Abstract: The present invention provides a VRG structure formed on a semiconductor wafer substrate. The VRG structure has a first source/drain region located in a semiconductor wafer substrate, and a conductive layer located adjacent the source/drain region, a second source/drain region and a conductive channel that extends from the first source/drain region to the second source/drain region. The conductive layer provides an electrical connection to the first source/drain region. The conductive layer may have a low sheet resistance that may be less than about 50 &OHgr;/square or less than about 20 &OHgr;/square, to the first source/drain region.

Abstract: The present invention is predicated upon the discovery by applicants of a relationship describing thermal decay of radiation-induced index changes and a mechanism which permits stabilization by accelerated aging. Specifically, the induced index change decays in proportion to 1/(1+At.sup..alpha.) where A and .alpha. are functions of temperature, and the decay can be accelerated by heat treatment. As a consequence, the extent of decay can be determined for arbitrary time and temperature and, significantly, an appropriate heat treatment can be scheduled for making a device stable within predeterminable limits.

Abstract: A heterostructure includes a stained epitaxial layer of either silicon or germanium that is located overlying a silicon substrate, with a spatially graded Ge.sub.x Si.sub.1-x epitaxial layer overlain by a ungraded Ge.sub.x.sbsb.0 Si.sub.1-x.sbsb.0 intervening between the silicon substrate and the strained layer. Such a heterostructure can serve as a foundation for such devices as surface emitting LEDs, either n-channel or p-channel silicon-based MODFETs, and either n-channel or p-channel silicon-based MOSFETs.