Corporation for National Research Initiatives

Paul Sunal

Michael A Huff

Michael Pedersen

Mehmet Ozgur

Lance Oh

A method and system for controlling the state of stress in deposited thin films are disclosed. According to the method and system, various process parameters, including: process pressure; substrate temperature; deposition rate; and ion-beam energies (controlled via the ion beam current, voltage, signal frequency and duty cycle) are varied using a step-by-step methodology to arrive at a pre-determined desired state of stress in thin films deposited using PVD. The method may be expressed as a computer algorithm, whereby the step-by-step procedure to obtain a pre-determined stress state, is coded for more efficient development and control of deposition processes. Alternatively, a closed-loop controlled PVD deposition system allows a pre-determined stress state of a thin film to be obtained quickly and efficiency using a feedback loop, algorithm and one or more sensors to monitor the substrate thin film stress and various process tool parameters.

Method and system for controlling the state of stress in deposited thin films

The present invention is directed to a method for the fabrication of electron field emitter devices, including carbon nanotube (CNT) field emission devices. The method of the present invention involves depositing one or more electrically conductive thin-film layers onto an electrically conductive substrate and performing lithography and etching on these thin film layers to pattern them into the desired shapes. The top-most layer may be of a material type that acts as a catalyst for the growth of single- or multiple-walled carbon nanotubes (CNTs). Subsequently, the substrate is etched to form a high-aspect ratio post or pillar structure onto which the previously patterned thin film layers are positioned. Carbon nanotubes may be grown on the catalyst material layer. The present invention also described methods by which the individual field emission devices may be singulated into individual die from a substrate.

Method for the fabrication of electron field emission devices including carbon nanotube electron field emission devices

The present invention is directed to a method for the fabrication of electron field emitter devices, including carbon nanotube (CNT) field emission devices. The method of the present invention involves depositing one or more electrically conductive thin-film layers onto a electrically conductive substrate and performing lithography and etching on these thin film layers to pattern them into the desired shapes. The top-most layer may be of a material type that acts as a catalyst for the growth of single- or multiple-walled carbon nanotubes (CNTs). Subsequently, the substrate is etched to form a high-aspect ratio post or pillar structure onto which the previously patterned thin film layers are positioned. Carbon nanotubes may be grown on the catalyst material layer. The present invention also described methods by which the individual field emission devices may be singulated into individual die from a substrate.

Method for the fabrication of electron field emission devices including carbon nanotube field electron emisson devices

A method and system are disclosed for controlling the state of stress in deposited thin films on microelectronics wafers for the integration of MEMS and NEMS devices with microelectronics. According to the method and system, various process parameters including: process pressure; substrate temperature; deposition rate; and ion-beam energies (controlled via the ion beam current, voltage, signal frequency and duty cycle) are varied using a step-by-step methodology to arrive at a pre-determined desired state of stress in thin films deposited using PVD at low temperatures and desired stress states onto wafers or substrates having microelectronics processing performed on them.

Method and system for integrated MEMS and NEMS using deposited thin films having pre-determined stress states

The present invention relates generally to a metallic alloy composed of Titanium and Tungsten that together form an alloy having a Coefficient of Thermal Expansion (CTE), wherein the content of the respective constituents can be adjusted so that the alloy material can be nearly perfectly matched to that of a commonly used semiconductor and ceramic materials. Moreover, alloys of Titanium-Tungsten have excellent electrical and thermal conductivities making them ideal material choices for many electrical, photonic, thermoelectric, MMIC, NEMS, nanotechnology, power electronics, MEMS, and packaging applications. The present invention describes a method for designing the TiW alloy so as to nearly perfectly match the coefficient of thermal expansion of a large number of different types of commonly used semiconductor and ceramic materials. The present invention also describes a number of useful configurations wherein the TiW material is made as well as how it can be shaped, formed and polished into heat sink, heat spreaders, and electrodes for many applications. The present invention also discloses the direct bonding of a TiW substrate to a semiconductor substrate.

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Arlington, VA, United States of America

Paul Sunal