Methods Of Forming One Or More Covered Voids In A Semiconductor Substrate

A method of forming a semiconductor-on-insulator substrate, comprising:

• providing a base region of a base substrate, a silicon-containing semiconductor region over the base region, and an insulative layer over the silicon-containing semiconductor region;
• etching trenches into the insulative layer to the silicon-containing semiconductor region;
• selectively growing relative to the insulative layer a bridging material over the insulative layer effective to bridge across the trenches with bridging material and form covered elongated trenches;
• providing a release region intermediate the silicon-containing semiconductor region and the base region of the base substrate;
• at an interface of the release region and the silicon-containing semiconductor region, separating a) the base region and release region from b) the silicon-containing semiconductor region, the insulative layer with the elongated covered trenches, and the bridging material;
• forming first field effect transistor gates within the covered trench voids;
• and
• forming second field effect transistor gates opposite the first field effect transistor gates over the silicon-containing semiconductor region, and forming field effect transistor channel regions within material of the silicon-containing semiconductor region received between the first and second field effect transistor gates.