Abstract of the Disclosure

This invention provides a high power, high speed transistor comprising two epitaxial layers of semiconductor material grown on a large area substrate. The growth of the two epitaxial layers is accomplished in one continuous process. Each epitaxial layer is grown to a desired thickness and has a specific type of semiconductivity having a preferred level of impurity concentration. A required third region of semiconductivity is formed by diffusion in one of the epitaxially grown layers of semiconductor material.

• Figures 1, 2 and 3 are cross-sectional side views of a body of semiconductor material being processed in accordance with the teachings of this invention.
• Figure 4 is a top view of a semiconductor device showing a preferred emitter edge design.
• Figures 5 and 6 are views in cross-section of the body of semiconductor material shown in Figures 1, 2, and 3, being processed further in accordance with the teachings of this invention.
• Figure 7 is a planar view of a slice of semiconductor material showing the location of mesa structures made by processing the slice in accordance with the teachings of this invention.

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