Leakage current sources

The MOSEET has three regions of operation. The cutoff region occurs for V g < Up. In this region, the drain-to-source current is the reverse saturation current of the back-to-back source and drain junctions. This leakage current is small but nonzero and allows charge to leak off capacitors which are isolated by cutoff MOSFETs. Because this is how bits are stored in dynamic memory (DRAM) ceUs, DRAMs must be regularly refreshed to retain their memory. 

The inkjet-printed (or inkjetted ) TFT operated with a mobility of 6.5cm2/ Vs and an on/off ratio of three digits as shown in Fig. 5.6b. This low mobility is attributed to the poor crystallinity and rough surface, whereas the large off current, which was confirmed to be the current between source and drain rather than a leakage current through the gate insulator, is also attributed to... 

CuPc thin films, and the enhanced physical connection between source-drain electrodes and semiconductor channel associated with the PMMA polymer layer, the OFET performance of this bottom-contact device was significantly improved with leakage current being reduced by roughly one order of magnitude and on-state current enhanced by almost one order of magnitude. The hole mobility of this bottom-contact OFET device reached 0.01 cm2 V-1 s 1, which is comparable with that of top-contact device but much higher than that of normal bottom-contact device without polymer layer [45],... 

Surface leakage current from the source (O) to the sink (S) in the PEVD system is negligible. 

It has often been the practice in conductance work to ground certain parts of the bridge network for the purpose of improving the sharpness of the sound minimum in the detector at the balance point unless this is done with care it is liable to introduce errors because of the existence of leakage currents to earth. The telephone earpiece must, however, be at ground potential, otherwise the capacity between the telephone coils and the observer will result in a leakage of current. Other sources of leakage are introduced by the use of vacuum-tube oscillator and amplifier, and by various unbalanced capacities to earth, etc. 

Electrical Measurements. DC leakage current measurements were made as a function of applied bias voltage over a range of -10 to +10 V. Data were obtained with a Keithley Model 616 Digital Electrometer. The voltage source was a battery-regulated potentiometer. 

In the fabrication of OTFT backplanes there are complications related to the order in which the organic semiconductor and source/drain contacts are deposited and how they are patterned. The semiconductor must be patterned in order to avoid large leakage currents through the ungated areas. Complications arise because the... 

Fig. 5.9. (a) A true Corbino, and (b) two partially shielded drain structures. While the Corbino architecture requires an additional metal layer to feed the drain electrode into the center without shorting the gate, it eliminates the need to pattern the semiconductor due to the source, which shields stray leakage currents. The partially shielded structures are a compromise between the lateral structure and a full Corbino architecture. The performance achieved depends on the layout details of the circuit in question and the ungated sheet resistance of the semiconductor. 

---