Browse Prior Art Database

Electrical Linewidth Testing of Trench Top Openings

IP.com Disclosure Number: IPCOM000120108D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Bruce, JA: AUTHOR [+6]

Abstract

A method is shown for utilizing the Van der Pauw electrical probe test structure to allow electrical testing of semiconductor structures that are normally considered non-conducting.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 63% of the total text.

Electrical Linewidth Testing of Trench Top Openings

      A method is shown for utilizing the Van der Pauw
electrical probe test structure to allow electrical testing of
semiconductor structures that are normally considered non-conducting.

      For trench level linewidth measurements several problems are
associated with performing electrical measurements. First, a
conducting material must form the electrical test pattern and this is
a problem for isolation trenches. Second, to measure the image at the
top of a trench, the conducting region must be relatively shallow
which is a problem when measuring deep storage trenches. Third,
problems are encountered with finding a suitable reference structure,
such as the Van der Pauw, because groundrules do not allow any large
trench openings. A test pattern and process by which electrical
linewidth measurements can be performed reliably and accurately to
determine a trench opening at the top of a trench is shown.

      Referring to the figure, the Van der Pauw test structure is
shown and the point of interest is magnified. The cross hatched area
of the figure represents unetched regions (no trenches), and trench
areas are shown in white surrounding the test structure. Test
structures are normally located in the kerf.

      To electrically measure linewidths, test wafers are processed
up through trench etch. At this point in the process, a low energy
implant is employed to render the test structure electrically
cond...