There has been increased interest in the study of resonant tunneling quantum well devices due to the fact that the characteristics of these devices can be engineered to have properties for very high-speed applications. In particular, their ability to exhibit negative differential conductance (NDC) regions lead to their potential use as gain elements and offers a new opportunity for circuit design. For these applications, the NDC portion of the I-V characteristic of the quantum well device is very difficult to measure. The difficulty in measuring the NDC can be easily seen since the NDC often causes jump phenomena, hysteresis , and oscillation in the tracing circuitry, especially when large NDC is involved [1-2]. Significant efforts have been devoted to develop different approaches [3-5] for determination of the I-V characteristic of a NDC device.
|