Sensing mode atomic force microscope

A microscope for determining the characteristics of the surface of a specimen, the microscope comprising:

• a flexible cantilever having a probe tip affixed proximate a free end;
• means for effecting relative X,Y and Z motion between said probe tip and the specimen;
• means for detecting contact between said probe tip and the specimen;
• and
• means for applying a force to said probe tip sufficient to overcome an adhesive force exhibited between said probe tip and the specimen.

A probe tip release system for an atomic force microscope having a flexible cantilever with a probe tip affixed to one end, the probe tip release system comprising:

• means for detecting contact between said probe tip and a specimen;
• means for inducing relative withdrawing motion between said probe tip and the specimen;
• and
• means for applying a force to said probe tip sufficient to overcome an adhesive force exhibited between said probe tip and the specimen.

A method of operating an atomic force microscope to perform a surface measurement of a specimen, the atomic force microscope including a flexible cantilever with a probe tip affixed to a free end, the method comprising the steps:

• advancing one of the cantilever and specimen;
• determining contact between the probe tip and specimen;
• withdrawing one of the cantilever and specimen;
• and
• applying a momentary force to the cantilever, proximate the probe tip,
• sufficient to overcome an adhesive force between the probe tip and specimen.

A method for measuring the surface properties of a specimen using an atomic force microscope, the atomic force microscope including:

• a flexible cantilever with a probe tip affixed to a free end, a displaceable cantilever base supporting the flexible cantilever and providing relative motion in the Z-axis between the cantilever and the specimen, a scanner providing relative motion in the X, Y and Z axes between the probe tip and specimen, a deflection detector, and a pulse release system, the scanner being driven to effect a scan of the specimen, the scan being defined by a plurality of X-Y coordinates, for each of X-Y coordinate, the method comprising the steps:
• driving one of the cantilever base and scanner to effect an approach between the specimen and probe tip;
• analyzing signals from the deflection detector to determine the point of contact between the probe tip and the specimen;
• determining the surface topology at the point of contact;
• withdrawing one of the cantilever base and scanner to effect withdrawal of the cantilever base from the specimen;
• activating the pulse release system, thereby generating a force on the cantilever free end sufficient to release the probe tip from the specimen;
• determining the approach distance;
• and
• adjusting one of the cantilever base and scanner to maintain a substantially constant approach distance.

A method of operating an atomic force microscope to perform a surface measurement of a specimen, said microscope including a cantilever having a movable base portion and a free end that is deflectable relative to the base portion, and having a probe tip affixed to said free end;

• the method comprising the steps:
• advancing one of the cantilever and specimen toward one another,
• substantially continuously monitoring the position of said cantilever base portion and cantilever deflection,
• substantially continuously controlling the position of the cantilever base portion and the cantilever deflection,
• determining contact between the probe tip and specimen, and responsive to said contact affecting a withdrawal of the cantilever base portion away from the specimen, and
• applying a momentary force to the cantilever sufficient to overcome an adhesive force between the probe tip and specimen.