The effects of dried O 2 on the surface conductance of silicon

In order to evaluate the effects of dried oxygen on the electrical transport properties of the silicon surface, ac field effect measurements on a CP‐4 etched surface have been made. The equilibrium surface potential of a sample stored in room air undergoes a 12 mv p‐type shift upon exposure to dried O 2 . The field effect mobility changes from 0.11 (n‐type) to 0.19 (p‐type) cm 2 /volt sec. After the sample is exposed to dried O 2 , the applied electric field produces a total variation of the charge trapped in the surface states of 22mμ coul/cm 2 with a corresponding variation in surface potential of 0.75 ( e φ / k T units).