Uneven Distribution of Silicon Crystalline Grains in RF-Sputtered β-FeSi₂ Films Deposited on Off-Oriented Silicon Substrate

抄録

  Applications in high-efficiency Si/β-FeSi₂ heterojunction solar cells require the preparation of crack-free β-FeSi₂ films on silicon. In a previous study, we obtained crack-free β-FeSi₂ films on silicon(100) just substrate by substrate heating during RF-sputtering even though we annealed the films at temperatures as high as 900°C after deposition. However, these films contained a numerous silicon crystalline grains because of substrate heating. Moreover, this process required more energy for substrate heating during deposition.
  In this study, FeSi_x films were deposited on silicon(100) substrate 4° off the [110] direction at room temperature through the RF sputtering method using an FeSi₃ target. The film annealed at 900°C also contained a large amount of silicon. Different from the films on silicon(100) just substrate, however, the film developed cracks on its surface.