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Quality Determination of Dielectric Layers

IP.com Disclosure Number: IPCOM000111181D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Euen, W: AUTHOR [+4]

Abstract

This article proposes a new method by using a modified pinhole test.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 81% of the total text.

Quality Determination of Dielectric Layers

      This article proposes a new method by using a modified pinhole
test.

      In order to qualify thin dielectric (oxid) layers (<50 nm) on
wafers the pinhole concentration in the layer is tested.  The test
arrangement comprises the wafer with the oxid layer on the top side
and a grounded back side.  An electrolyte is arranged above the top
side of the wafer having an electrode with adjustable potential
parallel to the wafer.  Pinholes in the dielectric layer provide gas
bubbles caused by the current between electrode and wafer.  The
bubbles can then be counted and the amount of bubbles is a dimension
figure for the defect density in the layer.

      By using a transparent conductive layer (e.g., SnIn) as
electrode material having a diameter corresponding to the diameter of
the wafer, a homogenious field distribution is obtained which allows
the integral meassurement of the defect density.  The defect density
is then determined by using a particle detector working according to
the scattered light principle.  The threshold of the detector is
adapted to the scattered light average of the gas bubbles.

      This arrangement and method avoids that only defects in arreas
with a high field strenght are detected because since the arrangement
is similar to parallel electrodes of a capacitor a homogenious field
distribution is obtained, thus allowing the detecting of the whole
area of the wafer.  This in turn pe...