[25a-D114-1~7] 15.5 Group IV crystals and alloys

▲ [25a-D114-5] Tensile Strained n-type Ge Grown by Continuous Wave Laser Annealing

〇Rahmat Hadi Saputro^1,2, Ryo Matsumura¹, Tatsuro Maeda³, Naoki Fukata^1,2 (1.NIMS, 2.Univ. of Tsukuba, 3.AIST)

Keywords:Germanium, Strain, Polycrystalline

Germanium (Ge) is one of the promising materials for optoelectronic device integration. It is widely known that Ge is an indirect-band semiconductor like Silicon (Si). However, by introducing tensile strain, the small difference (0.136 eV) between direct and indirect gaps can be reduced. Furthermore, it was reported that in 0.2-0.3% tensile strained Ge, n-type doping in the order of 10¹⁹ cm^-3 could result in quasi direct-band light emission. Recently, we have successfully crystallized amorphous Ge on quartz substrate by continuous wave laser annealing (CWLA), which also resulted in the introduction of 0.55-0.62% tensile strain. In this study, we applied the similar technique for the Sb-doped n-type Ge film. The results show the successful growth of tensile strained n-Ge films by the CWLA method.