Passivated deep p/n junction
First Claim
1. A semiconductor wafer with a passivated deep p/n junction obtained by ion implantation, comprising the steps of:
- (a) providing a semiconductor wafer;
(b) forming a lightly doped emitter region by ion implantation of a dopant material in one surface of said wafer to a depth of about one micrometer;
(c) thermally distributing said ion implanted dopant material to form said deep p/n junction; and
(d) passivating said deep p/n junction by forming a surface layer on said emitter region;
said lightly doped emitter region having a dopant concentration of no more than about 1019 cm-3 ; and
said ion implantation of said dopant material being effected at room temperature and within an energy range of between 5 keV and 50 keV and with a dose of about 1015 ions per cm2.
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Accused Products
Abstract
A passivated deep p/n junction obtained by ion implantation is disclosed. The passivated deep p/n junction is formed in a wafer, preferably a silicon wafer, thus providing an emitter region that is both lightly doped and extending to a depth of about one micrometer. The emitter region in turn is provided with a surface layer so as to reduce surface recombination. Preferably, the surface layer is a silicon oxide layer of about 0.01 micrometer thickness. The p/n junction is obtained by ion implantation whereby the dopant is introduced at room temperature and then distributed thermally. The surface layer preferably is formed near the end of the thermal distribution by admitting a small amount of dry oxygen to a gas stream, and passing the gas stream along the surface of the wafer.
19 Citations
5 Claims
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1. A semiconductor wafer with a passivated deep p/n junction obtained by ion implantation, comprising the steps of:
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(a) providing a semiconductor wafer; (b) forming a lightly doped emitter region by ion implantation of a dopant material in one surface of said wafer to a depth of about one micrometer; (c) thermally distributing said ion implanted dopant material to form said deep p/n junction; and (d) passivating said deep p/n junction by forming a surface layer on said emitter region; said lightly doped emitter region having a dopant concentration of no more than about 1019 cm-3 ; and said ion implantation of said dopant material being effected at room temperature and within an energy range of between 5 keV and 50 keV and with a dose of about 1015 ions per cm2. - View Dependent Claims (2, 3, 4, 5)
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Specification