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US 6,603,153 B2Granted
Fast recovery diode and method for its manufacture
AssigneeInternational Rectifier Corporation
InventorsRichard Francis, Chiu Ng
Life of this patent
Estimating the term…
Abstract
A soft recovery diode is made by first implanting helium into the die to a location below the P/N junction and the implant annealed. An E-beam radiation process then is applied to the entire wafer and is also annealed. The diode then has very soft recovery characteristics without requiring heavy metal doping.
Claims4
An ultra-soft recovery diode comprising:
- a wafer of silicon of one conductivity type;
- a plurality of spaced diffusions of the other conductivity type into the top surface of said wafer;
- an anode contact overlying and contacting said diffusions and the silicon in the spaces between said diffusions;
- a cathode contact on the bottom surface of said wafer;
- a helium implant having a peak located immediately below said plurality of spaced diffusions to create defects which reduce minority carrier lifetime in that area;
- and E-beam induced defects uniformly distributed over the full volume of said wafer;
- said wafer being free of intentional heavy metal lifetime killing atoms.
4 more elements
A diode comprising:
- a wafer of silicon of one conductivity type;
- at least one diffusion of the other conductivity type formed into a portion at the top surface of said wafer;
- a first main contact formed atop said wafer and contacting both said diffusion and a portion of said one conductivity type of said wafer;
- a second main control on the bottom surface of said wafer;
- a helium implant having a peak located immediately below said at least one diffusion to create defects which reduce minority carrier lifetime;
- and a beam induced defects uniformly distributed over the full volume of said wafer;
- said wafer being free of intentional heavy metal lifetime killing atoms.
4 more elements
Dependencies are inferred from the claim text.