A new, laminar flow photochemical vapor deposition method has been applied to prepare a-Si:H films The main feature of this method is introduction of Argon gas as a flow down gas through the lower part of the quartz window into the reaction chamber to keep the window highly transparent. The high deposition rate has been stably maintained Utilizing this method, high quality a-Si:H (i) films with high resistivity, low dangling bond density have been realized.
Si UlSI technology requires an unprecedented degree of crystal perfection of Si. Gettering, commonly used to remove impurities and defects from active device regions has received increasing interested for maintaining crystal perfection, Gettering is now in a new stage of research for the mega-bit age, Methods and mechanisms of Gettering are discussed. The role of point defects in silicon on gettering is much emphasized.
A short review of high performance BiCMOS technology is presented. Process design issues relating buried layer, epitaxial layer, well and isolation are briefly discussed. Then, SiGe base HBT-CMOS is demonstrated for future BiCMOS LSIs.