Circuits employing a double diffusion break (DDB) and single diffusion break (SDB) in different type diffusion region(s), and related fabrication methods
Aspects disclosed herein include circuits employing a double diffusion break (DDB) and a single diffusion break (SDB) in different type diffusion regions, and related fabrication methods are disclosed. In exemplary aspects disclosed herein, either a DDB or a SDB is formed in the N-type diffusion region(s) and the opposing type diffusion, either a SDB or DDB, is formed in the P-type diffusion region(s). Forming different diffusion breaks between a DDB and a SDB in different diffusion regions of the circuit can be employed to induce channel strain that will increase carrier mobility of either P-type or N-type semiconductor devices formed in respective P-type or N-type diffusion region(s), while avoiding or reducing such induced channel strain in either P-type or N-type semiconductor devices formed in respective P- or N-type diffusion region(s) that may degrade carrier mobility.
1. A circuit, comprising:
a substrate comprising a top surface;
a first diffusion region comprising either an N-type diffusion region or a P-type diffusion region disposed in the substrate,
the first diffusion region comprising at least one first semiconductor channel each having a first longitudinal axis in a first direction;
a second diffusion region comprising either a P-type diffusion region or an N-type diffusion region opposite of a diffusion type of the first diffusion region,
the second diffusion region disposed in the substrate and comprising at least one second semiconductor channel each having a second longitudinal axis parallel to the first longitudinal axis;
a first dummy gate extending along a third longitudinal axis orthogonal to the first longitudinal axis, the first dummy gate comprising a first dielectric material disposed above the first diffusion region and the second diffusion region, the first dielectric material extending from the top surface of the substrate to a first depth into the substrate;
a second dummy gate extending along a fourth longitudinal axis parallel to the third longitudinal axis, the second dummy gate comprising a second dielectric material disposed above the first diffusion region and the second diffusion region, the second dielectric material extending from the top surface of the substrate to a second depth into the substrate, the second dummy gate adjacent to the first dummy gate by a gate pitch;
a double diffusion break (DDB) in the first diffusion region, the DDB comprising:
a trench isolation structure between the first dummy gate and the second dummy gate in the first direction;
a portion of the first dummy gate in the first diffusion region; and
a portion of the second dummy gate in the first diffusion region; and
a single diffusion break (SDB) in the second diffusion region, the SDB comprising:
a portion of the first dummy gate in the second diffusion region; and
a portion of the second dummy gate in the second diffusion region.
2. The circuit of claim 1 , wherein:
the first diffusion region comprises a first N-type diffusion region; and
the at least one first semiconductor channel comprises at least one first N-type semiconductor channel structure;
the second diffusion region comprises a first P-type diffusion region; and
the at least one second semiconductor channel comprises at least one second P-type semiconductor channel structure.
3. The circuit of claim 2 , wherein the DDB is configured to induce a tensile strain in at least a portion of the at least one first semiconductor channel in the first diffusion region.
4. The circuit of claim 1 , wherein:
the first diffusion region comprises a first P-type diffusion region; and
the at least one first semiconductor channel comprises at least one first P-type semiconductor channel structure;
the second diffusion region comprises a first N-type diffusion region; and
the at least one second semiconductor channel comprises at least one second N-type semiconductor channel structure.
5. The circuit of claim 4 , wherein the DDB is configured to induce a compressive strain in at least a portion of the at least one first semiconductor channel in the first diffusion region.
6. The circuit of claim 1 , wherein the substrate further comprises a non-diffusion region disposed along a fifth longitudinal axis between the first diffusion region and the second diffusion region in the first direction.
7. The circuit of claim 6 , wherein the non-diffusion region comprises a trench isolation structure extending from the top surface of the substrate to a third depth into the substrate.
8. The circuit of claim 1 , further comprising a first active gate extending above the first diffusion region and the second diffusion region along a fifth longitudinal axis orthogonal to the first longitudinal axis.
