Browse Prior Art Database

Method of Formation of Non-Reflective Surface Using Etched Silicon Surface

IP.com Disclosure Number: IPCOM000099527D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 1 page(s) / 33K

Publishing Venue

IBM

Related People

Bestwick, TD: AUTHOR [+2]

Abstract

Disclosed is a process which forms a highly non-reflective surface on silicon by using reactive ion etching.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Method of Formation of Non-Reflective Surface Using Etched Silicon Surface

       Disclosed is a process which forms a highly non-reflective
surface on silicon by using reactive ion etching.

      The process described may be used to define a pattern of
optically absorbing areas on a silicon surface.  Such a process may
find application in the production of optical storage devices or in
the field of solar energy collection.

      The silicon surface is first subject to reactive ion etching
using a mixture of CF3Br and O2 .  The length of this etch is
important and may be used to determine the nature of the surface
texture.  In general, a short etch has been found to be satisfactory.
 A second reactive etching step is then carried out in the same tool,
without removing the sample.  This second etching step uses a mixture
of He and HBr and etches silicon very selectively with respect to
silicon dioxide.  The process is also very directional and results in
the etching of small voids into the silicon. Because the process
etches silicon dioxide very slowly, these voids can be etched deep
into the silicon.

      The surface formed by the process described above has a
columnar structure, and such surfaces are found to have a very low
optical reflectance.  This structure is different from the surface
roughening obtained in many reactive ion etching techniques, which
may produce conical features under certain conditions.