Browse Prior Art Database

Micro-Mechanical Test Sites On Wafers for Manufacturing Control

IP.com Disclosure Number: IPCOM000100475D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 86K

Publishing Venue

IBM

Related People

Cheng, DC: AUTHOR [+2]

Abstract

This article describes an unconventional approach to thin-film head process control in which micro-mechanical devices are fabricated on the wafers to measure mechanical-related properties such as magnetostriction and stress. Conventional test sites extensively practiced today are mainly restricted to magnetic, electrical, compositional, dimensional or morphological controls. However, the control of micro-mechanical properties will become essential in the near future when "head- instabilities" effects become more pronounced as all sizes are scaled down and mechanical properties play significant roles in head performance.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Micro-Mechanical Test Sites On Wafers for Manufacturing Control

       This article describes an unconventional approach to
thin-film head process control in which micro-mechanical devices are
fabricated on the wafers to measure mechanical-related properties
such as magnetostriction and stress.  Conventional test sites
extensively practiced today are mainly restricted to magnetic,
electrical, compositional, dimensional or morphological controls.
However, the control of micro-mechanical properties will become
essential in the near future when "head- instabilities" effects
become more pronounced as all sizes are scaled down and mechanical
properties play significant roles in head performance.

      Several kinds of structures for measuring magnetostriction, for
example, can be designed.  A schematic diagram illustrating how the
magnetostriction of the P1 permalloy film can be measured is
indicated in Fig. 1, where typical values of the parameters for film
thickness tf, substrate thickness ts, cantilever length 1, and
cantilever width w are indicated.  In this case, the test site is
several hundred microns in dimensions, fitting easily into the space
for a head.  The test site is initially fabricated with a "filling
material" that occupies the bottom side of the cantilever; this
material is chosen such that it can be easily etched away after the
test-site is made.  Such filling material can be photo-resist to be
dissolved by an organic solvent, or copper, to be dissolved by a
suitable acid without damaging other materials in the test structure.
Under cases where the filling mate...