面向超薄SOI材料的新型层转移技术及其机理研究

Compared to bulk Si technology, FDSOI technology realizes the full depletion of the transistor channel, which substantially improves the performance of FDSOI devices and circuits. However, due to the issues of thick transfer Si thickness and rough surface morphology caused by film splitting, Smart cut technology meets severe difficulties and challenges in fabricating FDSOI wafers. Based on this problem, a novel process is proposed to achieve controlled film splitting through H adsorption by a doped ultra-thin layer. Directed by the investigation of controlled layer transfer technology based on H enhanced adsorption, the researchers will investigate the dependence of H adsorption behaviors on the thickness, chemical composition, structure and doping concentration of interlayer. In addition, the researchers will observe and analyze the movement and aggregation behaviors of implanted H ions, and disclose the correlation with the stress evolution, as well as the defect evolution during annealing process. The introduction of the adsorption layer realizes controllable splitting film with definite layer thickness and smooth surface morphology. Current work is an important extension of our previous research, and could present some basic data and key techniques for the exploration of fabricating FDSOI materials.

与体硅技术相比，FDSOI技术实现了晶体管沟道的全耗尽，使FDSOI器件及电路的性能得到了大幅度的提高。然而，智能剥离技术由于剥离硅层厚，剥离表面粗糙等问题，在制备FDSOI材料时面临巨大的困难和挑战。基于此问题，申请人创新地提出基于H离子增强吸附原理实现薄膜可控剥离的方法。本项目拟开展B掺杂SiGe薄层对注H离子增强吸附的机理研究，掌握H吸附行为与B掺杂SiGe吸附层的厚度、化学组成、结构、薄膜中的掺杂量等之间的依赖关系。此外，研究工作将重点分析注入H离子的运动、聚集过程，揭示其与薄膜内应力衍变、缺陷衍变之间的关联，阐明吸附特性的产生与作用机理。基于本项目的研究成果，形成薄膜厚度可控、剥离表面平滑的可控剥离新技术。本项研究工作是在前期研究积累基础上的延伸和重要拓展，项目的实施将为制备FDSOI材料提供理论依据和关键技术。

绝缘体上硅（silicon on insulator, SOI）技术通过在传统硅材料中引入氧化层减小衬底的影响，从而提高CMOS器件的性能，因而被认为是推动集成电路沿摩尔定律继续发展的核心技术之一。本项目针对传统SOI材料的智能剥离技术中大剂量（6×1016 cm-2）、剥离界面粗糙（RMS﹥10 nm）等问题，利用掺杂应力层对注H离子的吸附作用，在传统注入剂量一半的情况下制备出高质量的绝缘体上硅材料。此项基于吸附剥离的新型层转移技术有效地降低了注入剂量、简化了制备过程，以及提高了剥离表面的平整度。此外，本项目揭示了异质薄膜制备、退火行为、剥离特性等物理机制，研制成功8英寸全耗尽绝缘体上硅（FDSOI）晶圆片，为特征线宽22 nm节点以下微纳电子时代提供新型SOI基衬底材料。