Integrated Device Technology, Inc.

Wanqing Cao

Shih-Ked Lee

Guo-Qiang Lo

Gaolong Jin

Eric Lee

Chuen-Der Lien

Sang-Yun Lee

Hongyong Xue

Guo-Qiang Patrick Lo

Robert B Hixson

Louis Huang

Dave Cobert

The present invention relates to a thin film resistor formed over a semiconductor substrate. A gate structure is formed and a dielectric layer is formed over the gate structure. A via is then etched that extends through the dielectric layer so as to expose a conductive layer of the gate structure. A layer of titanium nitride is deposited and a rapid thermal anneal is performed in an oxygen ambient. The rapid thermal anneal incorporates oxygen into the titanium nitride, forming titanium oxynitride film. A layer of dielectric material is then deposited and etched-back to form a dielectric plug that fills the remaining portion of the via. The titanium oxynitride film is patterned to form a titanium oxynitride structure that is electrically coupled to the gate structure.

Thin film resistor structure

The present invention includes SRAM memory cells and methods for forming SRAM cells having reduced soft error rate. The SRAM cell includes a first NMOS transistor and a first PMOS transistor having a common gate, and a second NMOS transistor and a second PMOS transistor having a common gate. A first resistor is electrically coupled on one end to the drains of the first PMOS transistor and the first NMOS transistor; and is electrically coupled on the other end to the common gate of the second NMOS and second PMOS transistors. A second resistor is electrically coupled on one end to the drains of the second PMOS transistor and the second NMOS transistor; and is electrically coupled on the other end to the common gate of the first NMOS transistor and the first PMOS transistor. The added resistor can be embedded in a contact opening such that it does not take up valuable surface area on the semiconductor substrate. Thereby, data loss from soft errors can be avoided while preserving small memory cell size.

Memory cell with reduced soft error rate

The present invention relates to a method for forming a thin film resistor and a thin film resistor formed over a semiconductor substrate. A gate structure is formed and a dielectric layer is formed over the gate structure. A via is then etched that extends through the dielectric layer so as to expose a portion of the gate structure. A layer of titanium nitride is deposited using a chemical vapor deposition process. A rapid thermal anneal is performed in an oxygen ambient. The rapid thermal anneal incorporates oxygen into the titanium nitride, forming titanium oxynitride film. A layer of dielectric material is then deposited and etched-back to form a dielectric plug that fills the remaining portion of the via. The titanium oxynitride film is patterned to form a titanium oxynitride structure that is electrically coupled to the gate structure. A metal layer is deposited and patterned to form an interconnect structure that electrically couples the titanium oxynitride structure to other circuitry.

Method for forming a thin film resistor structure

An improved method is provided for etching back a tungsten layer that overlies a titanium nitride adhesion layer on a semiconductor structure. This method includes the steps of: (1) performing a first plasma etchback of the tungsten layer for a first predetermined time period, such that a thin layer of tungsten remains over the adhesion layer at the end of the first plasma etchback, (2) actively or passively cooling the resulting semiconductor structure to a temperature of 35&#xb0; C. or lower, and then (3) performing a second plasma etchback of the tungsten layer until an endpoint is detected, thereby exposing the adhesion layer. Cooling the semiconductor structure prior to the second plasma etchback ensures that the titanium nitride adhesion layer is at a relatively low temperature during the second plasma etchback. The titanium nitride adhesion layer etches significantly slower at lower temperatures, thereby making it easier to stop the second plasma etchback on the adhesion layer.

Multi-step tungsten etchback process to preserve barrier integrity in an integrated circuit structure

A semiconductor structure is provided that includes a gate, a dielectric spacer located adjacent to a sidewall of the gate, a source/drain region, and a continuous silicide strap located over the gate, the dielectric spacer and the source/drain region. The silicide strap provides an electrical connection between the gate and the source drain region. In one embodiment, the silicide strap is formed by a method that includes the steps of (1) implanting a semiconductor material, such as silicon, into upper surfaces of the gate, the dielectric spacer, and the source/drain region, (2) depositing a refractory metal over the implanted semiconductor material, and (3) reacting the refractory metal with the implanted semiconductor material, thereby forming the continuous silicide strap at the upper surfaces of the gate, the dielectric spacer and the source/drain region. Advantageously, the dielectric spacer does not need to be removed prior to forming the silicide strap.

Conformal surface silicide strap on spacer and method of making same

Disclosed are methods and systems for forming salicide, in which a semiconductor substrate is provided with at least one exposed silicon surface. The semiconductor substrate is placed into a sputtering chamber. A silicide-forming metal layer, formed of a metal such as Co, Ni, is sputter-deposited over the exposed silicon surface. A process temperature is controlled below room temperature during the sputter deposition and preferably between approximately 0&deg; C. to 10&deg; C. The silicide-forming metal layer formed on the exposed silicon surface is first annealed to convert the silicide-forming metal layer into a salicide layer. Also, the system of the present invention is comprised of a sputter chamber including a mount for mounting a semiconductor substrate and a cooling mechanism coupled with the mount for cooling the semiconductor substrate. The cooling mechanism includes a controller to maintain a process temperature below room temperature. Improved device characteristics such as increased charge-to-breakdown can be achieved in the devices according to the present invention compared to the devices with high-temperature sputtered salicide.

Low-temperature sputtering system and method for salicide process

An improved method is provided for fabricating a cobalt silicide structure that includes the steps of: (1) forming a silicon structure, wherein a native oxide is located over a first surface of the silicon structure, (2) loading the silicon structure into a chamber, (3) introducing a vacuum to the chamber, (4) depositing a titanium layer over the first surface of the silicon structure, wherein the thickness of the titanium layer is selected to remove substantially all of the native oxide, (5) depositing a cobalt layer over the titanium layer, (6) depositing an oxygen impervious cap layer over the cobalt layer; and then (7) breaking the vacuum in the chamber, and (8) subjecting the silicon structure, the titanium layer, the cobalt layer and the cap layer to an anneal, thereby forming the cobalt silicide structure. The cap layer can be, for example, titanium or titanium nitride. The resulting cobalt silicide structure is substantially free from oxygen (i.e., oxide). Consequently, an underlying gate oxide or substrate is advantageously protected from the effects of cobalt silicide spiking.

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Portland, OR, United States of America

Wanqing Cao