EFFECT OF RF SUBSTRATE BIAS ON CRYSTALLINE ORIENTATION OF CHROMIUM AND MAGNETIC CHARACTERISTICS OF 84-PERCENT CO-16-PERCENT CR FILMS

This paper reports on the conditions for the formation of Cr films with a (110) planar orientation on glass substrates as a function of 13.56 MHz rf substrate bias and sputtering pressure. The Cr (110) planar orientation is dependent on the rf bias voltage as well as on the argon pressure. The developed dc bias voltages from the applied rf substrate bias voltages are measured (and reported) with respect to ground. At zero bias and at 3 mTorr pressure, Cr films exhibit a weak (110) planar crystalline orientation but at 10 mTorr pressure exhibit a random orientation and/or microcrystalline structure. Experimental results show that an optimum bias voltage (-150 V) and pressure (10 mTorr) occur for maximum Cr (110) planar orientation. Co84Cr16 (at %) alloy films were evaluated relative to their crystalline orientation as a function of rf substrate bias and pressure. The magnetic properties of Co84Cr16 films at optimum bias and argon pressure were evaluated on Cr underlayers with maximum (110) planar orientation on glass substrates. © 1990 IEEE