Broadband PureB Ge-on-Si Photodiodes

Broadband PureB Ge-on-Si photodiodes were fabricated by in-situ capping of n-type Ge-islands grown by chemical-vapor deposition on Si with a 10-nm-thick pure boron layer. Using deposition temperatures from 575°C - 700°C, the B-layer forms $\text{p}^{+}$ -like anodes with nm-shallow junctions and low dark currents, enabling close to ideal responsivities of 0.13, 0.37, 0.48, and 0.19 A/W at wavelengths 406, 670, 1310 and 1550 nm, respectively.