Patent ID: 7064042

Claim:
A process for manufacturing a device on a substrate comprising: forming in the substrate, deep and shallow trench isolations, buried layers and collector wells for the device; forming a layer of etch resistant material over the substrate; defining an active base region of the device by removal of the layer of etch resistant material over a portion of the surface of the substrate to expose an active base region; forming a boron doped oxide film over the base region and the layer of etch resistant material; anisotropically removing the boron doped oxide film from the active base region and the layer of etch resistant material leaving doped spacers of boron dope oxide film adjacent the active base region at a perimeter of the active base region; depositing an epitaxial polycrystalline film over the layer of etch resistant material and an epitaxial crystalline film over the active base region, wherein the epitaxial polycrystalline film and the epitaxial crystalline film form a crystalline/polycrystalline boundary.