Mfr. of charge coupled device - uses two stage polycrystalline silicon layer process allowing formation of MOSFET on same substrate

摘要

The charge-coupled device is made in such a way that MOSFETs can be built on the same substrate at the same time. The process includes local oxidation followed by photo-processing of the active region. After gate oxidation the first polycrystalline silicon layer is deposited. This silicon layer is photo-processed and oxidised. A second plycrystalline silicon layer is then deposited and photoprocessed in forming the CCD part. Oxide etching is carried out followed by diffusion of intermediate oxide. Aluminium is evaporated on to the surface for photoprocessing prior to covering with a final oxide layer. This is photo-processed to produced pad windows.