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Optimized Conductor Shape by Laser Reflow

IP.com Disclosure Number: IPCOM000103417D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 35K

Publishing Venue

IBM

Related People

Cronin, JE: AUTHOR

Abstract

A "laser reflow" technique is utilized to reshape metal patterned lines.

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This is the abbreviated version, containing approximately 100% of the total text.

Optimized Conductor Shape by Laser Reflow

      A "laser reflow" technique is utilized to reshape metal
patterned lines.

      Some interconnecting semiconductor line shapes are more
desirable than others for subsequent processing and for electrical
reasons.  One such conductor shape, a semicircular shape, is optimum
for capacitance because it does not have sharp points which can
generate high electric fields, and is optimum for subsequent
insulator fill between lines.  Vertical lines create large aspect
ratio holes to fill and circular line shapes have minimum aspect
ratio gaps which are more easily filled.  What is required is an easy
method for creating semicircular lines.

      By utilizing "laser reflow", a method which is being explored
for hole fill and planarization, conductive material tends to assume
a minimal surface energy or tension.  However, the conductor does not
flow without a wetting agent, i.e., a patterned metal line will not
flow outside of its original definition.  With an optimized laser
(wavelength, power and duration), a metal line can be made to flow
into a semicircular cross- section.  For example, a rectangular metal
line defined by lift-off or reactive ion etching may subsequently be
reflowed to a desired semicircular shape.

      Disclosed anonymously.