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Pre-low Temperature Epitaxial Surface Treatment

IP.com Disclosure Number: IPCOM000121893D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 3 page(s) / 1M

Publishing Venue

IBM

Related People

Ahlgren, D: AUTHOR [+7]

Abstract

A process that results in superior nucleation, hence, quality, of low temperature epitaxial (LTE) silicon, (650~C), is described in this article. The key point in the process is the placement of As at the surface to be deposited upon. This can be accomplished by various methods including I/I. This work showed the As surface concentrations, as low as 1E18/cm3, resulted in higher quality epitaxial films than counterparts fabricated without the As predisposition treatment. This result was confirmed by TEM analysis as well as via retention time measurements on thick LTE films, produced by the As treatment and compared to controls fabricated using conventional techniques.

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Pre-low Temperature Epitaxial Surface Treatment

      A process that results in superior nucleation, hence,
quality, of low temperature epitaxial (LTE) silicon, (650~C), is
described in this article.  The key point in the process is the
placement of As at the surface to be deposited upon.  This can be
accomplished by various methods including I/I.  This work showed the
As surface concentrations, as low as 1E18/cm3, resulted in higher
quality epitaxial films than counterparts fabricated without the As
predisposition treatment.  This result was confirmed by TEM analysis
as well as via retention time measurements on thick LTE films,
produced by the As treatment and compared to controls fabricated
using conventional techniques.

      TEMs shown in Figs. 1 and 2 clearly show that controls
exhibited more defects at the LTE/substrate interface than parts made
with LTE on 1E18/cm3 As surfaces.  In addition, retention time
studies were performed on MTE, medium temperature epi., which, in
turn, were grown on LTE films. It can be seen from Table I that the
resulting MTE quality improved dramatically when the underlying LTE
was produced via the As preparation process.  The apparent reason for
the LTE improvement is that the As changes the unwanted substrate
native oxide to a form that allows a greater degree of nucleation.

      TABLE I - DEFECT ANALYSIS OF MTE

      AS FUNCTION OF LTE CONDITIONS
           Sample                   ...