9. The circuit of claim 8 , further comprising a second active gate extending above the first diffusion region and the second diffusion region along a sixth longitudinal axis parallel to the third longitudinal axis; and
wherein the first dummy gate is adjacent to the second active gate by the gate pitch.
10. The circuit of claim 1 , further comprising an interlayer dielectric disposed above the first diffusion region, the second diffusion region, the first dummy gate, and the second dummy gate.
11. The circuit of claim 1 , wherein the trench isolation structure extends from the top surface of the substrate to a third depth into the substrate.
12. The circuit of claim 10 , wherein:
the first dummy gate in the first diffusion region of the DDB extends from a top surface of the interlayer dielectric, through the interlayer dielectric and from the top surface of the substrate to the first depth into the substrate; and
the second dummy gate in the first diffusion region of the DDB extends from the top surface of the interlayer dielectric, through the interlayer dielectric and from the top surface of the substrate to the second depth into the substrate.
13. The circuit of claim 10 , wherein:
the first dummy gate in the second diffusion region of the SDB extends from a top surface of the interlayer dielectric, through the interlayer dielectric and from the top surface of the substrate to the first depth into the substrate; and
the second dummy gate in the second diffusion region of the SDB extends from the top surface of the interlayer dielectric, through the interlayer dielectric and from the top surface of the substrate to the second depth into the substrate.
14. The circuit of claim 9 , further comprising:
a first Field-Effect Transistor (FET) in the first diffusion region, the first FET comprising:
a first gate comprising the first active gate;
a first semiconductor channel among the at least one first semiconductor channel;
a first source in a first end portion of the first semiconductor channel; and
a first drain in a second end portion of the first semiconductor channel; and
a second FET in the second diffusion region, the second FET comprising:
a second gate comprising the second active gate;
a second semiconductor channel among the at least one second semiconductor channel;
a second source in a first end portion of the second semiconductor channel; and
a second drain in a second end portion of the second semiconductor channel.
15. The circuit of claim 14 , wherein:
the first FET comprises a first FinFET, wherein:
the first semiconductor channel extends above the top surface of the substrate; and
the first active gate is disposed around at least a portion of the first semiconductor channel; and
the second FET comprises a second FinFET, wherein:
the second semiconductor channel extends above the top surface of the substrate; and
the second active gate is disposed around at least a portion of the second semiconductor channel.
16. The circuit of claim 14 , wherein:
the first FET comprises a first gate-all-around (GAA) FET, wherein:
the first semiconductor channel extends above the top surface of the substrate; and
the first active gate is disposed completely around the first semiconductor channel; and
the second FET comprises a second GAA FET, wherein:
the second semiconductor channel extends above the top surface of the substrate; and
the second active gate is disposed completely around the second semiconductor channel.
17. The circuit of claim 14 , wherein:
the first FET comprises a first planar FET, wherein:
the first semiconductor channel is disposed in the substrate below the top surface of the substrate; and
the first active gate is disposed above the top surface of the substrate above the first semiconductor channel; and
the second FET comprises a second planar FET, wherein:
the second semiconductor channel is disposed in the substrate below the top surface of the substrate; and
the second active gate is disposed above the top surface of the substrate above the second semiconductor channel.
18. The circuit of claim 1 integrated into a device selected from the group consisting of: a set top box; an entertainment unit; a navigation device; a communications device; a fixed location data unit; a mobile location data unit; a global positioning system (GPS) device; a mobile phone; a cellular phone; a smart phone; a session initiation protocol (SIP) phone; a tablet; a phablet; a server; a computer; a portable computer; a mobile computing device; a wearable computing device; a desktop computer; a personal digital assistant (PDA); a monitor; a computer monitor; a television; a tuner; a radio; a satellite radio; a music player; a digital music player; a portable music player; a digital video player; a video player; a digital video disc (DVD) player; a portable digital video player; an automobile; a vehicle component; avionics systems; a drone; and a multicopter.