Seal ring inductor and method of forming the same
Apparatuses and methods for providing inductance are disclosed. In one embodiment, a method for providing an inductor includes forming an electrical circuit on a substrate, forming a seal ring around the perimeter of the electrical circuit, providing a break in at least one layer of the seal ring, and electrically connecting the seal ring such that the seal ring operates as an inductor.
1. A method of forming an inductor, comprising:
forming an electrical circuit on a substrate, the electrical circuit configured to generate a radio frequency signal;
forming a seal ring around the electrical circuit;
providing a first break in a first coil of the seal ring, the first break defining a first end and a second end of the first coil; and
providing a second break in a second coil of the seal ring, the second break defining a first end and a second end of the second coil, the seal ring configured to operate as an inductor electrically connecting a first electrical node formed at the first end of the second coil to a second electrical node.
2. The method of claim 1 wherein the electrical circuit includes a capacitor configured to receive the radio frequency signal generated by the electrical circuit.
3. The method of claim 1 further comprising electrically connecting a capacitor to the first electrical node at the first end of the second coil.
4. The method of claim 1 further comprising electrically connecting the second end of the first coil to the first end of the second coil.
5. The method of claim 1 wherein the first break and the second break at least partially overlap when the first and second coils are viewed from a direction perpendicular to the substrate.
6. The method of claim 1 wherein the first break and the second break do not overlap when the first and second coils are viewed from a direction perpendicular to the substrate.
7. The method of claim 1 wherein the substrate is a gallium arsenide (GaAs) substrate.
8. The method of claim 1 further comprising electrically connecting the second electrical node to a bias circuit of the electrical circuit such that the seal ring is configured to prevent high-frequency components of the radio frequency signal from reaching the bias circuit.
9. The method of claim 1 further comprising electrically connecting the second electrical node to a ground supply or a power supply.
10. The method of claim 1 further comprising electrically connecting an antenna to the first electrical node at the first end of the second coil such that the seal ring is configured to shunt a portion of an electric charge associated with an electrostatic discharge event at the antenna.
11. The method of claim 10 further comprising electrically connecting a capacitor to the first electrical node at the first end of the second coil such that the capacitor is configured to assist the seal ring in protecting the electrical circuit from the electrostatic discharge event at the antenna.
12. The method of claim 1 further comprising electrically connecting the seal ring to another electrical circuit such that the seal ring is configured to filter signals between the two electrical circuits.
13. The method of claim 1 further comprising electrically connecting a capacitor and another inductor to the first electrical node at the first end of the second coil.
14. The method of claim 1 further comprising electrically connecting a first capacitor and a second capacitor to the first electrical node at the first end of the second coil.
15. A method of operating a seal ring, comprising:
providing an integrated circuit including a substrate, an electrical circuit disposed on the substrate, and a seal ring disposed on the substrate and surrounding the electrical circuit, the electrical circuit configured to generate a radio frequency signal, the seal ring including a first coil having a first break defining a first end and a second end of the first coil and a second coil having a second break defining a first end and a second end of the second coil; and
operating the seal ring as an inductor electrically connecting a first electrical node formed at the first end of the second coil to a second electrical node.
16. The method of claim 15 wherein the first end and the second end of the second coil are separated by a distance in a range of about 10 μm to about 20 μm.
17. The method of claim 15 wherein a distance between the first end and the second end of the second coil is equal to a minimum distance permitted by a processing technology.
18. A method of operating a seal ring, comprising:
providing a semiconductor die including a substrate, an electrical circuit fabricated on the substrate, and a seal ring fabricated on the substrate, the electrical circuit configured to generate a radio frequency signal, the seal ring including a first coil having a first break defining a first end and a second end of the first coil and a second coil having a second break defining a first end and a second end of the second coil; and
operating the seal ring as an inductor electrically connecting a first electrical node formed at the first end of the second coil to a second electrical node.
19. The method of claim 18 further comprising causing the seal ring to filter signals the electrical circuit and another electrical circuit external to the semiconductor die.
20. The method of claim 18 further comprising causing the seal ring to prevent high-frequency components of the radio frequency signal from reaching another component electrically connected to the second electrical node.