Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10633682 | Optical Materials | 2005 | 6 Pages |
Abstract
We fabricated impurity-doped β-FeSi2 thin films with boron as p-type and arsenic as n-type dopants by sputtering method. The doping source materials were elemental boron chips and heavily arsenic-doped Si chips. They were put on two separate silicon targets and were co-sputtered with silicon during Fe/Si multilayer deposition. For boron-doped p-type β-FeSi2 films, microstructures were affected by the temperature decrease rate after annealing at 800 °C, and cracks were observed when the temperature decrease rate was high as 20 °C/min. It was found that cracks were eliminated by slow cooling at the rate of 2 °C/min. By changing boron concentration, net hole concentration from 3.0 Ã 1017 to 1.0 Ã 1019 cmâ3 and Hall mobilities from 100 to 20 cm2/Vs were successfully achieved. SIMS measurements showed homogeneous distribution of boron dopant in β-FeSi2 film. For arsenic-doped n-type β-FeSi2 films, the activation of arsenic dopant requested longer annealing time at 800 °C than for boron. The microstructures were independent on the cooling rate after annealing. The doping level of net electron concentration from 2.0 Ã 1017 to 4.0 Ã 1017 cmâ3 and mobility from 250 to 160 cm2/Vs were obtained when the arsenic concentration was changed from about 1.2 Ã 1018 to 3.2 Ã 1018 cmâ3. β-FeSi2 thin film p/n homojunctions were formed by successive deposition of p- and n-type β-FeSi2 films on Si substrates in the same sputtering chamber. The diodes showed rectifying I-V characteristics and photoresponse to 1.3-1.6 μm near-infrared light.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Zhengxin Liu, Masato Osamura, Teruhisa Ootsuka, Shinan Wang, Yasuhiro Fukuzawa, Yasuhito Suzuki, Ryo Kuroda, Takahiro Mise, Naotaka Otogawa, Yasuhiko Nakayama, Hisao Tanoue, Yunosuke Makita,