Monolithic high voltage gated diode crosspoint array IC
A new gated diode crosspoint integrated circuit has been developed for telephone switching system applications. Central to the design of this high voltage device has been the extensive use of numerical modeling techniques. Two-dimensional simulation of the individual dielectrically isolated components that comprise the switch array has led to an improvement in their electrical parameters together with size reduction for each of their geometries. Additional calculations dealing with the routing of interconnect metalization about the perimeter of components has indicated how such runners may encroach upon these elements without degrading their performance so that higher density circuitry could be assembled onto a chip. The resulting IC therefore realizes substantial advances over its predecessors, including: increased scale of integration (9 vs. 4 crosspoint pairs), more compact design (2.1 vs, 3.6mm2per crosspoint pair), higher OFF state minimum blocking voltage (600 vs. 530 volts), and reduced ON state incremental resistance (10 vs. 18 ohms).
Observation and analysis of negative resistance in the forward I-V characteristics of dielectrically isolated high-voltage gated diode switches
A current-controlled negative resistance in the forward current-voltage characteristics is observed on some dielectrically isolated gated diode switches (GDS). Defect etching of the devices that exhibited negative resistance showed a high density of defects compared to devices that did not. The high density of defects in the cathode implied a possible resistive shunting of the n+-p junction. To verify this, special test structures were used with an external resistor shunting of the n+-p cathode to simulate the effects of defects. TheI-Vcharacteristics of the GDS with the externally connected resistor shunt exhibited negative resistance similar to that with high defect density devices. When the external shunt was removed the characteristics did not show any negative resistance. Thus we infer that the cause of the negative resistance in our original samples is the resistive shunting effect of the defects in the cathode. A simple physical model for the negative resistance is presented and corroborated with our experimental observations.
Strategies for glass based photonic system integration
There is a clear tendency to integrate more and more opto-electronic and micro-optical components like optical fibers, laser diodes, modulators, isolators, beam-splitting components and micro lenses in also increasingly dense and complex assemblies. The paper will discuss thin glass as a very promising base material for that kind of photonic packaging on interposer and board level including optical interconnection using fibers.