Image deconvolution techniques for probe scanning apparatus

#Not applicable.

#This invention relates generally to profilometry and more particularly, to image deconvolution techniques for probe scanning devices.

#As is known in the art, a structure having one characteristic dimension (e.g. height) which is more pronounced than the others (e.g. width and length) is referred to as a high aspect ratio structure. Examples of these type of structures include probes of atomic force and scanning tunnelling microscopes, field emission probes, micro-indenters and Micro Electro-Mechanical systems (MEM's) structures. Other high aspect ratio structures are found in quantum magnetic media for high-density data storage, compact disk stampers, crystalline structures, blades and biological systems such as virus particles. Such high aspect ratio structures have typical heights on the order of tens of micrometers and tip radii in the range of tens of nanometers. Further, these structures may or may not be conductive.

#The foregoing features of this invention, as well as the invention itself, may be more fully understood from the following description of the drawings in which:

#FIG. 1 shows a schematic diagram of an atomic force microscope;

#FIGS. 2A-2C demonstrate image deconvolution according to the present invention;

#Referring now to FIG. 1, a contact mode atomic force microscope (AFM) 10 includes a probe assembly 12 having a probe 14 mounted to the free end of a cantilever beam 16. The probe assembly 12 has a probe tip 18 adapted to contact a sample surface 20 of the sample 22 to be profiled. In this example, a sample 22 is disposed on a sample holder 24. It should be understood, however, that in other applications, sample 22 may be held by any fixture or surface. Any means of locating the sample 22 proximate the probe 14 may be used. A typical radius of the probe tip 18 is between 5 nm and 100 nm, a typical length of the probe 14 is on the order of 4.0 μm, and a typical length of the cantilever beam 16 is between 100 and 200 μm. It should be appreciated, however, that the present invention can be used in AFM's or other devices having probes and probe tips of any dimension.

#In use, the probe assembly 12 and sample 22 are moved relative to one another, causing the probe tip 18 to move over the sample surface 20. Movement of the probe tip 18 over features including high aspect ratio structures 26 on the sample surface 20 causes the cantilever beam 16 to deflect. The deflection of the cantilever beam 16 is measured to provide a measure of the surface topography. More particularly, a laser beam 30 generated by a laser source 32 is directed towards, and reflects off a surface 16a of the cantilever beam 16. The reflected laser signal 31 impinges upon a sensor, or detector 40, which may, for example, be provided as a photodetector array. In response to the reflected laser signal 31, the detector 40 generates an output signal 42 which is provided to a signal processor 44.

#Signal processor 44 processes the output signal 42 to provide processed signals 46, portions of which correspond to feed back control signals 48 and portions of which correspond to the topographical sample image signals 50. The control signals 48 are fed to a piezoelectric actuator 49 and the image signals 50 are fed to a display 52 on which the sample topographical image and other images can be displayed. A topographical sample view of the image 54 can be viewed on a display 52. The signal processor 44 can include a deconvolution processor 45. The display 52 is optional and the signal processor 44 operations can be automated.