非晶层占比对TEM样品成像的影响

研究了非晶层占比对半导体器件透射电子显微镜(TEM)样品成像的影响。聚焦离子束(FIB)是制备TEM样品的重要工具,在TEM样品制备过程中,离子束损伤会在样品表面产生非晶层而使TEM图像产生畸变失真。在28 nm技术节点以下半导体器件TEM样品制备中,传统的制备方法会使样品在TEM下呈现非晶像或者图像质量不佳而不再适用。制备了一种楔形样品并使用平面转截面的样品制备方法研究了TEM呈晶格像时和非晶层临界占比的关系。实验表明,当样品中非晶层的占比超过0.66时,其在TEM下的成像为非晶像;当低于这一数值时,其在TEM下的成像为晶格像。针对非晶层对样品成像的影响,使用了一种低电压减薄的制备方法,通过降低非晶层占比可以显著优化表面成像,提高TEM样品的质量。

Characterization of Ga NAs/ Ga As and Ga In NAs/ Ga As Quantum Wells Grown by Plasma-Assisted Molecular Beam Epitaxy: Effects of Ion Damage

The effects of ion damage on Ga NAs/Ga As and Ga In NAs/Ga As quantum wells ( QWs) grown by plas- ma- assisted molecular beam epitaxy have been investigated. Itis found thation damage is a key factor affecting the quality of Ga NAs and Ga In NAs QWs. Obvious appearance of pendello¨ sung fringes in X- ray diffraction pattern and remarkable im provement in the optical properties of the samples grown with ion removal magnets are observed.By removing nitrogen ions,the PL intensity of the Ga In NAs QW is improved so as to be comparable with that of Ga In As QW. The stronger is the magnetic field,the m ore obvious the PL intensity im provement would be.

大块金属玻璃Al_(7.5)Cu_(17.8)Ni_(10.7)Zr_(64)的耐Ar^(2+)离子辐照性能研究

利用能量为3 Me V的Ar^(12+)离子辐照金属玻璃Al_(7.5)Cu_(17.8)Ni_(10.7)Zr_(64)和金属W,研究了金属玻璃的Ar离子辐照损伤,辐照剂量分别为1×1014,1×1015和1×1016ions/cm^2。XRD分析发现在不同剂量辐照下Al_(7.5)Cu_(17.8)Ni_(10.7)Zr_(64)均保持非晶为主要结构。不同剂量辐照后的金属玻璃样品表面没有明显的辐照损伤,而金属W在剂量为1×016ions/cm2时表面出现大面积不规则的裂纹和孔洞。AFM分析显示Al_(7.5)Cu_(17.8)Ni_(10.7)Zr_(64)的表面均方根粗糙度随辐照剂量的增大而增大;辐照后金属玻璃的表面硬度略有降低,而金属W的硬度有所升高。在低于金属玻璃的玻璃化转变温度时,金属玻璃Al_(7.5)Cu_(17.8)Ni_(10.7)Zr_(64)的耐Ar^(12+)溅射能力好于金属W。