Browse Prior Art Database

Method for Adding Direct Current Capability to an Alternating Current Electromigration System

IP.com Disclosure Number: IPCOM000118441D
Original Publication Date: 1997-Feb-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Castellano, AJ: AUTHOR [+3]

Abstract

Disclosed is a technique for adding a Direct Current (DC) response capability to an Alternating Current (AC) electromigration tester without affecting the AC signal. With this capability, it is possible to apply an offset AC current and/or a pulsed DC current to the sample being tested.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 62% of the total text.

Method for Adding Direct Current Capability to an Alternating Current
Electromigration System

      Disclosed is a technique for adding a Direct Current (DC)
response capability to an Alternating Current (AC) electromigration
tester without affecting the AC signal.  With this capability, it is
possible to apply an offset AC current and/or a pulsed DC current to
the sample being tested.

      Under large current densities, aluminum films migrate in the
direction of current flow.  This phenomenon is known as
electromigration and can lead to open metal lines or shorts between
parallel conductor lines.  For bipolar circuitry large DC currents
are common so DC electromigration tests are performed.  For
Complementary Metal Oxide Semiconductor (CMOS) logic devices, which
do not operate under constant  current conditions, testing under
realistic operating conditions at high  frequency becomes important.
To this end, a high frequency bidirectional  current tester was
developed in (*).

      In an effort to improve the capability to test fine metal lines
using realistic currents found in modern CMOS devices, the ability to
test with an offset AC signal and to apply pulsed unidirectional
currents to samples at high frequency AC currents was added.  To
accomplish this,  the printed circuit board containing the 50 Ohm
microstrip line and the  trimmer capacitor in series with the sample
was modified by adding an inductor in parallel with the trimmer
capacitor.  A...