Lattice Defects and Exfoliation Efficiency of 6H-SiC via H2+ Implantation at Elevated Temperature

Abstract

Silicon carbide (SiC) is an important material used in semiconductor industries and nuclear power plants. SiC wafer implanted with H ions can be cleaved inside the damaged layer after annealing, in order to facilitate the transfer of a thin SiC slice to a handling wafer. This process is known as “ion-cut” or “Smart-Cut”. It is worth investigating the exfoliation efficiency and residual lattice defects in H-implanted SiC before and after annealing. In the present paper, lattice damage in the 6H-SiC implanted by H2+ to a fluence of 5 × 1016 H2+/cm2 at 450 and 900 °C was investigated by a combination of Raman spectroscopy and transmission electron microscopy. Different levels of damage caused by dynamic annealing were observed by Raman spectroscopy and transmission electron microscopy in the as-implanted sample. Atomic force microscopy and scanning white-light interferometry were used to observe the sample surface morphology. Surface blisters and exfoliations were observed in the sample implanted at 450 °C and then annealed at 1100 °C for 15 min, whereas surface blisters and exfoliation occurred in the sample implanted at 900 °C without further thermal treatment. This finding can be attributed to the increase in the internal pressure of platelets during high temperature implantation. The exfoliation efficiency, location, and roughness after exfoliation were investigated and possible reasons were discussed. This work provides a basis for further understanding and improving the high-efficiency “ion-cut” technology.

Simulation of the Irradiation Cascade Effect of 6H-SiC Based on Molecular Dynamics Principles

“…In fact, 6H-SiC crystals are a wide band gap material, meaning that the electronic devices made can work more reliably in harsh environments and can be widely used in aerospace, nuclear technology, and other high-temperature, high-radiation scenarios. In the study of phase transformation and amorphization of SiC, Aikaterini Flessa, M.Gloginjić, and others have done many experiments on the effect of irradiation cascade of 6H-SiC, and most of the researchers have studied the amorphization of 6H-SiC by high-energy, fast heavy ion injection using Raman spectroscopy and transmission electron microscopy methods [ 13 , 14 , 15 , 16 ]. K.Kamalakkannan et al, studied the induction behaviour and recrystallisation of 6H-SiC at different depths by low-energy ion injection [ 17 , 18 ].…”

Investigation of Exfoliation Efficiency of 6H-SiC Implanted Sequentially with He+ and H2+ Ions

“…There are three main processes of "smart-cut" technology. The first step is keV-MeV H ion implantation with a fluence of the order of 10 16 to 10 17 cm −2 at room temperature (10 16 cm −2 for Si, GaAs or SiC, and 10 17 cm −2 for GaN and ZnO) [5][6][7][8][9][10]. The second step is wafer bonding to another rigid substrate (handling wafer) before thermal annealing.…”