Process for producing an epitaxial layer with laterally varying doping

A process for forming over a top surface of a monocrystalline semiconductive body an epitaxial semiconductive layer whose conductivity characteristics vary laterally across the surface comprising the steps of:

• forming over the top surface of the monocrystalline semiconductive body a patterned insulating layer;
• growing over the top surface a first semiconductive layer that forms monocrystalline regions where it overlies the monocrystalline semiconductive body and polycrystalline regions where it overlies the patterned insulating layer;
• removing selectively the polycrystalline regions and the insulating layer;
• and
• growing over the top surface a second semiconductive layer with conductivity characteristics different from that of the first semiconductive layer for forming essentially monocrystalline regions of said different conductivity characteristic between the monocrystalline regions of said first semiconductive layer.