Advanced Applications With High Quality ALN Substrate
Aluminum Nitride (AlN) substrates boast superior thermal, electrical and mechanical properties – making them the ideal choice for high power semiconductor applications in harsh environments. Being nontoxic makes AlN an excellent material choice.
AlN’s low thermal conductivity, dielectric constant and loss tangent help ensure superior signal distortion and energy losses in high-frequency devices, providing for peak performance. Furthermore, its low coefficient of thermal expansion prevents thermal stress and failure.
High-Frequency and High-Power RF Devices
High-power RF devices play a pivotal role in wireless communication networks such as public agency radio equipment, amateur radio, and onboard vehicle telematics systems. To meet their demands effectively and reliably, these RF devices require reliable high-performance substrates with integrated EMI shielding layers to optimize power density, heat dissipation, thermal cycling capabilities and thermal cycling resistance. Furthermore, smart multilayer AlN substrates with embedded EMI shielding layers enable designers to design circuits with smaller footprints and shorter electrical contacts for reduced parasitic influences and lower parasitic influences significantly.
Optimizing Alumina and AlN ceramic substrates to their maximum performance involves controlling several variables. Cleaning the surface, selecting an AlN target material with pure or doped structures and setting chamber deposition parameters such as deposition pressure, N2/Ar ratio and magnetron power are all crucial steps.
HiPIMS processing dramatically enhances crystalline quality by increasing energy absorption by nitrogen and aluminium ions in film growth processes, improving c-axis orientation, grain polarization uniformity and defect/stress reduction while expanding potential uses of single crystal AlN substrates such as temperature sensors, piezoelectric actuators and quantum computing qubit substrates.
High-Temperature and High-Voltage Electronics
Aluminum nitride substrates are ideal for high-temperature electronic devices like LED packages, power modules and RF components due to their nontoxic material offering exceptional thermal properties with very low heat conduction loss for quick heat dissipation. Furthermore, its thermal expansion coefficient closely mirrors silicon wafers for stability across temperature ranges.
By carefully manipulating AlN thin film deposition conditions, it’s possible to enhance film crystal quality while reducing residual stress while maintaining dense and compact morphologies. Varying temperature T, pressure P and target-substrate distance changes will affect plasma species’ mean free path L which has a direct bearing on sputtering rates and orientation of deposited films.
Adjusting the lateral growth rate (d) enables precise control over particle distribution across a NPSS, further improving crystalline quality and film orientation. Furthermore, these parameters have an impactful on ion energy distribution function of deposition process which influences collision probability between plasma species and sputtered particles.
High-Power LED Applications
LEDs consume vast quantities of current, with drive current and junction temperature interactions creating significant restrictions. Localized heating from nonradiative recombination causes current crowding and elevated thermal load which may overheat the light-emitting stack resulting in loss of luminescence and reduced device lifetime.
High-power LEDs require advanced packaging materials and higher performance interconnects to handle their increased current flow. Differential thermal expansion between substrate and other device components may lead to cracks, delamination or failure of device components if thermal expansion gaps exist between them, leading to cracks or delamination within device itself.
Crystal IS’ NH3 growth-interruption process provides high-quality AlN substrates with low FWHM values, significantly improving LED device stability. We recently used these substrates to fabricate sub-230nm (far UV-C) LEDs achieving output powers between 1.4 and 3.1mW without any browning due to increased radiative recombination from reduced dislocation densities and relaxation of internal tensile strain in GaN epilayer. These devices boast excellent Color Rendering Index values for harsh-environment applications.
High-Power Battery Applications
AIN substrate’s excellent thermal conductivity and insulating properties enable efficient heat dissipation in power modules and LED packages, and its comparable coefficient of thermal expansion to that of silicon makes it an excellent choice for high-performance electronics applications.
This enables a range of advanced applications in various sectors, including RF/microwave devices, insulated-gate bipolar transistors (IGBTs), battery applications and piezoelectric generators. The single-crystal AlN substrate’s insulating and electrical properties ensure optimal performance in these applications, while its high-quality surface enhances integrity of deposition layer integrity to increase device reliability.
An efficient deposition process ensures that AlN films form with desirable orientations by carefully controlling gas flow rates, keeping substrate temperature within an ideal range and fine-tuning sputtering power settings. RF magnetron sputtering prevents oxygen incorporation into growing films for superior performance.