The Evolution, Advances and Future Directions of Semiconductor Smart-Cut Technology

Smart-Cut technology is a technique that utilizes ion implantation and wafer bonding to transfer ultrathin single-crystal layers. In advanced microelectronic systems, as one of the important technical means of heterogeneous integration for semiconductor materials, Smart-Cut technology has been widely concerned by academia and industry. Smart-Cut technology is the process of implanting H⁺, He⁺ ions or co-implanting into the surface of semiconductor materials with precisely controlled parameters (including energy, temperature, dose, dose rate, ion implantation sequence, etc.). After the bonding of implanted semiconductor material and substrate at low temperatures, an annealing process (with carefully regulated temperature, duration, and heating/cooling rates) is performed to generate parallel microcracks in the implantation layer, enabling successful layer transfer. In this paper, the research progress of the Smart-Cut technology applied to the first-, second-, third- and fourth-generation semiconductors in the past two decades is summarized. The microstructure and microcracks nucleation and growth mechanisms are analyzed. The reasons for the exfoliation thresholds of different semiconductors are discussed. The paper is helpful for understanding the application of Smart-Cut technology used in the fabricating of semiconductor devices.