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High Resolution Memory Medium Disclosure Number: IPCOM000108433D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 37K

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Related People

Boland, JJ: AUTHOR


Disclosed is a high resolution memory medium which has a minimum bit size of 20A~ .

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

High Resolution Memory Medium

      Disclosed is a high resolution memory medium which has a
minimum bit size of 20A~ .

      The outermost layer of the Si(111)-7x7 surface consists of a
layer of Si adatoms.  When this surface is exposed to a saturation
dose of hydrogen the adatoms in this outer layer ball up to form
islands on the surface.  These islands are stabilized by the presence
of hydrogen on the surface and can be readily seen with a scanning
tunneling microscope (STM) using a tunneling bias of 2V and a current
of .1nA. The islands are 15-20A~ in size.  If both the tunneling bias
and current are raised to 5V and 2nA, respectively, STM imaging under
these high power conditions causes the hydrogen to be desorbed from
the surface.  In the absence of hydrogen these islands are no longer
stable and the adatoms they contain are redistributed over the
surface.  The modified surface can be examined by STM using the
original low power (2V, .1nA) non-destructive conditions.

      Since STM has a spatial resolution of about 1A~, it is possible
to locally modify or write on small regions of the surface using the
high power conditions.  These regions may be later read using the
lower power, non-destructive imaging conditions.  The size of the
data bit written in this manner can be as small as 20A~, or about the
size of a single island.

      Disclosed anonymously.