| 摘要 |
<p>A method of making a high voltage MOSFET, wherein a substrate (2) of a first conductivity type is provided, an epitaxial layer (1) also of the first conductivity type is deposited on the substrate, a plurality of trenches (44, 46) are formed in the drift region of the epitaxial layer, the trenches, which extend toward the substrate from the first and second body regions (5a, 6a, 5b, 6b), are filled with a material that includes a dopant of the second conductivity type, and the dopant is diffused from the trenches into portions of the epitaxial layer adjacent the trenches. Furthermore, a breakdown voltage is measured in the epitaxial layer and compared to a desired breakdown voltage, an additional diffusion time being determined by using a predetermined relationship between diffusion time and breakdown voltage, and a further diffusionstep is perfomed for said additional diffusion time.</p> |
