Abstract
We report the results of a systematic study to understand low drive current of Ge-nMOSFET (metal–oxide–semiconductor field-effect transistor). The poor electron transport property is primarily attributed to the low dopant activation efficiency and high contact resistance. Results are supported by analyzing source/drain Ohmic metal contacts to n-type Ge using the transmission line method. Ni contacts to Ge nMOSFETs exhibit specific contact resistances of 10 − 3 –10 − 5 Ω cm 2, which is significantly higher than the 10 − 7 –10 − 8 Ω cm 2 of Ni contacts to Ge pMOSFETs. The high resistance of Ni Ohmic contacts to n-type Ge is attributed mainly to insufficient dopant activation in Ge (or high sheet resistance) and a high tunneling barrier. Results obtained in this work identify one of the root causes of the lower than expected Ge nMOSFET transport issue, advancing high mobility Ge channel technology.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have