1. Normal incidence p–i–n Ge heterojunction photodiodes on Si substrate grown by ultrahigh vacuum chemical vapor deposition
- Author
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Zhou, Zhiwen, He, Jingkai, Wang, Ruichun, Li, Cheng, and Yu, Jinzhong
- Subjects
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SEMICONDUCTORS , *HETEROJUNCTIONS , *PHOTODIODES , *CRYSTAL growth , *ULTRAHIGH vacuum , *CHEMICAL vapor deposition , *TEMPERATURE effect , *STRAINS & stresses (Mechanics) , *THERMAL expansion - Abstract
Abstract: We report on normal incidence p–i–n heterojunction photodiodes operating in the near-infrared region and realized in pure germanium on planar silicon substrate. The diodes were fabricated by ultrahigh vacuum chemical vapor deposition at 600°C without thermal annealing and allowing the integration with standard silicon processes. Due to the 0.14% residual tensile strain generated by the thermal expansion mismatch between Ge and Si, an efficiency enhancement of nearly 3-fold at 1.55μm and the absorption edge shifting to longer wavelength of about 40nm are achieved in the epitaxial Ge films. The diode with a responsivity of 0.23A/W at 1.55μm wavelength and a bulk dark current density of 10mA/cm2 is demonstrated. These diodes with high performances and full compatibility with the CMOS processes enable monolithically integrating microphotonics and microelectronics on the same chip. [Copyright &y& Elsevier]
- Published
- 2010
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