Geometric shape control of thin film ferroelectrics and resulting structures

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:873055

McKee, Rodney A ^[1]; Walker, Frederick J ^[2]

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1. Kingston, TN
2. Oak Ridge, TN

A monolithic crystalline structure and a method of making involves a semiconductor substrate, such as silicon, and a ferroelectric film, such as BaTiO.sub.3, overlying the surface of the substrate wherein the atomic layers of the ferroelectric film directly overlie the surface of the substrate. By controlling the geometry of the ferroelectric thin film, either during build-up of the thin film or through appropriate treatment of the thin film adjacent the boundary thereof, the in-plane tensile strain within the ferroelectric film is relieved to the extent necessary to permit the ferroelectric film to be poled out-of-plane, thereby effecting in-plane switching of the polarization of the underlying substrate material. The method of the invention includes the steps involved in effecting a discontinuity of the mechanical restraint at the boundary of the ferroelectric film atop the semiconductor substrate by, for example, either removing material from a ferroelectric film which has already been built upon the substrate, building up a ferroelectric film upon the substrate in a mesa-shaped geometry or inducing the discontinuity at the boundary by ion beam deposition techniques.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: AC05-96OR22464
• Assignee: UT-Battelle, LLC (Oak Ridge, TN)
• Patent Number(s): US 6080235
• OSTI ID: 873055
• Country of Publication: United States
• Language: English

Related Subjects

geometric
shape
control
film
ferroelectrics
resulting
structures
monolithic
crystalline
structure
method
involves
semiconductor
substrate
silicon
ferroelectric
batio
overlying
surface
atomic
layers
directly
overlie
controlling
geometry
build-up
appropriate
treatment
adjacent
boundary
in-plane
tensile
strain
relieved
extent
permit
poled
out-of-plane
effecting
switching
polarization
underlying
material
steps
involved
discontinuity
mechanical
restraint
atop
example
removing
built
building
mesa-shaped
inducing
beam
deposition
techniques
atomic layers
beam deposition
removing material
underlying substrate
semiconductor substrate
substrate material
deposition techniques
crystalline structure
ferroelectric film
geometric shape
deposition technique
appropriate treatment
shape control
resulting structure
line structure
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