DISSIPATIVE TUNNELING IN 2-STATE SYSTEMS AT THE SI SIO2 INTERFACE/

We have observed two-state systems (TSSs) in electrically stressed met al-oxide-silicon field-effects transistors, by studying random telegra ph signals at low temperatures. The TSSs are related to defects close to the Si/SiO2 interface. The asymmetry energy epsilon is linear in ga te voltage, permitting for the first time measurement of the dissipati ve tunneling rate as a function of epsilon independently of magnetic f ield. The electron coupling strength a lies in the range 10(-3) to 10( -2), allowing comparison with the standard theory in the previously un explored regime of weak coupling.