The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 2004
Filed:
Mar. 25, 2003
Other;
Abstract
A method of detecting the distribution of values of a physical property such as the dopant concentration of a semiconductor without being adversely affected by stray capacitance is offered. A scanning probe microscope capable of implementing this method is also offered. The method starts with applying an AC voltage of angular frequency &ohgr; between a probe and a sample from a fixed oscillator. The output from the oscillator is supplied to a piezoelectric device that drives the cantilever. The cantilever produces a deflection signal corresponding to forces corresponding to interactions between the probe and sample. A signal regarding the amplitude is extracted from the deflection signal. This signal is fed back to a means for controlling the distance between the probe and sample and supplied to a display device. As a result, an image of the surface topography of the sample is obtained. A harmonic component having a frequency higher than the triple or more of the angular frequency &ohgr; and contained in the cantilever deflection signal is extracted by a lock-in amplifier. As a result, information representing an image of differential capacitance (∂C/∂V) is obtained.