A new epitaxy technique for device isolation and advanced device structures

The authors introduce a novel silicon epitaxy technique useful for advanced device fabrication by providing for isolation between and within devices. Called CLSEG (confined lateral selective epitaxial growth), this technique involves selective growth of single-crystal silicon inside a thin but wide cavity formed on, but isolated from, a silicon substrate. Lateral-to-vertical dimension ratios (aspect ratio) of at least eight are possible, a result never before achieved with as-grown epitaxial films. Bipolar transistors and diodes fabricated entirely within CLSEG material show near-normal characteristics, indicating excellent crystal quality. CLSEG is a low-temperature processing technique, and is well-suited to stacked or three-dimensional device construction. Only standard equipment is needed to produce complete dielectric isolation, making CLSEG adaptable to production processes. A novel device concept is presented to show the advantages and applicability of the CLSEG technology