Autor: |
Simoen, Eddy R., Huang, Yuelong, Ma, Yue, Lauwaert, Johan, Clauws, Paul, Marc, Joan, Ulyashin, Alexander, Claeys, Cor |
Zdroj: |
ECS Transactions; October 2008, Vol. 16 Issue: 6 p129-150, 22p |
Abstrakt: |
The hydrogen-plasma-accelerated formation of shallow thermal donors in silicon has been studied for a wide range of doping density and interstitial oxygen content [Oi] by electrical and spectroscopic techniques. The plasma-hydrogenated material has been heat treated for different times in the temperature range of 275 to 500 oC. It is shown that besides Oxygen Thermal Donors (OTDs) also hydrogen related Shallow Thermal Donors (STDHs) play a crucial role in the hydrogen-assisted creation of excess carriers. The impact of different factors on the introduction rate of the shallow donors will be discussed, whereby a strong role is played by the doping density and type, i.e., the Fermi level position during the thermal anneal in air. Generally, shallow donor formation is faster in p- compared with n-type Si, which is associated with the different charge state of H. From combined Deep Level Transient Spectroscopy (DLTS) and Fourier Transform Infrared (FTIR) absorption spectroscopy it is concluded that the additional free carriers are contributed by both STDH and OTD centers, so that H not only plays a catalytic role but actively takes part in the donor formation, depending on the experimental conditions. Finally, from our data some conclusions can be made regarding the nature of the STDHs, which is still a matter of debate. |
Databáze: |
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