Magnetron Sputtered AlN Layers on LTCC Multilayer and Silicon Substrates

Abstract

This work compares the deposition of aluminum nitride by magnetron sputtering on silicon to multilayer ceramic substrates. The variation of sputter parameters in a wide range following a fractional factorial experimental design generates diverse crystallographic properties of the layers. Crystal growth, composition, and stress are distinguished because of substrate morphology and thermal conditions. The best c-axis orientation of aluminum nitride emerges on ceramic substrates at a heater temperature of 150 • C and sputter power of 400 W. Layers deposited on ceramic show stronger c-axis texture than those deposited on silicon due to higher surface temperature. The nucleation differs significantly dependent on the substrate. It is demonstrated that a ceramic substrate material with an adapted coefficient of thermal expansion to aluminum nitride allows reducing the layer stress considerably, independent on process temperature. Layers sputtered on silicon partly peeled off, while they adhere well on ceramic without crack formation. Direct deposition on ceramic enables thus the development of optimized layers, avoiding restrictions by stress compensating needs affecting functional properties.

Substrate Temperature Dependent Properties of Sputtered AlN:Er Thin Film for In-Situ Luminescence Sensing of Al/AlN Multilayer Coating Health

“…Aluminum nitride (AlN) is an attractive material, which has found wide applications in microelectronics, optoelectronics and acoustic devices, due to its wide bandgap, relatively high thermal conductivity, high electrical resistivity and high ultrasound velocity [7,8,9,10,11,12,13,14,15]. AlN has also been applied as surface protective coatings for active metals, due to its high hardness [16] and good corrosion resistance [17,18].…”

Mechanical Properties and Thermal Stability of CrZrN/CrZrSiN Multilayer Coatings with Different Bilayer Periods

“…Most recently, multilayered hard coatings have gained increasing attention from the industrial and scientific fields because of the enhanced mechanical properties compared to those usually revealed in the corresponding monolithic coatings. As reported in many publications, the multilayer coatings exhibited superior mechanical and tribological properties relative to single-layer hard coatings [16][17][18][19][20][21][22]. These improved properties could be attributed to a multilayered structure, consisting of alternating layers with different interface number, composition, and thickness.…”