Lsi Logic Corporation

Lsi Corporation

John Q Walker

Todd A Randazzo

Derryl D J Allman

Verne C Hornback

Carl A Monzel

Franklin Duan

Steven L Howard

Jeffrey P Burleson

Minxuan Liu

Scott A Service

Nabil Monsour

A method for reducing variation in a desired property between transistors in an integrated circuit that is fabricated with a given process. The process is characterized to form a mathematical model that associates changes in polysilicon density and active density in the integrate circuit with changes in gate length and gate width in the transistors, and associates changes in the gate length and the gate width to the desired property. The integrated circuit is laid out with space sufficient to adjust the gate length and the gate width of the transistors without violating design rules of the transistors. The integrated circuit is divided into portions, and for at least a given one of the portions of the integrated circuit, the polysilicon density and the active density of the given portion is measured. For at least one of the transistors in the given portion of the integrated circuit, at least one of the gate length and the gate width of the transistor is selectively adjusted according to the mathematical model, based on at least one of the polysilicon density and the active density of the given portion, to reduce variation in the desired property between the transistors in the integrated circuit.

On chip local MOSFET sizing

A test methodology which provides that test structures, such as transistors, are arranged in a plurality of rows. A logic circuit controls which row is to be measured. An incrementer receives a triggering signal and functions as an address adder. Each time the triggering signal rises from 0 to 1, the output of the incrementer increases by 1. The output of the incrementer serves as the address input into a decoder. The decoder is connected to the rows of test structures. Preferably, each test structure contains a control circuit which is controlled by this signal (i.e., the output of the decoder). If the test structures are transistors, bias to each of the transistors can be applied separately with a common gate, source and well, and measurement can be done with a separate drain node.

Methodology to measure many more transistors on the same test area

A varactor is formed with a semiconductor junction having a retrograde dopant concentration profile in a depletion region. The retrograde dopant concentration profile results in an approximately linear capacitance/voltage characteristic response of the varactor. The retrograde dopant concentration profile also enables a peak of the dopant concentration to function as a low resistance conductive path connecting to the varactor.

CMOS varactor with constant dC/dV characteristic

A metal-insulator-metal capacitor is formed between interconnect layers of an integrated circuit with one of the plates of the capacitor formed integrally with one of the interconnect layers. A dielectric layer is formed on top of the interconnect layer, and a top capacitor plate is formed thereon. A bottom plate is defined by the interconnect layer and extends laterally beyond the top plate so that via interconnects may connect to both plates. An intermetal dielectric (IMD) layer separates the interconnect layer and the capacitor from the next interconnect layer above, and the via interconnects are formed through the IMD layer to connect the above interconnect layer to the capacitor plates. The dielectric layer on top of the interconnect layer that defines the bottom plate and another dielectric layer formed on top of the top plate may serve as etch stops for forming the vias for the via interconnects to different levels.

Interconnect-integrated metal-insulator-metal capacitor and method of fabricating same

Growing community of inventors

Colorado Springs, CO, United States of America

John Q Walker