Diode with contact structure including an improved barrier region and related manufacturing process
The present disclosure is directed to a diode with a semiconductor body of silicon including a cathode region, which has a first conductivity type and is delimited by a front surface; and an anode region, which has a second conductivity type and extends into the cathode region from the front surface. The diode further includes a barrier region of cobalt disilicide, arranged on the anode region; and a metallization region of aluminum or of an aluminum alloy, arranged on the barrier region. The barrier region contacts the anode region.
1 . A diode comprising:
a semiconductor body;
a cathode region in the semiconductor body and delimited by a front surface of the semiconductor body, the cathode region having a first conductivity type;
an anode region in the semiconductor body and extending into the cathode region from the front surface, the anode region having a second conductivity type, the anode region including an inner portion and a peripheral portion;
a field oxide region on the semiconductor body and on the peripheral portion of the anode region;
a front dielectric region on the field oxide region;
a first opening in the field oxide region and the front dielectric region, the first opening overlying the inner portion of the anode region;
a barrier region including cobalt disilicide, the barrier region extending in the first opening, in direct contact with the inner portion of the anode region; and
a metallization region including aluminum, arranged on the barrier region.
2 . The diode according to claim 1 , wherein
the semiconductor body includes silicon,
the second conductivity type is a P-type conductivity, and
the anode region has a peak doping level between 1*10 14 cm −3 and 1*10 16 cm −3 .
3 . The diode according to claim 1 , wherein the metallization region extends on the front dielectric region and in the first opening.
4 . The diode according to claim 1 , wherein the semiconductor body includes an enriched anode region having the second conductivity type, and
the enriched anode region extends into the inner portion of the anode region, and has a doping level higher than a doping level of the anode region.
5 . The diode according to claim 1 , wherein
the barrier region extends on the inner portion and on the peripheral portion of the anode region,
the front dielectric region is on a portion of the barrier region that is on the peripheral portion of the anode region, and
the metallization region extends on the front dielectric region and on the portion of the barrier region that is on the inner portion of the anode region.
6 . The diode according to claim 1 , wherein
the anode region includes an enriched anode region extending into the inner portion,
the enriched anode region has a doping level that is greater than a doping level of the inner portion and the peripheral portion, and
the barrier region extends inside the first opening, on the enriched anode region.
7 . A device, comprising:
a semiconductor substrate;
a cathode region in the semiconductor substrate;
an anode region in the cathode region;
a barrier region on the anode region;
a first dielectric layer on the semiconductor substrate, the first dielectric layer having a first opening overlying the barrier region;
a second dielectric layer on the first dielectric layer, the second dielectric layer having a second opening overlying the first opening;
a first metallization structure on a first side of the semiconductor substrate; and
a second metallization structure on a second side, opposite to the first side, of the semiconductor substrate, on the second dielectric layer, and in the second opening, the second metallization structure including aluminum.
8 . The device of claim 7 , wherein a portion of the second dielectric layer is spaced from the anode region by a portion of the barrier region.
9 . The device of claim 7 , further comprising:
an enriched anode region in the anode region and underlying the barrier region.
10 . A diode comprising:
a semiconductor body;
a cathode region in the semiconductor body and delimited by a front surface of the semiconductor body, the cathode region having a first conductivity type;
an anode region in the semiconductor body and extending into the cathode region from the front surface, the anode region having a second conductivity type, the anode region including an inner portion, a peripheral portion, and an enriched anode region extending into the inner portion, the enriched anode region having a doping level that is greater than a doping level of the inner portion and the peripheral portion;
a field oxide region on the peripheral portion;
a front dielectric region on the field oxide region; and
a first opening in the field oxide region and the front dielectric region, and overlying the enriched anode region, and
a barrier region including cobalt disilicide, extending inside the first opening, on the enriched anode region; and
a metallization region including aluminum, arranged on the barrier region.
11 . The diode according to claim 10 , wherein
the semiconductor body includes silicon,
the second conductivity type is a P-type conductivity, and
the anode region has a peak doping level between 1*10 14 cm −3 and 1*10 16 cm −3 .
12 . The diode according to claim 10 , wherein the metallization region extends on the front dielectric region and in the first opening.
13 . The diode according to claim 10 , wherein
the barrier region extends on the inner portion and on the peripheral portion of the anode region,
the front dielectric region is on a portion of the barrier region that is on the peripheral portion of the anode region, and
the metallization region extends on the front dielectric region and on the portion of the barrier region that is on the inner portion of the anode region.