Browse Prior Art Database

Double Cantilever Sensor for Thin Film Hardness Testing and Mass Storage Application

IP.com Disclosure Number: IPCOM000107573D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Greschner, J: AUTHOR [+2]

Abstract

A micromechanically fabricated double cantilever sensor is described which permits measuring the hardness of thinnest films in two steps. In the first step, the film to be measured (typically, 10 to 100 nm) is permanently indented with the aid of both cantilevers by a tip positioned on the lower cantilever. In the second step, this indentation is measured in the "atomic force mode" by the lower cantilever whose stiffness is about 1000 times lower than that of the upper cantilever.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 68% of the total text.

Double Cantilever Sensor for Thin Film Hardness Testing and Mass Storage Application

       A micromechanically fabricated double cantilever sensor
is described which permits measuring the hardness of thinnest films
in two steps.  In the first step, the film to be measured (typically,
10 to 100 nm) is permanently indented with the aid of both
cantilevers by a tip positioned on the lower cantilever.  In the
second step, this indentation is measured in the "atomic force mode"
by the lower cantilever whose stiffness is about 1000 times lower
than that of the upper cantilever.

      If such measurement is to be carried out by only one cantilever
(1,2), a compromise will have to be struck with regard to stiffness,
with the consequence of hard films showing either no indentations
(cantilever too soft) or of indentations, if produced, being but
inaccurately measurable (cantilever too stiff).

      For measuring layers of 10 to 100 nm, the ideal indentation
depth will be about 10% of the layer thickness. The lower cantilever,
deflected by 10 nm, will apply a load of 10-8 N at a stiffness of
1 N/m.  The load imposed by the upper cantilever deflected by 10 mm
will be 10-2 N at a stiffness of 1000 N/m.

      The upper cantilever is preferably made of silicon. The lower
cantilever consists of silicon with a hard coating of Si3N4, SiC,
etc., or of very hard layers of such materials.  Both cantilevers
with integrated tips may be produced by the subtractive method
...