Browse Prior Art Database

Method of Inspection of Reactive Ion Etched Trenches

IP.com Disclosure Number: IPCOM000108188D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 39K

Publishing Venue

IBM

Related People

Bronner, GB: AUTHOR [+3]

Abstract

Disclosed is a design of lithography and method of inspection of deep trenches etched in a semiconductor material by reactive ion etching (RIE). We propose putting keyhole like trenches in the kerf between chips to use in conjunction with or in place of the cleaving of test wafers to inspect deep trench (RIE) etching. Figure 1 shows the basic idea, where an electron beam 1 from a scanning electron microscope (SEM) is used to illuminate the end of the trench 2 etched in the silicon surface 3. The large hole 4 is etched to allow the beam 1 to impinge on the edge of the trench 2 and into the trench 2 so that the secondary electrons 5 can be collected.

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Method of Inspection of Reactive Ion Etched Trenches

      Disclosed is a design of lithography and method of inspection
of deep trenches etched in a semiconductor material by reactive ion
etching (RIE).  We propose putting keyhole like trenches in the kerf
between chips to use in conjunction with or in place of the cleaving
of test wafers to inspect deep trench (RIE) etching.  Figure 1 shows
the basic idea, where an electron beam 1 from a scanning electron
microscope (SEM) is used to illuminate the end of the trench 2 etched
in the silicon surface 3.  The large hole 4 is etched to allow the
beam 1 to impinge on the edge of the trench 2 and into the trench
2 so that the secondary electrons 5 can be collected.  Clearly, the
loading effect will change the trench profile near the end of the
trench, but there should be a correlation between the profiles seen
in cleaving and the secondary electron pictures taken in the normal
way.

      Another idea would be to take pictures using the low loss
electrons 6 forward scattered by the walls and bottom of the trench
sketched in figure 2.  These low angle of incidence pictures formed
from the forward scattered electrons are extremely sensitive to
surface topography, and ridges or bumps would stand out clearly.  The
profile of the trench bottom could also be seen in the middle of the
trench with such a scheme.

      Disclosed anonymously.