Electron subband structure in strained silicon UTB films from the Hensel–Hasegawa–Nakayama model – Part 1 analytical consideration and strain-induced valley splitting

Multi-gate FinFETs and ultra-thin silicon body SOI FETs are considered as perfect candidates for future technology nodes. Strong size quantization leads to a formation of quasi-two-dimensional subbands in carrier systems within thin silicon films. The employed Hensel–Hasegawa–Nakayama k·p Hamiltonian accurately describes the bulk structure up to the energies of 0.5–0.8 eV and includes a shear strain component. Shear strain is responsible for effective mass modification and is therefore an important source of the electron mobility enhancement in ultra-thin silicon films. The influence of shear strain on the subband structure in thin silicon films is investigated.