Standard cell circuits employing high aspect ratio voltage rails for reduced resistance

Patent metadata

Field	Value
Publication number	US-10090244-B2
Application number	US-201715634039-A
Country	US
Kind code	B2
Filing date	Jun 27, 2017
Priority date	Jul 27, 2016
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

Standard cell circuits employing high aspect ratio voltage rails for reduced resistance are disclosed. In one aspect, a standard cell circuit is provided that employs a first high aspect ratio voltage rail configured to receive a first supply voltage. A second high aspect ratio voltage rail is employed that is disposed substantially parallel to the first high aspect ratio voltage rail. A voltage differential between the first and second high aspect ratio voltage rails is used to power a circuit device in the standard cell circuit. The first and second high aspect ratio voltage rails each have a height-to-width ratio greater than 1.0. The height of each respective first and second high aspect ratio voltage rail is greater than each respective width. Employing the first and second high aspect ratio voltage rails allows each to have a cross-sectional area that limits the resistance and corresponding IR drop.

First claim

What is claimed is:

1. A standard cell circuit, comprising:
a plurality of metal layers disposed in parallel along a vertical axis;
a first high aspect ratio voltage rail extending along a first longitudinal axis in a first direction perpendicular to the vertical axis and through at least one metal layer among the plurality of metal layers along the vertical axis, the first high aspect ratio voltage rail having a height-to-width ratio defined as a ratio between a respective height and a respective width of the first high aspect ratio voltage rail greater than 1.0 and configured to receive a first supply voltage;
a second high aspect ratio voltage rail extending along a second longitudinal axis in the first direction substantially parallel to the first high aspect ratio voltage rail and through the at least one metal layer along the vertical axis, the second high aspect ratio voltage rail having a height-to-width ratio defined as a ratio between a respective height and a respective width of the second high aspect ratio voltage rail greater than 1.0; and
a circuit device electrically coupled to the first high aspect ratio voltage rail and the second high aspect ratio voltage rail, wherein a voltage differential between the first high aspect ratio voltage rail and the second high aspect ratio voltage rail provides power to the circuit device.

2. The standard cell circuit of claim 1 , further comprising one or more metal lines extending along one or more corresponding longitudinal axes different from the first longitudinal axis and the second longitudinal axis in the first direction substantially parallel to the first high aspect ratio voltage rail and the second high aspect ratio voltage rail, wherein:
each metal line of the one or more metal lines has a width approximately equal to a critical dimension of a process technology of the standard cell circuit;
the first high aspect ratio voltage rail has a width between approximately two (2) and three (3) times the width of each metal line of the one or more metal lines; and
the second high aspect ratio voltage rail has a width approximately between two (2) and three (3) times the width of each metal line of the one or more metal lines.

3. The standard cell circuit of claim 2 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 4.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 4.0.

4. The standard cell circuit of claim 2 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 3.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 3.0.

5. The standard cell circuit of claim 2 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 2.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 2.0.

6. The standard cell circuit of claim 1 , further comprising one or more metal lines extending along one or more corresponding longitudinal axes different from the first longitudinal axis and the second longitudinal axis in the first direction substantially parallel to the first high aspect ratio voltage rail and the second high aspect ratio voltage rail, wherein:
each metal line of the one or more metal lines has a width approximately equal to a critical dimension of a process technology of the standard cell circuit;
the first high aspect ratio voltage rail has a width between approximately one (1) and two (2) times the width of each metal line of the one or more metal lines disposed in a metal layer; and
the second high aspect ratio voltage rail has a width between approximately one (1) and two (2) times a critical dimension of a metal line of the one or more metal lines.

7. The standard cell circuit of claim 6 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 4.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 4.0.

8. The standard cell circuit of claim 6 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 3.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 3.0.

9. The standard cell circuit of claim 6 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 2.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 2.0.

10. The standard cell circuit of claim 1 , further comprising one or more metal lines extending along one or more corresponding longitudinal axes different from the first longitudinal axis and the second longitudinal axis in the first direction substantially parallel to the first high aspect ratio voltage rail and the second high aspect ratio voltage rail, wherein:
each metal line of the one or more metal lines has a width approximately equal to a critical dimension of a process technology of the standard cell circuit;
the first high aspect ratio voltage rail has a width approximately equal to the width of each metal line of the one or more metal lines disposed in a metal layer; and
the second high aspect ratio voltage rail has a width approximately equal to the width of each metal line of the one or more metal lines.

11. The standard cell circuit of claim 10 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 4.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 4.0.

12. The standard cell circuit of claim 10 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 3.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 3.0.

13. The standard cell circuit of claim 10 , wherein:
the height-to-width ratio of the first high aspect ratio voltage rail is approximately equal to 2.0; and
the height-to-width ratio of the second high aspect ratio voltage rail is approximately equal to 2.0.

14. The standard cell circuit of claim 1 , wherein the second high aspect ratio voltage rail is configured to receive a second supply voltage.

15. The standard cell circuit of claim 1 , wherein the second high aspect ratio voltage rail is electrically coupled to ground.

16. The standard cell circuit of claim 1 integrated into an integrated circuit (IC).

17. The standard cell 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.

18. A standard cell circuit, comprising:

Assignees

• Qualcomm Inc

Inventors

• Xu Jeffrey Junhao
• Badaroglu Mustafa
• Yang Da
• Chidambaram Periannan

Classifications

• H10W20/4441

  the principal metal being a refractory metal · CPC title

• H10W20/4403 Primary

  based on metals, e.g. alloys, metal silicides (H10W20/4484 takes precedence) · CPC title

• H10W20/0698

  Local interconnections · CPC title

• H10W20/427

  Power or ground buses · CPC title

• H10W20/425

  Barrier, adhesion or liner layers · CPC title