Vertically integrated SCR structure with SOI-based raised trigger element
The present disclosure relates to a structure including a trigger element within a semiconductor-on-insulator (SOI) substrate, and a silicon controlled rectifier (SCR) under a buried insulator layer of the SOI substrate. The trigger element is between an anode and a cathode of the SCR.
1 . A structure comprising:
a trigger element within a semiconductor-on-insulator (SOI) substrate, the trigger element comprising a buried insulator layer of the SOI substrate, a semiconductor layer of the SOI substrate, the semiconductor layer of the SOI substrate between a first raised N+ region and a second raised N+ region, the first and second raised N+ regions being at a first level, a raised drain region above the first raised N+ region, a raised source region above the second raised N+ region, and a gate dielectric material above the semiconductor layer of the SOI substrate, the first raised N+ region and the second raised N+ region, and between the raised drain region and the raised source region, a third raised P+ region and a fourth raised P+ region on a second level being isolated from the first raised N+ and second raised N+ regions by a shallow trench isolation structure extending into the underlying SOI substrate below the buried insulator layer of the SOI substrate; and
a silicon controlled rectifier (SCR) under the buried insulator layer of the SOI substrate, the trigger element being between an anode and a cathode of the SCR.
2 . The structure of claim 1 , wherein the anode is connected to a P+ region in an N-well below the buried insulator layer of the SOI substrate.
3 . The structure of claim 1 , wherein the cathode is connected to an N+ region in a P-well below the buried insulator layer of the SOI substrate.
4 . The structure of claim 1 , wherein the first raised N+ region comprises a first epitaxial raised N+ region under the raised drain region and raised the second N+ region comprises a second epitaxial raised N+ region under the raised source region, the first epitaxial raised N+ region is separated from the second epitaxial raised N+ region by the semiconductor layer of the SOI substrate, and the cathode is connected to the second epitaxial raised N+ region.
5 . The structure of claim 4 , wherein the SCR is on a trap-rich layer.
6 . The structure of claim 4 , wherein portions of the raised source region and the raised drain region are unsilicided.
7 . The structure of claim 6 , further comprising at least two STI structures on the side of a P-well below the buried insulator layer of the SOI substrate.
8 . The structure of claim 6 , wherein the raised source region and a gate electrode material are connected to an N+ region and a P+ region in a P-well below the buried insulator layer of the SOI substrate.
9 . The structure of claim 1 , further comprising three shallow trench isolation (STI) structures on a side of an N-well below the buried insulator layer of the SOI substrate.
10 . The structure of claim 1 , wherein the trigger element comprises an N+ region under the raised source region and a P+ region under the raised drain region, and the cathode is connected to the P+ region.
11 . A circuit comprising:
a silicon controlled rectifier (SCR) below a buried insulator layer; and
a trigger element comprising a single crystalline semiconductor material above the buried insulator layer, and further comprising a plurality of raised doped regions surrounding the single crystalline semiconductor material, wherein the plurality of doped regions comprises raised N+ regions and raised P+ regions, the raised N+ regions sandwiching the single crystalline semiconductor material at a first level, and the raised P+ regions on a second level being isolated from the raised N+ regions by a shallow trench isolation structure extending into an underlying semiconductor substrate below the buried insulator layer.
12 . The circuit of claim 11 , wherein the trigger element is between an anode and a cathode of the SCR.
13 . The circuit of claim 12 , wherein the anode is connected to a P+ region in an N-well below the buried insulator layer.
14 . The circuit of claim 12 , wherein the cathode is connected to an N+ region in a P-well below the buried insulator layer.
15 . The circuit of claim 12 , wherein the raised N+ doped regions comprise at least two epitaxial raised N+ regions.
16 . The circuit of claim 15 , wherein a first raised epitaxial N+ region of the at least two raised epitaxial N+ regions is separated from a second raised epitaxial N+ region of the at least two raised epitaxial N+ regions by the single crystalline semiconductor material, and further comprising a raised drain region above the first raised epitaxial N+ region and a source region above the second raised epitaxial N+ region.
17 . The circuit of claim 15 , further comprising a blocking layer adjacent to a drain region and a source region of the trigger element.
18 . The circuit of claim 11 , wherein the trigger element comprises a gate electrode material, a raised drain region, and a raised source region, the raised source region and the raised drain region being above a raised epitaxial semiconductor layer comprising the raised doped regions.
19 . A method comprising:
forming a trigger element within a silicon-on-insulator (SOI) substrate, the trigger element comprising a buried insulator layer of the SOI substrate, a semiconductor layer of the SOI substrate, the semiconductor layer of the SOI substrate being between a first raised N+ region and a second raised N+ region, the first and second raised N+ regions being at a first level, a raised drain region above the first raised N+ region, a raised source region above the second raised N+ region, and a gate dielectric material above the semiconductor layer of the SOI substrate, the first raised N+ region and the second raised N+ region, and between the raised drain region and the raised source region; a third raised P+ region and a fourth raised P+ region on a second level being isolated from the first raised N+ and second raised N+ regions by a shallow trench isolation structure extending into the underlying SOI substrate below the buried insulator layer of the SOI substrate; and
forming a silicon controlled rectifier (SCR) under the buried insulator layer of the SOI substrate, which is a buried oxide (BOX) layer, and wherein the trigger element is between an anode and a cathode of the SCR.