Browse Prior Art Database

Beol Characterization using Picosecond Pulses

IP.com Disclosure Number: IPCOM000108621D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 55K

Publishing Venue

IBM

Related People

Ketchen, M: AUTHOR [+3]

Abstract

Disclosed is a process and structure for introducing picosecond electrical pulses onto integrated circuit structures for the purpose of electrical testing.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 78% of the total text.

Beol Characterization using Picosecond Pulses

       Disclosed is a process and structure for introducing
picosecond electrical pulses onto integrated circuit structures for
the purpose of electrical testing.

      The primary focus of BEOL (back end of line) characterization
has been on DC testing for yield and reliability.  As integrated
circuit dimensions shrink, AC characterization of propagation delays,
crosstalk and loss tangent becomes increasingly important.  The
disclosed technique makes use of integrated electro-optic switches to
generate picosecond electrical pulses onto BEOL test structures.  The
electro-optic switch is fabricated at the polysilicon level and is
implanted to reduce carrier lifetime.  Incident laser illumination
will then cause an increase in polysilicon conductivity on a
timescale similar to that of the incident laser pulse.  The BEOL
(transmission line) structure is connected to the switch as shown in
the figure using standard VLSI fabrication techniques.  The only
major design constraint is the elimination of any metal (or opaque)
structure above the optical switch itself.  Given the relatively
small size of the switch (several square microns), this poses little
difficulty.  In addition, once implanted, the switch should not be
annealed either intentionally or through high temperature process
steps. Such thermal treatment will result in increased carrier
lifetimes and in broadening of the input pulse.

      Detection of ...