62 results about "Stress engineering" patented technology

An example embodiment of a strained channel transistor structure comprises the following: a strained channel region comprising a first semiconductor material with a first natural lattice constant; a gate dielectric layer overlying the strained channel region; a gate electrode overlying the gate dielectric layer; and a source region and drain region oppositely adjacent to the strained channel region, one or both of the source region and drain region are comprised of a stressor region comprised of a second semiconductor material with a second natural lattice constant different from the first natural lattice constant; the stressor region has a graded concentration of a dopant impurity and/or of a stress inducing molecule. Another example embodiment is a process to form the graded impurity or stress inducing molecule stressor embedded S/D region, whereby the location/profile of the S/D stressor is not defined by the recess depth/profile.

Structures and methods of manufacturing are disclosed of dislocation free stressed channels in bulk silicon and SOI (silicon on insulator) CMOS (complementary metal oxide semiconductor) devices by gate stress engineering with SiGe and/or Si:C. A CMOS device comprises a substrate of either bulk Si or SOI, a gate dielectric layer over the substrate, and a stacked gate structure of SiGe and/or Si:C having stresses produced at the interfaces of SSi(strained Si)/SiGe or SSi/Si:C in the stacked gate structure. The stacked gate structure has a first stressed film layer of large grain size Si or SiGe over the gate dielectric layer, a second stressed film layer of strained SiGe or strained Si:C over the first stressed film layer, and a semiconductor or conductor such as p(poly)-Si over the second stressed film layer.

A process is disclosed which incorporates implantation of a carbon cluster into a substrate to improve the characteristics of transistor junctions when the substrates are doped with Boron and Phosphorous in the manufacturing of PMOS transistor structures in integrated circuits. There are two processes which result from this novel approach: (1) diffusion control for USJ formation; and (2) high dose carbon implantation for stress engineering. Diffusion control for USJ formation is demonstrated in conjunction with a boron or shallow boron cluster implant of the source/drain structures in PMOS. More particularly, first, a cluster carbon ion, such as C₁₆H_x⁺, is implanted into the source/drain region at approximately the same dose as the subsequent boron implant; followed by a shallow boron, boron cluster, phosphorous or phosphorous cluster ion implant to form the source/drain extensions, preferably using a borohydride cluster, such as B₁₈H_x⁺ or B₁₀H_x⁺. Upon subsequent annealing and activation, the boron diffusion is reduced, due to the gettering of interstitial defects by the carbon atoms.

In semiconductor devices in which both NMOS devices and PMOS devices are used to perform in different modes such as analog and digital modes, stress engineering is selectively applied to particular devices depending on their required operational modes. That is, the appropriate mechanical stress, i.e., tensile or compressive, can be applied to and/or removed from devices, i.e., NMOS and/or PMOS devices, based not only on their conductivity type, i.e., n-type or p-type, but also on their intended operational application, for example, analog/digital, low-voltage/high-voltage, high-speed/low-speed, noise-sensitive/noise-insensitive, etc. The result is that performance of individual devices is optimized based on the mode in which they operate. For example, mechanical stress can be applied to devices that operate in high-speed digital settings, while devices that operate in analog or RF signal settings, in which electrical noise such as flicker noise that may be introduced by applied stress may degrade performance, have no stress applied.

During the formation of a transistor element, sidewalls spacers are removed or at least partially etched back after ion implantation and silicidation, thereby rendering the mechanical coupling of a contact etch stop layer to the underlying drain and source regions more effective. Hence, the mechanical stress may be substantially induced by the contact etch step layer rather than by a combination of the spacer elements and the etch stop layer, thereby significantly facilitating the stress engineering in the channel region. By additionally performing a plasma treatment, different amounts of stress may be created in different transistor devices without unduly contributing to process complexity.

The present invention provides an STI bounded transistor structure having enhanced performance which is not diminished due to embedded stressor facets that can be present at the edge of the source/drain regions that contacts an embedded stressor material. Considering that the facet in the prior art is due to an STI divot formed during several necessary wet etching processes, the MOSFET source/drain edge of the inventive structure is surrounded by a liner to prevent facet growth during the epitaxial growth of the stressor material. As such, a part of the semiconductor substrate edge is preserved. The liner employed in the present invention is a stress engineering material such as, for example, silicon nitride.

While embedded silicon germanium alloy and silicon carbon alloy provide many useful applications, especially for enhancing the mobility of MOSFETs through stress engineering, formation of alloyed silicide on these surfaces degrades device performance. The present invention provides structures and methods for providing unalloyed silicide on such silicon alloy surfaces placed on semiconductor substrates. This enables the formation of low resistance contacts for both mobility enhanced PFETs with embedded SiGe and mobility enhanced NFETs with embedded Si:C on the same semiconductor substrate. Furthermore, this invention provides methods for thick epitaxial silicon alloy, especially thick epitaxial Si:C alloy, above the level of the gate dielectric to increase the stress on the channel on the transistor devices.

A first dielectric layer is formed over a PFET gate and an NFET gate, and lithographically patterned to expose a PFET area, while covering an NFET area. Exposed PFET active area is etched and refilled with a SiGe alloy, which applies a uniaxial compressive stress to a PFET channel. A second dielectric layer is formed over the PFET gate and the NFET gate, and lithographically patterned to expose the NFET area, while covering the PFET area. Exposed NFET active area is etched and refilled with a silicon-carbon alloy, which applies a uniaxial tensile stress to an NFET channel. Dopants may be introduced into the SiGe and silicon-carbon regions by in-situ doping or by ion implantation.

