Doping free connection structures and methods
Structures with doping free connections and methods of fabrication are provided. An exemplary structure includes a substrate; a first region of a first conductivity type formed in the substrate; an overlying layer located over the substrate; a well region of a second conductivity type formed in the overlying layer; a conductive plug laterally adjacent to the well region and extending through the overlying layer to electrically contact with the first region; and a passivation layer located between the conductive plug and the well region.
1 . A structure comprising:
a first region of a first conductivity type;
an overlying layer located over the first region;
a well region of a second conductivity type formed in the overlying layer;
a conductive plug laterally adjacent to the well region and extending through the overlying layer to electrically contact with the first region; and
a passivation layer located between the conductive plug and the well region, wherein the passivation layer is an oxide.
2 . The structure of claim 1 , wherein the passivation layer surrounds the conductive plug.
3 . The structure of claim 1 , wherein:
the first region extends from a first end to a second end and has a central portion therebetween;
the well region lies over the central portion of the first region;
the conductive plug comprises a first conductive plug portion and a second conductive plug portion;
the first conductive plug portion extends to contact the first end of the first region;
the second conductive plug portion extends to contact the second end of the first region;
a first portion of the passivation layer is located between the first portion of the conductive plug and the well region; and
a second portion of the passivation layer is located between the second portion of the conductive plug and the well region.
4 . The structure of claim 3 , wherein the conductive plug is an annular ring, and wherein the first conductive plug portion and the second conductive plug portion are portions of the annular ring.
5 . The structure of claim 3 , wherein the first conductive plug portion is not connected to the second conductive plug portion, and wherein the first portion of the passivation layer is not connected to the second portion of the passivation layer.
6 . The structure of claim 1 , wherein the conductive plug has a first height, wherein the overlying layer has a second height, and wherein the first height is greater than or equal to the second height.
7 . The structure of claim 1 , wherein the overlying layer is comprised of silicon and the well region is comprised of germanium.
8 . The structure of claim 1 , further comprising a deep trench isolation, wherein the conductive plug is located between the deep trench isolation and the well region.
9 . A cell comprising:
an anode and a cathode;
a first-type doped well connected to the anode;
a second-type doped buried layer;
a conductive plug directly connected to the buried layer and to the cathode; and
a passivation layer located between the conductive plug and the well.
10 . The cell of claim 9 , wherein the passivation layer surrounds the conductive plug.
11 . The cell of claim 9 , further comprising an epitaxial layer, wherein the well is formed in the epitaxial layer, wherein the conductive plug passes through the epitaxial layer, and wherein the passivation layer prevents contact between the conductive plug and the epitaxial layer.
12 . The cell of claim 9 , further comprising a deep trench isolation defining a perimeter of the cell, wherein the conductive plug is located between the deep trench isolation and the well.
13 . The cell of claim 9 , wherein the conductive plug is an annular ring surrounding the well.
14 . The cell of claim 9 , wherein the passivation layer is an oxide.
15 . The cell of claim 9 , wherein the passivation layer is a high-k dielectric material.
16 . The cell of claim 9 , wherein the conductive plug has a first height, the epitaxial layer has a second height, and the first height is greater than or equal to the second height.
17 . The cell of claim 9 , wherein the buried layer extends from a first end to a second end and has a central portion therebetween, the well lies over the central portion of the buried layer, and the conductive plug extends to contact at least one of the first end or the second end of the buried layer.
18 . The cell of claim 9 , wherein the conductive plug is a metal plug.
19 . A structure comprising:
a first region of a first conductivity type;
an overlying layer located over the first region;
a well region of a second conductivity type formed in the overlying layer;
a deep trench isolation; and
a conductive plug located between the deep trench isolation and the well region and extending through the overlying layer to electrically contact with the first region.
20 . The structure of claim 19 , further comprising a passivation layer located between the conductive plug and the well region.