Zhang Jiaqi, Wu Yichang, Yang Guofang, Chen Dazheng, Zhang Jincheng, You Hailong, Zhang Chunfu, Hao Yue
State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, 2 South Taibai Road, Xi'an 710071, China.
Nanomaterials (Basel). 2021 Nov 16;11(11):3085. doi: 10.3390/nano11113085.
As one of the important technologies in the field of heterogeneous integration, transfer technology has broad application prospects and unique technical advantages. This transfer technology includes the wet chemical etching of a sacrificial layer, such that silicon nano-film devices are released from the donor substrate and can be transferred. However, in the process of wet etching the SiO sacrificial layer present underneath the single-crystal silicon nano-film by using the transfer technology, the etching is often incomplete, which seriously affects the efficiency and quality of the transfer and makes the device preparation impossible. This article analyzes the principle of incomplete etching, and compares the four factors that affect the etching process, including the size of Si nano-film on top of the sacrificial layer, the location of the anchor point, the shape of Si nano-film on top of the sacrificial layer, and the thickness of the sacrificial layer. Finally, the etching conditions are obtained to avoid the phenomenon of incomplete etching of the sacrificial layer, so that the transfer technology can be better applied in the field of heterogeneous integration. Additionally, Si MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) on sapphire substrate were fabricated by using the optimized transfer technology.
作为异质集成领域的重要技术之一，转移技术具有广阔的应用前景和独特的技术优势。这种转移技术包括对牺牲层进行湿化学蚀刻，从而使硅纳米薄膜器件从施主衬底上释放出来并能够被转移。然而，在使用转移技术对单晶硅纳米薄膜下方的SiO牺牲层进行湿法蚀刻的过程中，蚀刻往往不完全，这严重影响了转移的效率和质量，导致器件制备无法进行。本文分析了蚀刻不完全的原理，并比较了影响蚀刻过程的四个因素，包括牺牲层上方硅纳米薄膜的尺寸、锚点的位置、牺牲层上方硅纳米薄膜的形状以及牺牲层的厚度。最后，得出了避免牺牲层蚀刻不完全现象的蚀刻条件，以便转移技术能够更好地应用于异质集成领域。此外，还利用优化后的转移技术在蓝宝石衬底上制备了硅金属氧化物半导体场效应晶体管（Si MOSFETs）。
