Trench isolation for thyristor-based device
View Patent ↗A semiconductor device includes a thyristor body having at least one region in a substrate. According to an example embodiment of the present invention, a trench is in a substrate and adjacent to a thyristor body region in the substrate. The trench is lined with an insulative material and further includes conductive material that is insulated from the thyristor body region in the substrate by the liner material. A conductive thyristor control port is located in the trench and adapted for capacitively coupling to the thyristor body region in the substrate and to control current in the thyristor body by causing an outflow of minority carriers in the thyristor. With this approach, conductive material can be used to fill a portion of the trench while using the trench portion including the conductive material to electrically isolate a portion of the thyristor body in the substrate. This approach is particularly useful, for example, in high-density applications where insulative trenches having high aspect ratios are desired.
1. A semiconductor device comprising:
a substrate;
a thyristor body having a plurality of regions including opposite end regions and at least one body region in the substrate;
a trench region in the substrate and laterally adjacent to said at least one thyristor body region in the substrate, the trench region including an insulative liner material and a conductive material in a portion of the trench region that is lined, the insulative liner material being arranged to electrically insulate the conductive material from said at least one body region in the substrate; and
a conductive thyristor control port in the trench and configured and arranged for capacitively coupling at least one voltage transition to the at least one thyristor body region in the substrate, wherein the at least one thyristor body region in the substrate has a cross section adapted so that the capacitive coupling of at least one voltage transition from the control port results in an outflow of minority carriers from said one thyristor body region and switches the thyristor-based semiconductor device at least from a current-passing mode to a current-blocking mode for current flow between the opposite end regions of the thyristor body;
wherein the conductive material is over the control port.
2. A semiconductor device comprising:
a substrate;
a thyristor body having a plurality of regions including opposite end regions and at least one body region in the substrate;
a trench region in the substrate and laterally adjacent to said at least one thyristor body region in the substrate, the trench region including an insulative liner material and a conductive material in a portion of the trench region that is lined, the insulative liner material being arranged to electrically insulate the conductive material from said at least one body region in the substrate; and
a conductive thyristor control port in the trench and configured and arranged for capacitively coupling at least one voltage transition to the at least one thyristor body region in the substrate, wherein the at least one thyristor body region in the substrate has a cross section adapted so that the capacitive coupling of at least one voltage transition from the control port results in an outflow of minority carriers from said one thyristor body region and switches the thyristor-based semiconductor device at least from a current-passing mode to a current-blocking mode for current flow between the opposite end regions of the thyristor body;
wherein the control port is shorted to the conductive material and wherein the insulative liner is adapted to inhibit the shorted conductive material from switching a portion of the thyristor body region in the substrate adjacent to the conductive material between a blocking state and a conducting state.
3. A semiconductor device comprising:
a substrate;
a thyristor body having a plurality of regions including opposite end regions and at least one body region in the substrate;
a trench region in the substrate and laterally adjacent to said at least one thyristor body region in the substrate, the trench region including an insulative liner material and a conductive material in a portion of the trench region that is lined, the insulative liner material being arranged to electrically insulate the conductive material from said at least one body region in the substrate; and
a conductive thyristor control port in the trench and configured and arranged for capacitively coupling at least one voltage transition to the at least one thyristor body region in the substrate, wherein the at least one thyristor body region in the substrate has a cross section adapted so that the capacitive coupling of at least one voltage transition from the control port results in an outflow of minority carriers from said one thyristor body region and switches the thyristor-based semiconductor device at least from a current-passing mode to a current-blocking mode for current flow between the opposite end regions of the thyristor body;
wherein the trench region at least partially surrounds the at least one thyristor body region in the substrate;
wherein the conductive thyristor control port at least partially surrounds the at least one thyristor body region in the substrate; and
wherein the conductive thyristor control port surrounds at least two opposite sides of the at least one thyristor body region in the substrate.
4. A semiconductor device comprising:
a substrate;
a thyristor body having a plurality of regions including opposite end regions and at least one body region in the substrate;
a trench region in the substrate and laterally adjacent to said at least one thyristor body region in the substrate, the trench region including an insulative liner material and a conductive material in a portion of the trench region that is lined, the insulative liner material being arranged to electrically insulate the conductive material from said at least one body region in the substrate; and
a conductive thyristor control port in the trench and configured and arranged for capacitively coupling at least one voltage transition to the at least one thyristor body region in the substrate, wherein the at least one thyristor body region in the substrate has a cross section adapted so that the capacitive coupling of at least one voltage transition from the control port results in an outflow of minority carriers from said one thyristor body region and switches the thyristor-based semiconductor device at least from a current-passing mode to a current-blocking mode for current flow between the opposite end regions of the thyristor body;
wherein the conductive material is disposed on an unlined bottom portion of the trench.
5. A semiconductor device comprising:
a substrate;
a thyristor body having a plurality of regions including opposite end regions and at least one body region in the substrate;
a trench region in the substrate and laterally adjacent to said at least one thyristor body region in the substrate, the trench region including an insulative liner material and a conductive material in a portion of the trench region that is lined, the insulative liner material being arranged to electrically insulate the conductive material from said at least one body region in the substrate; and
a conductive thyristor control port in the trench and configured and arranged for capacitively coupling at least one voltage transition to the at least one thyristor body region in the substrate, wherein the at least one thyristor body region in the substrate has a cross section adapted so that the capacitive coupling of at least one voltage transition from the control port results in an outflow of minority carriers from said one thyristor body region and switches the thyristor-based semiconductor device at least from a current-passing mode to a current-blocking mode for current flow between the opposite end regions of the thyristor body;
wherein the conductive material is shorted to a conductor in the semiconductor device in a manner that maintains the conductive material at a voltage level of the conductor.
6. The semiconductor device of claim 5 , wherein the conductive material is shorted to a conductor that is adapted to hold the conductive material at a voltage level that reduces stress on dielectric material adjacent to the conductive material.
7. The semiconductor device of claim 5 , the conductive material is shorted to a portion of a thyristor that includes the thyristor body region in the substrate.
8. The semiconductor device of claim 5 , wherein the conductive material is shorted to a well region adjacent to the trench.