Interface-State Capture Kinetics by Variable Duty Cycle Charge Pumping
Asahiko Matsuda, Jason T. Ryan, Jason P. Campbell, Kin P. Cheung
We demonstrated a new variant of the charge-pumping technique featuring varying duty cycle gate pulses to directly probe the interface-state carrier capture process in the time domain. This technique retains the exceptional sensitivity of charge pumping while adding the ability to probe capture kinetics down to sub-nanoseconds. We further demonstrated that the capture kinetics can be analyzed using the transition-state theory. The key advantage of this approach is the complete absence of fudge factor such as capture cross section. Everything is based on simple physics. With proper accounting of the carrier concentration and quantum confinement effect, the extracted interface-state energy distribution is in good agreement with the result obtained from steady-state spectroscopic charge pumping technique. This agreement verifies the transition-state theory approach.