Browse Prior Art Database

Independent Magnetostriction Control Loop for Thin Film Magnetic Head Production

IP.com Disclosure Number: IPCOM000112216D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 4 page(s) / 69K

Publishing Venue

IBM

Related People

Baratte, H: AUTHOR [+5]

Abstract

This article describes a method for calculating the Ni-composition during the fabrication of thin film magnetic heads by measuring magnetostriction.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 73% of the total text.

Independent Magnetostriction Control Loop for Thin Film Magnetic
Head Production

      This article describes a method for calculating the
Ni-composition during the fabrication of thin film magnetic heads by
measuring magnetostriction.

      Nickel/iron composition control is crucial for the read back
pulse stability of thin film magnetic heads.  Also the
magnetostriction is the actual parameter of interest for a
calculation of magnetic energies in the head, the composition
parameter is measured with huge efforts.

      Tremendous effort has been spent in the past to maximize the
accuracy of the Microprobe composition measurement tool or minimize
its drifts over time.

      An independent process control scheme is provided to improve
the accuracy of the NiFe magnetostriction (composition) measurement.
By using the established correlation of Lambda vs.  wt% Ni, a special
plating set up is implemented to control each individual plateing
cell in the manufacturing line.

      Using 5" wafers with about 10 &mu.m of sputtered Al[2]O[3]  and
a NiFe seed of 80 nm, a 1 micron thick NiFe film is plated.  The
plating current was set to deliver the same current density and
homogenity of production wafers.  After plating the wafers were
measured with a method described in [*]  to calculate the
magnetostriction.  Fig. 1 shows the data collected.  The correlation
Lambda = f(wt% Ni) establishes a sensitivity of 0.1 x 10(-6)  Lambda
per 0.13 wt% Ni.  Fig. 2...