An (AlInGaN) based semiconductor device, comprising a first layer that is a semipolar or nonpolar nitride (AlInGaN) layer having a lattice constant that is partially or fully relaxed, deposited on a substrate or a template, wherein there are one or more dislocations at a heterointerface between the first layer and the substrate or the template; one or more strain compensated layers on the first layer, for defect reduction and stress engineering in the device, that is lattice matched to a larger lattice constant of the first layer; and one or more nonpolar or semipolar (AlInGaN) device layers on the strain compensated layers.

Riser stress-engineering-assessment equipment to verify the integrity and the in-deployment-integrity of a riser string by knowing the status, details and location of each riser joint and by monitoring the deployment parameters. When the failure risk exceeds an acceptable level, the equipment activates a local and/or a remote alarm using voice, sound and lights. The system comprises a computer with communication means, a material properties and geometry detection system, a data acquisition system acquiring deployment and other parameters, a database comprising of riser historical data and captured expert knowledge, a failure-criteria calculation to calculate maximum-stresses under different loads and the combined effects of the different loads to determine if the riser string is still fit-for-deployment.

Riser stress-engineering-assessment equipment to verify the integrity and the in-deployment-integrity of a riser string by knowing the status, details and location of each riser joint and by monitoring the deployment parameters. When the failure risk exceeds an acceptable level, the equipment activates a local and/or a remote alarm using voice, sound and lights. The system comprises a computer with communication means, a material properties and geometry detection system, a data acquisition system acquiring deployment and other parameters, a database comprising of riser historical data and captured expert knowledge, a failure-criteria calculation to calculate maximum-stresses under different loads and the combined effects of the different loads to determine if the riser string is still fit-for-deployment.

A method for engineering stress in the channels of MOS transistors of different conductivity using highly stressed nitride films in combination with selective semiconductor-on-insulator (SOI) device architecture is described. A method of using compressive and tensile nitride films in the shallow trench isolation (STI) process is described. High values of stress are achieved when the method is applied to a selective SOI architecture.

A resistance-change memory device using stress engineering is described, including a first layer including a first conductive electrode, a second layer above the first layer including a resistive-switching element, a third layer above the second layer including a second conductive electrode, where a first stress is created in the switching element at a first interface between the first layer and the second layer upon heating the memory element, and where a second stress is created in the switching element at a second interface between the second layer and the third layer upon the heating. A stress gradient equal to a difference between the first stress and the second stress has an absolute value greater than 50 MPa, and a reset voltage of the memory element has a polarity relative to a common electrical potential that has a sign opposite the stress gradient when applied to the first conductive electrode.

A method for fabricating a semiconductor structure uses a volumetric change ion implanted into a volumetric change portion of a gate electrode that is located over a channel region within a semiconductor substrate to form a volume changed portion of the gate electrode located over the channel region within the semiconductor substrate. The volume changed portion of the gate electrode is typically bidirectionally symmetrically graded in a vertical direction. The volume-changed portion of the gate electrode has a first stress that induces a second stress different than the first stress into the channel region of the semiconductor substrate.

An IC is provided that includes at least one SRAM cell in which the performance of the SRAM cell is enhanced, yet maintaining good stability and writability. In particular, the present invention provides an IC including at least one SRAM cell wherein the gamma ratio is about 1 or greater. In the present invention, the gamma ratio is increased with degraded pFET device performance. Moreover, in the inventive IC there is no stress liner boundary present in the SRAM region and ion variation for all devices is reduced as compared to that of a conventional SRAM structure. The present invention, solves the above by providing an integrated circuit (IC) that comprises at least one static random access memory cell including at least one nFET and at least one pFET; and a continuous relaxed stressed liner located above and adjoining the at least one nFET and the at least one pFET.

In complex metallization systems of sophisticated semiconductor devices, appropriate stress compensation mechanisms may be implemented in order to reduce undue substrate deformation during the overall manufacturing process. For example, additional dielectric material and/or functional layers of one or more metallization layers may be provided with appropriate internal stress levels so as to maintain substrate warpage at a non-critical level, thereby substantially reducing yield losses in the manufacturing process caused by non-reliable attachment of substrates to substrate holders in process and transport tools.

There is provided a method for fabricating a semiconductor device comprising the formation of a first device in the first device region, the first device comprising first diffusion regions. A stressor layer covering the substrate in the first device region and the first device is subsequently formed, the stressor layer having a first stress value. A laser anneal to memorize at least a portion of the first stress value in the first device is carried out followed by an activation anneal after the laser anneal to activate dopants in the first diffusion regions.

A design structure embodied in a machine readable medium is provided for use in the design, manufacturing, and/or testing of Ics that include at least one SRAM cell. In particular, the present invention provides a design structure of an IC embodied in a machine readable medium, the IC including at least one SRAM cell with a gamma ratio of about 1 or greater. In the present invention, the gamma ratio is increased with degraded pFET device performance. Moreover, in the inventive IC, there is no stress liner boundary present in the SRAM region and ion variation for all devices is reduced as compared to that of a conventional SRAM structure. The present invention provides a design structure of an IC embodied in a machine readable medium, the IC comprising at least one static random access memory cell including at least one nFET and at least one pFET; and a continuous relaxed stressed liner located above and adjoining the at least one nFET and the at least one pFET.