Patent Application
20080060426
The detailed description is described with reference to the accompanying figures.
Described herein are exemplary embodiments of atomic force microscopes. In the following description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments. However, it will be understood by those skilled in the art that the various embodiments may be practiced without the specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the particular embodiments.
Referring to
A sensor (or probe) 124 is coupled to beam 120 and positioned such that, in use, sensor 124 is positioned proximate to or in contact with the surface 132 of object 130. In some embodiments, sensor 124 may be tapered such that the tip of sensor 124 defines a point of interaction between sensor 124 and surface 132.
Referring to
Referring back to
In some embodiments, motion inducing assembly 150 may induce harmonic oscillation of beam 120. In an embodiment in which the beam 120 is connected directly to frame 110, the beam 120 will oscillate at a resonance frequency that is characterized by the geometry of the beam 120 and the physical characteristics of the material from which the beam 120 is constructed. In an embodiment in which the beam 120 is connected to frame 110 by one or more flexures 122, the beam 120 will oscillate at a resonance frequency that is characterized by the geometry of the beam 120 and the physical characteristics of the material from which the beam 120 is constructed and the geometry and materials of the flexures 122.
Oscillation in the beam 120 causes relative motion between probe 124 and the surface 132 of object 130. When the probe 124 is mounted in the center of the beam 120 (or membrane), the motion of the probe 124 is perpendicular to the surface 132. When the probe 124 is mounted off center, then the motion of the tip would be at an angle, which may be of use to measure a side wall of a feature on the surface 132 of object 130.
Motion inducing assembly 150 may further induce lateral motion between the object 130 and the atomic force microscope 100 to permit the microscope 100 to scan the surface of object 130. Motion inducing assembly 150 may move object 130 relative to atomic force microscope 100, or may move atomic force microscope 100 relative to object 130, or both.
Atomic force microscope 100 further comprises a detection assembly 160. In operation, detection assembly 160 detects a characteristic of the beam, membrane, or flexure. A variety of techniques may be used to detect a characteristic of the underlying surface. In some embodiments the detection assembly detects a property related to the position, motion, or deformation of the beam, membrane, or flexure. For example, detection assembly 160 may be embodied as an interferometer assembly, a capacitive sensing assembly, an inductive sensing assembly, a piezoelectric response assembly, or an optical cantilever assembly.
In some embodiments atomic force microscope 100 may comprises a radiation assembly 170. In operation, radiation assembly 170 may be embodied as a scanning assembly which directs radiation onto the surface 132 of object 130, and measures one or more characteristics of surface 132 using radiation induced from surface 132. Various radiation assemblies and techniques for surface inspection are described in U.S. Pat. Nos. 6,665,078, 6,717,671, and 6,757,056, and 6,909,500 to Meeks, et al., the disclosures of which are incorporated herein by reference in their entirety. The radiation assembly can either scan (i.e., like a scanning laser microscope) or flood an area and image it (i.e., as in a conventional microscope). The radiation may be constant or it might be modulated in intensity, wavelength, phase, or polarization. In addition to using the radiation reflected for the surface, transmitted, scattered or diffracted radiation may be used. Additionally, the radiation may be used to modify or modulate the properties of the sample or the beam/membrane.
In some embodiments, at least a portion of beam (or membrane) 120 may be formed from a material that is at least partially transmissive to radiation from radiation assembly 170. In such embodiments, the beam (or membrane) 120 may be a passive element or may be an active element such as, e.g., a lens that focuses radiation onto a point of surface 132 of object 130.
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an implementation. The appearances of the phrase “in one embodiment” in various places in the specification may or may not be all referring to the same embodiment.
Although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that claimed subject matter may not be limited to the specific features or acts described. Rather, the specific features and acts are disclosed as sample forms of implementing the claimed subject matter.
