가획득방괴조치위12Ω/cm2적규화오,차가각식성능호.재규화오각식전이용전자속소묘발현,15 min적경불산화10 min농류산여과양화경혼합용액(SPM)재300 W초성파조건하적신습법청세공예.능거제84.7%적표면미립급잔류취합물.정합상술우화공예가이장규화오잔류조성적65 nm동태수궤존저기심편실효솔유31.3%강도1.9%,위연구하일대산품제공유효차감.
Dynamic random access memory (DRAM) suffers from the bridge issue due to the WSi, residue on gate sidewall, which is the bottleneck to enhancing the product's yield and reliability. Thus, the Si/W atomic ratio of WSix is optimized to 2.45 by using X-ray fluorescence (XRF) and scanning electron microscope (SEM). Analysis by transmission electron microscopy (TEM) and electronic testing shows that after 30 s rapid thermal annealing( RTA) at 1 000℃, the sheet resistance of WSi2.45 film is 12 Ω/cm2 and can be easily etched off . Electron beam scanning before the WSix film etching shows that about 84. 7% of the surface particles and polymer residue can be effectively removed through a novel wet cleaning process by 15 min HF and 10 min sulfuric-peroxide mixture (SPM) with 300 W megasonic. With these integrated optimized processes, the yield loss due to the WSi, residue on the 65 nm DRAM products can be reduced from the original 31. 3% to 1. 9% , which also serves as a good guideline for future advanced DRAM process development.