【摘要】 应用减压化学气相沉积技术,在弛豫Si_0．7Ge_0．3层/组分渐变Si_1-xGe_x层/Si衬底这一多层复合结构的基础上制作了应变硅材料,其中组分渐变Si_1-xGe_x层Ge的摩尔分数x从0线性增加到0．2．对该复合结构的性能进行了表征,由原子力显傲镜和Raman光谱测试结果计算出应变硅层的表面粗糙度和应变度分别为4．12 nm和1．2%,材料中的位错密度为4×10⁴cm^-2．经受了高热开销过程后,应变硅层的应变度及其表面形貌基本上保持不变．更多还原

【Abstract】 The strained Si material has been fabricated on a relaxed Si_0.7Ge_0.3/graded Si_1-xGe_x/Si substrate multilayer structure using a reduced pressure chemical vapor deposition （RPCVD） process.In the graded Si_1-xGe_x layer,the mole fraction of Ge increases linearly from 0 to 0.2.The multilayer structure has been evaluated using various analysis techniques.The results showed that the root mean square （rms） of strained Si surface roughness is 4.12 nm,the strain in the strained Si cap layer is about 1.2%,and the threading dislocation density is about 4×10⁴cm^-2.Further rapid thermal annealing （RTA） experiment demonstrated that the strain state and surface morphology of the strained cap Si layer are almost unchanged even suffered from the high thermal budget.It will be particularly useful for the fabrication of strained Si devices.更多还原