Ronald D. Pinker

Realization of high breakdown voltage (>700 V) in thin SOI devices

The avalanche breakdown voltage of silicon on insulator (SOI) lateral diodes is investigated theoretically and experimentally. Theoretically, a condition is derived for achieving a uniform lateral electric field and thus optimizing the breakdown voltage. Using this condition, it is shown that, for SOI thicknesses below about 1 mu m, diode breakdown voltage increases with decreasing SOI layer thickness. Experimentally, breakdown voltages in excess of 700 V have been demonstrated for the first time on diodes having approximately 0.1- mu m-thick SOI layers and 2- mu m-thick buried oxide layers. The results obtained demonstrate the feasibility of making high-voltage thin-film SOI LDMOS transistors and, more importantly, the ability to integrate such devices with high-performance ultra-thin SOI CMOS circuits on a single chip.<<ETX>>

High-breakdown-voltage devices in ultra-thin SOI

The possible advantages of an SOI (silicon-on-insulator) RESURF (reduced surface electric field) device are explored with an idealized lateral diode structure consisting of a P/sup +/ diffusion into an N-silicon-on-insulator film, supported by an N/sup +/ silicon substrate. An optimized structure is shown to have a uniform lateral electric field and a vanishing vertical electric field along the top surface of the depletion region. An analytical model based on ionization integrals indicates that, for very thin SOI, the breakdown voltage increases with decreasing SOI thickness. Two-dimensional numerical breakdown simulations also support this finding. Experimentally, breakdown voltages in excess of 700 V have been demonstrated on diodes having approximately 0.1- mu m-thick SOI layers and 2- mu m-thick buried oxide layers, in excellent agreement with theory. An obvious advantage of this concept lies in the integration of high-voltage devices with high-performance SOI CMOS circuits on a single chip.<<ETX>>

Microfabricated high intensity discharge lamps

Miniaturization of high intensity discharge lamps can lead to cheaper, more efficient, and novel lighting systems for the lighting industry. We are applying micromachining and techniques used for manufacturing integrated circuits, to develop such miniature lamps. We have fabricated electrodeless and electroded high-pressure mercury discharge lamps in quartz substrates using integrated circuit and micromachining techniques, such as photolithography, etching, and wafer bonding. Patterned quartz wafers were bonded together using fusion wafer bonding. The resulting cavities are strong enough to withstand the high pressures (124 atm) and high temperatures (1000 °C) in these lamps. Lamps containing varying amounts of mercury were fabricated to obtain high-pressure discharges in the range of 10–175 atm. The electrodeless lamps were excited by a microwave source, operating at 2.45 GHz and the electroded lamps with a dc voltage. Lamp efficacies over 40 lumens (lm)/W were obtained for the electrodeless lamps and ov...

HIGH PRESSURE DISCHARGES IN CAVITIES FORMED BY MICROFABRICATION TECHNIQUES

High pressure discharges are the basis of small high intensity light sources. In this work, we demonstrate the formation of high pressure discharges, in cavities formed by applying micromachining and integrated circuit techniques to quartz substrates. Cavities containing varying amounts of mercury and argon were fabricated to obtain high pressure discharges. A high pressure mercury discharge was formed in the electrodeless cavities by exciting them with a microwave source, operating at 2.45 GHz and in the electroded cavities by applying a dc voltage. The contraction of the discharge into a high pressure arc was observed. A broad emission spectrum due to self-absorption and collisions between excited atoms and normal atoms, typical of high pressure mercury discharges, was measured. The light output and efficacy increased with increasing pressure. The measured voltage was used to estimate the pressure within the electroded cavities, which is as high as 127 atm for one of the two cavities discussed in this w...