Tantalum Nitride Seed Layers for Bcc Tantalum Coatings Deposited on Steel by Magnetron Sputtering

Abstract

Tantalum, a tough refractory metal with excellent corrosion resistance, is an attractive protective coating material for steel subjected to mechanical wear in harsh chemical environments. The coatings deposited by sputtering usually contain a hard and brittle tetragonal phase mixed with the desirable tough and ductile bcc phase of Ta. One of the methods of promoting the growth of the bcc phase at a moderate substrate temperature is deposition of an interfacial or seed layer of tantalum nitride. Ta coatings were deposited by dc magnetron sputtering in argon, and the interfacial nitride layers by reactive sputtering performed in the same chamber with nitrogen gas added to argon. The critical thickness, stoichiometry, and structure of the seed layer required for bcc Ta growth were studied by scanning electron microscopy and X-ray diffraction. The results of adhesion testing of the Ta coatings deposited on the interfacial layers are also reported.

Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

“…Transition metal nitrides, especially tantalum nitride (TaN), are in high demand for a wide range of applications due to their high melting point, hardness, excellent wear and corrosion resistance, refractory character, mechanical and high-temperature stability, chemical inertness, and histocompatibility [1][2][3][4][5][6]. Some prominent examples of such applications are as a protective coating material against oxidation and corrosion [7], as a diffusion barrier for Al and Cu metallization in advanced microelectronics [8][9][10][11], in phosphide and nitride optoelectronics as ohmic contact [3,4], in artificial heart valves as histocompatibility materials [12], thin film resistors [13], as ceramic pressure sensors [14], and also different mechanical applications [5,6]. The large interest for TaN arises since it is considered recently as a high thermal conductive material in microelectronic chips for the θ-TaN phase [15].…”

Influence of N₂ Flows on Sputtered Ta(N) films: Electrical, Structural, Chemical and Optical Properties

“…Transition metal nitrides, especially tantalum nitride (TaN) are highly demanded in a wide range of applications due to their high melting point, hardness, excellent wear and corrosion resistance, refractory character, mechanical and high-temperature stability, chemical inertness, and histocompatibility [1][2][3][4][5][6]. Some prominent examples of such applications as a protective coating material for protection against oxidation and corrosion [7], as a diffusion barrier for Al and Cu metallization in advanced microelectronics [8][9][10][11], in phosphide and nitride optoelectronics as ohmic contact [3,4], in artificial heart valves as histocompatibility materials [12], thin film resistor [13], as ceramic pressure sensors [14], and also different mechanical applications [5,6]. The large interest for TaN arises since it is considered recently as a high thermal conductive material in microelectronic chips for the θ-TaN phase [15].…”