Oh Kyong Kwon

Silicon‐based 0.69‐inch AMOEL microdisplay with integrated driver circuits

Abstract Silicon‐based 0.69‐inch AMOEL microdisplay with integrated driver and timing controller circuits for microdisplay applications has been developed using 0.35 μm 1‐poly 4‐metal standard CMOS process with 5 V CMOS devices and CMP (Chemical Mechanical Polishing) technology. To reduce the large data programming time consumed in a conventional current programming pixel circuit technique and to achieve uniform display, de‐amplifying current mirror pixel circuit and the current‐mode data driver circuit with threshold roltage compensation are proposed. The proposed current‐mode data driver circuit is inherently immune to the ground‐bouncing effect. The Monte‐Carlo simulation results show that the proposed current‐mode data driver circuit has channel‐to‐channel non‐uniformity of less than ±0.6 LSB under ±70 mV threshold voltage variaions for both NMOS and PMOS transistors, which gives very good display uniformity.

Trade-Off between Hot Carrier Effect and Current Driving Capability Due to Drain Contact Structures in Deep Submicron MOSFETs

We, for the first time, have analyzed the contact structure dependent hot carrier effect in quarter-micron n-channel metal semiconductor field effect transistor (nMOSFETs). We measured the DC stressed current degradation characteristics, the substrate current characteristics, and the hot carrier induced photon emission characteristics of MOSFETs with W/L=20/0.25 microns having various contact structures. From experiments, we consistently observed that the degradation increases rapidly as the number of contact holes increases while current driving capability improves moderately. We also calculated the average electron temperature in devices with different contact structures from the energy distribution of emitted photons. The electron temperatures of 3- and 26-contact hole devices were about 4700 K and 6000 K, respectively. We have developed a HSPICE circuit model to simulate various contact structures. Both simulation and experimental results indicate that the current driving capability saturates at more than 5 contact holes of n-channel MOSFET with W/L=20/0.25 microns.