On the Mechanisms of Hydrogen Implantation Induced Silicon Surface Layer Cleavage

Abstract

ZusammenfassungDer sogenannte "Ion-Cut", ein Schichtabspaltungsprozess mittels WasserstoffIonenimplantation und darauffolgender Probenerwärmung ist eine effektive, vielseitige und ökonomische Methode, um Siliziumschichten mit einer Dicke von nur einigen Nanometern von einem Siliziumsubstrat auf andere Materialien zu transferieren. Somit ermöglicht der Ion-Cut die Produktion von Siliziumschichen auf isolierenden Materalien ("silicon-on-insulator" (SOI) AbstractThe "Ion-Cut", a layer splitting process by hydrogen ion implantation and subsequent annealing is a versatile and efficient technique of transferring thin silicon surface layers from bulk substrates onto other substrates, thus enabling the production of silicon-oninsulator (SOI) materials. Cleavage is induced by the coalescence of the highly pressurized sub-surface H 2 -gas bubbles, which form upon thermal annealing. A fundamental understanding of the basic mechanisms on how the cutting process occurs is still unclear, inhibiting further optimization of the Ion-Cut process. This work elucidates the physical mechanisms behind the Ion-Cut process in hydrogen-implanted silicon. The investigation of the cleavage process reveals the cut to be largely controlled by the lattice damage, generated by the hydrogen ion irradiation process, and its effects on the local stress field and the fracture toughness within the implantation zone rather than by the depth of maximum H-concentration. Furthermore, this work elucidates the different kinetics in the H-complex formations in silicon crystals with different conductivity types, and examines the mechanically induced damage accumulation caused by the crack propagation through the silicon sample in the splitting step of the Ion-Cut process. Additionally, the influence of boron pre-implantation on the Ion-Cut in hydrogen implanted silicon is investigated. These studies reveal, that both, the atomic interaction between the boron implant and the hydrogen implant and the shift of the Fermi level due to the electrical activation of the implanted boron have a tremendous enhancing effect on the Ion-Cut process.

Ultra-thin chips for high-performance flexible electronics

“…165 e Proton-Induced Exfoliation technique and blister created after heating hydrogen implanted wafer. 166 f Illustration of controlled spalling and flexible wafer over polyimide. 155 Figure reproduced with permission from: b ref.…”

“…165 , under a Creative Commons license (https:// creativecommons.org/licenses/by/4.0/), e ref. 166 , 1999 © AIP Publishing LLC and f ref. 155 , under a Creative Commons license (https:// creativecommons.org/licenses/by/3.0/) Anisotropic wet etching: This well-established technology has been used traditionally to realize MEMS (microelectromechanical systems) structures.…”

Xenon Nanobubbles and Residual Defects in Annealed Xe‐Implanted Si(001): Analysis by the Combination of Advanced Synchrotron X‐Ray Diffraction and Transmission Electron Microscopy Techniques

“…The blistering phenomenon arises on the substrate surface after thermal annealing as the result of the local elastic relaxation of the surface layer subjected to the vertical stress exerted by pressurized cavities or nanobubbles filled with inert gas that provoke micro-cracks and the delamination of the Si. [94,95] Therefore, the internal gas pressure in the bubbles is an important aspect for predicting inter-bubble fracture and surface blistering. [96] TEM images comparison of the #1 and #4 samples certifies that the Xe nanobubbles had grown during the annealing.…”