Browse Prior Art Database

Thin Film Lateral Overgrowth

IP.com Disclosure Number: IPCOM000103800D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 1 page(s) / 58K

Publishing Venue

IBM

Related People

Hodgson, RT: AUTHOR [+3]

Abstract

Disclosed is a method of producing thin (N500 o) layers of single crystal silicon over an insulating surface.

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This is the abbreviated version, containing approximately 96% of the total text.

Thin Film Lateral Overgrowth

      Disclosed is a method of producing thin (N500 o) layers of
single crystal silicon over an insulating surface.

      Presently, the epitaxial lateral (ELO) technique has single
crystal silicon growing from a hole in an oxide over silicon.  The
crystal grows in height as it grows in width.  It must then be
polished down to a few thousand o to be usable.  The thickness should
be only 500 o.  We propose the scheme sketched in the figure.  A
silicon wafer 1 is oxidized with about 1000 o SiO2 2.  Holes 3 are
opened in the oxide layer 2 and silicon is regrown in the holes.  At
this point, either the surface of the wafer can be flat, or the
silicon can be grown out over the oxide and polished back to stop at
the oxide to give a structure sketched in the first figure.

      A thin layer 500 o of polysilicon is then grown on the wafer
surface.  Over the single crystal part of the surface, the silicon
will grow single crystal, but the crystal will not reach out more
than the film thickness over the oxide.  A uniform laser beam can now
be used to heat the surface polycrystal to the melting point.  The
silicon over the single crystal material 3 will be much cooler, since
the insulating layer 2 of SiO&sub2. is missing.  After the laser
pulse is over, the cooler silicon over the single crystal material
will act as a seed for the lateral growth of single crystal epitaxial
with the crystal in the underlying wafer 1 as sketched in t...