Method of manufacturing photo-diodes utilizing sequential diffusion
AssigneeU.S. Philips Corporation
InventorJean-Louis Digoy
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Abstract
A method of manufacturing a diode comprising a semiconductor body including at least first and second adjoining regions of the same conductivity type. The first region includes the diode junction and has a high resistivity, while the second region has a high impurity concentration that varies gradually and increases with increasing distance from the interface between the first and the second regions. The second region comprises two adjoining zones, the zone removed from the first region being more highly doped than the zone proximate said region. The second region is obtained by performing two successive diffusions of the same conductivity type as the first region to produce the two zones in said second region.
Claims5
A method of producing a diode comprising the steps of:
- a. providing a semiconductor body of a first conductivity type and having a high resistivity;
- b. carrying out from at least one surface of said semi-conductor body at least two successive diffusions with a higher concentration of doping impurities of the said first conductivity type, a first region of said semiconductor diode being formed by the portion of said semiconductor body that is substantially free of said diffused doping impurities and the diffused portion of said semiconductor body forming a more highly doped second region of said semiconductor body, said doping impurity concentration in said second region having a graded distribution such that said impurity concentration increases with increasing distance from the interface between said first and second region;
- c. reducing the thickness of said first region;
- and then
- d. providing in said first region a zone of opposite conductivity type so as to form a diode junction in said first region.
Dependencies are inferred from the claim text.