Abstract of the Disclosure

A semiconductor device having a plurality of electrical elements thereon which are electrically isolated by a PN junction, the device including a substrate of one conductivity type and an epitaxial layer of the other conductivity type thereover, the epitaxial layer including polycrystalline areas through which an impurity is diffused to provide the isolating PN junction.

• Figure 1 is a view in perspective of a substrate which can be used according to the present invention.
• Figure 2 is a greatly enlarged cross-sectional view of the semiconductor device after the polycrystalline areas and the singel crystal areas have been applied to the substrate.
• Figure 3 is a view similar to Figure 2 but illustrating the components after diffusion of an impurity resulting in the formation of PN junctions.
• Figure 4 is a view similar to Figure 3 but illustrating a modified form of diffusion process which can be employed.
• Figure 5 is a greatly enlarged view of a modified form of a semiconductor device produced according to the present invention.

 Citations [54]:
  
3,189,973  06/1965  Edwards
3,375,418  03/1968  Garnache
3,335,038  09/1967  Doo
3,327,182  06/1967  Kisinko
3,370,980  02/1968  Anderson