White noise study of JFET´s on a new mixed rad-hard technology

A new technology, called DMILL and based on re-epitaxied SIMOX structures, is being developped, with which both logic (CMOS) and analogic (JFET and BICMOS) devices are available. A good radiation hardness and a complete isolation between components is achieved. Isolation between analog and digital parts of a circuit corresponds to the trends for future low-noise mixed circuit applications. JFET´s are used as input stage because of their high input impedance and low l/f excess noise. An excess white noise level in or near saturation, depending on channel doping and gate length is observed and studied. Precise measurements are used to compare several theoretical explanations.