[18a-D103-1~10] 15.7 Crystal characterization, impurities and crystal defects

[18a-D103-9] Formation mechanism of Cu₄ complex in silicon

〇Koun Shirai¹, Takayoshi Fujimura¹ (1.ISIR, Osaka Univ.)

Keywords:Cu complex, Formation mechanism

A new structural model for Cu complex Cu4 was proposed by the authors. The structure is a tetrahedron formed by four Cu with a vacancy as the center of the tetrahedron. Based on this structural model, the formation mechanism of Cu4 complex has been studied. The formation of Cu complex is very complicated. The initial forming of Cu4 is performed at high temperature by diffusion process. Then, the formed Cu4 is stabilized by quenching to room temperature. However, the stabilized Cu4 is eliminated by annealing about T=250°C, and by raising further the annealing temperature, Cu4 complex is recovered. This heat cycle has been explained by considering thermodynamic equilibria with vacancies and Cu precipitations.