[19a-Z19-1~12] 10.4 Semiconductor spintronics, superconductor, multiferroics

▲ [19a-Z19-11] Effect of forming gas annealing on the enhancement of the electron spin lifetime in the inversion channel of Si-based spin MOSFETs

〇(P)Shoichi Sato^1,2, Shota Okamoto¹, Masaaki Tanaka^1,2, Ryosho Nakane¹ (1.EEIS, Tokyo Univ., 2.CSRN, Tokyo Univ)

Keywords:Semiconductor Spintronics, Silicon, MOSFET

Long spin lifetime is essential for highly-efficient spin transport in Si-based spin MOSFETs [1]. Our previous study revealed that the spin lifetime τ_S is proportional to the electron momentum lifetime τ, and the ratio τ_S/τ (~25000) was almost constant, irrespective of the applied gate voltage V_GS, indicating that the Elliott-Yafet mechanism governs the spin relaxation. From this result, the enhancement of τ_S is expected with increasing τ. In this study, we perform a forming gas annealing (FGA), which is effective for increasing τ, on a spin MOSFET and studied the changes of τ_S and τ by FGA at various temperatures T. We found that FGA increases τ_S along with τ, whereas the ratio τ_S/τ remains almost constant (~25000). Therefore, we conclude that longer τ leads to longer τ_S in the Si inversion channel.