Preparation and Ignition Properties of Tantalum Nitride Thin-Film Energy Transducers

Tantalum nitride (TaN) has excellent electrical properties that can be used as an energy transducer in the ignition field. In this study, TaN film transducers with different bridge parameters were designed and fabricated in an attempt to reduce its energy consumption. The ignition sensitivity of the film transducers was tested using the Langley method. The results revealed that the ignition voltage is the lowest when the thickness of the film is 0.9 µm. If the thickness and length of the bridge film are fixed, the ignition voltage of the transducer first decreases and then increases with the width of the bridge film increases. When the thickness and width of the bridge film are fixed, the ignition voltage of the transducer is first decrease and then increase with the length of the bridge film increases. We also evaluated the ignition mechanism of TaN film transducers. By comparing the performance of TaN, semiconductor bridge (SCB), and nickel–chromium (Ni–Cr) film transducers, the TaN and SCB transducers are proven to have similar ignition performances, which are better than the Ni–Cr transducer. The negative temperature coefficient of TaN and the positive feedback after the initial electrothermal ignition promoted the growth and strengthening of plasma in the bridge film, allowing the medicament to ignite quickly. When the feasibility of the process and the influence of the bridge film parameters on ignition sensitivity are considered, the preferred design parameters of the transducer are a thickness of 0.9 µm and a bridge film size of 0.3 mm×0.3 mm. This study shows that TaN can be utilized as a high-performance transducer.

Separation of AlN layers from silicon substrates by KOH etching

In this work, the AlN/Si(111) epitaxial structures grown consistently by plasma assisted molecular beam epitaxy (PA MBE) and hydride vapour phase epitaxy (HVPE) methods were studied. The PA MBE AlN buffer layers were synthesized via coalescence overgrowth of self-catalyzed AlN nanocolumns on Si(111) substrates and were used as templates for further HVPE growth of thick AlN layer. It was shown that described approaches can be used to obtain AlN layers with sufficiently smooth morphology. It was found that HVPE AlN inherited crystallographic polarity of the AlN layer grown by PA MBE. It was demonstrated that the etching of such AlN/Si(111) epitaxial structures results in partial separation of the AlN epilayers from the Si(111) substrate and allows to form suspended structures. Moreover, the avoidance of surface damage and backside overetching was achieved by use thin Cr film as surface protective coating and by increasing the layer thickness accordingly.

Computer simulation of temperature fields in the Cr (film)-Zr (substrate) system during pulsed electron-beam irradiation

The paper presents the results of numerical simulation of the distribution of thermal fields during the formation of Cr-Zr surface alloy using a pulsed low-energy high-current electron beam (LEHCEB). The melting thresholds of the Cr-Zr system for different thicknesses of Cr films were calculated. The melting threshold of the Cr-Zr system increases linearly with increasing Cr film thickness. A linear regression dependency model of the melting threshold on the film thickness is proposed. Evaporation thresholds of the Cr-Zr system for different thicknesses of Cr films were calculated. The evaporation threshold of the Cr-Zr system increases linearly with increasing Cr film thickness. A linear regression dependency model of the evaporation threshold on the film thickness is proposed. The value of the LEHCEB energy density at which the lifetime of the film and substrate are equal is calculated. This value is a maximum value for the effective formation of Cr-Zr. A model of the LEHCEB energy density, at which the lifetime of the film and the substrate are equal, in the form of a third-degree polynomial is proposed.

Reliability Failure in Microelectronic Interconnects by Electric Current Induced Chemical Reaction

The electric field-induced chemical reaction in Cr thin film by a micro/nano-probe has been recently reported with detailed characterization. Although the phenomenon is employed for micro-nano fabrication, this can act as a reliability failure, where Cr is used as an adhesion layer or main interconnects in microelectronic circuits. Here, we present an investigation on the role of electric current density for such failure using a specifically designed sample. A 100 μm width and 100 nm thin Cr film is deposited perpendicular to the Pt film of similar dimensions. The anode probe (20 μm diameter) is positioned onto the Pt film, whereas the cathode probe onto the Cr film. It is observed that the chemical reaction, for an applied voltage, initiates at the edge of the Pt film and not at the cathode probe. The localized chemical reaction causes to damage the interconnection line. The analysis based on the COMSOL multiphysics simulation illustrates that the chemical reaction evolves at the high current density locations. The study also builds a fundamental understanding of the mechanism of evolution of patterning by electric field-induced chemical reactions.

Design, Simulation, and Experimental Verification of a Destruction Mechanism of Transient Electronic Devices

To quickly destroy electronic devices and ensure information security, a destruction mechanism of transient electronic devices was designed in this paper. By placing the Ni-Cr film resistance and the energetic material between the chip and the package and heating the resistance by an electric current, the energetic material expanded and the chip cracked. The information on the chip was destroyed. The author simulated the temperature distribution and stress of the power-on structure in different sizes by ANSYS software. The simulation results indicate that the chip cracks within 50 ms under the trigger current of 0.5 A when a circular groove with an area of 1 mm2 and depth of 0.1 mm is filled with an expansion material with an expansion coefficient of 10−5°C−1. Then, the author prepared a sample for experimental verification. Experimental results show that the sample chip quickly cracks and fails within 10 ms under the trigger current of 1 A. The simulation and experimental results confirm the feasibility of the structure in quick destruction, which lays the foundation for developing instantaneous-failure integrated circuit products to meet information security applications.