Micromechanical atomic force sensor head
First Claim
1. A micromechanical atomic force sensor head comprising at least one cantilever beam fixed at one end and carrying a sharp point at a location distant from said fixed end for interaction with a surface of a sample to be investigated, and detection means for detecting the deflection of said cantilever beam as it interacts with said investigated surface, said cantilever beam and said detection means forming one integral part micromechanically manufactured from one piece of material.said detection means extending in parallel with said cantilever beam from a common base, there being a gap between said cantilever beam and said detection means,a pair of tunnel electrodes attached to facing surfaces of said cantilever beam and said detection means, the distance between said tunnel electrodes being adjustable, anda pair of electrostatic electrodes across which a potential is applied to adjust the distance between said electrostatic electrodes, said electrostatic electrodes being located with respect to said cantilever beam and said detection means that a potential applied across said electrostatic electrodes varies said adjustable distance between said tunneling electrodes thereby adjusting the tunnel current there between.
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Accused Products
Abstract
The micromechanical sensor head is designed to measure forces down to 10-13 N. It comprises a common base from which a cantilever beam and a beam member extend in parallel. The cantilever beam carries a sharply pointed tip of a hard material, dielectric or not, for interaction with the surface of a sample to be investigated. Bulges forming a tunneling junction protrude from facing surfaces of said beams, the gap between said bulges being adjustable by means of electrostatic forces generated by a potential (Vd) applied to a pair of electrodes respectively coated onto parallel surface of said beams. The sensor head consists of one single piece of semiconductor material, such as silicon or gallium arsenide (or any other compounds thereof) which is fabricated to the dimensions required for the application by means of conventional semiconductor chip manufacturing techniques.
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Citations
21 Claims
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1. A micromechanical atomic force sensor head comprising at least one cantilever beam fixed at one end and carrying a sharp point at a location distant from said fixed end for interaction with a surface of a sample to be investigated, and detection means for detecting the deflection of said cantilever beam as it interacts with said investigated surface, said cantilever beam and said detection means forming one integral part micromechanically manufactured from one piece of material.
said detection means extending in parallel with said cantilever beam from a common base, there being a gap between said cantilever beam and said detection means, a pair of tunnel electrodes attached to facing surfaces of said cantilever beam and said detection means, the distance between said tunnel electrodes being adjustable, and a pair of electrostatic electrodes across which a potential is applied to adjust the distance between said electrostatic electrodes, said electrostatic electrodes being located with respect to said cantilever beam and said detection means that a potential applied across said electrostatic electrodes varies said adjustable distance between said tunneling electrodes thereby adjusting the tunnel current there between.
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9. A micromechanical atomic force sensor head for examining the surface of a sample including:
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at least one cantilever beam of such dimensions and material that atomic forces existing between atoms and molecules are sufficient to deflect said cantilever beam, said cantilever beam having a free end and a fixed end and including a pointed tip located along said beam and spaced from said fixed end, said pointed tip being held in close proximity to said surface to be examined, the atomic forces existing between said pointed tip and said surface causing said cantilever beam to be deflected, detection means for detecting the deflection of said cantilever beam when atomic forces exist between said surface and said pointed tip, said detection means and said cantilever beam forming an integral structure micromachined from a single piece of material, said detection means and said cantilever beam being spaced from one another by a gap, said detection means including a tunnel junction formed between two tunnel electrodes, at least one of which is located such that a deflection of said cantilever beam will move said at least one electrode, means for producing a tunnel current in said tunnel junction, and means for adjusting the spacing between said two tunnel electrodes to thereby adjust the magnitude of said tunnel current, said means for adjusting including at least two electrostatic deflection electrodes across which a potential is applied for varying the distance between said two deflection electrodes, said deflection electrodes being located with respect to said cantilever beam that the spacing between said tunnel electrodes is adjustable depending on the magnitude of the potential applied between said deflecting electrodes. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification