查看文章

In this paper, the impact of the plasma process for III-V/Ge heterostructure etching on both the morphology and the photovoltaic performance is investigated for the fabrication of multijunction solar cells with a through cell via contact architecture. Three different plasma chemistries (BCl 3/Cl 2, SiCl 4/Cl 2, and SiCl 4/H 2/Cl 2) have been studied in order to obtain anisotropic etching through the multijunction heterostructure without inducing photovoltaic performance loss. SiCl 4-based plasma chemistries have been found more suitable to achieve deep via hole etching (∼ 30 µm) without lateral etching. The study suggests that SiCl x passivation is more efficient to protect the sidewalls compared to BCl x. The addition of H 2 in SiCl 4/Cl 2 mixture appears to reinforce the sidewall passivation and thus to limit the lateral etching. III-V/Ge triple junction solar cells with standard grid line and busbar front and back contact have …